:root {
  --navy: #0b1d33;
  --navy-2: #12304d;
  --ink: #122033;
  --muted: #5b6b7c;
  --paper: #f4f1e8;
  --card: #fffcf6;
  --line: #e3dccf;
  --amber: #f0c000;
  --amber-dark: #c9a000;
  --primary: #0b1d33;
  --primary-soft: #e7eef6;
  --ok: #0f7a4a;
  --ok-soft: #e3f6ee;
  --danger: #c1121f;
  --danger-soft: #fdecea;
  --shadow: 0 12px 32px rgba(11, 29, 51, 0.08);
  --radius: 18px;
  --font: "IBM Plex Sans", system-ui, sans-serif;
  --display: "IBM Plex Serif", Georgia, serif;
  --link: #1a4d80;
  --option-bg: #fff;
  --header-fg: #fff;
  --input-bg: #fff;
  --disclaimer-bg: #fff4c4;
  --disclaimer-border: #e7c84a;
  --testbar-bg: rgba(244, 241, 232, 0.94);
  --hero-glow: #dbe7f4;
}
html[data-theme="dark"] {
  --navy: #0a1018;
  --navy-2: #141c28;
  --ink: #e7eef6;
  --muted: #9aa8b8;
  --paper: #0e141c;
  --card: #171f2a;
  --line: #2a3545;
  --amber: #f0c000;
  --amber-dark: #e0b000;
  --primary: #e7eef6;
  --primary-soft: #1c2736;
  --ok: #3dba7a;
  --ok-soft: #143326;
  --danger: #f07178;
  --danger-soft: #3a1518;
  --shadow: 0 12px 32px rgba(0, 0, 0, 0.35);
  --link: #8cbcf0;
  --option-bg: #121922;
  --header-fg: #fff;
  --input-bg: #121922;
  --disclaimer-bg: #3a3110;
  --disclaimer-border: #8a7420;
  --testbar-bg: rgba(14, 20, 28, 0.94);
  --hero-glow: #1a2433;
}
.theme-toggle {
  background: transparent; color: var(--header-fg); border: 1px solid rgba(255,255,255,0.22);
  border-radius: 999px; width: 2.1rem; height: 2.1rem; cursor: pointer; font-size: 1rem;
}
.theme-toggle:hover { border-color: var(--amber); color: var(--amber); }

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    linear-gradient(180deg, rgba(240, 192, 0, 0.07), transparent 28%),
    radial-gradient(900px 420px at 100% -10%, var(--hero-glow) 0%, transparent 55%),
    var(--paper);
  color: var(--ink);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: min(1080px, calc(100% - 2rem)); margin: 0 auto; }
.muted { color: var(--muted); }
.skip-link {
  position: absolute; left: -999px; top: 0;
}
.skip-link:focus { left: 1rem; top: 1rem; background: white; padding: .5rem 1rem; z-index: 50; }
.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--amber-dark);
  margin: 0 0 0.5rem;
}

.site-header {
  position: sticky; top: 0; z-index: 30;
  background: var(--navy);
  color: white;
  border-bottom: 3px solid var(--amber);
}
.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.85rem 0; gap: 1rem;
}
.logo {
  display: flex; align-items: center; gap: 0.55rem;
  color: white !important; text-decoration: none !important; font-weight: 700;
}
.logo-mark {
  width: 2.1rem; height: 2.1rem; display: grid; place-items: center;
}
.logo-text { font-family: var(--display); font-size: 1.25rem; letter-spacing: 0.01em; }
.nav { display: flex; align-items: center; gap: 0.85rem; flex-wrap: wrap; }
.nav a { color: rgba(255,255,255,0.88); font-weight: 500; text-decoration: none; }
.nav a:hover { color: var(--amber); }
.nav-toggle {
  display: none; background: transparent; color: white; border: 1px solid rgba(255,255,255,0.25);
  border-radius: 10px; padding: 0.35rem 0.6rem; font-size: 1.1rem; cursor: pointer;
}
.lang-switch {
  display: inline-flex; border: 1px solid rgba(255,255,255,0.22);
  border-radius: 999px; overflow: hidden; margin-left: 0.25rem;
}
.lang-switch a {
  padding: 0.28rem 0.6rem; font-size: 0.78rem; font-weight: 700; letter-spacing: 0.04em;
  color: rgba(255,255,255,0.75) !important; text-decoration: none !important;
}
.lang-switch a.active { background: var(--amber); color: var(--navy) !important; }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.4rem;
  border: 1px solid transparent; border-radius: 999px;
  padding: 0.65rem 1.15rem; font: inherit; font-weight: 600; cursor: pointer;
  text-decoration: none !important; transition: 0.15s ease;
}
.btn-primary { background: var(--amber); color: var(--navy) !important; }
.btn-primary:hover { background: #ffd23a; }
.btn-ghost { background: transparent; border-color: rgba(255,255,255,0.28); color: white !important; }
.nav .btn-ghost:hover { border-color: var(--amber); color: var(--amber) !important; }
.main .btn-ghost, .auth-card .btn-ghost, .panel .btn-ghost, .result-hero .btn-ghost, .topic-card .btn-ghost {
  border-color: var(--line); color: var(--ink) !important;
}
.main .btn-ghost:hover, .topic-card .btn-ghost:hover { border-color: var(--navy); }
.btn-lg { padding: 0.85rem 1.4rem; font-size: 1.02rem; }
.btn-block { width: 100%; }
.btn-donate {
  background: #0070ba;
  color: #fff !important;
  border-color: #0070ba;
}
.btn-donate:hover { background: #005ea6; border-color: #005ea6; }
.donate-lead { margin: 0.85rem 0 0; max-width: 36rem; }
.footer-donate { margin: 0.7rem 0 0; }
.site-footer .btn-donate { text-decoration: none !important; }

