/* =====================================================================
   BIO — China Market Access Platform
   Design System / Global Stylesheet
   Palette: brand blue · cool white · graphite · silver-blue accents
   Type: Spectral (serif headlines) + Inter (sans body) + Montserrat (logo)
   ===================================================================== */

:root {
  /* Brand (variable names kept stable; values are brand blue) */
  --teal:        #1F50C8;   /* primary brand blue */
  --teal-700:    #1A43A6;
  --teal-900:    #0E2A63;   /* deep navy for dark sections */
  --teal-300:    #5C84E2;
  --teal-100:    #DEE7FB;
  --gold:        #3A78EE;   /* accent blue */
  --gold-200:    #B9CEF7;
  --gold-50:     #E7EEFD;
  --ink:         #16213A;
  --slate:       #515E6B;
  --slate-light: #7C8893;
  --bg:          #F6F8FC;
  --surface:     #FFFFFF;
  --surface-alt: #EDF1F8;
  --line:        #E0E6F0;
  --pale:        #B9CDEE;

  /* Type */
  --font-serif: 'Spectral', Georgia, 'Times New Roman', serif;
  --font-sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-logo:  'Montserrat', 'Inter', sans-serif;

  /* Layout */
  --container: 1180px;
  --radius: 14px;
  --radius-sm: 10px;
  --shadow-sm: 0 1px 2px rgba(14,42,99,.06), 0 4px 14px rgba(14,42,99,.06);
  --shadow-md: 0 10px 30px rgba(14,42,99,.12);
  --shadow-lg: 0 24px 60px rgba(14,42,99,.16);
  --ease: cubic-bezier(.4,0,.2,1);
}

/* ---------- Reset / base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  color: var(--slate);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg { max-width: 100%; display: block; }
a { color: var(--teal); text-decoration: none; transition: color .2s var(--ease); }
a:hover { color: var(--gold); }

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--ink);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 .5em;
}
h1 { font-size: clamp(2.4rem, 4.6vw, 3.5rem); }
h2 { font-size: clamp(1.9rem, 3.2vw, 2.6rem); }
h3 { font-size: 1.3rem; }
p  { margin: 0 0 1.1em; }
ul { margin: 0 0 1.1em; padding-left: 1.2em; }
li { margin-bottom: .4em; }

/* ---------- Layout helpers ---------- */
.container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 28px; }
.section { padding: 92px 0; }
.section--tight { padding: 64px 0; }
.section--alt { background: var(--surface-alt); }
.section--white { background: var(--surface); }
.section--dark { background: var(--teal-900); color: #C7D4EC; }
.section--dark h1, .section--dark h2, .section--dark h3 { color: #FFFFFF; }

.eyebrow {
  font-family: var(--font-sans);
  font-size: .8rem;
  font-weight: 600;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--gold);
  margin: 0 0 14px;
}
.section--dark .eyebrow { color: var(--gold-200); }
.lead { font-size: 1.22rem; line-height: 1.6; color: var(--slate); max-width: 60ch; }
.section--dark .lead { color: #C2D1EC; }
.section-head { max-width: 760px; margin-bottom: 52px; }
.section-head.center { margin-left: auto; margin-right: auto; text-align: center; }
.text-center { text-align: center; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .55em;
  font-family: var(--font-sans); font-weight: 600; font-size: .98rem;
  padding: 14px 26px; border-radius: 999px; border: 1px solid transparent;
  cursor: pointer; transition: all .22s var(--ease); white-space: nowrap;
}
.btn svg { width: 17px; height: 17px; }
.btn--primary { background: var(--teal); color: #fff; }
.btn--primary:hover { background: var(--teal-700); color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn--gold { background: var(--gold); color: #fff; }
.btn--gold:hover { background: var(--teal-300); color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn--ghost { background: transparent; color: var(--teal); border-color: rgba(31,80,200,.32); }
.btn--ghost:hover { border-color: var(--teal); background: rgba(31,80,200,.05); color: var(--teal); }
.btn--light { background: rgba(255,255,255,.1); color: #fff; border-color: rgba(255,255,255,.4); }
.btn--light:hover { background: rgba(255,255,255,.2); color: #fff; }
.btn-row { display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(246,248,252,.9);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 74px; }
.brand { display: inline-flex; align-items: center; }
.brand:hover { color: inherit; }
.wordmark {
  font-family: var(--font-logo); font-weight: 800; font-size: 1.55rem;
  color: var(--teal); line-height: .92; letter-spacing: -.02em; display: inline-block;
}
.wordmark small {
  display: block; font-family: var(--font-logo); font-weight: 600;
  font-size: .46rem; letter-spacing: .34em; color: var(--slate); margin-top: 4px; padding-left: 2px;
}
.nav-links { display: flex; align-items: center; gap: 26px; list-style: none; margin: 0; padding: 0; }
.nav-links a { font-family: var(--font-sans); font-size: .93rem; font-weight: 500; color: var(--slate); }
.nav-links a:hover, .nav-links a.active { color: var(--teal); }
.nav-actions { display: flex; align-items: center; gap: 14px; }
.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 24px; height: 2px; background: var(--ink); margin: 5px 0; transition: .25s var(--ease); }

