/* ==========================================================================
   澜启智算 · 企业官网
   Style: OpenAI-style reference — light, typographic, editorial, monochrome
   ========================================================================== */

:root {
  /* Colors */
  --color-obsidian: #000000;
  --color-graphite: #666666;
  --color-smoke: #8f8f8f;
  --color-paper: #ffffff;
  --color-ash: #f1f1f1;
  --color-hairline: rgba(0, 0, 0, 0.12);
  --color-whisper: rgba(0, 0, 0, 0.04);

  /* Typography */
  --font-sans: 'Inter', -apple-system, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;

  /* Spacing */
  --sp-2: 2px; --sp-4: 4px; --sp-8: 8px; --sp-12: 12px; --sp-16: 16px;
  --sp-20: 20px; --sp-24: 24px; --sp-32: 32px; --sp-40: 40px; --sp-52: 52px;
  --sp-64: 64px; --sp-80: 80px; --sp-120: 120px;

  /* Shapes */
  --radius-card: 6px;
  --radius-pill: 9999px;

  /* Layout */
  --page-max: 1200px;
  --nav-h: 64px;
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  letter-spacing: -0.01em;
  font-weight: 400;
  color: var(--color-obsidian);
  background: var(--color-paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: #000; color: #fff; }

img { display: block; max-width: 100%; height: auto; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
button { font: inherit; background: none; border: 0; cursor: pointer; }

.container { max-width: var(--page-max); margin: 0 auto; padding: 0 var(--sp-32); }

.icon { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; flex: none; }
.icon-sm { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; flex: none; }

section[id], footer { scroll-margin-top: calc(var(--nav-h) + 16px); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 24px; border-radius: var(--radius-pill);
  font-size: 14px; font-weight: 500; letter-spacing: -0.01em; line-height: 1.5;
  transition: background .18s ease, color .18s ease, border-color .18s ease, box-shadow .18s ease;
  white-space: nowrap;
}
.btn-solid { background: var(--color-obsidian); color: #fff; }
.btn-solid:hover { background: #2d2d2d; }
.btn-outline { background: transparent; color: var(--color-obsidian); border: 1px solid var(--color-hairline); }
.btn-outline:hover { background: var(--color-whisper); box-shadow: rgba(0,0,0,.02) 0 4px 6px 0, rgba(0,0,0,.05) 0 0 2px 0; }
.btn-sm { padding: 7px 18px; font-size: 14px; }

/* ---------- Chips ---------- */
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 6px 16px; border-radius: var(--radius-pill);
  border: 1px solid var(--color-hairline);
  font-size: 14px; font-weight: 500; letter-spacing: -0.01em; line-height: 1.5;
  color: var(--color-obsidian); background: transparent;
}
.chip-check .icon-sm { width: 13px; height: 13px; }
.chip-row { display: flex; flex-wrap: wrap; gap: var(--sp-8); }
.chips-wrap { margin-top: var(--sp-16); }
.chips-sm .chip { padding: 4px 12px; font-size: 13px; }
.chips-sm-tag { padding: 2px 10px; font-size: 12px; color: var(--color-graphite); }

/* ---------- Navigation ---------- */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}
.nav.scrolled { border-bottom-color: var(--color-hairline); }
.nav-inner {
  max-width: var(--page-max); margin: 0 auto; padding: 0 var(--sp-32);
  height: var(--nav-h); display: flex; align-items: center; gap: var(--sp-32);
}
.brand { display: inline-flex; align-items: center; gap: 10px; }
.brand-logo { width: 28px; height: 28px; display: block; }
.brand-name { font-size: 16px; font-weight: 600; letter-spacing: -0.01em; }

.nav-links { display: flex; align-items: center; gap: var(--sp-24); margin-left: auto; }
.nav-links a {
  font-size: 14px; font-weight: 500; letter-spacing: -0.01em; color: var(--color-obsidian);
  padding: 6px 2px; border-radius: 4px; position: relative; color: var(--color-graphite);
  transition: color .15s ease;
}
.nav-links a:hover, .nav-links a.active { color: var(--color-obsidian); }

