/* =========================================================
   shan學習 · English vocabulary trainer
   Liquid-glass visual system (fu-liquiglass) +
   web-design-guidelines + design-taste-frontend
   ========================================================= */

/* ---------- Tokens ---------- */
:root {
  color-scheme: light;

  /* type */
  --font-sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", "PingFang TC", "Microsoft JhengHei", "Noto Sans TC", sans-serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;

  /* radii rule: cards 20px, inputs 14px, interactive pills full */
  --r-card: 20px;
  --r-input: 14px;
  --r-pill: 999px;

  /* light palette (cool neutral green family, one accent) */
  --bg: #eef3f0;
  --ink: #15231d;
  --ink-2: #51645b;
  --ink-3: #6c7d75;
  --hairline: rgba(21, 35, 29, 0.09);
  --accent: #0c7a59;
  --accent-deep: #0a6449;
  --accent-ink: #ffffff;
  --accent-soft: rgba(12, 122, 89, 0.12);
  --accent-line: rgba(12, 122, 89, 0.32);
  --good: #0f766e;
  --bad: #b3261e;

  /* liquid glass */
  --glass-tint: rgba(255, 255, 255, 0.46);
  --glass-tint-strong: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.62);
  --glass-highlight: rgba(255, 255, 255, 0.65);
  --glass-blur: 22px;
  --glass-sat: 150%;
  --shadow-sm: 0 6px 18px rgba(23, 51, 40, 0.08);
  --shadow-md: 0 16px 44px rgba(23, 51, 40, 0.12);
  --shadow-lg: 0 26px 70px rgba(23, 51, 40, 0.16);

  /* background glow blobs */
  --blob-a: rgba(20, 184, 166, 0.26);
  --blob-b: rgba(52, 211, 153, 0.22);
  --blob-c: rgba(34, 211, 238, 0.18);
}

[data-theme="dark"] {
  color-scheme: dark;

  --bg: #101d17;
  --ink: #eaf6f0;
  --ink-2: #b7c9c0;
  --ink-3: #8fa399;
  --hairline: rgba(234, 246, 240, 0.1);
  --accent: #2fd493;
  --accent-deep: #17a878;
  --accent-ink: #04241a;
  --accent-soft: rgba(47, 212, 147, 0.18);
  --accent-line: rgba(47, 212, 147, 0.42);
  --good: #34d399;
  --bad: #fb7185;

  --glass-tint: rgba(255, 255, 255, 0.09);
  --glass-tint-strong: rgba(255, 255, 255, 0.14);
  --glass-border: rgba(255, 255, 255, 0.18);
  --glass-highlight: rgba(255, 255, 255, 0.26);
  --shadow-sm: 0 6px 18px rgba(0, 0, 0, 0.34);
  --shadow-md: 0 16px 44px rgba(0, 0, 0, 0.46);
  --shadow-lg: 0 26px 70px rgba(0, 0, 0, 0.56);

  --blob-a: rgba(47, 212, 147, 0.3);
  --blob-b: rgba(45, 212, 191, 0.26);
  --blob-c: rgba(34, 211, 238, 0.18);
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--bg);
  min-height: 100dvh;
}
h1, h2, h3, p, ul, ol, figure { margin: 0; }
ul, ol { padding: 0; list-style: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
input, select { font: inherit; color: inherit; }
img, svg { display: block; }
a { color: var(--accent-deep); text-decoration: none; }
a:hover { text-decoration: underline; }
[data-theme="dark"] a { color: var(--accent); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 6px; }

