:root {
  --brand: #6338ed;
  --brand-strong: #5428de;
  --brand-dark: #30205f;
  --brand-soft: #f0ecff;
  --brand-pale: #f8f6ff;
  --ink: #201b3d;
  --ink-soft: #3e4560;
  --muted: #7b8298;
  --muted-2: #a3a8b8;
  --line: #e6e3f1;
  --line-strong: #d7d1eb;
  --paper: #f7f7fb;
  --surface: #ffffff;
  --surface-soft: #faf9fe;
  --success: #20ad78;
  --success-soft: #e8f8f1;
  --warning: #f28b38;
  --warning-soft: #fff3e8;
  --danger: #df5c6a;
  --danger-soft: #fff0f2;
  --info: #4f86e8;
  --info-soft: #eef4ff;
  --aqua: #16b8b1;
  --aqua-soft: #e7fbf8;
  --sun: #f2b93b;
  --sun-soft: #fff8df;
  --code-bg: #191729;
  --code-surface: #211e35;
  --shadow-sm: 0 4px 14px rgba(39, 27, 86, .06);
  --shadow-md: 0 14px 38px rgba(43, 29, 95, .09);
  --radius-sm: 9px;
  --radius-md: 14px;
  --radius-lg: 20px;
  font-family: "Microsoft YaHei UI", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; min-width: 320px; background: var(--paper); color: var(--ink); }
button, input, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: .42; }
button:focus-visible, input:focus-visible, textarea:focus-visible, summary:focus-visible, a:focus-visible {
  outline: 3px solid rgba(99, 56, 237, .28);
  outline-offset: 3px;
}
[hidden] { display: none !important; }

.auth-screen {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(390px, .65fr);
  align-items: stretch;
  background:
    linear-gradient(90deg, rgba(247,247,251,.05) 0%, rgba(247,247,251,.14) 50%, rgba(247,247,251,.96) 72%),
    url("../pic/dashboard-hero.png") 32% center / cover no-repeat;
}
.auth-brand { display: grid; align-content: center; justify-items: start; max-width: 650px; padding: 9vw; }
.auth-logo { width: 72px; height: 72px; overflow: hidden; margin-bottom: 24px; border-radius: 16px; box-shadow: 0 16px 34px rgba(63,39,151,.25); }
.auth-logo img { width: 100%; height: 100%; object-fit: cover; transform: scale(1.7); }
.auth-brand h1 { margin: 10px 0 8px; font-size: 52px; line-height: 1.1; }
.auth-brand p { max-width: 450px; margin: 0; color: var(--ink-soft); font-size: 16px; line-height: 1.8; }
.login-panel { align-self: center; width: min(430px, calc(100% - 48px)); margin: 24px auto; padding: 34px; background: rgba(255,255,255,.94); border: 1px solid rgba(215,209,235,.95); border-radius: 18px; box-shadow: 0 24px 70px rgba(39,27,86,.14); backdrop-filter: blur(14px); }
.login-heading h2 { margin: 7px 0 5px; font-size: 28px; }
.login-heading p { margin: 0; color: var(--muted); font-size: 12px; }
#login-form { display: grid; gap: 17px; margin-top: 26px; }
#login-form label { display: grid; gap: 7px; color: var(--ink-soft); font-size: 11px; font-weight: 700; }
.field-shell { min-height: 48px; display: grid; grid-template-columns: 22px 1fr auto; align-items: center; gap: 6px; padding: 0 13px; background: #fff; border: 1px solid var(--line-strong); border-radius: 10px; transition: border-color .18s ease, box-shadow .18s ease; }
.field-shell:focus-within { border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-soft); }
.field-shell > i { color: var(--muted); font-size: 18px; }
.field-shell input { min-width: 0; height: 44px; padding: 1px 0 4px; color: var(--ink); background: transparent; border: 0; outline: 0; line-height: 1.5; }
#login-password { font-family: "Cascadia Code", Consolas, "Courier New", monospace; font-variant-ligatures: none; }
.field-shell button { width: 32px; height: 32px; display: grid; place-items: center; color: var(--muted); background: transparent; border: 0; border-radius: 8px; }
.field-shell button:hover { color: var(--brand); background: var(--brand-pale); }
.login-error { min-height: 18px; margin: -5px 0 -2px; color: var(--danger); font-size: 11px; line-height: 1.6; }
.identity-match { display: grid; grid-template-columns: 28px minmax(0, 1fr); align-items: center; gap: 9px; min-height: 46px; margin-top: -8px; padding: 8px 11px; color: #176e59; background: var(--success-soft); border: 1px solid #bce8d7; border-radius: 8px; }
.identity-match i { display: grid; place-items: center; width: 28px; height: 28px; color: var(--success); background: #fff; border-radius: 6px; font-size: 17px; }
.identity-match span { min-width: 0; display: grid; gap: 2px; font-size: 11px; }
.identity-match strong { overflow: hidden; color: var(--ink); font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.registration-entry { display: flex; align-items: center; justify-content: center; gap: 8px; margin-top: 14px; color: var(--muted); font-size: 11px; }
.registration-entry .text-button { min-height: 30px; }
.login-note { display: flex; align-items: flex-start; gap: 8px; margin-top: 18px; padding-top: 17px; color: var(--muted); border-top: 1px solid var(--line); font-size: 10px; line-height: 1.65; }
.login-note i { color: var(--success); font-size: 17px; }

.app-shell { min-height: 100vh; display: grid; grid-template-columns: 190px minmax(0, 1fr); }
.app-sidebar {
  position: sticky; top: 0; z-index: 30; height: 100vh; display: flex; flex-direction: column;
  padding: 18px 12px 16px; border-right: 1px solid var(--line); background: var(--surface);
}
.brand { display: flex; align-items: center; gap: 9px; padding: 0 3px 18px; color: inherit; text-decoration: none; }
.brand-logo { flex: 0 0 40px; width: 40px; height: 40px; overflow: hidden; border-radius: 11px; box-shadow: 0 8px 18px rgba(99, 56, 237, .2); }
.brand-logo img { width: 100%; height: 100%; object-fit: cover; transform: scale(1.7); }
.brand-copy { display: grid; gap: 2px; }
.brand-copy strong { font-size: 16px; letter-spacing: .01em; white-space: nowrap; }
.brand-copy small { color: var(--muted); font-family: Bahnschrift, sans-serif; font-size: 9px; letter-spacing: .14em; }

.primary-nav { display: grid; gap: 8px; }
.nav-item {
  min-height: 44px; display: grid; grid-template-columns: 21px 1fr auto; align-items: center; gap: 9px;
  width: 100%; padding: 0 11px; color: #535a70; text-align: left; background: transparent;
  border: 1px solid transparent; border-radius: 12px; transition: color .18s ease, background .18s ease, transform .18s ease;
}
.nav-item i { font-size: 19px; }
.nav-item span { font-size: 12px; font-weight: 600; }
.nav-item:hover { color: var(--brand); background: var(--brand-pale); transform: translateX(2px); }
.nav-item.active { color: #fff; background: var(--brand); box-shadow: 0 10px 22px rgba(99, 56, 237, .22); }
.nav-badge { min-width: 24px; padding: 2px 6px; color: var(--muted); text-align: center; background: #f0f0f5; border-radius: 999px; font-size: 10px !important; }
.nav-item.active .nav-badge { color: var(--brand); background: #fff; }
.nav-dot { width: 7px; height: 7px; background: var(--danger); border-radius: 50%; }
.sidebar-spacer { flex: 1; min-height: 28px; }
.rank-card { position: relative; display: grid; grid-template-columns: 38px 1fr; gap: 8px; padding: 12px; border: 1px solid var(--line); border-radius: 13px; background: var(--surface-soft); }
.rank-icon { position: relative; width: 36px; height: 36px; display: grid; place-items: center; color: var(--brand); }
.rank-icon i { position: absolute; font-size: 36px; }
.rank-icon strong { position: relative; z-index: 1; font-family: Bahnschrift, sans-serif; font-size: 12px; }
.rank-card > div:nth-child(2) { display: grid; align-content: center; gap: 3px; }
.rank-card span, .rank-card small { color: var(--muted); font-size: 10px; }
.rank-card strong { font-size: 13px; }
.rank-progress { grid-column: 1 / -1; height: 5px; overflow: hidden; background: #e9e6f4; border-radius: 999px; }
.rank-progress span { display: block; height: 100%; background: var(--brand); border-radius: inherit; }
.rank-card > small { grid-column: 1 / -1; text-align: right; }
.settings-button { margin-top: 10px; }
.logout-button { color: var(--danger); }

