/* ============================================================
   Trạm luyện phát âm — Matrix Hanzi
   Inherits the app design system (vi/index.html tokens):
   warm light-first theme, dark mode via .light-mode removal,
   Plus Jakarta Sans / Inter / Noto Serif SC.
   ============================================================ */

:root {
  /* Color Palette - Dark Mode (Default) */
  --color-bg: #17130f;
  --color-card: #292119;
  --color-soft: #342a21;
  --color-text: #f6ede0;
  --color-muted: #b8aa98;
  --color-line: rgba(214, 176, 111, 0.2);
  --color-gold: #d09a43;
  --color-gold-dark: #8d5918;
  --color-green: #27836a;
  --color-red: #a94736;

  --shadow-md: 0 18px 45px rgba(0, 0, 0, 0.27);
  --shadow-lg: 0 35px 100px rgba(0, 0, 0, 0.46);

  --font-ui: 'Plus Jakarta Sans', 'Inter', sans-serif;
  --font-han: 'Noto Serif SC', 'Microsoft YaHei', serif;
  --font-body: 'Inter', sans-serif;
  --font-ipa: 'Segoe UI', 'DejaVu Sans', 'Noto Sans', sans-serif;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 2rem;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;

  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;

  --bg: var(--color-bg);
  --card: var(--color-card);
  --soft: var(--color-soft);
  --text: var(--color-text);
  --muted: var(--color-muted);
  --line: var(--color-line);

  /* milestone accents */
  --ms1: #27836a;
  --ms2: #d09a43;
  --ms3: #a94736;
  --ms4: #6d5bd0;

  color-scheme: dark;
}

body.light-mode {
  --color-bg: #f6f3ea;
  --color-card: #fffdf8;
  --color-soft: #efeadd;
  --color-text: #202722;
  --color-muted: #6b6f68;
  --color-line: rgba(32, 39, 34, 0.14);
  --color-gold: #a26b21;
  --color-gold-dark: #8d5918;
  --color-green: #277964;
  --color-red: #a33120;
  --ms4: #5a4bc4;

  --shadow-md: 0 18px 45px rgba(32, 39, 34, 0.1);
  --shadow-lg: 0 30px 80px rgba(32, 39, 34, 0.16);
  color-scheme: light;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-body);
  background: var(--color-bg);
  color: var(--color-text);
  transition: background var(--transition-base), color var(--transition-base);
  line-height: 1.6;
}
img { display: block; max-width: 100%; }
a { color: inherit; }
button { font-family: inherit; }
:focus-visible { outline: 2px solid var(--color-gold); outline-offset: 2px; }
.han { font-family: var(--font-han); }
.ipa { font-family: var(--font-ipa); }

.shell { width: min(1280px, calc(100% - 40px)); margin: 0 auto; }

/* ============ header ============ */
.header {
  position: sticky; top: 0; z-index: 90;
  display: flex; align-items: center; justify-content: space-between; gap: var(--space-4);
  padding: var(--space-4) 0;
  background: color-mix(in srgb, var(--color-bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-line);
}
.brand { display: inline-flex; align-items: center; gap: var(--space-3); min-width: 0; font-family: var(--font-ui); font-weight: 800; text-decoration: none; }
.brand__icon { width: 42px; height: 42px; border-radius: var(--radius-lg); background: linear-gradient(135deg, var(--color-gold), var(--color-red)); color: #fff; display: grid; place-items: center; font-family: var(--font-han); font-size: var(--text-xl); flex-shrink: 0; }
.brand__text { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.brand__title { margin: 0; font-size: var(--text-base); }
.brand__subtitle { margin: 0; color: var(--color-muted); font-size: var(--text-xs); font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.topnav { display: flex; align-items: center; gap: var(--space-2); flex-wrap: wrap; margin-left: auto; }
.topnav a {
  padding: 8px 12px; border-radius: var(--radius-full);
  text-decoration: none; color: var(--color-muted);
  font-family: var(--font-ui); font-weight: 700; font-size: var(--text-sm);
  border: 1px solid transparent; transition: all var(--transition-fast); white-space: nowrap;
}
.topnav a:hover { color: var(--color-text); border-color: var(--color-line); background: var(--color-soft); }

/* ============ buttons ============ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border-radius: var(--radius-full); border: 1px solid transparent;
  padding: 11px 18px; font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 800;
  cursor: pointer; text-decoration: none; transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast), border-color var(--transition-fast);
  white-space: nowrap; user-select: none;
}
.btn:active { transform: scale(0.97); }
.btn--primary { background: var(--color-gold); color: #fff; box-shadow: 0 10px 24px rgba(208, 154, 67, 0.22); }
.btn--primary:hover { background: var(--color-gold-dark); }
.btn--ghost { background: transparent; border-color: var(--color-line); color: var(--color-text); }
.btn--ghost:hover { background: var(--color-soft); }
.btn--green { background: var(--color-green); color: #fff; }
.btn--green:hover { filter: brightness(1.08); }
.btn--icon { padding: 8px; width: 40px; height: 40px; }
.btn[disabled] { opacity: 0.5; cursor: not-allowed; }