/* ---------- Ambient background ---------- */
.page-bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(1100px 720px at 8% -8%, var(--blob-a), transparent 62%),
    radial-gradient(900px 680px at 104% 14%, var(--blob-b), transparent 60%),
    radial-gradient(1000px 800px at 50% 118%, var(--blob-c), transparent 64%),
    var(--bg);
}
.page-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(rgba(21, 35, 29, 0.055) 1px, transparent 1px);
  background-size: 26px 26px;
  -webkit-mask-image: radial-gradient(ellipse at 50% 0%, #000 0%, transparent 78%);
  mask-image: radial-gradient(ellipse at 50% 0%, #000 0%, transparent 78%);
  pointer-events: none;
}
[data-theme="dark"] .page-bg::after {
  background-image: radial-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px);
}

/* ---------- Glass primitive ---------- */
.glass {
  position: relative;
  isolation: isolate;
  border: 1px solid var(--glass-border);
  border-radius: var(--r-card);
  background: var(--glass-tint);
  box-shadow: var(--shadow-md), inset 0 1px 0 var(--glass-highlight);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-sat));
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-sat));
}
.glass::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: inherit;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.28), transparent 40%, rgba(255, 255, 255, 0.06));
  pointer-events: none;
}
.glass-strong {
  background: var(--glass-tint-strong);
}
/* fallback when backdrop-filter unsupported */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass { background: var(--glass-tint-strong); }
}

/* ---------- Layout ---------- */
.wrap {
  width: 100%;
  max-width: 1080px;
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 32px);
}
main { padding-top: 28px; padding-bottom: 72px; }

/* ---------- Header / nav ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  padding-top: max(10px, env(safe-area-inset-top));
  padding-bottom: 10px;
  background: linear-gradient(to bottom, var(--bg) 0%, transparent 100%);
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 8px 10px 8px 16px;
  min-height: 60px;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.01em;
  font-size: 1.06rem;
  white-space: nowrap;
}
.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  color: var(--accent-ink);
  border-radius: 11px;
  background: linear-gradient(140deg, var(--accent), var(--accent-deep));
  box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255, 255, 255, 0.35);
}
.brand small {
  display: block;
  font-weight: 600;
  font-size: 0.68rem;
  letter-spacing: 0.14em;
  color: var(--ink-3);
}
.nav {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px;
  border-radius: var(--r-pill);
}
.nav-btn {
  padding: 9px 16px;
  border-radius: var(--r-pill);
  font-size: 0.94rem;
  font-weight: 600;
  color: var(--ink-2);
  white-space: nowrap;
}
.nav-btn:hover { color: var(--ink); }
.nav-btn[aria-current="page"] {
  color: var(--accent-ink);
  background: linear-gradient(140deg, var(--accent), var(--accent-deep));
  box-shadow: var(--shadow-sm);
}
.top-actions { display: flex; align-items: center; gap: 8px; }
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 7px 12px;
  border-radius: var(--r-pill);
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--accent-deep);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
  white-space: nowrap;
}
[data-theme="dark"] .chip { color: var(--accent); }
.icon-btn {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: var(--r-pill);
  color: var(--ink-2);
  border: 1px solid var(--glass-border);
  background: var(--glass-tint);
}
.icon-btn:hover { color: var(--ink); background: var(--glass-tint-strong); }
.icon-btn svg { width: 20px; height: 20px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 20px;
  border-radius: var(--r-pill);
  font-weight: 700;
  font-size: 0.98rem;
  line-height: 1.1;
  white-space: nowrap;
  transition: transform 120ms ease, box-shadow 180ms ease, background 160ms ease, border-color 160ms ease;
  user-select: none;
}
.btn:active { transform: scale(0.98); }
.btn svg { width: 18px; height: 18px; }
.btn-primary {
  color: var(--accent-ink);
  background: linear-gradient(140deg, var(--accent), var(--accent-deep));
  box-shadow: var(--shadow-sm), inset 0 1px 0 rgba(255, 255, 255, 0.28);
}
.btn-primary:hover { box-shadow: var(--shadow-md), inset 0 1px 0 rgba(255, 255, 255, 0.28); }
.btn-ghost {
  color: var(--ink);
  background: var(--glass-tint);
  border: 1px solid var(--glass-border);
}
.btn-ghost:hover { background: var(--glass-tint-strong); }
.btn-soft {
  color: var(--accent-deep);
  background: var(--accent-soft);
  border: 1px solid var(--accent-line);
}
[data-theme="dark"] .btn-soft { color: var(--accent); }
.btn-soft:hover { filter: brightness(1.04); }
.btn-danger {
  color: var(--bad);
  background: color-mix(in srgb, var(--bad) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--bad) 40%, transparent);
}
.btn:disabled { opacity: 0.55; cursor: not-allowed; }
.nav-scroll { display: none; }