.password-dialog, .settings-dialog, .registration-dialog { width: min(480px, calc(100vw - 32px)); padding: 0; border: 1px solid var(--line); border-radius: 8px; color: var(--ink); background: #fff; box-shadow: 0 24px 70px rgba(35, 28, 83, .22); }
.password-dialog::backdrop, .settings-dialog::backdrop, .registration-dialog::backdrop { background: rgba(26, 22, 49, .48); backdrop-filter: blur(3px); }
.password-dialog form, .settings-dialog form, .registration-dialog form { display: grid; gap: 16px; padding: 24px; }
.password-dialog label, .settings-dialog label, .registration-dialog label { display: grid; gap: 7px; color: var(--ink); font-size: 13px; font-weight: 700; }
.dialog-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; }
.dialog-heading h2 { margin: 5px 0 0; font-size: 22px; }
.dialog-copy { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 10px; padding-top: 4px; }
.settings-section { display: grid; gap: 13px; padding: 16px 0; border-top: 1px solid var(--line); }
.settings-section-head { display: grid; grid-template-columns: 32px 1fr; gap: 10px; align-items: start; }
.settings-section-head > i { display: grid; place-items: center; width: 32px; height: 32px; color: var(--brand); background: var(--brand-pale); border-radius: 7px; font-size: 18px; }
.settings-section h3 { margin: 0; font-size: 14px; }
.settings-section p { margin: 4px 0 0; color: var(--muted); font-size: 12px; line-height: 1.55; }
.settings-section select { min-height: 42px; padding: 0 12px; border: 1px solid var(--line-strong); border-radius: 7px; color: var(--ink); background: #fff; font: inherit; }
.settings-command { justify-self: start; }
.password-hint { margin: -7px 0 0; color: var(--muted); font-size: 11px; line-height: 1.55; }
.secondary-button { min-height: 42px; padding: 0 18px; border: 1px solid var(--line-strong); border-radius: 7px; background: #fff; color: var(--ink); font-weight: 700; }

.app-main { min-width: 0; }
.app-header {
  position: sticky; top: 0; z-index: 20; min-height: 68px; display: flex; align-items: center; gap: 18px;
  padding: 9px 24px; background: rgba(255, 255, 255, .96); border-bottom: 1px solid var(--line);
}
.header-title { min-width: 0; display: grid; gap: 2px; }
.header-title > span { display: none; color: var(--muted); font-size: 11px; }
.header-title h1 { margin: 0; font-size: 21px; line-height: 1.3; }
.header-actions { margin-left: auto; display: flex; align-items: center; gap: 12px; }
.streak-chip { min-height: 38px; display: flex; align-items: center; gap: 6px; padding: 0 13px; border: 1px solid var(--line); border-radius: 999px; background: var(--surface); color: var(--muted); font-size: 12px; }
.streak-chip i { color: var(--warning); font-size: 18px; }
.streak-chip strong { color: var(--danger); }
.week-strip { display: flex; gap: 5px; padding: 5px 9px; border: 1px solid var(--line); border-radius: 999px; background: var(--surface); }
.week-strip span { width: 25px; height: 25px; display: grid; place-items: center; color: var(--muted-2); border-radius: 50%; font-size: 9px; }
.week-strip span.done { color: #fff; background: #a99cf4; }
.week-strip span.today { color: var(--brand); border: 1px solid var(--brand); }
.icon-button { width: 40px; height: 40px; display: inline-grid; place-items: center; color: var(--ink-soft); background: var(--surface); border: 1px solid var(--line); border-radius: 11px; transition: .18s ease; }
.icon-button:hover { color: var(--brand); border-color: #bcb0ed; background: var(--brand-pale); }
.notification-button { position: relative; border: 0; }
.notification-button i { font-size: 22px; }
.notification-button span { position: absolute; top: -3px; right: -2px; min-width: 18px; height: 18px; display: grid; place-items: center; padding: 0 4px; color: #fff; background: var(--danger); border: 2px solid #fff; border-radius: 999px; font-size: 9px; font-weight: 700; }
.profile-button { min-height: 48px; display: flex; align-items: center; gap: 8px; padding: 3px 6px 3px 3px; color: var(--ink); background: transparent; border: 0; border-radius: 999px; }
.profile-button:hover { background: var(--brand-pale); }
.profile-button img { width: 44px; height: 44px; object-fit: cover; object-position: center 42%; border: 2px solid #fff; border-radius: 50%; box-shadow: 0 4px 12px rgba(33, 27, 61, .14); transform: scale(1.12); }
.profile-copy { display: grid; gap: 2px; text-align: left; }
.profile-copy strong { font-size: 11px; }
.profile-copy small { color: var(--muted); font-size: 9px; }
.mobile-menu { display: none; }

.view { padding: 18px 24px 34px; }
.dashboard-view { max-width: 1680px; margin: 0 auto; }
.continue-card { min-height: 214px; overflow: hidden; position: relative; display: flex; align-items: stretch; border: 1px solid #cfc6f5; border-radius: var(--radius-lg); background: #eeebff url("../pic/dashboard-hero.png") center right / cover no-repeat; box-shadow: var(--shadow-sm); }
.continue-content { position: relative; z-index: 1; width: 58%; display: grid; align-content: center; justify-items: start; padding: 24px 30px; }
.eyebrow { display: block; color: var(--muted); font-family: Bahnschrift, "Microsoft YaHei UI", sans-serif; font-size: 10px; font-weight: 700; letter-spacing: .12em; }
.eyebrow.purple { color: var(--brand); }
.eyebrow i { margin-right: 5px; font-size: 14px; vertical-align: -2px; }
.continue-card h2 { margin: 8px 0 3px; font-size: 26px; letter-spacing: -.02em; }
.continue-card p { margin: 0; color: var(--ink-soft); font-size: 14px; }
.continue-progress { width: min(100%, 490px); margin: 15px 0 13px; }
.continue-progress > div:first-child { display: grid; grid-template-columns: auto auto 1fr; align-items: end; gap: 12px; }
.continue-progress span { color: var(--muted); font-size: 11px; }
.continue-progress strong { font-family: Bahnschrift, sans-serif; font-size: 31px; line-height: 1; }
.continue-progress small { justify-self: end; color: var(--ink-soft); font-size: 11px; }
.progress-track { height: 7px; margin-top: 9px; overflow: hidden; background: rgba(255,255,255,.75); border-radius: 999px; }
.progress-track span { display: block; height: 100%; background: var(--brand); border-radius: inherit; }
.primary-button, .secondary-button, .text-button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-weight: 700; transition: .18s ease; }
.primary-button { min-height: 43px; padding: 0 20px; color: #fff; background: var(--brand); border: 1px solid var(--brand); border-radius: 10px; box-shadow: 0 7px 16px rgba(99,56,237,.18); }
.primary-button:hover { background: var(--brand-strong); border-color: var(--brand-strong); transform: translateY(-1px); }
.primary-button.wide { width: 100%; }
.primary-button.compact { min-height: 39px; padding: 0 16px; }
.secondary-button { min-height: 40px; padding: 0 14px; color: var(--ink-soft); background: var(--surface); border: 1px solid var(--line-strong); border-radius: 10px; }
.secondary-button:hover { color: var(--brand); border-color: #b9ade8; background: var(--brand-pale); }
.text-button { min-height: 34px; padding: 0 2px; color: var(--brand); background: transparent; border: 0; font-size: 12px; }
.text-button:hover { color: var(--brand-strong); }

.metrics-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; margin-top: 14px; }
.metric-card { min-height: 88px; display: flex; align-items: center; gap: 12px; padding: 14px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }
.metric-icon { flex: 0 0 44px; width: 44px; height: 44px; display: grid; place-items: center; border-radius: 13px; }
.metric-icon i { font-size: 28px; }
.metric-card > div { min-width: 0; display: grid; gap: 2px; }
.metric-card > div > span { color: var(--muted); font-size: 11px; }
.metric-card strong { font-family: Bahnschrift, "Microsoft YaHei UI", sans-serif; font-size: 26px; }
.metric-card strong small { font-size: 12px; }
.metric-card > div > small { color: var(--muted-2); font-size: 10px; }
.metric-card > div > small b { color: var(--success); }
.purple-metric .metric-icon { color: var(--brand); background: var(--brand-soft); }
.green-metric .metric-icon { color: var(--success); background: var(--success-soft); }
.blue-metric .metric-icon { color: var(--info); background: var(--info-soft); }
.orange-metric .metric-icon { color: var(--warning); background: var(--warning-soft); }