.nav-actions { display: flex; align-items: center; gap: var(--sp-16); }

.nav-toggle { display: none; width: 36px; height: 36px; position: relative; }
.nav-toggle span {
  position: absolute; left: 8px; right: 8px; height: 1.5px; background: #000;
  transition: transform .2s ease, top .2s ease;
}
.nav-toggle span:nth-child(1) { top: 14px; }
.nav-toggle span:nth-child(2) { top: 21px; }
.nav-toggle.open span:nth-child(1) { top: 17.5px; transform: rotate(45deg); }
.nav-toggle.open span:nth-child(2) { top: 17.5px; transform: rotate(-45deg); }

/* ---------- Hero ---------- */
.hero { position: relative; padding: calc(var(--nav-h) + var(--sp-80)) 0 0; overflow: hidden; }
.hero-dots {
  position: absolute; inset: 0; pointer-events: none;
  background-image: radial-gradient(circle, rgba(0,0,0,.07) 1px, transparent 1px);
  background-size: 26px 26px;
  -webkit-mask-image: radial-gradient(ellipse 70% 62% at 50% 0%, #000 30%, transparent 75%);
  mask-image: radial-gradient(ellipse 70% 62% at 50% 0%, #000 30%, transparent 75%);
}
.hero-inner { position: relative; text-align: center; max-width: 880px; }
.hero-eyebrow {
  display: inline-block; font-size: 14px; font-weight: 500; color: var(--color-graphite);
  border: 1px solid var(--color-hairline); border-radius: var(--radius-pill);
  padding: 6px 16px; margin-bottom: var(--sp-32);
}
.hero-title {
  font-size: 64px; font-weight: 600; line-height: 1.14; letter-spacing: -0.025em;
  margin-bottom: var(--sp-24);
}
.hero-sub {
  font-size: 18px; line-height: 1.6; color: var(--color-graphite);
  max-width: 620px; margin: 0 auto var(--sp-32);
}
.hero-cta { display: flex; justify-content: center; gap: var(--sp-12); margin-bottom: var(--sp-24); }
.hero-trust { font-size: 13px; color: var(--color-smoke); letter-spacing: 0; margin-bottom: var(--sp-64); }

/* ---------- Stats band ---------- */
.stats {
  position: relative;
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--color-hairline);
  border-bottom: 1px solid var(--color-hairline);
  padding: var(--sp-32) 0; margin-bottom: var(--sp-8);
}
.stats-tight { margin: var(--sp-40) 0 var(--sp-64); }
.stat { text-align: center; padding: 0 var(--sp-16); }
.stat + .stat { border-left: 1px solid var(--color-hairline); }
.stat-num {
  font-size: 40px; font-weight: 500; letter-spacing: -0.03em; line-height: 1.16;
  font-variant-numeric: tabular-nums;
}
.stat-label { font-size: 13px; color: var(--color-graphite); margin-top: var(--sp-4); }

/* ---------- Sections ---------- */
.section { padding: var(--sp-120) 0 0; }
.sec-head { max-width: 760px; margin-bottom: var(--sp-52); }
.eyebrow {
  font-size: 14px; font-weight: 500; color: var(--color-graphite);
  letter-spacing: .02em; margin-bottom: var(--sp-12);
}
.sec-title {
  font-size: 48px; font-weight: 600; line-height: 1.18; letter-spacing: -0.025em;
  margin-bottom: var(--sp-20);
}
.sec-lede { font-size: 18px; line-height: 1.6; color: var(--color-graphite); }
.sub-title { font-size: 28px; font-weight: 600; letter-spacing: -0.02em; line-height: 1.21; margin: var(--sp-64) 0 var(--sp-8); }
.sub-note { font-size: 15px; color: var(--color-graphite); margin-bottom: var(--sp-24); }
.sub-title + .grid, .sub-title + .sub-note + .grid { margin-top: var(--sp-24); }
.chip-row + .sub-title { margin-top: var(--sp-52); }

/* ---------- Grids & cards ---------- */
.grid { display: grid; gap: var(--sp-16); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  border: 1px solid var(--color-hairline); border-radius: var(--radius-card);
  background: transparent; padding: var(--sp-24);
  transition: background .18s ease;
}
.card:hover { background: var(--color-whisper); }