/* ---------- Utility ---------- */
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: fixed; left: 16px; top: -80px; z-index: 200;
  padding: 10px 16px; border-radius: var(--r-pill);
  background: var(--accent); color: #fff; font-weight: 700;
  transition: top 160ms ease;
}
.skip-link:focus { top: 12px; }
[data-theme="dark"] .skip-link { color: #04241a; }
.view { display: none; }
.view.active { display: block; animation: fadeUp 260ms cubic-bezier(0.2, 0.8, 0.2, 1); }
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- Typography ---------- */
.page-title {
  font-size: clamp(1.8rem, 2.4vw + 1rem, 2.4rem);
  line-height: 1.15;
  letter-spacing: -0.02em;
  font-weight: 800;
  max-width: 22ch;
}
.lede {
  margin-top: 10px;
  color: var(--ink-2);
  font-size: 1.02rem;
  max-width: 56ch;
}
.section-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin: 34px 0 16px;
}
.section-head h2 { font-size: 1.28rem; letter-spacing: -0.01em; font-weight: 800; }
.section-head .meta { color: var(--ink-3); font-size: 0.9rem; }

/* ---------- Home: packs ---------- */
.pack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(250px, 100%), 1fr));
  gap: 16px;
}
.pack-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 20px;
  text-align: left;
  min-height: 176px;
  color: inherit;
  transition: transform 180ms ease, box-shadow 180ms ease, background 160ms ease;
}
.pack-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg), inset 0 1px 0 var(--glass-highlight); }
.pack-card.is-featured { grid-column: span 2; }
.pack-top { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.pack-badge {
  width: 42px; height: 42px; border-radius: 13px;
  display: grid; place-items: center;
  background: var(--accent-soft);
  color: var(--accent-deep);
  border: 1px solid var(--accent-line);
}
[data-theme="dark"] .pack-badge { color: var(--accent); }
.pack-badge svg { width: 22px; height: 22px; }
.pack-count { font-size: 0.82rem; color: var(--ink-3); font-weight: 600; }
.pack-card h3 { font-size: 1.2rem; font-weight: 800; letter-spacing: -0.01em; }
.pack-card .en { font-size: 0.86rem; color: var(--ink-3); font-weight: 600; letter-spacing: 0.02em; }
.pack-progress { margin-top: auto; }
.progress-line {
  height: 6px; border-radius: 999px;
  background: color-mix(in srgb, var(--ink) 8%, transparent);
  overflow: hidden;
}
.progress-line > span {
  display: block; height: 100%; width: 0%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 55%, #34d399));
  transition: width 300ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.progress-note {
  display: flex; justify-content: space-between; margin-top: 8px;
  font-size: 0.82rem; color: var(--ink-3); font-weight: 600;
}