.dashboard-section { margin-top: 20px; }
.section-heading, .panel-heading { display: flex; align-items: center; justify-content: space-between; gap: 18px; }
.section-heading h2, .panel-heading h2 { margin: 4px 0 0; font-size: 20px; }
.module-cards { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 12px; margin-top: 11px; }
.module-card { min-width: 0; min-height: 154px; position: relative; display: flex; flex-direction: column; padding: 13px; text-align: left; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease; }
.module-card:hover { transform: translateY(-3px); border-color: #bcb0ed; box-shadow: var(--shadow-md); }
.module-card.active { border-color: var(--brand); }
.module-card-head { display: flex; align-items: center; gap: 9px; }
.module-number { flex: 0 0 26px; width: 26px; height: 26px; display: grid; place-items: center; color: var(--brand); background: var(--brand-soft); border-radius: 8px; font-family: Bahnschrift, sans-serif; font-size: 10px; font-weight: 700; }
.module-card-title { overflow: hidden; color: var(--ink); font-size: 13px; font-weight: 700; text-overflow: ellipsis; white-space: nowrap; }
.module-card-meta { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: 12px; color: var(--muted); font-size: 10px; }
.module-status { padding: 3px 7px; color: var(--muted); background: #f2f2f6; border-radius: 999px; }
.module-status.progress { color: var(--brand); background: var(--brand-soft); }
.module-progress { height: 5px; margin-top: 8px; overflow: hidden; background: #eeecf4; border-radius: 999px; }
.module-progress span { display: block; height: 100%; background: var(--brand); border-radius: inherit; }
.module-visual { flex: 1; min-height: 64px; display: grid; place-items: center; overflow: hidden; margin-top: 10px; color: var(--brand); background: var(--brand-pale); border: 1px solid #ece8fb; border-radius: 8px; }
.module-visual > span { width: 100%; min-width: 0; display: grid; grid-template-rows: 37px minmax(14px, auto); justify-items: center; align-items: center; padding: 4px 10px 5px; }
.module-visual i { display: block; line-height: 1; font-size: 34px; }
.module-visual small { width: 100%; overflow: hidden; color: var(--muted); font-family: "Cascadia Code", Consolas, monospace; font-size: 9px; line-height: 1.25; text-align: center; text-overflow: ellipsis; white-space: nowrap; }

.dashboard-bottom { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(380px, .85fr); gap: 16px; margin-top: 18px; }
.dashboard-panel { min-width: 0; padding: 16px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius-md); box-shadow: var(--shadow-sm); }
.table-wrap { margin-top: 14px; overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 10px 8px; text-align: left; border-bottom: 1px solid #efedf5; font-size: 11px; white-space: nowrap; }
th { color: var(--muted); background: var(--surface-soft); font-size: 10px; font-weight: 600; }
tbody tr { transition: background .15s ease; }
tbody tr:hover { background: var(--brand-pale); }
.language-chip { display: inline-grid; place-items: center; width: 23px; height: 20px; margin-right: 4px; border-radius: 6px; font-family: Bahnschrift, sans-serif; font-size: 9px; font-weight: 700; }
.language-chip.python { color: #7d5a00; background: #fff2bb; }
.language-chip.cpp { color: #255fae; background: #e8f2ff; }
.status-chip { padding: 4px 7px; border-radius: 999px; font-size: 9px; font-weight: 700; }
.status-chip.accepted { color: var(--success); background: var(--success-soft); }
.status-chip.wrong { color: var(--danger); background: var(--danger-soft); }
.status-chip.partial { color: var(--warning); background: var(--warning-soft); }
.soft-tag { padding: 5px 9px; color: var(--brand); background: var(--brand-soft); border-radius: 999px; font-size: 10px; font-weight: 700; }
.contest-main { display: flex; gap: 14px; align-items: center; margin: 17px 0; padding: 15px; background: var(--surface-soft); border: 1px solid var(--line); border-radius: 12px; }
.contest-icon { flex: 0 0 55px; width: 55px; height: 55px; display: grid; place-items: center; color: var(--brand); background: var(--brand-soft); border-radius: 16px; }
.contest-icon i { font-size: 29px; }
.contest-main span { color: var(--muted); font-size: 10px; }
.contest-main h3 { margin: 4px 0; font-size: 16px; }
.contest-main p { margin: 0; color: var(--muted); font-size: 10px; }
.contest-stats { display: grid; grid-template-columns: repeat(3, 1fr); margin-bottom: 15px; border: 1px solid var(--line); border-radius: 11px; overflow: hidden; }
.contest-stats span { display: grid; justify-items: center; gap: 2px; padding: 10px 6px; border-right: 1px solid var(--line); }
.contest-stats span:last-child { border-right: 0; }
.contest-stats i { color: var(--brand); font-size: 17px; }
.contest-stats small { color: var(--muted); font-size: 9px; }
.contest-stats strong { font-size: 10px; }

