/* Thinkdown public site. Colors and shapes follow the app's visual system (see the product spec). */
:root {
  --accent: #ff385c;
  --accent-pressed: #e31c5f;
  --bg: #ffffff;
  --surface: #f7f7f7;
  --card: #ffffff;
  --border: #dddddd;
  --text: #222222;
  --text-2: #717171;
  --success: #008a05;
  --error: #c13515;
  --shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 6px 24px rgba(0, 0, 0, 0.1);
  --radius: 12px;
  --font: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', 'PingFang SC',
    'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --accent: #ff4f6d;
    --bg: #121212;
    --surface: #1a1a1a;
    --card: #1e1e1e;
    --border: #333333;
    --text: #f7f7f7;
    --text-2: #a0a0a0;
    --success: #34c759;
    --error: #ff6b57;
    --shadow: 0 0 0 1px var(--border);
    --shadow-lg: 0 0 0 1px var(--border);
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 6px; }

img { max-width: 100%; display: block; }

.wrap { width: 100%; max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 20px; letter-spacing: -0.01em; }
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; }
.nav { display: flex; align-items: center; gap: 24px; font-size: 15px; }
.nav a { color: var(--text); }
.nav a.pill { color: #fff; }
@media (max-width: 640px) { .nav a:not(.pill) { display: none; } }

/* Buttons */
.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  border: 0;
}
.pill:hover { background: var(--accent-pressed); text-decoration: none; }
.pill.outline { background: transparent; color: var(--text); border: 1px solid var(--text); }
.pill.outline:hover { background: var(--surface); }
.pill.large { padding: 14px 28px; font-size: 17px; }

/* Hero */
.hero { padding: 72px 0 40px; }
.hero .wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--surface);
  color: var(--text-2);
  font-size: 14px;
  font-weight: 500;
}
.eyebrow .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); }
h1 {
  font-size: clamp(40px, 6vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 20px 0 16px;
  font-weight: 700;
}
h1 em { font-style: normal; color: var(--accent); }
.lede { font-size: 20px; color: var(--text-2); margin: 0 0 28px; max-width: 34em; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.platforms { margin-top: 20px; color: var(--text-2); font-size: 14px; }

/* Demo card: transcript in, note out */
.lang-radio { position: absolute; opacity: 0; pointer-events: none; }
.lang-tabs { display: inline-flex; gap: 4px; padding: 4px; margin-bottom: 14px; border-radius: 999px; background: var(--surface); }
.lang-tabs label { padding: 6px 14px; border-radius: 999px; font-size: 14px; font-weight: 600; color: var(--text-2); cursor: pointer; }
.lang-tabs label:hover { color: var(--text); }
#lang-zh:checked ~ .lang-tabs [for="lang-zh"],
#lang-es:checked ~ .lang-tabs [for="lang-es"],
#lang-fr:checked ~ .lang-tabs [for="lang-fr"] { background: var(--card); color: var(--text); box-shadow: var(--shadow); }
#lang-zh:focus-visible ~ .lang-tabs [for="lang-zh"],
#lang-es:focus-visible ~ .lang-tabs [for="lang-es"],
#lang-fr:focus-visible ~ .lang-tabs [for="lang-fr"] { outline: 3px solid var(--accent); outline-offset: 2px; }
.ex { display: none; }
#lang-zh:checked ~ .demo .ex-zh,
#lang-es:checked ~ .demo .ex-es,
#lang-fr:checked ~ .demo .ex-fr { display: block; }
.demo { position: relative; }
.demo-card {
  background: var(--card);
  border-radius: 20px;
  box-shadow: var(--shadow-lg);
  padding: 22px 22px 18px;
}
.demo-card + .demo-card { margin-top: -6px; }
.demo-label { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--text-2); font-weight: 600; margin-bottom: 10px; }
.wave { display: flex; align-items: center; gap: 3px; height: 28px; margin-bottom: 10px; }
.wave span { width: 4px; border-radius: 2px; background: var(--accent); opacity: 0.85; }
.transcript { color: var(--text-2); font-size: 15px; margin: 0; }
.transcript s { color: var(--error); text-decoration-thickness: 1.5px; }
.arrow { display: flex; justify-content: center; padding: 10px 0; color: var(--accent); }
.note-title { font-size: 20px; font-weight: 700; margin: 0 0 8px; letter-spacing: -0.01em; }
.note-body { margin: 0 0 6px; font-size: 15px; }
.note-body ul { margin: 6px 0 0; padding-left: 20px; }
.known { text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--accent) 60%, transparent); text-underline-offset: 3px; text-decoration-thickness: 2px; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 12px; }
.chip { font-size: 12px; padding: 3px 10px; border-radius: 8px; background: var(--surface); color: var(--text-2); }
.chip.fix { color: var(--success); }