/* play buttons */
.playbtn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  border: 1px solid var(--color-line); background: var(--color-soft); color: var(--color-text);
  border-radius: var(--radius-full); padding: 8px 14px; cursor: pointer;
  font-family: var(--font-ui); font-weight: 800; font-size: var(--text-sm);
  transition: all var(--transition-fast);
}
.playbtn:hover { border-color: var(--color-gold); color: var(--color-gold); }
.playbtn.playing { background: var(--color-gold); border-color: var(--color-gold); color: #fff; animation: pulseGold 1s ease infinite; }
.playbtn--slow { font-weight: 700; }
@keyframes pulseGold { 0%, 100% { box-shadow: 0 0 0 0 rgba(208, 154, 67, 0.4); } 50% { box-shadow: 0 0 0 8px rgba(208, 154, 67, 0); } }

/* ============ hero ============ */
.hero { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr); gap: var(--space-10); align-items: center; padding: var(--space-12) 0 var(--space-8); }
.hero__copy { display: grid; gap: var(--space-5); }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; margin: 0;
  color: var(--color-green); font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 800;
  letter-spacing: 0.08em; text-transform: uppercase;
}
.eyebrow::before { content: ''; width: 24px; height: 2px; background: currentColor; border-radius: 2px; }
h1 { margin: 0; font-family: var(--font-ui); font-size: clamp(2rem, 4.4vw, 3.4rem); line-height: 1.15; font-weight: 800; letter-spacing: -0.02em; }
.hero__lead { margin: 0; color: var(--color-muted); font-size: var(--text-lg); max-width: 62ch; }
.pills { display: flex; flex-wrap: wrap; gap: var(--space-2); margin: 0; padding: 0; list-style: none; }
.pill {
  margin: 0; padding: 7px 12px; border-radius: var(--radius-full);
  border: 1px solid var(--color-line); background: var(--color-card);
  font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 700; color: var(--color-muted); white-space: nowrap;
}
.pill strong { color: var(--color-text); }
.hero__actions { display: flex; flex-wrap: wrap; gap: var(--space-3); }
.hero__visual { position: relative; margin: 0; align-self: center; }
.hero__visual img { width: 100%; height: auto; border-radius: var(--radius-2xl); border: 1px solid var(--color-line); background: #fff; }
.freebar { display: flex; flex-wrap: wrap; gap: var(--space-4); padding: var(--space-4) var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); font-size: var(--text-sm); color: var(--color-muted); }
.freebar strong { color: var(--color-text); }

/* ============ sections ============ */
.section { padding: var(--space-12) 0; border-top: 1px solid var(--color-line); }
.section__head { display: grid; gap: var(--space-3); margin-bottom: var(--space-8); max-width: 860px; }
.section__head h2 { margin: 0; font-family: var(--font-ui); font-size: clamp(1.5rem, 3vw, 2.2rem); font-weight: 800; letter-spacing: -0.01em; }
.section__head p { margin: 0; color: var(--color-muted); }
.label { font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; color: var(--color-gold); margin: 0; }

/* ============ milestone cards ============ */
.milestones { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-4); }
.ms-card {
  display: flex; flex-direction: column; gap: var(--space-3);
  padding: var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl);
  background: var(--color-card); transition: transform var(--transition-base), border-color var(--transition-base);
  position: relative; overflow: hidden;
}
.ms-card:hover { transform: translateY(-4px); border-color: var(--color-gold); }
.ms-card__num { font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; }
.ms-card[data-ms="1"] .ms-card__num { color: var(--ms1); }
.ms-card[data-ms="2"] .ms-card__num { color: var(--ms2); }
.ms-card[data-ms="3"] .ms-card__num { color: var(--ms3); }
.ms-card[data-ms="4"] .ms-card__num { color: var(--ms4); }
.ms-card img { width: 100%; height: auto; border-radius: var(--radius-lg); background: #fff; border: 1px solid var(--color-line); }
.ms-card h3 { margin: 0; font-family: var(--font-ui); font-size: var(--text-lg); }
.ms-card p { margin: 0; color: var(--color-muted); font-size: var(--text-sm); flex: 1; }