.view-heading { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-bottom: 18px; padding: 12px 2px; }
.view-heading h2 { margin: 5px 0 4px; font-size: 26px; }
.view-heading p { margin: 0; color: var(--muted); font-size: 12px; }
.records-view, .admin-view, .platforms-view { max-width: 1480px; margin: 0 auto; }
.platforms-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; padding: 12px 2px 18px; }
.platforms-heading h2 { margin: 5px 0 4px; font-size: 26px; }
.platforms-heading p { max-width: 720px; margin: 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.platform-language { flex: 0 0 auto; }
.platform-language.segmented-tabs { display: flex; }
.platform-language.segmented-tabs button { min-width: 92px; min-height: 38px; font-size: 12px; }
.platform-route { display: grid; grid-template-columns: 48px minmax(0, 1fr); align-items: center; gap: 15px; padding: 17px 19px; color: var(--ink); background: var(--brand-pale); border: 1px solid #dcd5f8; border-radius: 8px; }
.platform-route-icon { width: 48px; height: 48px; display: grid; place-items: center; color: var(--brand); background: #fff; border: 1px solid #ded8f6; border-radius: 8px; font-size: 25px; }
.platform-route div:last-child { min-width: 0; display: grid; gap: 4px; }
.platform-route span { color: var(--brand); font-size: 10px; font-weight: 700; }
.platform-route strong { font-size: 15px; line-height: 1.55; overflow-wrap: anywhere; }
.platform-route p { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.6; }
.platform-list-heading { display: flex; align-items: end; justify-content: space-between; gap: 16px; margin: 24px 2px 10px; }
.platform-list-heading h3 { margin: 0; font-size: 19px; }
.platform-list-heading p { margin: 4px 0 0; color: var(--muted); font-size: 11px; }
.platform-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.platform-item { min-width: 0; display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: start; gap: 16px; padding: 18px; background: var(--surface); border: 1px solid var(--line); border-radius: 8px; box-shadow: var(--shadow-sm); }
.platform-item-main { min-width: 0; }
.platform-item-title { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; }
.platform-item-title h3 { margin: 0 3px 0 0; font-size: 16px; }
.platform-item-title span { padding: 3px 7px; color: var(--brand); background: var(--brand-pale); border-radius: 999px; font-size: 9px; font-weight: 700; }
.platform-item-title span:last-child { color: #176e59; background: var(--success-soft); }
.platform-item-main > p { min-height: 38px; margin: 9px 0 12px; color: var(--ink-soft); font-size: 12px; line-height: 1.65; }
.platform-item dl { display: grid; gap: 8px; margin: 0; }
.platform-item dl > div { display: grid; grid-template-columns: 58px minmax(0, 1fr); gap: 9px; }
.platform-item dt { color: var(--muted); font-size: 10px; font-weight: 700; }
.platform-item dd { margin: 0; color: var(--ink-soft); font-size: 10px; line-height: 1.6; }
.platform-link { min-height: 36px; display: inline-flex; align-items: center; justify-content: center; gap: 6px; padding: 0 11px; color: var(--brand); text-decoration: none; white-space: nowrap; background: var(--brand-pale); border: 1px solid #d8d0f7; border-radius: 7px; font-size: 11px; font-weight: 700; }
.platform-link:hover { color: #fff; background: var(--brand); border-color: var(--brand); }
.record-summary { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; margin-bottom: 16px; }
.record-summary > div { display: grid; gap: 7px; padding: 17px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; box-shadow: var(--shadow-sm); }
.record-summary span { color: var(--muted); font-size: 10px; }
.record-summary strong { font-size: 21px; }
.records-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.record-list { display: grid; gap: 9px; margin-top: 15px; }
.record-item { display: grid; grid-template-columns: 38px minmax(0, 1fr) auto; align-items: center; gap: 11px; padding: 12px; background: var(--surface-soft); border: 1px solid var(--line); border-radius: 10px; }
.record-item > i { width: 36px; height: 36px; display: grid; place-items: center; color: var(--brand); background: var(--brand-soft); border-radius: 9px; font-size: 19px; }
.record-item.mistake > i { color: var(--danger); background: var(--danger-soft); }
.record-item div { min-width: 0; }
.record-item strong, .record-item small { display: block; }
.record-item strong { overflow: hidden; font-size: 11px; text-overflow: ellipsis; white-space: nowrap; }
.record-item small { margin-top: 3px; color: var(--muted); font-size: 9px; line-height: 1.5; }
.record-item time { color: var(--muted-2); font-size: 9px; white-space: nowrap; }
.empty-list { min-height: 150px; display: grid; place-items: center; align-content: center; gap: 7px; color: var(--muted); text-align: center; }
.empty-list i { color: var(--success); font-size: 30px; }
.empty-list strong { color: var(--ink-soft); font-size: 12px; }
.empty-list span { font-size: 10px; }
.admin-layout { display: grid; grid-template-columns: minmax(560px, 1.2fr) minmax(360px, .8fr); gap: 16px; align-items: start; }
.registration-admin-panel { margin-bottom: 16px; }
.registration-admin-head { display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.registration-admin-head h2 { margin: 4px 0 0; font-size: 20px; }
.registration-admin-head p { margin: 5px 0 0; color: var(--muted); font-size: 12px; line-height: 1.55; }
.switch-control { position: relative; flex: 0 0 auto; display: grid; grid-template-columns: 42px auto; align-items: center; gap: 9px; cursor: pointer; }
.switch-control input { position: absolute; inset: 0; z-index: 2; width: 100%; height: 100%; margin: 0; opacity: 0; cursor: pointer; }
.switch-track { width: 42px; height: 24px; padding: 3px; background: #c8cbd5; border-radius: 999px; transition: background .18s ease; }
.switch-track span { display: block; width: 18px; height: 18px; background: #fff; border-radius: 50%; box-shadow: 0 2px 5px rgba(27,23,47,.18); transition: transform .18s ease; }
.switch-control input:checked + .switch-track { background: var(--success); }
.switch-control input:checked + .switch-track span { transform: translateX(18px); }
.switch-control input:focus-visible + .switch-track { outline: 3px solid rgba(99,56,237,.28); outline-offset: 3px; }
.switch-control strong { min-width: 72px; color: var(--ink-soft); font-size: 11px; }
.registration-inbox-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line); }
.registration-inbox-heading h3 { margin: 0; font-size: 14px; }
.registration-request-list { display: grid; margin-top: 10px; border: 1px solid var(--line); border-radius: 7px; }
.registration-request-row { display: grid; grid-template-columns: minmax(160px, 1fr) minmax(260px, auto); align-items: center; gap: 14px; min-height: 70px; padding: 11px 13px; border-bottom: 1px solid var(--line); }
.registration-request-row:last-child { border-bottom: 0; }
.registration-request-person { min-width: 0; display: grid; grid-template-columns: 34px minmax(0, 1fr); gap: 9px; align-items: center; }
.registration-request-person > i { display: grid; place-items: center; width: 34px; height: 34px; color: var(--info); background: var(--info-soft); border-radius: 7px; font-size: 19px; }
.registration-request-person div { min-width: 0; display: grid; gap: 3px; }
.registration-request-person strong { overflow: hidden; font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.registration-request-person small { color: var(--muted); font-size: 10px; }
.registration-request-actions { display: flex; align-items: center; justify-content: flex-end; gap: 7px; }
.registration-request-actions input { width: 150px; min-height: 36px; padding: 0 10px; border: 1px solid var(--line-strong); border-radius: 7px; outline: 0; font-size: 11px; }
.registration-request-actions input:focus { border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-soft); }
.registration-request-actions .secondary-button, .registration-request-actions .primary-button { min-height: 36px; padding: 0 11px; font-size: 11px; }
.registration-request-status { justify-self: end; display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 11px; }
.registration-request-status.approved { color: var(--success); }
.registration-request-status.rejected { color: var(--danger); }
.registration-request-empty { display: grid; justify-items: center; gap: 6px; padding: 24px 16px; color: var(--muted); text-align: center; font-size: 11px; }
.registration-request-empty i { color: var(--success); font-size: 24px; }
.admin-users-panel tbody tr { cursor: pointer; }
.admin-users-panel tbody tr.active { background: var(--brand-soft); }
.user-cell { display: grid; gap: 2px; }
.user-cell strong { font-size: 11px; }
.user-cell small { color: var(--muted); font-size: 9px; }
.admin-user-detail { position: sticky; top: 86px; min-height: 420px; }
.empty-state { min-height: 380px; display: grid; place-items: center; align-content: center; gap: 8px; color: var(--muted); text-align: center; }
.empty-state i { color: var(--brand); font-size: 34px; }
.empty-state strong { color: var(--ink-soft); font-size: 13px; }
.empty-state span { font-size: 10px; }
.detail-heading { display: flex; align-items: center; gap: 11px; padding-bottom: 14px; border-bottom: 1px solid var(--line); }
.detail-avatar { width: 42px; height: 42px; display: grid; place-items: center; color: #fff; background: var(--brand); border-radius: 10px; font-size: 16px; font-weight: 700; }
.detail-heading div { min-width: 0; }
.detail-heading h3 { margin: 0; font-size: 15px; }
.detail-heading p { margin: 3px 0 0; color: var(--muted); font-size: 9px; }
.detail-metrics { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 14px 0; }
.detail-metrics span { display: grid; gap: 4px; padding: 10px; background: var(--surface-soft); border: 1px solid var(--line); border-radius: 8px; }
.detail-metrics small { color: var(--muted); font-size: 8px; }
.detail-metrics strong { font-size: 11px; }
.module-progress-list { display: grid; gap: 8px; }
.module-progress-row { display: grid; grid-template-columns: 85px 1fr 34px; align-items: center; gap: 8px; font-size: 9px; }
.module-progress-row > span:first-child { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.mini-track { height: 5px; overflow: hidden; background: #eceaf4; border-radius: 999px; }
.mini-track span { display: block; height: 100%; background: var(--success); border-radius: inherit; }
.detail-section-title { margin: 16px 0 9px; color: var(--ink-soft); font-size: 11px; }

/* Lesson workspace: explain first, observe second, code third */
.lesson-view { max-width: 1540px; margin: 0 auto; }
.lesson-toolbar { display: flex; align-items: center; gap: 16px; margin-bottom: 16px; }
.lesson-breadcrumb { min-width: 0; display: flex; align-items: center; gap: 7px; color: var(--muted); font-size: 11px; }
.lesson-breadcrumb strong { color: var(--ink-soft); }
.lesson-toolbar > .icon-button { margin-left: auto; }
.lesson-intro { position: relative; overflow: hidden; display: flex; align-items: flex-start; justify-content: space-between; gap: 42px; padding: 34px 36px; background: linear-gradient(90deg, rgba(249,247,255,.98) 0%, rgba(249,247,255,.94) 57%, rgba(249,247,255,.68) 100%), url("../pic/dashboard-hero.png") right 38% / cover no-repeat; border: 1px solid #d8cef9; border-radius: 22px; box-shadow: 0 16px 34px rgba(72,47,151,.09); }
.lesson-intro > div { position: relative; z-index: 1; }
.lesson-intro h2 { margin: 7px 0; font-size: 34px; letter-spacing: -.03em; }
.lesson-title-row { display: flex; align-items: center; gap: 11px; }
.lesson-intro p { max-width: 760px; margin: 0; color: #666d86; font-size: 14px; line-height: 1.9; }
.difficulty-chip { padding: 5px 9px; color: var(--warning); background: var(--warning-soft); border-radius: 999px; font-size: 10px; font-weight: 700; }
.lesson-meta { display: flex; gap: 10px; }
.lesson-meta span { min-width: 106px; display: grid; gap: 6px; padding: 14px 16px; background: rgba(255,255,255,.9); border: 1px solid rgba(219,213,240,.9); border-radius: 14px; box-shadow: 0 8px 20px rgba(50,35,104,.06); }
.lesson-meta span:nth-child(1) { border-top: 3px solid var(--success); }
.lesson-meta span:nth-child(2) { border-top: 3px solid var(--brand); }
.lesson-meta span:nth-child(3) { border-top: 3px solid var(--warning); }
.lesson-meta small { color: var(--muted); font-size: 9px; }
.lesson-meta strong { font-size: 12px; }
.level-strip { margin-top: 20px; padding: 20px 24px; background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow-sm); }
.level-strip-heading { display: flex; align-items: center; justify-content: space-between; gap: 15px; }
.level-strip-heading h3 { margin: 4px 0 0; font-size: 15px; }
.level-strip-heading > span { color: var(--muted); font-size: 10px; }
.level-nav { display: grid; grid-template-columns: repeat(10, minmax(96px, 1fr)); gap: 10px; margin-top: 16px; overflow-x: auto; padding: 2px 1px 7px; scrollbar-width: thin; scrollbar-color: #d7cff7 transparent; }
.level-item { min-width: 96px; min-height: 58px; display: flex; align-items: center; gap: 9px; padding: 10px; color: var(--muted); text-align: left; background: #fbfaff; border: 1px solid #e8e4f4; border-radius: 13px; }
.level-item:hover { border-color: #b9ade8; }
.level-item.active { color: var(--brand); background: #f2edff; border-color: var(--brand); box-shadow: 0 7px 16px rgba(99,56,237,.11); }
.level-number { flex: 0 0 24px; width: 24px; height: 24px; display: grid; place-items: center; color: var(--brand); background: var(--brand-soft); border-radius: 7px; font-family: Bahnschrift, sans-serif; font-size: 10px; font-weight: 700; }
.level-item.active .level-number { color: #fff; background: var(--brand); }
.level-item strong { display: block; font-size: 11px; }
.level-item small { display: block; max-width: 86px; margin-top: 3px; overflow: hidden; color: var(--muted-2); text-overflow: ellipsis; white-space: nowrap; font-size: 9px; }
.level-done-dot { width: 6px; height: 6px; margin-left: auto; background: var(--success); border-radius: 50%; }