/* ---------- Hero ---------- */
.hero { position: relative; overflow: hidden; background:
    radial-gradient(900px 500px at 88% -8%, rgba(31,80,200,.14), transparent 60%),
    linear-gradient(180deg, #FBFCFE 0%, #ECF1FA 100%); }
.hero-inner { display: grid; grid-template-columns: 1.05fr .95fr; gap: 56px; align-items: center; padding: 96px 0 88px; }
.hero h1 { margin-bottom: 22px; }
.hero .lead { margin-bottom: 30px; }
.hero-visual { position: relative; }
.page-hero { padding: 86px 0 60px; background:
    radial-gradient(700px 380px at 92% -20%, rgba(31,80,200,.12), transparent 60%),
    linear-gradient(180deg, #FBFCFE 0%, #EFF3FB 100%);
  border-bottom: 1px solid var(--line); }
.page-hero h1 { max-width: 18ch; }
.page-hero .lead { margin-top: 6px; }

/* ---------- Metrics band ---------- */
.metrics { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.metric { background: var(--surface); padding: 30px 26px; }
.metric .num { font-family: var(--font-serif); font-size: 1.7rem; color: var(--teal); font-weight: 600; margin-bottom: 4px; }
.metric .lbl { font-size: .92rem; color: var(--slate-light); }
.section--dark .metric { background: var(--teal-700); }
.section--dark .metric .num { color: var(--gold-200); }
.section--dark .metric .lbl { color: #AEBFE0; }

/* ---------- Cards ---------- */
.cards { display: grid; gap: 24px; }
.cards.cols-2 { grid-template-columns: repeat(2, 1fr); }
.cards.cols-3 { grid-template-columns: repeat(3, 1fr); }
.cards.cols-4 { grid-template-columns: repeat(4, 1fr); }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px; box-shadow: var(--shadow-sm); transition: transform .25s var(--ease), box-shadow .25s var(--ease);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.card h3 { margin-bottom: 10px; }
.card p:last-child { margin-bottom: 0; }
.card-icon { width: 46px; height: 46px; border-radius: 11px; display: grid; place-items: center; background: var(--teal-100); color: var(--teal); margin-bottom: 18px; }
.card-icon svg { width: 24px; height: 24px; }
.card--gold .card-icon { background: var(--gold-50); color: var(--gold); }
.card .tag { display:inline-block; font-size:.72rem; font-weight:600; letter-spacing:.08em; text-transform:uppercase; color: var(--gold); margin-bottom: 12px; }
.section--dark .card { background: rgba(255,255,255,.05); border-color: rgba(255,255,255,.14); box-shadow: none; }
.section--dark .card p { color: #B6C5E2; }
.section--dark .card-icon { background: rgba(91,132,226,.22); color: var(--gold-200); }

/* ---------- Platform diagram ---------- */
.platform { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 18px; align-items: stretch; }
.platform-col { background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.16); border-radius: var(--radius); padding: 26px 24px; }
.platform-col.center { background: linear-gradient(160deg, var(--teal-300), var(--teal)); border-color: rgba(185,206,247,.6); box-shadow: 0 18px 50px rgba(0,0,0,.3); }
.platform-col h3 { font-size: 1.12rem; color: #fff; margin-bottom: 14px; }
.platform-col.center h3 { color: #fff; }
.platform-col ul { list-style: none; padding: 0; margin: 0; }
.platform-col li { font-size: .92rem; color: #C5D3EF; padding: 7px 0; border-bottom: 1px dashed rgba(255,255,255,.14); }
.platform-col.center li { color: #EAF0FC; border-color: rgba(255,255,255,.24); }
.platform-col li:last-child { border-bottom: 0; }
.platform-arrow { display: grid; place-items: center; color: var(--gold-200); }
.platform-arrow svg { width: 30px; height: 30px; }