/* ---------- Study shell ---------- */
.study-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; flex-wrap: wrap; margin-bottom: 6px;
}
.study-head .back { display: inline-flex; align-items: center; gap: 6px; color: var(--ink-2); font-weight: 700; padding: 8px 6px; border-radius: 12px; }
.study-head .back:hover { color: var(--ink); }
.study-head .back svg { width: 18px; height: 18px; }
.seg {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  border-radius: var(--r-pill);
  background: color-mix(in srgb, var(--ink) 7%, transparent);
}
.seg button {
  padding: 9px 16px; border-radius: var(--r-pill);
  font-weight: 700; font-size: 0.92rem; color: var(--ink-2); white-space: nowrap;
}
.seg button[aria-pressed="true"] {
  color: var(--accent-ink);
  background: linear-gradient(140deg, var(--accent), var(--accent-deep));
  box-shadow: var(--shadow-sm);
}
.stage {
  margin-top: 18px;
  padding: clamp(20px, 4vw, 34px);
}
.stage-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.stage-bar .counter { font-size: 0.86rem; color: var(--ink-3); font-weight: 700; font-variant-numeric: tabular-nums; }
.stage-bar .progress-line { flex: 1; max-width: 320px; }

/* Flashcard */
.card-zone { perspective: 1400px; }
.flip-card {
  position: relative;
  min-height: 300px;
  transform-style: preserve-3d;
  transition: transform 420ms cubic-bezier(0.2, 0.8, 0.2, 1);
}
.flip-card.flipped { transform: rotateY(180deg); }
.flip-face {
  position: absolute; inset: 0;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 10px; text-align: center; padding: 28px;
  border-radius: var(--r-card);
  border: 1px solid var(--glass-border);
  background: var(--glass-tint-strong);
  box-shadow: var(--shadow-md), inset 0 1px 0 var(--glass-highlight);
  -webkit-backdrop-filter: blur(28px) saturate(var(--glass-sat));
  backdrop-filter: blur(28px) saturate(var(--glass-sat));
  -webkit-backface-visibility: hidden;
  backface-visibility: hidden;
}
.flip-back { transform: rotateY(180deg); }
.word-en {
  font-size: clamp(2rem, 4vw + 0.6rem, 3.2rem);
  font-weight: 800; letter-spacing: -0.02em; line-height: 1.1;
  overflow-wrap: anywhere;
}
.word-ipa { font-family: var(--font-mono); font-size: 1rem; color: var(--ink-2); }
.word-pos {
  font-size: 0.8rem; font-weight: 700; letter-spacing: 0.14em;
  color: var(--accent-deep); text-transform: uppercase;
}
[data-theme="dark"] .word-pos { color: var(--accent); }
.word-zh { font-size: clamp(1.5rem, 2vw + 0.6rem, 2rem); font-weight: 800; }
.word-ex { margin-top: 12px; max-width: 46ch; color: var(--ink-2); font-size: 1.02rem; }
.word-ex .zh { display: block; margin-top: 4px; color: var(--ink-3); font-size: 0.92rem; }
.listen {
  margin-top: 6px;
  display: inline-flex; align-items: center; gap: 6px;
  color: var(--accent-deep); font-weight: 700; font-size: 0.92rem;
  padding: 8px 12px; border-radius: var(--r-pill);
}
.listen:hover { background: var(--accent-soft); }
[data-theme="dark"] .listen { color: var(--accent); }
.listen svg { width: 18px; height: 18px; }
.flip-hint { margin-top: 14px; color: var(--ink-3); font-size: 0.84rem; text-align: center; }

/* Answer controls */
.answer-row {
  display: flex; justify-content: center; gap: 12px; flex-wrap: wrap;
  margin-top: 22px;
}
.answer-row .btn { min-width: 150px; }