.main { flex: 1; padding: 2rem 0 3rem; }
.site-footer {
  background: var(--navy); color: rgba(255,255,255,0.78);
  padding: 1.4rem 0; font-size: 0.92rem;
  border-top: 3px solid var(--amber);
}
.site-footer a { color: var(--amber); }
.footer-inner { display: grid; gap: 0.3rem; }
.footer-copy { margin: 0; font-weight: 700; }
.footer-copy a { color: white; text-decoration: none; }
.footer-copy a:hover { color: var(--amber); }

.flash-wrap { display: grid; gap: 0.5rem; margin-bottom: 1rem; }
.flash { padding: 0.85rem 1rem; border-radius: 12px; border: 1px solid var(--line); background: var(--card); }
.flash-success { background: var(--ok-soft); border-color: #b7e4cf; }
.flash-danger { background: var(--danger-soft); border-color: #f3c0bb; }
.flash-warning { background: #fff6e5; border-color: #f0d9a8; }
.flash-info { background: #e8f1ff; border-color: #c5d8f7; }

.disclaimer {
  display: flex; gap: 0.9rem; align-items: flex-start;
  background: var(--disclaimer-bg); border: 1px solid var(--disclaimer-border); border-left: 6px solid var(--amber);
  border-radius: 14px; padding: 1rem 1.15rem; margin-bottom: 1.8rem;
  box-shadow: var(--shadow);
}
.disclaimer p { margin: 0.15rem 0 0; }
.disclaimer-title { font-weight: 700; margin: 0 !important; }
.disclaimer-icon {
  width: 2rem; height: 2rem; border-radius: 50%; flex-shrink: 0;
  background: var(--navy); color: var(--amber);
  display: grid; place-items: center; font-weight: 800;
}

.hero {
  display: grid; grid-template-columns: 1.25fr 1fr; gap: 2rem;
  align-items: center; margin-bottom: 3rem;
}
.hero h1, .dash-head h1, .prose h1, .result-hero h1, .auth-card h1 {
  font-family: var(--display); font-size: clamp(1.9rem, 4vw, 2.8rem);
  line-height: 1.12; margin: 0 0 1rem;
}
.lead { font-size: 1.12rem; color: var(--muted); max-width: 40rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1.5rem; }
.hero-cards, .stats-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0.85rem; }
.class-cards .stat-card p { margin: 0.35rem 0 0; font-size: 0.85rem; }
.class-tabs {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin: -0.4rem 0 1.4rem;
}
.class-tab {
  border: 1px solid var(--line); background: var(--card); color: var(--ink) !important;
  text-decoration: none !important; border-radius: 999px; padding: 0.45rem 0.95rem;
  font-weight: 600; font-size: 0.92rem;
}
.class-tab:hover { border-color: var(--navy); }
.class-tab.active { background: var(--navy); color: white !important; border-color: var(--navy); }
.stat-card, .panel, .auth-card, .question-card, .review-card, .feature, .topic-card {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.stat-card { padding: 1.1rem 1.2rem; }
.stat-card.accent { background: linear-gradient(160deg, var(--navy), var(--navy-2)); color: white; border: none; }
.stat-card.accent .stat-label { color: rgba(255,255,255,0.82); }
.stat-num { font-family: var(--display); font-size: 2rem; font-weight: 700; }
.stat-label { color: var(--muted); font-size: 0.92rem; }