/* ============ phoneme cards (initials/finals) ============ */
.group-block { margin-bottom: var(--space-10); }
.group-head { display: flex; align-items: center; gap: var(--space-4); margin-bottom: var(--space-4); flex-wrap: wrap; }
.group-head img { width: 104px; height: 104px; object-fit: contain; border-radius: var(--radius-lg); background: #fff; border: 1px solid var(--color-line); flex-shrink: 0; }
.group-head h3 { margin: 0; font-family: var(--font-ui); font-size: var(--text-xl); }
.group-head p { margin: 2px 0 0; color: var(--color-muted); font-size: var(--text-sm); }
.phoneme-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: var(--space-4); align-items: start; }
.ph-card {
  display: flex; flex-direction: column; gap: var(--space-3);
  padding: var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl);
  background: var(--color-card); transition: border-color var(--transition-base), transform var(--transition-base);
}
.ph-card:hover { border-color: var(--color-gold); transform: translateY(-2px); }
.ph-card__top { display: flex; align-items: center; justify-content: space-between; gap: var(--space-2); }
.ph-card__letter { font-family: var(--font-ui); font-size: var(--text-3xl); font-weight: 800; line-height: 1; }
.ph-card__ipa { font-family: var(--font-ipa); color: var(--color-muted); font-size: var(--text-sm); }
.ph-card__call { font-size: var(--text-sm); color: var(--color-muted); }
.ph-card__call b { color: var(--color-text); font-family: var(--font-han); font-weight: 600; }
.ph-card__plays { display: flex; gap: var(--space-2); flex-wrap: wrap; }
.ph-card__vi { margin: 0; font-size: var(--text-sm); color: var(--color-text); font-weight: 600; }
.ph-card details { border-top: 1px dashed var(--color-line); padding-top: var(--space-2); }
.ph-card summary { cursor: pointer; font-family: var(--font-ui); font-weight: 700; font-size: var(--text-sm); color: var(--color-gold); list-style: none; padding: 5px 0; min-height: 32px; }
.ph-card summary::before { content: '▸ '; }
.ph-card details[open] summary::before { content: '▾ '; }
.ph-card .detail-body { margin-top: var(--space-2); display: grid; gap: var(--space-2); font-size: var(--text-sm); color: var(--color-muted); }
.ph-card .detail-body p { margin: 0; }
.ph-card .detail-body strong { color: var(--color-text); }
.warn { padding: 8px 10px; border-radius: var(--radius-sm); background: color-mix(in srgb, var(--color-red) 12%, transparent); border: 1px solid color-mix(in srgb, var(--color-red) 35%, transparent); color: var(--color-text); font-size: var(--text-sm); margin: 0; }
.warn::before { content: '⚠ '; color: var(--color-red); font-weight: 800; }
.demo-chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  padding: 7px 12px; min-height: 32px; display: inline-flex; align-items: center;
  border-radius: var(--radius-full); border: 1px solid var(--color-line);
  background: var(--color-soft); color: var(--color-muted); cursor: pointer;
  font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 700; transition: all var(--transition-fast);
}
.chip:hover { color: var(--color-text); border-color: var(--color-gold); }
.chip.common {
  background: color-mix(in srgb, var(--color-gold) 18%, var(--color-soft));
  border-color: color-mix(in srgb, var(--color-gold) 38%, var(--color-line));
  color: var(--color-text);
}

/* aspiration tip box */
.tipbox {
  display: grid; grid-template-columns: 140px minmax(0, 1fr); gap: var(--space-5); align-items: center;
  padding: var(--space-6); border: 1px solid var(--color-line); border-radius: var(--radius-xl);
  background: var(--color-soft); margin: var(--space-6) 0;
}
.tipbox img { width: 140px; height: 140px; object-fit: contain; border-radius: var(--radius-lg); background: #fff; }
.tipbox h4 { margin: 0 0 6px; font-family: var(--font-ui); font-size: var(--text-lg); }
.tipbox p { margin: 0; color: var(--color-muted); font-size: var(--text-sm); }

/* ============ tones ============ */
.tone-layout { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: var(--space-8); align-items: start; }
.tone-chart { border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); padding: var(--space-5); }
.tone-chart svg { width: 100%; height: auto; display: block; }
.tone-chart figcaption { color: var(--color-muted); font-size: var(--text-sm); margin-top: var(--space-3); }
.tone-list { display: grid; gap: var(--space-4); }
.tone-card { display: grid; grid-template-columns: auto minmax(0, 1fr); gap: var(--space-4); padding: var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); }
.tone-card__badge { width: 54px; height: 54px; border-radius: var(--radius-lg); display: grid; place-items: center; font-family: var(--font-han); font-size: var(--text-2xl); color: #fff; }
.tone-card[data-tone="1"] .tone-card__badge { background: var(--ms1); }
.tone-card[data-tone="2"] .tone-card__badge { background: var(--ms2); }
.tone-card[data-tone="3"] .tone-card__badge { background: var(--ms3); }
.tone-card[data-tone="4"] .tone-card__badge { background: var(--ms4); }
.tone-card[data-tone="5"] .tone-card__badge { background: var(--color-muted); }
.tone-card h3 { margin: 0 0 4px; font-family: var(--font-ui); font-size: var(--text-lg); }
.tone-card .contour { font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 800; color: var(--color-gold); letter-spacing: 0.06em; }
.tone-card p { margin: 6px 0 0; font-size: var(--text-sm); color: var(--color-muted); }
.tone-card .tone-card__plays { display: flex; gap: var(--space-2); margin-top: var(--space-3); flex-wrap: wrap; }