/* Sections */
section { padding: 72px 0; }
section.alt { background: var(--surface); }
.section-head { max-width: 640px; margin-bottom: 40px; }
h2 { font-size: clamp(30px, 4vw, 40px); line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 12px; }
.section-head p { color: var(--text-2); font-size: 18px; margin: 0; }

.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; counter-reset: step; }
.step { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 24px; }
.step::before {
  counter-increment: step;
  content: counter(step);
  display: inline-grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 14px;
}
.step h3, .feature h3 { margin: 0 0 6px; font-size: 18px; }
.step p, .feature p { margin: 0; color: var(--text-2); font-size: 15px; }

.features { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.feature { padding: 24px; border-radius: var(--radius); background: var(--card); box-shadow: var(--shadow); }
.feature svg { width: 28px; height: 28px; color: var(--accent); margin-bottom: 12px; }

/* Personal context */
.context .wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.glossary { background: var(--card); border-radius: 20px; box-shadow: var(--shadow-lg); overflow: hidden; }
.glossary-row { display: grid; grid-template-columns: 84px 1fr; gap: 12px; padding: 14px 20px; border-top: 1px solid var(--border); font-size: 15px; }
.glossary-row:first-child { border-top: 0; }
.glossary-row .type { font-size: 12px; font-weight: 600; color: var(--text-2); padding-top: 2px; }
.glossary-row strong { display: block; }
.glossary-row span { color: var(--text-2); font-size: 14px; }
.ticks { list-style: none; padding: 0; margin: 20px 0 0; }
.ticks li { position: relative; padding-left: 28px; margin-bottom: 10px; }
.ticks li::before { content: ''; position: absolute; left: 4px; top: 8px; width: 10px; height: 6px; border-left: 2px solid var(--accent); border-bottom: 2px solid var(--accent); transform: rotate(-45deg); }

/* Platforms */
.platform-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.platform { text-align: center; padding: 32px 24px; border-radius: var(--radius); border: 1px solid var(--border); }
.platform svg { width: 36px; height: 36px; color: var(--text); margin: 0 auto 12px; display: block; }
.platform h3 { margin: 0 0 6px; font-size: 18px; }
.platform p { margin: 0; color: var(--text-2); font-size: 15px; }

/* Closing CTA */
.closing { text-align: center; }
.closing img { width: 88px; height: 88px; margin: 0 auto 20px; }
.closing p { color: var(--text-2); font-size: 18px; max-width: 32em; margin: 0 auto 28px; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: 28px 0 40px; color: var(--text-2); font-size: 14px; }
.site-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
.site-footer a { color: var(--text-2); }
.site-footer nav { display: flex; gap: 20px; }

/* Long-form pages (privacy) */
.doc { max-width: 720px; padding: 56px 20px 80px; margin: 0 auto; }
.doc h1 { font-size: clamp(34px, 5vw, 48px); margin-top: 0; }
.doc h2 { font-size: 24px; margin: 40px 0 10px; }
.doc p, .doc li { color: var(--text); }
.doc .updated { color: var(--text-2); font-size: 15px; margin-top: -4px; }
.doc table { width: 100%; border-collapse: collapse; font-size: 15px; margin: 12px 0; }
.doc th, .doc td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--border); vertical-align: top; }
.doc th { color: var(--text-2); font-weight: 600; font-size: 13px; }

/* Responsive */
@media (max-width: 900px) {
  .hero .wrap, .context .wrap { grid-template-columns: 1fr; gap: 40px; }
  .steps, .features, .platform-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .hero { padding: 40px 0 24px; }
  section { padding: 56px 0; }
  .steps, .features, .platform-grid { grid-template-columns: 1fr; }
  .doc table { display: block; overflow-x: auto; }
}