.features h2, .panel h2, .auth-card h2 { font-family: var(--display); margin: 0 0 1rem; }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; }
.feature { padding: 1.3rem; }
.feature-icon {
  width: 2.2rem; height: 2.2rem; border-radius: 50%;
  background: #fff3c2; color: var(--navy);
  display: grid; place-items: center; font-weight: 700; margin-bottom: 0.8rem;
}
.feature h3 { margin: 0 0 0.4rem; }

.auth-card { width: min(460px, 100%); margin: 1rem auto; padding: 2rem; }
.account-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; }
.account-grid .auth-card { width: auto; margin: 0; }
.form { display: grid; gap: 0.9rem; margin-top: 1.2rem; }
.form label { display: grid; gap: 0.35rem; font-weight: 600; font-size: 0.92rem; }
.form input[type="text"],
.form input[type="email"],
.form input[type="password"] {
  width: 100%; padding: 0.75rem 0.9rem; border-radius: 12px;
  border: 1px solid var(--line); font: inherit; background: var(--input-bg); color: var(--ink);
}
.form input:focus { outline: 2px solid #ffe58a; border-color: var(--amber-dark); }
.form input:disabled { background: #f3f0ea; color: var(--muted); }
.form .check { display: flex; align-items: center; gap: 0.5rem; font-weight: 500; color: var(--muted); }
.auth-switch { margin-top: 1.2rem; color: var(--muted); }

.dash-head {
  display: flex; justify-content: space-between; gap: 1rem;
  align-items: flex-start; margin-bottom: 1.5rem; flex-wrap: wrap;
}
.stats-row { margin-bottom: 1.5rem; grid-template-columns: repeat(4, 1fr); }
.panel { padding: 1.4rem; margin-bottom: 1.2rem; }
.table-wrap { overflow-x: auto; }
.table { width: 100%; border-collapse: collapse; }
.table th, .table td { text-align: left; padding: 0.75rem 0.5rem; border-bottom: 1px solid var(--line); }
.badge { display: inline-block; padding: 0.2rem 0.6rem; border-radius: 999px; font-size: 0.82rem; font-weight: 700; }
.badge-pass { background: var(--ok-soft); color: var(--ok); }
.badge-fail { background: var(--danger-soft); color: var(--danger); }

.topic-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.7rem; margin-top: 0.8rem; }
.topic-card {
  display: flex; justify-content: space-between; align-items: center; gap: 0.8rem;
  padding: 0.9rem 1rem; margin: 0;
}
.topic-card span { display: block; font-size: 0.85rem; }

.test-bar {
  display: flex; justify-content: space-between; gap: 1rem; align-items: flex-start;
  margin-bottom: 0.8rem; flex-wrap: wrap;
  position: sticky; top: 62px; z-index: 12;
  background: var(--testbar-bg); backdrop-filter: blur(8px);
  padding: 0.8rem 0 0.6rem; border-bottom: 1px solid var(--line);
}
.test-bar h1 { font-family: var(--display); font-size: 1.45rem; margin: 0 0 0.2rem; }
.test-meta { text-align: right; }
.timer { font-family: var(--display); font-size: 1.8rem; font-weight: 700; color: var(--navy); }
.q-nav {
  display: flex; flex-wrap: wrap; gap: 0.35rem; margin: 0.8rem 0 1.1rem;
  position: sticky; top: 132px; z-index: 11;
  background: var(--testbar-bg); padding: 0.35rem 0 0.55rem;
}
.q-nav-dot {
  width: 2rem; height: 2rem; border-radius: 8px; display: grid; place-items: center;
  font-size: 0.75rem; font-weight: 700; color: var(--ink); background: var(--option-bg);
  border: 1px solid var(--line); text-decoration: none !important;
}
.q-nav-dot.done { background: var(--navy); color: white; border-color: var(--navy); }
.q-nav-dot.current { outline: 2px solid var(--amber); }