.sandhi-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: var(--space-4); margin-top: var(--space-6); }
.sandhi-card { padding: var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); display: grid; gap: var(--space-2); }
.sandhi-card__rule { font-family: var(--font-ui); font-weight: 800; font-size: var(--text-sm); color: var(--color-gold); }
.sandhi-card__hanzi { font-family: var(--font-han); font-size: var(--text-2xl); }
.sandhi-card__marked { font-family: var(--font-ui); font-weight: 700; font-size: var(--text-sm); }
.sandhi-card p { margin: 0; font-size: var(--text-sm); color: var(--color-muted); }

/* ============ matrix ============ */
.matrix-controls { display: flex; flex-wrap: wrap; gap: var(--space-3); align-items: center; margin-bottom: var(--space-5); }
.matrix-controls input[type="search"] {
  flex: 1; min-width: 220px; padding: 11px 16px; border-radius: var(--radius-full);
  border: 1px solid var(--color-line); background: var(--color-card); color: var(--color-text);
  font-family: var(--font-ui); font-size: var(--text-sm);
}
.matrix-controls input[type="search"]:focus { border-color: var(--color-gold); box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-gold) 28%, transparent); }
.search-note { flex-basis: 100%; margin: 0; font-size: var(--text-sm); font-weight: 600; color: var(--color-red); }
.filter-pills { display: flex; gap: var(--space-2); flex-wrap: wrap; }
.filter-pill { padding: 8px 14px; border-radius: var(--radius-full); border: 1px solid var(--color-line); background: var(--color-card); color: var(--color-muted); cursor: pointer; font-family: var(--font-ui); font-weight: 800; font-size: var(--text-xs); transition: all var(--transition-fast); }
.filter-pill:hover { border-color: var(--color-gold); color: var(--color-text); }
.filter-pill.active { background: var(--color-gold); border-color: var(--color-gold); color: #fff; }
.filter-pill[aria-pressed="true"] { background: var(--color-gold); border-color: var(--color-gold); color: #fff; }
.matrix-hint { margin: var(--space-2) 0 0; font-size: var(--text-xs); color: var(--color-muted); }
.progress-note { font-size: var(--text-sm); color: var(--color-muted); margin: 0 0 var(--space-4); }
.progress-note strong { color: var(--color-gold); }

.matrix-scroll { overflow-x: auto; border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); padding: var(--space-2); }
table.matrix { border-collapse: separate; border-spacing: 3px; min-width: 100%; }
table.matrix th, table.matrix td { padding: 0; }
table.matrix thead th {
  font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 800; color: var(--color-muted);
  padding: 6px 4px; text-align: center; position: sticky; top: 0; background: var(--color-card); z-index: 2; white-space: nowrap;
}
table.matrix tbody th {
  text-align: center; padding: 4px 8px; position: sticky; left: 0; background: var(--color-card); z-index: 1;
  font-family: var(--font-ui); font-weight: 800; font-size: var(--text-sm); white-space: nowrap; cursor: pointer; border-radius: var(--radius-sm);
}
table.matrix tbody th:hover { color: var(--color-gold); }
table.matrix tbody th .th-ipa { display: block; font-family: var(--font-ipa); font-weight: 400; font-size: 10px; color: var(--color-muted); }
td.cell { min-width: 58px; height: 40px; text-align: center; }
.cellbtn {
  width: 100%; height: 100%; min-height: 38px; border-radius: var(--radius-sm);
  border: 1px solid transparent; background: var(--color-soft); color: var(--color-text);
  font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 700; cursor: pointer;
  transition: all var(--transition-fast); position: relative; padding: 2px 4px;
}
.cellbtn.common { background: color-mix(in srgb, var(--color-gold) 18%, var(--color-soft)); border-color: color-mix(in srgb, var(--color-gold) 38%, var(--color-line)); font-weight: 800; }
/* Same subtle gold tint on phoneme cards (initials/finals) and demo chips
   that appear in common syllables — consistent with the matrix cells. */
.ph-card.common { background: color-mix(in srgb, var(--color-gold) 18%, var(--color-soft)); border-color: color-mix(in srgb, var(--color-gold) 38%, var(--color-line)); }
.cellbtn:hover { border-color: var(--color-gold); background: color-mix(in srgb, var(--color-gold) 14%, var(--color-soft)); }
.cellbtn[data-ms="1"] { box-shadow: inset 0 -3px 0 var(--ms1); }
.cellbtn[data-ms="2"] { box-shadow: inset 0 -3px 0 var(--ms2); }
.cellbtn[data-ms="3"] { box-shadow: inset 0 -3px 0 var(--ms3); }
.cellbtn.empty { background: transparent; cursor: default; box-shadow: none; }
.cellbtn.empty:hover { border-color: transparent; background: transparent; }
.cellbtn.visited::after { content: ''; position: absolute; top: 4px; right: 4px; width: 6px; height: 6px; border-radius: 50%; background: var(--color-green); }
.cellbtn.match { border-color: var(--color-gold); background: color-mix(in srgb, var(--color-gold) 22%, var(--color-soft)); }
.cellbtn.dim { opacity: 0.18; }
.matrix-legend { display: flex; gap: var(--space-4); flex-wrap: wrap; margin-top: var(--space-4); font-size: var(--text-xs); color: var(--color-muted); font-family: var(--font-ui); font-weight: 700; }
.matrix-legend span::before { content: ''; display: inline-block; width: 10px; height: 10px; border-radius: 3px; margin-right: 6px; }
.matrix-legend .lg1::before { background: var(--ms1); }
.matrix-legend .lg2::before { background: var(--ms2); }
.matrix-legend .lg3::before { background: var(--ms3); }
.matrix-legend .lgc::before { background: color-mix(in srgb, var(--color-gold) 26%, var(--color-soft)); border: 1px solid var(--color-gold); }