/* ---------- Timeline / process ---------- */
.timeline { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; counter-reset: step; }
.timeline.steps-6 { grid-template-columns: repeat(6, 1fr); }
.step { position: relative; padding-top: 30px; }
.step::before {
  counter-increment: step; content: counter(step);
  position: absolute; top: 0; left: 0; width: 38px; height: 38px; border-radius: 50%;
  background: var(--teal); color: #fff; font-family: var(--font-serif); font-weight: 600;
  display: grid; place-items: center; box-shadow: var(--shadow-sm);
}
.step::after { content: ''; position: absolute; top: 18px; left: 46px; right: -16px; height: 2px; background: linear-gradient(90deg, var(--gold-200), transparent); }
.timeline .step:last-child::after { display: none; }
.step h4 { font-size: 1.02rem; margin: 16px 0 6px; }
.step p { font-size: .88rem; color: var(--slate-light); margin: 0; }

/* ---------- Dashboard cards ---------- */
.dash { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.dash-card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow-sm); }
.dash-card .kpi { font-family: var(--font-serif); color: var(--teal); font-size: 1.05rem; font-weight: 600; margin-bottom: 8px; display:flex; align-items:center; gap:9px; }
.dash-card .kpi svg { width: 20px; height: 20px; color: var(--gold); }
.dash-card p { font-size: .9rem; color: var(--slate-light); margin: 0; }
.bars { display: flex; align-items: flex-end; gap: 6px; height: 46px; margin-top: 14px; }
.bars span { flex: 1; background: linear-gradient(180deg, var(--teal-300), var(--teal)); border-radius: 3px 3px 0 0; opacity: .85; }

/* ---------- Feature split ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split.reverse .split-media { order: 2; }
.checklist { list-style: none; padding: 0; margin: 0; }
.checklist li { position: relative; padding-left: 32px; margin-bottom: 14px; color: var(--slate); }
.checklist li::before { content: ''; position: absolute; left: 0; top: 3px; width: 20px; height: 20px; border-radius: 50%; background: var(--teal-100);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%231F50C8' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: center; }

/* ---------- Case cards ---------- */
.case { background: var(--surface); border: 1px solid var(--line); border-left: 3px solid var(--gold); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow-sm); }
.case .role { font-size: .78rem; font-weight: 600; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); margin-bottom: 10px; }
.case h3 { font-size: 1.12rem; }

/* ---------- CTA band ---------- */
.cta-band { background: linear-gradient(150deg, var(--teal) 0%, var(--teal-900) 100%); border-radius: 20px; padding: 64px 56px; color: #fff; text-align: center; position: relative; overflow: hidden; }
.cta-band::after { content:''; position:absolute; inset:0; background: radial-gradient(500px 240px at 85% 120%, rgba(91,132,226,.4), transparent 60%); pointer-events:none; }
.cta-band h2 { color: #fff; position: relative; }
.cta-band p { color: #CBD8F2; max-width: 56ch; margin: 0 auto 26px; position: relative; }
.cta-band .btn-row { justify-content: center; position: relative; }

/* ---------- Insights / article cards ---------- */
.article { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow-sm); transition: transform .25s var(--ease), box-shadow .25s var(--ease); display:flex; flex-direction:column; }
.article:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }
.article .thumb { aspect-ratio: 16/9; background: linear-gradient(140deg, var(--teal-300), var(--teal-900)); position: relative; }
.article .thumb svg { position:absolute; inset:0; width:100%; height:100%; opacity:.5; }
.article-body { padding: 24px; flex:1; display:flex; flex-direction:column; }
.article .cat { font-size: .74rem; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--gold); margin-bottom: 10px; }
.article h3 { font-size: 1.12rem; margin-bottom: 8px; }
.article p { font-size: .92rem; color: var(--slate-light); }
.chips { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 8px; }
.chip { font-size: .85rem; font-weight: 500; padding: 7px 16px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--slate); cursor: pointer; }
.chip.is-active { background: var(--teal); color: #fff; border-color: var(--teal); }