.question-card { padding: 1.3rem; margin-bottom: 1rem; }
.q-head { display: flex; gap: 0.6rem; align-items: center; flex-wrap: wrap; margin-bottom: 0.6rem; }
.q-num {
  font-size: 0.8rem; font-weight: 700; color: var(--navy);
  background: #fff3c2; padding: 0.2rem 0.55rem; border-radius: 999px;
}
.q-cat { font-size: 0.82rem; color: var(--muted); }
.q-text { font-size: 1.15rem; margin: 0 0 1rem; line-height: 1.4; }
.q-lang-note { margin: -0.4rem 0 0.8rem; font-size: 0.88rem; }
.q-image { margin: 0 0 1rem; }
.q-image img {
  max-width: min(100%, 520px); max-height: 280px; width: auto; height: auto;
  border-radius: 12px; border: 1px solid var(--line); background: #fff;
  display: block; object-fit: contain;
}
.q-image img[src$=".svg"],
.q-image img[src*="no_"] {
  background:
    radial-gradient(circle at 50% 50%, #fff 0%, #fff 62%, #f4f1e8 100%);
  padding: 0.6rem;
}
.options { display: grid; gap: 0.55rem; }
.option {
  display: flex; gap: 0.75rem; align-items: flex-start;
  padding: 0.85rem 1rem; border: 1px solid var(--line); border-radius: 12px;
  cursor: pointer; background: var(--option-bg); transition: 0.12s ease;
}
.option:hover { border-color: #d6c37a; }
.option.selected, .option:has(input:checked) {
  border-color: var(--navy); background: #eef3f8;
}
.option input { margin-top: 0.2rem; }
.opt-key {
  width: 1.5rem; height: 1.5rem; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--paper); font-weight: 700; font-size: 0.8rem; flex-shrink: 0;
}
.option.selected .opt-key, .option:has(input:checked) .opt-key {
  background: var(--navy); color: white;
}
.submit-bar {
  position: sticky; bottom: 0; display: flex; justify-content: space-between;
  align-items: center; gap: 1rem; flex-wrap: wrap; padding: 1rem;
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow); margin-top: 1rem;
}

.result-hero {
  text-align: center; padding: 2rem 1.5rem; border-radius: var(--radius);
  margin-bottom: 1.5rem; border: 1px solid var(--line);
}
.result-hero.pass { background: linear-gradient(180deg, #e3f6ee, var(--card)); }
.result-hero.fail { background: linear-gradient(180deg, #fdecea, var(--card)); }
.result-score { font-size: 1.2rem; margin-bottom: 0.4rem; }
.review-head { display: flex; justify-content: space-between; gap: 1rem; align-items: center; flex-wrap: wrap; }
.filter-pills { display: flex; gap: 0.4rem; }
.pill {
  border: 1px solid var(--line); background: var(--option-bg); border-radius: 999px; color: var(--ink);
  padding: 0.3rem 0.75rem; font: inherit; font-weight: 600; cursor: pointer;
}
.pill.active { background: var(--navy); color: white; border-color: var(--navy); }
.cat-grid { display: grid; gap: 0.75rem; }
.cat-item { display: grid; grid-template-columns: 12rem 1fr 3.5rem; gap: 0.75rem; align-items: center; }
.cat-name { font-weight: 600; font-size: 0.92rem; }
.cat-bar { height: 0.55rem; background: #ebe4d8; border-radius: 999px; overflow: hidden; }
.cat-fill { height: 100%; background: var(--navy); border-radius: 999px; }
.cat-score { text-align: right; color: var(--muted); font-size: 0.9rem; }
.review-card { padding: 1.2rem; margin-bottom: 0.9rem; }
.review-card.ok { border-left: 4px solid var(--ok); }
.review-card.bad { border-left: 4px solid var(--danger); }
.review-options { list-style: none; padding: 0; margin: 0 0 0.8rem; }
.review-options li { padding: 0.45rem 0.6rem; border-radius: 8px; margin-bottom: 0.3rem; }
.review-options li.is-correct { background: var(--ok-soft); }
.review-options li.is-wrong { background: var(--danger-soft); }
.explanation {
  margin: 0; padding: 0.8rem 1rem; background: var(--primary-soft);
  border-radius: 10px; color: var(--ink); line-height: 1.45;
}
.prose h2 { font-family: var(--display); margin-top: 1.6rem; }
.prose ul { line-height: 1.6; }

@media (max-width: 860px) {
  .hero, .feature-grid, .account-grid { grid-template-columns: 1fr; }
  .stats-row, .topic-grid { grid-template-columns: 1fr 1fr; }
  .cat-item { grid-template-columns: 1fr; gap: 0.25rem; }
  .test-meta { text-align: left; }
  .nav-toggle { display: inline-flex; }
  .nav {
    display: none; width: 100%; flex-direction: column; align-items: stretch;
    padding: 0.4rem 0 0.8rem;
  }
  .nav.open { display: flex; }
  .header-inner { flex-wrap: wrap; }
  .q-nav { top: 150px; }
}
@media (max-width: 520px) {
  .stats-row, .topic-grid { grid-template-columns: 1fr; }
}