/* Quiz */
.quiz-prompt { text-align: center; margin-bottom: 8px; }
.quiz-word { font-size: clamp(1.8rem, 3vw + 0.5rem, 2.6rem); font-weight: 800; letter-spacing: -0.02em; overflow-wrap: anywhere; }
.quiz-sub { color: var(--ink-2); font-size: 0.96rem; margin-top: 6px; }
.options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(230px, 100%), 1fr));
  gap: 12px; margin-top: 24px;
}
.opt {
  min-height: 64px; padding: 12px 16px;
  border-radius: var(--r-input);
  border: 1px solid var(--glass-border);
  background: var(--glass-tint);
  font-weight: 700; font-size: 1.02rem; text-align: left;
  transition: transform 120ms ease, border-color 160ms ease, background 160ms ease;
}
.opt:hover:not(:disabled) { background: var(--glass-tint-strong); transform: translateY(-1px); }
.opt:active:not(:disabled) { transform: scale(0.985); }
.opt .opt-key {
  display: inline-grid; place-items: center;
  width: 26px; height: 26px; margin-right: 10px;
  border-radius: 8px; font-size: 0.78rem;
  background: color-mix(in srgb, var(--ink) 9%, transparent);
  color: var(--ink-2);
  vertical-align: middle;
}
.opt.is-correct { border-color: var(--good); background: color-mix(in srgb, var(--good) 14%, transparent); }
.opt.is-wrong { border-color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, transparent); }
.opt:disabled { cursor: default; }
.feedback { margin-top: 18px; text-align: center; }
.feedback-box {
  display: inline-block; padding: 10px 16px; border-radius: var(--r-input);
  font-weight: 700;
}
.feedback-box.ok { color: var(--good); background: color-mix(in srgb, var(--good) 12%, transparent); border: 1px solid color-mix(in srgb, var(--good) 35%, transparent); }
.feedback-box.no { color: var(--bad); background: color-mix(in srgb, var(--bad) 10%, transparent); border: 1px solid color-mix(in srgb, var(--bad) 35%, transparent); }

/* Spelling */
.spell-prompt { text-align: center; }
.spell-input {
  display: block; margin: 22px auto 0;
  width: min(360px, 100%);
  padding: 14px 18px;
  font-size: 1.35rem; font-weight: 700; letter-spacing: 0.04em;
  text-align: center;
  border-radius: var(--r-input);
  border: 1.5px solid var(--accent-line);
  background: var(--glass-tint-strong);
  box-shadow: var(--shadow-sm), inset 0 1px 0 var(--glass-highlight);
}
.spell-input::placeholder { color: var(--ink-3); font-weight: 500; font-size: 0.95rem; }
.spell-status { margin-top: 14px; min-height: 1.6em; text-align: center; font-weight: 700; }
.spell-status.ok { color: var(--good); }
.spell-status.no { color: var(--bad); }

/* Results */
.result-hero { text-align: center; padding: clamp(26px, 5vw, 46px) 20px; }
.result-score {
  font-size: clamp(2.6rem, 5vw + 1rem, 4rem);
  font-weight: 800; letter-spacing: -0.03em; line-height: 1;
}
.result-score small { font-size: 1.1rem; color: var(--ink-3); font-weight: 700; letter-spacing: 0; }
.result-list { margin-top: 26px; }
.result-item {
  display: flex; align-items: baseline; gap: 10px;
  padding: 13px 4px;
  border-top: 1px solid var(--hairline);
}
.result-item .w { font-weight: 800; }
.result-item .m { color: var(--ink-2); font-size: 0.95rem; }
.result-actions { display: flex; justify-content: center; gap: 12px; margin-top: 30px; flex-wrap: wrap; }