/* special syllables */
.special-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: var(--space-4); margin-top: var(--space-6); }
.special-card { padding: var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); display: grid; gap: var(--space-2); }
.special-card__py { font-family: var(--font-ui); font-weight: 800; font-size: var(--text-xl); }
.special-card p { margin: 0; font-size: var(--text-sm); color: var(--color-muted); }

/* ============ shadowing section ============ */
.loop-steps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--space-4); margin-top: var(--space-6); }
.loop-step { padding: var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-card); }
.loop-step__n { width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center; background: var(--color-gold); color: #fff; font-family: var(--font-ui); font-weight: 800; margin-bottom: var(--space-3); }
.loop-step h4 { margin: 0 0 6px; font-family: var(--font-ui); }
.loop-step p { margin: 0; font-size: var(--text-sm); color: var(--color-muted); }

/* ============ modal (dissection space) ============ */
.modal-backdrop { position: fixed; inset: 0; z-index: 140; background: rgba(10, 8, 6, 0.72); backdrop-filter: blur(6px); display: grid; place-items: center; padding: 20px; }
.modal-backdrop[hidden] { display: none; }
.modal {
  width: min(880px, 100%); max-height: min(88vh, 900px); overflow: auto;
  border: 1px solid var(--color-line); border-radius: var(--radius-2xl);
  background: var(--color-card); box-shadow: var(--shadow-lg); padding: var(--space-6);
}
.modal__top { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); margin-bottom: var(--space-4); }
.modal__nav { display: flex; gap: var(--space-2); }
.modal__title { margin: 0; font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 800; color: var(--color-muted); letter-spacing: 0.06em; text-transform: uppercase; }
.dissect-hero { display: flex; align-items: center; gap: var(--space-6); flex-wrap: wrap; }
.dissect-py { font-family: var(--font-ui); font-size: clamp(2.4rem, 6vw, 3.6rem); font-weight: 800; line-height: 1; letter-spacing: -0.01em; }
.dissect-hanzi { font-family: var(--font-han); font-size: clamp(2.8rem, 7vw, 4.2rem); line-height: 1; color: var(--color-gold); }
.dissect-ipa { font-family: var(--font-ipa); color: var(--color-muted); font-size: var(--text-lg); }
.tone-pills { display: flex; gap: var(--space-2); flex-wrap: wrap; margin: var(--space-4) 0; }
.tone-pill { padding: 8px 16px; border-radius: var(--radius-full); border: 1px solid var(--color-line); background: var(--color-soft); cursor: pointer; font-family: var(--font-ui); font-weight: 800; font-size: var(--text-sm); color: var(--color-muted); transition: all var(--transition-fast); }
.tone-pill:hover { border-color: var(--color-gold); }
.tone-pill.active { background: var(--color-gold); border-color: var(--color-gold); color: #fff; }
.dissect-plays { display: flex; gap: var(--space-3); flex-wrap: wrap; margin: var(--space-4) 0; }
.word-box { padding: var(--space-4) var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-lg); background: var(--color-soft); margin-bottom: var(--space-4); }
.word-box__zh { font-family: var(--font-han); font-size: var(--text-2xl); }
.word-box__label { display: block; font-family: var(--font-ui); font-size: 10px; font-weight: 800; letter-spacing: 0.06em; text-transform: uppercase; color: var(--color-muted); margin-bottom: 2px; }
.word-box__py { font-family: var(--font-ui); font-weight: 700; color: var(--color-gold); font-size: var(--text-sm); }
.word-box__vi { color: var(--color-muted); font-size: var(--text-sm); margin: 2px 0 0; }
.dissect-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: var(--space-4); margin-bottom: var(--space-5); }
.dissect-block { padding: var(--space-4) var(--space-5); border: 1px solid var(--color-line); border-radius: var(--radius-lg); background: var(--color-card); }
.dissect-block h5 { margin: 0 0 8px; font-family: var(--font-ui); font-size: var(--text-xs); font-weight: 800; letter-spacing: 0.06em; text-transform: uppercase; color: var(--color-gold); }
.dissect-block p { margin: 0 0 6px; font-size: var(--text-sm); color: var(--color-muted); }
.dissect-block p:last-child { margin-bottom: 0; }
.dissect-block strong { color: var(--color-text); }