.algorithm-guide { margin-top: 20px; overflow: hidden; padding: 28px; background: linear-gradient(135deg, #ffffff 0%, #fbf8ff 58%, #eef9ff 100%); border-color: #ddd4fa; border-radius: 20px; box-shadow: 0 12px 30px rgba(66,45,136,.08); }
.algorithm-guide-head { display: flex; align-items: center; gap: 16px; }
.algorithm-guide-head > div { min-width: 0; }
.algorithm-guide-head h3 { margin: 5px 0 4px; font-size: 22px; }
.algorithm-guide-head p { margin: 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.guide-hero-icon { flex: 0 0 54px; width: 54px; height: 54px; display: grid; place-items: center; color: #fff; background: var(--brand); border-radius: 17px; box-shadow: 0 10px 22px rgba(99,56,237,.22); }
.guide-hero-icon i { font-size: 29px; }
.guide-module-chip { margin-left: auto; padding: 8px 12px; color: var(--brand); background: #fff; border: 1px solid #d9cdfd; border-radius: 999px; font-size: 11px; font-weight: 700; white-space: nowrap; }
.algorithm-guide-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 14px; margin-top: 22px; }
.guide-motion { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(280px, .78fr) minmax(560px, 1.22fr); gap: 28px; align-items: center; padding: 22px 24px; background: #f7f4ff; border: 1px solid #dfd6fb; border-radius: 14px; }
.guide-motion-intro h4 { margin: 6px 0 9px; font-size: 20px; line-height: 1.45; }
.guide-motion-intro p { max-width: 460px; margin: 0; color: var(--ink-soft); font-size: 14px; line-height: 1.8; }
.guide-motion-kicker { display: inline-flex; align-items: center; gap: 5px; color: var(--brand); font-size: 11px; font-weight: 700; }
.guide-motion-showcase { display: grid; gap: 17px; min-width: 0; }
.motion-demo { display: grid; grid-template-columns: auto minmax(0, 1fr); align-items: start; gap: 9px 11px; min-height: 58px; padding: 13px; background: rgba(255,255,255,.86); border: 1px solid #ddd4fa; border-radius: 10px; }
.motion-demo-label { align-self: center; color: var(--muted); font-size: 13px; font-weight: 700; white-space: nowrap; }
.motion-demo-input { min-width: 0; padding: 8px 10px; color: var(--brand-dark); background: var(--brand-soft); border: 1px solid #d2c4ff; border-radius: 7px; font-family: "Cascadia Code", Consolas, monospace; font-size: 13px; font-weight: 700; line-height: 1.6; white-space: normal; overflow-wrap: anywhere; animation: demo-input-float 4.8s ease-in-out infinite; }
.motion-demo-arrow { display: none; }
.motion-demo-checks { grid-column: 1 / -1; display: grid; gap: 7px; min-width: 0; }
.motion-demo-check { min-width: 0; display: grid; grid-template-columns: 16px minmax(0, 1fr); align-items: start; gap: 6px; padding: 8px 9px; border: 1px solid transparent; border-radius: 6px; font-size: 13px; line-height: 1.55; overflow-wrap: anywhere; animation: demo-check-reveal 4.8s ease-in-out infinite; animation-delay: var(--check-delay); }
.motion-demo-check i { font-size: 14px; }
.motion-demo-check.passed { color: #176f51; background: var(--success-soft); border-color: #b7e5d3; }
.motion-demo-check.failed { color: #a83f4b; background: var(--danger-soft); border-color: #efc3c8; }
.motion-demo-result { grid-column: 1 / -1; justify-self: end; padding: 8px 10px; border: 1px solid transparent; border-radius: 7px; font-size: 14px; font-weight: 700; white-space: normal; animation: demo-result-pulse 4.8s ease-in-out infinite 2s; }
.motion-demo-result.accept { color: #176f51; background: var(--success-soft); border-color: #b7e5d3; }
.motion-demo-result.reject { color: #a83f4b; background: var(--danger-soft); border-color: #efc3c8; }
.guide-motion-flow { display: flex; align-items: center; min-width: 0; }
.motion-step { flex: 1 1 0; min-width: 126px; display: grid; justify-items: center; gap: 5px; text-align: center; animation: motion-step-reveal 4.8s ease-in-out infinite; animation-delay: var(--step-delay); }
.motion-step-icon { width: 43px; height: 43px; display: grid; place-items: center; color: var(--brand); background: #fff; border: 1px solid #d9cdfd; border-radius: 11px; box-shadow: 0 5px 12px rgba(99,56,237,.08); }
.motion-step-icon i { font-size: 23px; }
.motion-step strong { color: var(--brand-dark); font-size: 13px; }
.motion-step small { max-width: 164px; color: var(--muted); font-size: 12px; line-height: 1.55; }
.motion-connector { flex: 0 1 42px; min-width: 20px; height: 2px; margin: 0 6px; background: #d9cdfd; overflow: hidden; }
.motion-connector::after { width: 12px; height: 100%; display: block; content: ""; background: var(--brand); animation: motion-travel 2.2s ease-in-out infinite; }
@keyframes motion-step-reveal { 0%, 12%, 100% { transform: translateY(0); } 20%, 36% { transform: translateY(-4px); } }
@keyframes motion-travel { 0% { transform: translateX(-14px); opacity: 0; } 25% { opacity: 1; } 75% { opacity: 1; } 100% { transform: translateX(58px); opacity: 0; } }
@keyframes demo-input-float { 0%, 18%, 100% { transform: translateX(0); } 8% { transform: translateX(5px); } 12% { transform: translateX(0); } }
@keyframes demo-arrow-pulse { 0%, 100% { opacity: .45; transform: translateX(0); } 20%, 54% { opacity: 1; transform: translateX(3px); } }
@keyframes demo-check-reveal { 0%, 10%, 100% { transform: scale(.96); opacity: .5; } 18%, 36% { transform: scale(1); opacity: 1; } }
@keyframes demo-result-pulse { 0%, 45%, 100% { transform: scale(1); } 55%, 64% { transform: scale(1.07); } }
.guide-block { min-width: 0; display: flex; align-items: flex-start; gap: 13px; padding: 18px; border: 1px solid transparent; border-radius: 16px; }
.guide-block-icon { flex: 0 0 38px; width: 38px; height: 38px; display: grid; place-items: center; background: rgba(255,255,255,.82); border-radius: 12px; }
.guide-block-icon i { font-size: 21px; }
.guide-block small { color: var(--muted); font-size: 10px; font-weight: 700; }
.guide-block h4 { margin: 4px 0 7px; font-size: 14px; }
.guide-block p { margin: 0; color: var(--ink-soft); font-size: 12px; line-height: 1.85; overflow-wrap: anywhere; }
.guide-core { background: #f0ebff; border-color: #ded3ff; }
.guide-core .guide-block-icon { color: var(--brand); }
.guide-process { background: var(--aqua-soft); border-color: #c8eee9; }
.guide-process .guide-block-icon { color: var(--aqua); }
.guide-complexity { background: var(--info-soft); border-color: #d7e5ff; }
.guide-complexity .guide-block-icon { color: var(--info); }
.guide-pitfall { background: var(--sun-soft); border-color: #f5e8b9; }
.guide-pitfall .guide-block-icon { color: #d59119; }