/* Library rows */
.filter-row { display: flex; gap: 10px; flex-wrap: wrap; align-items: center; margin-bottom: 18px; }
.search-box { position: relative; flex: 1; min-width: 220px; }
.search-box svg { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); width: 18px; height: 18px; color: var(--ink-3); pointer-events: none; }
.search-box input {
  width: 100%; padding: 12px 16px 12px 44px;
  border-radius: var(--r-input);
  border: 1px solid var(--glass-border);
  background: var(--glass-tint);
  font-size: 0.98rem;
}
.search-box input::placeholder { color: var(--ink-3); }
.select {
  padding: 12px 16px;
  border-radius: var(--r-input);
  border: 1px solid var(--glass-border);
  background: var(--glass-tint);
  font-weight: 600; font-size: 0.94rem; color: var(--ink);
}
.word-row {
  width: 100%;
  display: flex; align-items: center; gap: 12px;
  padding: 12px 16px;
  border-radius: var(--r-input);
  border: 1px solid transparent;
  text-align: left;
}
.word-row:hover { background: var(--glass-tint); border-color: var(--glass-border); }
.word-row .w { font-weight: 800; font-size: 1.06rem; }
.word-row .p { font-family: var(--font-mono); font-size: 0.84rem; color: var(--ink-3); }
.word-row .m { flex: 1; color: var(--ink-2); font-size: 0.95rem; min-width: 0; }
.word-row .chev { color: var(--ink-3); flex: none; }
.word-row .chev svg { width: 18px; height: 18px; transition: transform 180ms ease; }
.word-row[aria-expanded="true"] .chev svg { transform: rotate(180deg); }
.word-detail { padding: 4px 16px 16px; color: var(--ink-2); }
.word-detail .ex { max-width: 60ch; }
.word-detail .zh { color: var(--ink-3); }
.list-empty { text-align: center; color: var(--ink-3); padding: 40px 0; }

/* Stats */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(170px, 100%), 1fr));
  gap: 14px;
}
.stat-tile { padding: 20px; }
.stat-num { font-size: 2rem; font-weight: 800; letter-spacing: -0.02em; line-height: 1.1; font-variant-numeric: tabular-nums; }
.stat-label { margin-top: 6px; color: var(--ink-2); font-size: 0.92rem; font-weight: 600; }
.stat-sub { margin-top: 2px; color: var(--ink-3); font-size: 0.84rem; }
.bars { margin-top: 26px; padding: 22px; }
.bar-row { display: grid; grid-template-columns: 92px 1fr 46px; gap: 14px; align-items: center; padding: 9px 0; }
.bar-row .lbl { font-weight: 700; font-size: 0.92rem; }
.bar-row .val { color: var(--ink-2); font-variant-numeric: tabular-nums; font-weight: 700; font-size: 0.92rem; text-align: right; }

/* Footer */
footer { margin-top: 40px; padding: 26px 0 40px; border-top: 1px solid var(--hairline); }
.foot-inner { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; color: var(--ink-3); font-size: 0.86rem; }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
  .view.active { animation: none; }
}

/* Responsive */
@media (max-width: 760px) {
  .topbar { background: none; padding-top: max(6px, env(safe-area-inset-top)); }
  .topbar-inner {
    flex-wrap: wrap;
    gap: 8px;
    padding: 8px 10px;
    border-radius: 22px;
    box-shadow: var(--shadow-md), inset 0 1px 0 var(--glass-highlight);
  }
  .topbar-inner.glass {
    background: rgba(255, 255, 255, 0.45);
    -webkit-backdrop-filter: blur(30px) saturate(180%);
    backdrop-filter: blur(30px) saturate(180%);
  }
  [data-theme="dark"] .topbar-inner.glass {
    background: rgba(24, 40, 33, 0.48);
    -webkit-backdrop-filter: blur(30px) saturate(180%);
    backdrop-filter: blur(30px) saturate(180%);
  }
  .brand { flex: 0 0 auto; }
  .brand small { display: none; }
  .nav {
    order: 4;
    flex: 1 1 0;
    min-width: 0;
    width: auto;
    justify-content: flex-start;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    overscroll-behavior-inline: contain;
    padding: 0;
    border: 0;
    background: transparent;
    box-shadow: none;
  }
  .nav::-webkit-scrollbar { display: none; }
  .nav-scroll {
    display: grid;
    order: 3;
    place-items: center;
    flex: 0 0 40px;
    width: 40px;
    height: 40px;
    align-self: center;
    border-radius: 50%;
    color: var(--ink-2);
    background: color-mix(in srgb, var(--ink) 7%, transparent);
    border: 1px solid var(--glass-border);
  }
  .nav-scroll svg { width: 20px; height: 20px; }
  .nav-scroll-next { order: 5; }
  .nav-scroll:active { transform: scale(0.94); }
  .nav { scroll-snap-type: x proximity; }
  .nav-btn { flex: 0 0 auto; min-width: 110px; white-space: nowrap; padding: 10px 14px; scroll-snap-align: start; }
  .chip { display: none; }
  .pack-card.is-featured { grid-column: auto; }
  .options { grid-template-columns: 1fr; }
  .stage-bar .progress-line { max-width: none; }
  .flip-card { min-height: 280px; }
  .word-row { flex-wrap: wrap; }
  .word-row .m { flex-basis: 100%; }
}
@media (max-width: 380px) {
  .btn { width: 100%; }
  .answer-row .btn { min-width: 0; }
}