/* shadowing inside modal */
.shadow-box { border: 1px solid var(--color-line); border-radius: var(--radius-xl); background: var(--color-soft); padding: var(--space-5); display: grid; gap: var(--space-3); }
.shadow-box__row { display: flex; gap: var(--space-3); align-items: center; flex-wrap: wrap; }
.mic-btn {
  width: 58px; height: 58px; border-radius: 50%; border: none; cursor: pointer;
  background: var(--color-red); color: #fff; display: grid; place-items: center;
  transition: transform var(--transition-fast), background var(--transition-fast); flex-shrink: 0;
}
.mic-btn:hover { transform: scale(1.06); }
.mic-btn.recording { animation: pulseRed 1.1s ease infinite; background: var(--color-red); }
@keyframes pulseRed { 0%, 100% { box-shadow: 0 0 0 0 rgba(169, 71, 54, 0.5); } 50% { box-shadow: 0 0 0 14px rgba(169, 71, 54, 0); } }
.shadow-status { font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 700; color: var(--color-muted); margin: 0; }
.shadow-result { display: grid; gap: 6px; margin: 0; }
.shadow-result[hidden] { display: none; }
.shadow-score { font-family: var(--font-ui); font-weight: 800; font-size: var(--text-lg); }
.shadow-score.good { color: var(--color-green); }
.shadow-score.mid { color: var(--color-gold); }
.shadow-score.low { color: var(--color-red); }
.shadow-heard { font-size: var(--text-sm); color: var(--color-muted); margin: 0; }
.shadow-heard .han { font-size: var(--text-base); color: var(--color-text); }
.shadow-replay { display: none; }
.shadow-replay.show { display: inline-flex; }

/* toast */
.toast {
  position: fixed; bottom: 22px; left: 50%; transform: translateX(-50%) translateY(80px);
  z-index: 200; padding: 12px 20px; border-radius: var(--radius-full);
  background: var(--color-card); border: 1px solid var(--color-gold); color: var(--color-text);
  font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 700; box-shadow: var(--shadow-md);
  transition: transform var(--transition-base); max-width: min(92vw, 560px); text-align: center;
}
.toast.show { transform: translateX(-50%) translateY(0); }

/* footer */
.footer { border-top: 1px solid var(--color-line); padding: var(--space-10) 0 var(--space-12); display: grid; gap: var(--space-4); }
.footer p { margin: 0; color: var(--color-muted); font-size: var(--text-sm); max-width: 90ch; }
.footer a { color: var(--color-gold); text-decoration: none; font-weight: 700; }
.footer a:hover { text-decoration: underline; }

/* loading skeleton */
.loading-note { padding: var(--space-12); text-align: center; color: var(--color-muted); font-family: var(--font-ui); font-weight: 700; }

/* ============ minimal speaking popup (Free / AI-beta) ============ */
@property --p { syntax: '<number>'; inherits: true; initial-value: 0; }

.spk-backdrop {
  position: fixed; inset: 0; z-index: 160;
  background: rgba(10, 8, 6, 0.74); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  display: grid; place-items: center; padding: var(--space-4);
  animation: spkFadeIn 0.2s ease-out;
}
.spk-backdrop[hidden] { display: none; }
@keyframes spkFadeIn { from { opacity: 0; } to { opacity: 1; } }
.spk-modal {
  width: min(460px, 100%); max-height: min(92vh, 760px); overflow-y: auto;
  display: grid; gap: var(--space-4);
  border: 1px solid var(--color-line); border-radius: var(--radius-2xl);
  background: var(--color-card); box-shadow: var(--shadow-lg); padding: var(--space-5);
  animation: spkPop 0.24s cubic-bezier(.22,.61,.36,1);
}
@keyframes spkPop { from { transform: scale(0.94) translateY(10px); opacity: 0; } to { transform: none; opacity: 1; } }

.spk__top { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); }
.spk__title { margin: 0; font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 800; color: var(--color-gold); letter-spacing: 0.05em; text-transform: uppercase; }