.lesson-workspace { display: grid; grid-template-columns: minmax(330px, .72fr) minmax(560px, 1.28fr); gap: 20px; align-items: start; margin-top: 20px; }
.lesson-card { min-width: 0; background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: 0 10px 28px rgba(42,30,91,.06); }
.brief-column { display: grid; gap: 18px; }
.brief-column .lesson-card { padding: 24px; }
.card-heading { display: flex; align-items: center; gap: 10px; }
.card-heading h3 { margin: 4px 0 0; font-size: 18px; }
.card-icon { flex: 0 0 42px; width: 42px; height: 42px; display: grid; place-items: center; border-radius: 13px; }
.card-icon i { font-size: 19px; }
.purple-icon { color: var(--brand); background: var(--brand-soft); }
.blue-icon { color: var(--info); background: var(--info-soft); }
.problem-card > p { margin: 20px 0; color: var(--ink-soft); font-size: 14px; line-height: 2; overflow-wrap: anywhere; }
.problem-details { display: grid; gap: 10px; margin: 0; }
.problem-details div { padding: 14px; background: #faf9fe; border: 1px solid #ece8f5; border-radius: 12px; }
.problem-details dt { margin-bottom: 6px; color: var(--muted); font-size: 10px; }
.problem-details dd { margin: 0; color: var(--ink-soft); font-size: 12px; line-height: 1.7; overflow-wrap: anywhere; }
.learning-tip { display: flex; align-items: flex-start; gap: 14px; color: #655122; background: var(--sun-soft); border-color: #f3e4ae; }
.learning-tip-icon { flex: 0 0 40px; width: 40px; height: 40px; display: grid; place-items: center; color: #d59119; background: #fff; border-radius: 13px; }
.learning-tip-icon i { font-size: 21px; }
.learning-tip h3 { margin: 5px 0 7px; font-size: 15px; }
.learning-tip p { margin: 0; color: #79683d; font-size: 12px; line-height: 1.8; }
.theory-card details { border-top: 1px solid var(--line); }
.theory-card summary { display: flex; align-items: center; justify-content: space-between; padding-top: 12px; color: var(--brand); font-size: 11px; font-weight: 700; cursor: pointer; list-style: none; }
.theory-card details p { margin: 10px 0 0; color: var(--muted); font-size: 11px; line-height: 1.7; }
.insight-card { display: grid; gap: 12px; }
.insight-card > div { display: grid; gap: 6px; }
.insight-card > div + div { padding-top: 12px; border-top: 1px solid var(--line); }
.insight-card span { color: var(--muted); font-size: 10px; }
.insight-card span i { margin-right: 4px; color: var(--brand); }
.insight-card strong, .insight-card p { margin: 0; color: var(--ink-soft); font-size: 11px; line-height: 1.6; }

.visual-column, .coding-column { padding: 26px; }
.coding-column { grid-column: 1 / -1; }
.panel-heading h3, .coding-head h3 { margin: 5px 0 0; font-size: 23px; }
.phase-label { padding: 6px 9px; color: var(--brand); background: var(--brand-soft); border-radius: 999px; font-size: 11px; font-weight: 700; }
.phase-rail { display: flex; align-items: flex-start; margin: 22px 0 16px; overflow-x: auto; padding: 4px 2px 8px; scrollbar-width: none; }
.phase-rail::-webkit-scrollbar { display: none; }
.phase-dot { min-width: 80px; display: grid; justify-items: center; gap: 6px; color: var(--muted-2); text-align: center; }
.phase-dot i { width: 28px; height: 28px; display: grid; place-items: center; background: #f0eff4; border: 1px solid #e1dfeb; border-radius: 50%; font-size: 11px; font-style: normal; }
.phase-dot b { max-width: 94px; font-size: 11px; font-weight: 600; line-height: 1.35; }
.phase-dot.done i { color: var(--success); background: var(--success-soft); border-color: #a9dfcb; }
.phase-dot.current { color: var(--brand); }
.phase-dot.current i { color: #fff; background: var(--brand); border-color: var(--brand); box-shadow: 0 0 0 4px var(--brand-soft); }
.phase-connector { flex: 1; min-width: 12px; height: 1px; margin-top: 14px; background: var(--line); }
.process-readout { min-height: 54px; display: flex; align-items: flex-start; gap: 10px; padding: 13px 15px; color: var(--ink-soft); background: var(--brand-pale); border-left: 4px solid var(--brand); border-radius: 10px; }
.process-readout i { margin-top: 2px; color: var(--brand); }
.process-readout p { margin: 0; font-size: 14px; line-height: 1.75; }
.visual-stage { min-height: 0; display: flex; align-items: center; justify-content: center; margin: 20px 0 16px; padding: 28px 18px; background: linear-gradient(145deg, #fcfbff 0%, #f6f2ff 100%); border: 1px solid #e9e3fb; border-radius: 16px; overflow: hidden; transition: min-height .2s ease; }
.visual-stage.binary-stage { min-height: 190px; }
.visual-stage.prefix-stage, .visual-stage.difference-stage, .visual-stage.dp-stage { min-height: 220px; }
.visual-stage.candidates-stage { min-height: 250px; padding: 24px 16px; }
.visual-stage.intervals-stage, .visual-stage.grid-stage { min-height: 270px; }
.step-caption { min-height: 60px; display: grid; grid-template-columns: 32px 1fr; gap: 10px; align-items: start; padding: 12px 13px; background: var(--brand-pale); border-radius: 9px; }
.step-caption span { width: 28px; height: 28px; display: grid; place-items: center; color: var(--brand); background: #fff; border-radius: 7px; font-family: Bahnschrift, sans-serif; font-size: 11px; font-weight: 700; }
.step-caption p { margin: 2px 0 0; color: var(--ink-soft); font-size: 14px; line-height: 1.75; }
.playback { display: flex; align-items: center; gap: 7px; margin: 13px 0; }
.playback .icon-button { margin-left: auto; }
.variables { display: flex; flex-wrap: wrap; gap: 6px; padding-top: 13px; border-top: 1px solid var(--line); }
.variable-chip { display: inline-flex; align-items: center; gap: 5px; padding: 7px 9px; color: var(--muted); background: #f3f2f7; border-radius: 7px; font-family: "Cascadia Code", Consolas, monospace; font-size: 11px; }
.variable-chip strong { color: var(--brand-dark); }

.coding-head { display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.segmented-tabs { display: flex; gap: 3px; padding: 3px; background: #f0eff5; border-radius: 9px; }
.segmented-tabs button { min-height: 30px; padding: 0 11px; color: var(--muted); background: transparent; border: 0; border-radius: 7px; font-size: 10px; }
.segmented-tabs button.active { color: var(--brand); background: #fff; box-shadow: 0 2px 7px rgba(37,27,76,.08); font-weight: 700; }
.segmented-tabs.small button { min-height: 25px; padding: 0 8px; font-size: 9px; }
.coding-prompt-wrap { display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; margin: 18px 0 14px; padding: 16px 18px; background: #faf9fe; border: 1px solid #ece8f5; border-radius: 13px; }
.coding-prompt-wrap p { max-width: 1100px; margin: 0; color: var(--ink-soft); font-size: 13px; line-height: 1.9; overflow-wrap: anywhere; }
.coding-prompt-wrap .text-button { white-space: nowrap; }
.reference-code-panel { margin-bottom: 10px; overflow: hidden; border: 1px solid #38334f; border-radius: 10px; }
.reference-head { display: flex; align-items: center; justify-content: space-between; padding: 8px 10px; color: #beb8d5; background: var(--code-surface); font-size: 9px; }
.code-view { max-height: 235px; padding: 10px 0; background: var(--code-bg); overflow: auto; }
.code-line { display: grid; grid-template-columns: 28px minmax(150px, auto) minmax(120px, 1fr); gap: 8px; padding: 4px 11px; color: #c6c0dd; font-family: "Cascadia Code", Consolas, monospace; font-size: 9px; line-height: 1.55; white-space: pre-wrap; }
.code-line-number { color: #716b88; text-align: right; user-select: none; }
.code-line.active { background: #3a2f67; border-left: 3px solid #b59eff; padding-left: 8px; }
.code-source { color: #f3efff; }
.code-comment { color: #85b9a6; overflow-wrap: anywhere; }
.editor-shell { overflow: hidden; border: 1px solid #312d47; border-radius: 15px; background: var(--code-bg); box-shadow: 0 16px 34px rgba(25,23,41,.14); }
.editor-topbar { min-height: 38px; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 0 12px; color: #aaa4c2; background: var(--code-surface); border-bottom: 1px solid #332f49; font-family: "Cascadia Code", Consolas, monospace; font-size: 9px; }
.editor-topbar i { margin-right: 5px; color: #b7a8f7; }
.coding-status { font-family: "Microsoft YaHei UI", sans-serif; }
.coding-status.success { color: #7ee0b8; }
.coding-status.error { color: #ff9ba5; }
.submission-code { width: 100%; min-height: 340px; resize: vertical; padding: 22px 24px; color: #f5f2ff; caret-color: #b39aff; background: var(--code-bg); border: 0; outline: 0; font-family: "Cascadia Code", Consolas, monospace; font-size: 13px; line-height: 1.85; tab-size: 4; }
.submission-code:focus { box-shadow: inset 0 0 0 2px rgba(178,151,255,.28); }
.coding-meta { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 12px; margin-top: 14px; }
.coding-meta > div { min-width: 0; padding: 14px 16px; background: var(--surface-soft); border: 1px solid var(--line); border-radius: 12px; }
.coding-meta span { color: var(--muted); font-size: 10px; }
.coding-meta pre, .coding-meta p { max-height: 90px; margin: 7px 0 0; color: var(--ink-soft); font-family: "Cascadia Code", Consolas, monospace; font-size: 11px; line-height: 1.65; white-space: pre-wrap; overflow: auto; }
.coding-actions { display: flex; gap: 8px; margin-top: 10px; }
.run-output { min-height: 64px; max-height: 145px; margin: 10px 0 0; padding: 11px; color: #615b76; background: #f4f3f8; border: 1px solid var(--line); border-radius: 9px; font-family: "Cascadia Code", Consolas, monospace; font-size: 9px; line-height: 1.6; white-space: pre-wrap; overflow: auto; }
.run-output.success { color: #176f51; background: var(--success-soft); border-color: #b7e5d3; }
.run-output.error { color: #93404b; background: var(--danger-soft); border-color: #efc3c8; }
.quick-practice { margin-top: 13px; padding-top: 13px; border-top: 1px solid var(--line); }
.quick-practice h4 { margin: 4px 0 8px; font-size: 12px; }
.practice-form { display: flex; gap: 7px; }
.practice-form input { flex: 1; min-width: 0; min-height: 39px; padding: 0 10px; color: var(--ink); background: #fff; border: 1px solid var(--line-strong); border-radius: 9px; outline: 0; font-size: 11px; }
#practice-feedback { min-height: 18px; margin: 7px 0 0; font-size: 10px; }
#practice-feedback.success { color: var(--success); }
#practice-feedback.error { color: var(--danger); }