/* Forced colors */
@media (forced-colors: active) {
  .glass, .flip-face, .btn, .opt { background: Canvas; border: 1px solid CanvasText; color: CanvasText; }
  .page-bg::after { display: none; }
}

/* ---------- Layout extras & cleanups ---------- */
.cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 22px; }
.stat-grid { margin-top: 22px; }
.reset-row { margin-top: 26px; display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.row-wrap { border-top: 1px solid var(--hairline); }
.row-wrap:first-child { border-top: 0; }
.accent-text { color: var(--accent-deep); }
[data-theme="dark"] .accent-text { color: var(--accent); }
#view-study .seg { margin-top: 12px; }

.note { color: var(--ink-3); font-size: 0.86rem; }

/* ---------- Grade picker ---------- */
.grade-wrap { margin-top: 26px; padding: 18px 20px; }
.grade-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; margin-bottom: 12px; }
.grade-title { font-weight: 800; font-size: 1.05rem; }
.grade-wrap .seg { flex-wrap: wrap; }
.grade-note { margin-top: 10px; color: var(--ink-3); font-size: 0.84rem; }

/* ---------- Auth zone ---------- */
.auth-zone { display: inline-flex; align-items: center; gap: 6px; }
.auth-link {
  padding: 7px 12px; border-radius: var(--r-pill);
  font-weight: 700; font-size: 0.88rem;
  color: var(--ink-2); white-space: nowrap;
}
.auth-link:hover { color: var(--ink); background: var(--glass-tint); }
.auth-link.primary { color: var(--accent-ink); background: linear-gradient(140deg, var(--accent), var(--accent-deep)); }
.auth-chip {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 8px 6px 13px; border-radius: var(--r-pill);
  background: var(--accent-soft); border: 1px solid var(--accent-line);
  color: var(--accent-deep); font-weight: 700; font-size: 0.88rem; white-space: nowrap;
}
[data-theme="dark"] .auth-chip { color: var(--accent); }
.auth-chip .role { font-weight: 600; font-size: 0.72rem; letter-spacing: 0.08em; opacity: 0.85; }
.auth-chip .logout {
  width: 26px; height: 26px; border-radius: 50%;
  display: grid; place-items: center; color: currentColor;
}
.auth-chip .logout:hover { background: color-mix(in srgb, currentColor 14%, transparent); }