/* Zone 1: mode picker */
.spk-modes { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-2); }
.spk-mode {
  display: grid; gap: 2px; text-align: left; cursor: pointer;
  padding: 10px 12px; border-radius: var(--radius-lg);
  border: 1.5px solid var(--color-line); background: var(--color-soft);
  transition: all var(--transition-fast);
}
.spk-mode b { font-family: var(--font-ui); font-size: var(--text-base); font-weight: 800; color: var(--color-text); display: flex; align-items: center; gap: 6px; }
.spk-mode b .ai-tag { font-style: normal; font-size: 9px; font-weight: 800; letter-spacing: 0.04em; padding: 1px 5px; border-radius: var(--radius-full); background: var(--color-gold); color: #fff; }
.spk-mode span { font-size: 11px; color: var(--color-muted); line-height: 1.35; }
.spk-mode:hover:not([disabled]) { border-color: var(--color-gold); }
.spk-mode.active { border-color: var(--color-gold); background: color-mix(in srgb, var(--color-gold) 14%, var(--color-card)); box-shadow: 0 4px 14px rgba(208, 154, 67, 0.16); }
.spk-mode.active b { color: var(--color-gold); }
.spk-mode[disabled] { opacity: 0.5; cursor: not-allowed; }

/* Zone 2: read + scored answer */
.spk-stage {
  display: grid; gap: var(--space-3); justify-items: center; text-align: center;
  padding: var(--space-5) var(--space-4);
  border: 1px solid var(--color-line); border-radius: var(--radius-xl);
  background: linear-gradient(180deg, var(--color-soft), var(--color-card));
}
.spk-eyebrow { margin: 0; font-family: var(--font-ui); font-size: 10px; font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; color: var(--color-muted); }
.spk-target { display: grid; gap: 4px; }
.spk-target__py { font-family: var(--font-ui); font-size: var(--text-base); font-weight: 800; color: var(--color-gold); letter-spacing: 0.02em; }
.spk-target__han { font-family: var(--font-han); font-size: clamp(2.4rem, 12vw, 3.4rem); line-height: 1.1; color: var(--color-text); }
.spk-target__vi { font-size: var(--text-sm); color: var(--color-muted); }
.spk-heard { cursor: pointer; }
.spk-plays { display: flex; gap: var(--space-2); flex-wrap: wrap; justify-content: center; }
.spk-mic {
  width: 72px; height: 72px; border-radius: 50%; border: none; cursor: pointer;
  display: grid; place-items: center; color: #fff;
  background: linear-gradient(135deg, var(--color-gold), var(--color-gold-dark));
  box-shadow: 0 10px 24px rgba(208, 154, 67, 0.32);
  transition: transform var(--transition-fast), background var(--transition-fast);
}
.spk-mic:hover { transform: scale(1.05); }
.spk-mic:active { transform: scale(0.96); }
.spk-mic.recording { background: var(--color-red); animation: pulseRed 1.1s ease infinite; }
.spk-hint { margin: 0; min-height: 1.4em; font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 700; color: var(--color-muted); }
.spk-hint.run { color: var(--color-gold); }
.spk-hint.ok { color: var(--color-green); }
.spk-hint.err { color: var(--color-red); }
.spk-quota { font-family: var(--font-ui); font-size: 11px; font-weight: 700; color: var(--color-muted); }
.spk-quota[hidden] { display: none; }

.spk-result { width: 100%; display: grid; gap: var(--space-3); animation: spkSlideUp 0.28s cubic-bezier(.22,.61,.36,1); }
.spk-result[hidden] { display: none; }
@keyframes spkSlideUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.spk-ring {
  --p: 0; --ring-color: var(--color-green);
  width: 96px; height: 96px; margin: 0 auto; border-radius: 50%;
  display: grid; place-items: center; position: relative;
  background: conic-gradient(var(--ring-color) calc(var(--p) * 1%), var(--color-line) 0);
  transition: --p 0.7s ease;
}
.spk-ring::before { content: ""; position: absolute; inset: 8px; border-radius: 50%; background: var(--color-card); }
.spk-ring span { position: relative; z-index: 1; font-family: var(--font-ui); font-size: 30px; font-weight: 800; color: var(--color-text); }
.spk-ring.mid { --ring-color: var(--color-gold); }
.spk-ring.low { --ring-color: var(--color-red); }
.spk-result__body { display: grid; gap: 6px; }
.spk-result__eyebrow { margin: 0; font-family: var(--font-ui); font-size: 10px; font-weight: 800; letter-spacing: 0.07em; text-transform: uppercase; color: var(--color-muted); }
.spk-heard { margin: 0; font-family: var(--font-han); font-size: var(--text-xl); color: var(--color-text); overflow-wrap: anywhere; }
.spk-words { display: flex; gap: 6px; flex-wrap: wrap; justify-content: center; }
.spk-words:empty { display: none; }
.spk-word { font-family: var(--font-han); font-size: var(--text-xs); font-weight: 700; padding: 4px 9px; border-radius: var(--radius-sm); background: color-mix(in srgb, var(--color-green) 16%, transparent); color: var(--color-green); }
.spk-word.mid { background: color-mix(in srgb, var(--color-gold) 16%, transparent); color: var(--color-gold); }
.spk-word.low { background: color-mix(in srgb, var(--color-red) 16%, transparent); color: var(--color-red); }
.spk-tip { margin: 0; font-size: var(--text-sm); color: var(--color-muted); }
.spk-norec { margin: 0; font-size: 11px; color: var(--color-muted); font-style: italic; }
.spk-norec[hidden] { display: none; }