/* Algorithm visualization primitives */
.array-wrap, .interval-wrap, .dp-wrap { width: 100%; max-width: 620px; }
.candidate-wrap { max-width: 590px; }
.array-label, .dp-label { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px 18px; margin-bottom: 16px; color: var(--ink-soft); font-size: 14px; line-height: 1.55; }
.array, .binary-array, .dp-table { display: flex; gap: 6px; justify-content: center; flex-wrap: wrap; }
.array-cell { position: relative; width: 52px; height: 62px; display: grid; place-items: center; color: var(--brand-dark); background: #fff; border: 1px solid #d8d3e9; border-radius: 9px; font-family: "Cascadia Code", monospace; font-size: 15px; font-weight: 700; }
.candidate-wrap .array { gap: 6px; padding-top: 26px; }
.candidate-wrap .array-cell { width: 50px; height: 57px; font-size: 15px; }
.array-cell.current { color: var(--brand); background: var(--brand-soft); border-color: var(--brand); transform: translateY(-3px); }
.array-cell.accepted { color: var(--success); background: var(--success-soft); border-color: #9ad7c0; }
.array-cell.rejected { color: var(--danger); background: var(--danger-soft); border-color: #e8b0b7; }
.cell-index { position: absolute; bottom: 5px; color: var(--muted); font-size: 12px; font-weight: 400; }
.cell-tag { position: absolute; top: -31px; left: 50%; z-index: 2; padding: 4px 7px; color: var(--brand); background: #fff; border: 1px solid #d9d0fb; border-radius: 6px; box-shadow: 0 4px 10px rgba(54,35,117,.08); font-family: "Microsoft YaHei UI", sans-serif; font-size: 13px; font-weight: 700; line-height: 1; white-space: nowrap; transform: translateX(-50%); }
.candidate-inspection { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 7px 10px; margin-top: 20px; padding: 10px 12px; background: #fff; border: 1px solid #e3dff0; border-radius: 9px; color: var(--ink-soft); font-size: 14px; line-height: 1.55; }
.inspection-candidate { padding-right: 8px; color: var(--brand-dark); border-right: 1px solid var(--line); font-family: "Cascadia Code", monospace; font-weight: 700; }
.inspection-rule { display: inline-flex; align-items: center; gap: 3px; }
.inspection-rule i { font-size: 14px; }
.inspection-rule.passed { color: #197457; }
.inspection-rule.failed { color: #b34b56; }
.candidate-inspection.has-failed-rule { background: #fffafa; border-color: #f1c7cc; }
.prefix-row { display: flex; justify-content: center; gap: 4px; margin-top: 20px; flex-wrap: wrap; }
.prefix-cell { min-width: 52px; padding: 9px 7px; color: var(--brand-dark); text-align: center; background: var(--brand-soft); border-radius: 7px; font-family: "Cascadia Code", monospace; font-size: 13px; line-height: 1.5; }
.prefix-cell.active { color: #fff; background: var(--brand); }
.prefix-caption { margin-top: 15px; color: var(--ink-soft); text-align: center; font-size: 14px; line-height: 1.65; }
.interval-track { display: grid; gap: 9px; }
.interval-row { position: relative; height: 29px; }
.interval-name { position: absolute; left: 0; width: 58px; color: var(--ink-soft); font-size: 12px; }
.interval-line { position: absolute; left: 66px; right: 0; top: 6px; height: 14px; background: #eceaf3; border-radius: 999px; }
.interval-bar { position: absolute; height: 11px; border-radius: 999px; background: #c8c3da; }
.interval-bar.order-current { background: var(--brand); }
.interval-bar.selected { background: var(--success); }
.interval-bar.rejected { background: #eab0b7; }
.interval-axis { display: flex; justify-content: space-between; margin: 5px 0 0 66px; color: var(--muted); font-size: 12px; }
.binary-cell { width: 52px; padding: 11px 5px 8px; color: var(--brand-dark); text-align: center; background: #fff; border: 1px solid #d8d3e9; border-radius: 8px; font-family: "Cascadia Code", monospace; font-size: 15px; }
.binary-cell.out { opacity: .22; }
.binary-cell.mid { color: var(--brand); background: var(--brand-soft); border-color: var(--brand); }
.binary-cell.found { color: var(--success); background: var(--success-soft); border-color: var(--success); }
.binary-index { display: block; margin-top: 5px; color: var(--muted); font-size: 12px; }
.range-label { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px 16px; margin-top: 14px; color: var(--ink-soft); font-size: 14px; }
.grid-wrap { width: min(100%, 680px); display: grid; gap: 15px; justify-items: center; }
.grid-status { width: 100%; display: grid; grid-template-columns: minmax(220px, 1.4fr) minmax(120px, .6fr) minmax(220px, 1fr); gap: 10px; }
.grid-status span { min-width: 0; padding: 9px 11px; color: var(--ink-soft); background: #fff; border: 1px solid var(--line); border-radius: 8px; font-size: 13px; line-height: 1.55; overflow-wrap: anywhere; }
.grid-status strong { display: block; margin-bottom: 2px; color: var(--brand-dark); font-size: 14px; }
.grid { display: grid; grid-template-columns: repeat(var(--grid-columns, 3), 58px); gap: 7px; }
.grid-cell { width: 58px; height: 58px; display: grid; place-items: center; align-content: center; gap: 1px; color: var(--muted); background: #fff; border: 1px solid #d8d3e9; border-radius: 8px; font-size: 16px; }
.grid-cell strong { font-size: inherit; }
.grid-cell small { font-size: 12px; line-height: 1.2; }
.grid-cell.wall { color: #9792aa; background: #e9e8ef; }
.grid-cell.visited { color: var(--info); background: var(--info-soft); border-color: #adc8f2; }
.grid-cell.frontier { color: var(--brand); background: var(--brand-soft); border-color: #b9ade8; }
.grid-cell.current { outline: 3px solid rgba(99,56,237,.24); outline-offset: 2px; }
.grid-cell.path { color: var(--success); background: var(--success-soft); border-color: var(--success); }
.grid-legend { display: flex; gap: 10px 16px; flex-wrap: wrap; justify-content: center; color: var(--ink-soft); font-size: 13px; }
.legend-item { display: inline-flex; align-items: center; gap: 6px; }
.legend-dot { width: 12px; height: 12px; border-radius: 3px; background: var(--info-soft); border: 1px solid #adc8f2; }
.legend-dot.current { background: #fff; border: 3px solid rgba(99,56,237,.52); }
.legend-dot.frontier { background: var(--brand-soft); border-color: #b9ade8; }
.legend-dot.wall { background: #e9e8ef; border-color: #d2cfdd; }
.dp-cell { min-width: 72px; padding: 11px 8px; text-align: center; background: #fff; border: 1px solid #d8d3e9; border-radius: 8px; }
.dp-cell .value { display: block; color: var(--ink-soft); font-size: 13px; }
.dp-cell strong { display: block; margin-top: 5px; color: var(--brand-dark); font-family: "Cascadia Code", monospace; font-size: 17px; }
.dp-cell.current { background: var(--brand-soft); border-color: var(--brand); }
.dp-cell.best { background: var(--success-soft); border-color: var(--success); }

.toast { position: fixed; right: 24px; bottom: 24px; z-index: 80; max-width: 360px; padding: 12px 15px; color: #fff; background: #2c2548; border-radius: 11px; box-shadow: 0 15px 36px rgba(31,24,56,.24); font-size: 12px; transform: translateY(24px); opacity: 0; pointer-events: none; transition: .22s ease; }
.toast.show { transform: translateY(0); opacity: 1; }
.sidebar-backdrop { position: fixed; inset: 0; z-index: 25; background: rgba(25,19,50,.34); }