/* ---------- Auth dialogs ---------- */
.auth-dialog {
  width: min(420px, calc(100vw - 32px));
  border: 1px solid var(--glass-border);
  border-radius: var(--r-card);
  padding: 0;
  color: var(--ink);
  background: var(--glass-tint-strong);
  -webkit-backdrop-filter: blur(30px) saturate(160%);
  backdrop-filter: blur(30px) saturate(160%);
  box-shadow: var(--shadow-lg);
}
.auth-dialog::backdrop { background: rgba(8, 15, 12, 0.45); -webkit-backdrop-filter: blur(3px); backdrop-filter: blur(3px); }
.auth-form { display: flex; flex-direction: column; gap: 8px; padding: 24px; }
.auth-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.auth-head h2 { font-size: 1.3rem; font-weight: 800; letter-spacing: -0.01em; }
.auth-head .icon-btn { width: 38px; height: 38px; }
.auth-label { font-weight: 700; font-size: 0.9rem; margin-top: 6px; color: var(--ink-2); }
.auth-input {
  width: 100%; padding: 12px 14px;
  border-radius: var(--r-input);
  border: 1px solid var(--accent-line);
  background: var(--glass-tint-strong);
  font-size: 1rem; color: var(--ink);
}
.auth-input:focus-visible { outline: 3px solid var(--accent); outline-offset: 1px; }
.auth-msg { min-height: 1.2em; color: var(--bad); font-size: 0.9rem; font-weight: 600; }
.auth-form .btn-primary { margin-top: 8px; }
.auth-switch { margin-top: 10px; font-size: 0.9rem; color: var(--ink-2); }
.auth-switch button { color: var(--accent-deep); font-weight: 700; }
[data-theme="dark"] .auth-switch button { color: var(--accent); }

/* ---------- Admin ---------- */
.admin-bar { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(150px,100%),1fr)); gap: 12px; margin-bottom: 18px; }
.admin-table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
.admin-table th {
  text-align: left; font-size: 0.78rem; letter-spacing: 0.06em; text-transform: uppercase;
  color: var(--ink-3); padding: 8px 10px; border-bottom: 1px solid var(--hairline);
}
.admin-table td { padding: 10px; border-bottom: 1px solid var(--hairline); vertical-align: middle; }
.admin-table .u-name { font-weight: 800; }
.admin-table .tag {
  display: inline-block; padding: 2px 9px; border-radius: var(--r-pill);
  font-size: 0.76rem; font-weight: 700;
}
.tag-admin { color: #7a4a00; background: color-mix(in srgb, #d97706 18%, transparent); }
[data-theme="dark"] .tag-admin { color: #fbbf24; }
.tag-user { color: var(--ink-2); background: color-mix(in srgb, var(--ink) 9%, transparent); }
.tag-disabled { color: var(--bad); background: color-mix(in srgb, var(--bad) 12%, transparent); }
.mini-btn {
  padding: 5px 10px; border-radius: var(--r-pill); font-weight: 700; font-size: 0.8rem;
  color: var(--accent-deep); border: 1px solid var(--accent-line);
}
[data-theme="dark"] .mini-btn { color: var(--accent); }
.mini-btn:hover { background: var(--accent-soft); }
.mini-btn.danger { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 40%, transparent); }
.mini-btn.danger:hover { background: color-mix(in srgb, var(--bad) 10%, transparent); }
.admin-empty { text-align: center; color: var(--ink-3); padding: 30px 0; }

/* ---------- Theme auto ---------- */
.icon-btn .icon-auto {
  font-weight: 800; font-style: normal;
  font-family: var(--font-mono);
  font-size: 0.95rem; line-height: 1;
}
[data-theme="dark"] .icon-moon { display: none; }
.icon-auto { display: none; }
body[data-mode="auto"] .icon-sun { display: none; }
body[data-mode="auto"] .icon-moon { display: none; }
body[data-mode="auto"] .icon-auto { display: block; }
body[data-mode="light"] .icon-sun { display: block; }
body[data-mode="light"] .icon-moon { display: none; }
body[data-mode="light"] .icon-auto { display: none; }
body[data-mode="dark"] .icon-sun { display: none; }
body[data-mode="dark"] .icon-moon { display: block; }
body[data-mode="dark"] .icon-auto { display: none; }
@media (max-width: 560px) {
  .auth-link { padding: 6px 9px; font-size: 0.82rem; }
  .auth-zone { gap: 4px; }
}

.pack-card:disabled { opacity: 0.55; cursor: not-allowed; }
.pack-card:disabled:hover { transform: none; box-shadow: var(--shadow-md), inset 0 1px 0 var(--glass-highlight); }