/* Zone 3: replay */
.spk-replay { display: flex; gap: var(--space-2); flex-wrap: wrap; }
.spk-replay .playbtn { flex: 1; min-width: 120px; }
.spk-replay .playbtn[disabled] { opacity: 0.45; cursor: not-allowed; }
.spk-replay .playbtn[disabled]:hover { border-color: var(--color-line); color: var(--color-text); }
.spk-full {
  display: block; text-align: center; font-family: var(--font-ui); font-size: var(--text-sm); font-weight: 700;
  color: var(--color-gold); text-decoration: none;
}
.spk-full:hover { text-decoration: underline; }

/* ============ responsive ============ */
@media (max-width: 900px) {
  /* compact sticky header: brand + theme on row 1, single-line scrollable nav on row 2 */
  .header { flex-wrap: wrap; row-gap: 0; padding: var(--space-3) 0; }
  .brand { flex: 1 1 auto; }
  .topnav {
    order: 5; flex-basis: 100%; margin-left: 0; flex-wrap: nowrap; overflow-x: auto;
    gap: var(--space-4); padding: 2px 0 4px; scrollbar-width: none; -webkit-overflow-scrolling: touch;
  }
  .topnav::-webkit-scrollbar { display: none; }
  .topnav a { flex: 0 0 auto; white-space: nowrap; }
}
@media (max-width: 1024px) {
  .hero { grid-template-columns: 1fr; padding-top: var(--space-8); }
  .hero__visual { max-width: 420px; margin: 0 auto; }
  .milestones { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .tone-layout { grid-template-columns: 1fr; }
  .loop-steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 640px) {
  .shell { width: calc(100% - 28px); }
  .brand__subtitle { display: none; }
  .milestones { grid-template-columns: 1fr; }
  .loop-steps { grid-template-columns: 1fr; }
  .tipbox { grid-template-columns: 1fr; }
  .tipbox img { width: 100px; height: 100px; }

  /* dissect modal -> bottom sheet, easier on phones */
  .modal-backdrop { display: flex; align-items: flex-end; padding: 0; }
  .modal {
    width: 100%; max-width: 100%; max-height: 92vh;
    border-radius: var(--radius-2xl) var(--radius-2xl) 0 0;
    padding: var(--space-5) var(--space-4) calc(var(--space-5) + env(safe-area-inset-bottom, 0px));
  }
  .modal__top { position: sticky; top: calc(-1 * var(--space-5)); z-index: 3; padding-top: var(--space-1); margin-top: calc(-1 * var(--space-1)); background: var(--color-card); }
  .dissect-hero { gap: var(--space-3); justify-content: center; text-align: center; }
  .dissect-py { font-size: 2rem; }
  .dissect-hanzi { font-size: 2.4rem; }
  .dissect-ipa { font-size: var(--text-base); }
  .dissect-grid { grid-template-columns: 1fr; gap: var(--space-3); margin-bottom: var(--space-4); }
  .dissect-block { padding: var(--space-4); }
  .word-box { padding: var(--space-4); }
  .shadow-box { padding: var(--space-4); }
  .shadow-box__row .btn { flex: 1; }

  /* minimal speaking popup -> bottom sheet */
  .spk-backdrop { display: flex; align-items: flex-end; padding: 0; }
  .spk-modal {
    width: 100%; max-width: 100%; max-height: 94vh;
    border-radius: var(--radius-2xl) var(--radius-2xl) 0 0;
    padding: var(--space-4) var(--space-4) calc(var(--space-5) + env(safe-area-inset-bottom, 0px));
    gap: var(--space-3);
  }
  .spk-stage { padding: var(--space-4) var(--space-3); }
  .spk-mic { width: 66px; height: 66px; }
  .spk-target__han { font-size: 2.6rem; }
  .spk-ring { width: 84px; height: 84px; }
  .spk-ring span { font-size: 26px; }
}
@media (max-width: 380px) {
  .spk-modes { grid-template-columns: 1fr; }
  .spk-replay .playbtn { min-width: 100%; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
  html { scroll-behavior: auto; }
}