.focus-mode .app-shell { grid-template-columns: 1fr; }
.focus-mode .app-sidebar, .focus-mode .app-header, .focus-mode .lesson-intro, .focus-mode .level-strip, .focus-mode .algorithm-guide, .focus-mode .brief-column { display: none; }
.focus-mode .lesson-toolbar { position: fixed; top: 14px; right: 14px; z-index: 90; display: block; margin: 0; }
.focus-mode .lesson-toolbar > :not(.icon-button) { display: none; }
.focus-mode .lesson-toolbar > .icon-button { margin: 0; box-shadow: var(--shadow-md); }
.focus-mode .lesson-view { max-width: none; padding: 14px; }
.focus-mode .lesson-workspace { grid-template-columns: minmax(440px, .95fr) minmax(560px, 1.05fr); margin-top: 0; }
.focus-mode .coding-column { grid-column: auto; }

@media (max-width: 1420px) {
  .app-shell { grid-template-columns: 190px minmax(0, 1fr); }
  .app-sidebar { padding-left: 12px; padding-right: 12px; }
  .module-cards { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .module-card { min-height: 164px; }
  .algorithm-guide-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .guide-motion { grid-template-columns: 1fr; gap: 16px; }
  .lesson-workspace { grid-template-columns: minmax(300px, .68fr) minmax(480px, 1.32fr); }
  .coding-column { grid-column: 1 / -1; }
  .brief-column { grid-row: span 1; }
  .focus-mode .lesson-workspace { grid-template-columns: minmax(390px, .95fr) minmax(500px, 1.05fr); }
  .focus-mode .coding-column { grid-column: auto; }
}

@media (max-width: 1050px) {
  .auth-screen { grid-template-columns: 1fr; background: linear-gradient(rgba(247,247,251,.76), rgba(247,247,251,.96)), url("../pic/dashboard-hero.png") center / cover no-repeat; }
  .auth-brand { align-content: end; padding: 42px 42px 18px; }
  .auth-brand h1 { font-size: 38px; }
  .login-panel { align-self: start; margin-top: 10px; }
  .app-shell { display: block; }
  .app-sidebar { position: fixed; left: 0; transform: translateX(-105%); width: 260px; box-shadow: 16px 0 40px rgba(31,24,56,.18); transition: transform .22s ease; }
  .app-sidebar.open { transform: translateX(0); }
  .mobile-menu { display: inline-grid; }
  .week-strip { display: none; }
  .continue-content { width: 66%; }
  .metrics-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .dashboard-bottom { grid-template-columns: 1fr; }
  .admin-layout { grid-template-columns: 1fr; }
  .admin-user-detail { position: static; }
  .lesson-intro { display: block; }
  .lesson-meta { margin-top: 17px; }
  .lesson-workspace { grid-template-columns: 1fr; }
  .coding-column { grid-column: auto; }
}

@media (max-width: 760px) {
  .auth-brand { padding: 32px 22px 8px; }
  .auth-logo { width: 54px; height: 54px; margin-bottom: 14px; }
  .auth-brand h1 { font-size: 30px; }
  .auth-brand p { font-size: 13px; }
  .login-panel { width: calc(100% - 28px); padding: 24px 20px; }
  .app-header { min-height: 68px; padding: 10px 14px; }
  .header-title > span { display: block; }
  .header-title h1 { font-size: 16px; }
  .streak-chip span { display: none; }
  .streak-chip { padding: 0 10px; }
  .notification-button { display: none; }
  .profile-button img { width: 38px; height: 38px; }
  .profile-copy { display: none; }
  .view { padding: 16px 14px 32px; }
  .continue-card { min-height: 330px; background-position: 64% center; }
  .continue-content { width: 100%; align-content: end; padding: 20px; background: rgba(250,249,255,.8); }
  .continue-card h2 { font-size: 23px; }
  .metrics-grid { grid-template-columns: 1fr; gap: 10px; }
  .metric-card { min-height: 88px; }
  .module-cards { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .module-card { min-height: 154px; padding: 12px; }
  .module-card-title { font-size: 11px; }
  .dashboard-panel { padding: 14px; }
  .record-summary { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .records-grid { grid-template-columns: 1fr; }
  .platforms-heading { flex-direction: column; gap: 14px; }
  .platform-language { align-self: stretch; width: 100%; }
  .platform-language.segmented-tabs button { flex: 1 1 0; min-width: 0; }
  .platform-list { grid-template-columns: 1fr; }
  .platform-item { grid-template-columns: 1fr; gap: 13px; }
  .platform-item-main > p { min-height: 0; }
  .platform-link { width: 100%; }
  .view-heading { align-items: flex-start; flex-direction: column; }
  .registration-admin-head { align-items: flex-start; flex-direction: column; gap: 14px; }
  .registration-request-row { grid-template-columns: 1fr; }
  .registration-request-actions { justify-content: flex-start; flex-wrap: wrap; }
  .registration-request-actions input { flex: 1 1 180px; width: auto; }
  .registration-request-status { justify-self: start; }
  .admin-layout { display: block; }
  .admin-user-detail { margin-top: 12px; }
  .contest-stats { grid-template-columns: 1fr; }
  .contest-stats span { border-right: 0; border-bottom: 1px solid var(--line); }
  .contest-stats span:last-child { border-bottom: 0; }
  .lesson-toolbar { flex-wrap: wrap; }
  .lesson-breadcrumb { order: 3; width: 100%; overflow-x: auto; }
  .lesson-intro { padding: 18px; }
  .lesson-intro h2 { font-size: 24px; }
  .lesson-meta { display: grid; grid-template-columns: repeat(3, 1fr); }
  .lesson-meta span { min-width: 0; padding: 9px; }
  .lesson-workspace { display: block; }
  .algorithm-guide { padding: 20px; }
  .algorithm-guide-head { align-items: flex-start; flex-wrap: wrap; }
  .guide-module-chip { margin-left: 0; }
  .algorithm-guide-grid { grid-template-columns: 1fr; }
  .guide-motion { padding: 18px; }
  .guide-motion-flow { align-items: flex-start; overflow-x: auto; padding-bottom: 4px; }
  .motion-demo { grid-template-columns: 1fr; }
  .motion-demo-label, .motion-demo-input, .motion-demo-checks, .motion-demo-result { grid-column: 1; }
  .motion-demo-result { justify-self: start; }
  .motion-step { flex-basis: 126px; }
  .motion-connector { flex-basis: 24px; }
  .brief-column, .visual-column, .coding-column { margin-top: 12px; }
  .visual-column, .coding-column { padding: 14px; }
  .visual-stage { min-height: 0; padding: 22px 12px; }
  .visual-stage.binary-stage { min-height: 180px; }
  .visual-stage.prefix-stage, .visual-stage.difference-stage, .visual-stage.dp-stage { min-height: 210px; }
  .visual-stage.candidates-stage { min-height: 240px; }
  .visual-stage.intervals-stage, .visual-stage.grid-stage { min-height: 250px; }
  .grid-status { grid-template-columns: 1fr; }
  .grid-status span { font-size: 13px; }
  .grid { grid-template-columns: repeat(var(--grid-columns, 3), 54px); }
  .grid-cell { width: 54px; height: 54px; }
  .dp-cell { min-width: 68px; }
  .playback { flex-wrap: wrap; }
  .playback .icon-button { margin-left: 0; }
  .coding-head, .coding-prompt-wrap { align-items: flex-start; flex-direction: column; }
  .coding-meta { grid-template-columns: 1fr; }
  .submission-code { min-height: 240px; font-size: 11px; }
  .coding-actions { flex-wrap: wrap; }
  .coding-actions .primary-button, .coding-actions .secondary-button { flex: 1; }
  .code-line { grid-template-columns: 24px minmax(0, 1fr); }
  .code-comment { grid-column: 2; padding-left: 8px; }
}

@media (max-width: 450px) {
  .header-actions { gap: 5px; }
  .registration-entry { align-items: flex-start; flex-direction: column; gap: 1px; }
  .registration-request-actions .primary-button, .registration-request-actions .secondary-button { flex: 1; }
  .profile-button i { display: none; }
  .module-cards { grid-template-columns: 1fr; }
  .platform-route { grid-template-columns: 1fr; }
  .platform-list-heading { align-items: flex-start; flex-direction: column; gap: 8px; }
  .platform-item dl > div { grid-template-columns: 1fr; gap: 2px; }
  .module-card { min-height: 145px; }
  .lesson-meta { grid-template-columns: 1fr; }
  .continue-progress > div:first-child { grid-template-columns: auto auto; }
  .continue-progress small { grid-column: 1 / -1; justify-self: start; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; animation: none !important; }
}