/* ---------- Forms ---------- */
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.field { display: flex; flex-direction: column; gap: 7px; }
.field.full { grid-column: 1 / -1; }
.field label { font-size: .85rem; font-weight: 600; color: var(--ink); }
.field input, .field select, .field textarea {
  font-family: var(--font-sans); font-size: .98rem; color: var(--ink);
  padding: 12px 14px; border: 1px solid var(--line); border-radius: var(--radius-sm); background: var(--surface);
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.field input:focus, .field select:focus, .field textarea:focus { outline: none; border-color: var(--teal); box-shadow: 0 0 0 3px rgba(31,80,200,.12); }
.field textarea { resize: vertical; min-height: 130px; }
.form-note { font-size: .82rem; color: var(--slate-light); }
.aside-panel { background: var(--teal-900); color: #CBD8EE; border-radius: var(--radius); padding: 32px; }
.aside-panel h3 { color: #fff; }
.aside-panel ul { list-style: none; padding: 0; margin: 0; }
.aside-panel li { padding: 9px 0; border-bottom: 1px solid rgba(255,255,255,.14); font-size: .94rem; }
.aside-panel li:last-child { border: 0; }

/* ---------- AI floating launcher ---------- */
.ai-fab {
  position: fixed; right: 22px; bottom: 22px; z-index: 60;
  display: inline-flex; align-items: center; gap: 9px;
  background: var(--teal); color: #fff; padding: 13px 20px; border-radius: 999px;
  box-shadow: var(--shadow-md); font-family: var(--font-sans); font-weight: 600; font-size: .95rem;
  transition: all .22s var(--ease);
}
.ai-fab:hover { background: var(--teal-700); color: #fff; transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.ai-fab svg { width: 22px; height: 22px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--teal-900); color: #A9BCE0; padding: 70px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
.site-footer h4 { color: #fff; font-family: var(--font-sans); font-size: .82rem; letter-spacing: .12em; text-transform: uppercase; margin-bottom: 16px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 10px; }
.site-footer a { color: #A9BCE0; font-size: .94rem; }
.site-footer a:hover { color: var(--gold-200); }
.footer-brand .brand { margin-bottom: 14px; }
.site-footer .wordmark { color: #fff; }
.site-footer .wordmark small { color: #9DB0D8; }
.footer-brand p { font-size: .94rem; color: #93A6CC; max-width: 34ch; }
.footer-tagline { font-family: var(--font-serif); font-size: 1.15rem; color: #fff; max-width: 30ch; margin-top: 4px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.14); padding-top: 24px; display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: .85rem; color: #8195BE; }

/* ---------- Misc ---------- */
.badge-row { display:flex; flex-wrap:wrap; gap:10px; }
.badge { font-size:.8rem; font-weight:600; color: var(--teal); background: var(--teal-100); padding:7px 14px; border-radius:999px; }
.divider { height:1px; background: var(--line); border:0; margin: 0; }
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.reveal.in { opacity: 1; transform: none; }
.embed-frame { width: 100%; height: 720px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow-sm); }

/* ---------- Responsive ---------- */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; padding: 64px 0; }
  .hero-visual { order: -1; }
  .split, .split.reverse .split-media { grid-template-columns: 1fr; }
  .split.reverse .split-media { order: 0; }
  .cards.cols-3, .cards.cols-4, .dash { grid-template-columns: repeat(2, 1fr); }
  .timeline, .timeline.steps-6 { grid-template-columns: repeat(2, 1fr); }
  .step::after { display: none; }
  .platform { grid-template-columns: 1fr; }
  .platform-arrow { transform: rotate(90deg); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  .nav-links { position: fixed; inset: 74px 0 auto 0; flex-direction: column; align-items: flex-start; gap: 0; background: var(--bg); border-bottom: 1px solid var(--line); padding: 10px 28px 22px; transform: translateY(-130%); transition: transform .3s var(--ease); box-shadow: var(--shadow-md); }
  .nav-links.open { transform: translateY(0); }
  .nav-links li { width: 100%; }
  .nav-links a { display: block; padding: 12px 0; border-bottom: 1px solid var(--line); width: 100%; }
  .nav-toggle { display: block; }
  .nav-actions .btn { padding: 10px 16px; font-size: .85rem; }
  .wordmark small { display: none; }
  .metrics { grid-template-columns: 1fr 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .cta-band { padding: 44px 24px; }
  .section { padding: 64px 0; }
}
@media (max-width: 600px) {
  .ai-fab span { display: none; }
  .ai-fab { padding: 14px; }
}
@media (max-width: 480px) {
  .cards.cols-3, .cards.cols-4, .dash, .metrics, .timeline, .timeline.steps-6 { grid-template-columns: 1fr; }
}