.card-index { font-size: 13px; font-weight: 500; color: var(--color-smoke); font-variant-numeric: tabular-nums; }
.card-tag { font-size: 13px; font-weight: 500; color: var(--color-graphite); margin-bottom: var(--sp-8); }
.mode-card h4, .cap-card h4 { font-size: 17px; font-weight: 600; letter-spacing: -0.01em; margin-bottom: var(--sp-8); }
.mode-card .card-tag { margin-top: var(--sp-4); }
.mode-card h4 { margin-top: var(--sp-8); }

.card-list li {
  position: relative; padding-left: 18px;
  font-size: 15px; color: var(--color-graphite); line-height: 1.6;
  margin-top: var(--sp-8);
}
.card-list li::before {
  content: ""; position: absolute; left: 2px; top: .62em;
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--color-smoke);
}
.card-list li strong { color: var(--color-obsidian); font-weight: 500; }

.cap-card .icon { margin-bottom: var(--sp-16); }
.cap-card p { font-size: 15px; color: var(--color-graphite); line-height: 1.6; }

/* ---------- Sites (datacenter layout) ---------- */
.sites { display: grid; grid-template-columns: repeat(6, 1fr); gap: var(--sp-16); }
.site-card {
  grid-column: span 2;
  border: 1px solid var(--color-hairline); border-radius: var(--radius-card);
  overflow: hidden; background: transparent;
  display: flex; flex-direction: column;
  transition: background .18s ease;
}
.site-card:hover { background: var(--color-whisper); }
.site-featured { grid-column: span 3; }
.site-media { margin: 0; aspect-ratio: 16 / 9; overflow: hidden; border-bottom: 1px solid var(--color-hairline); }
.site-media img { width: 100%; height: 100%; object-fit: cover; transition: transform .4s ease; }
.site-card:hover .site-media img { transform: scale(1.025); }
.site-body { padding: var(--sp-20) var(--sp-24) var(--sp-24); display: flex; flex-direction: column; flex: 1; }
.site-card-plain .site-body { padding-top: var(--sp-24); }
.site-loc {
  display: flex; align-items: center; gap: 6px;
  font-size: 13px; font-weight: 500; color: var(--color-graphite);
  margin-bottom: var(--sp-8);
}
.site-body h3 { font-size: 20px; font-weight: 600; letter-spacing: -0.015em; line-height: 1.3; margin-bottom: var(--sp-8); }
.site-badge {
  display: inline-block; vertical-align: 3px; margin-left: 8px;
  font-size: 11px; font-weight: 500; color: var(--color-graphite);
  border: 1px solid var(--color-hairline); border-radius: var(--radius-pill);
  padding: 1px 8px;
}
.site-desc { font-size: 15px; color: var(--color-graphite); line-height: 1.6; }
.site-metric { margin-top: auto; padding-top: var(--sp-16); }
.site-metric strong {
  display: block; font-size: 30px; font-weight: 500; letter-spacing: -0.03em; line-height: 1.16;
  font-variant-numeric: tabular-nums;
}
.site-metric span { font-size: 13px; color: var(--color-graphite); }

/* ---------- Token section ---------- */
.pillars { margin-top: var(--sp-8); }
.pillar-card h3 { font-size: 22px; font-weight: 600; letter-spacing: -0.015em; margin-bottom: var(--sp-12); }
.pillar-desc { font-size: 15px; color: var(--color-graphite); line-height: 1.65; }
.pillar-note { font-size: 13px; color: var(--color-smoke); margin: var(--sp-12) 0 var(--sp-16); }
.pillar-card .chips-sm { margin-top: auto; }

.token-feats { grid-template-rows: 1fr 1fr; }
.tok-card {
  border: 1px solid var(--color-hairline); border-radius: var(--radius-card);
  padding: var(--sp-20) var(--sp-24); transition: background .18s ease;
}
.tok-card:hover { background: var(--color-whisper); }
.tok-card h4 { font-size: 16px; font-weight: 600; letter-spacing: -0.01em; margin-bottom: var(--sp-4); }
.tok-card p { font-size: 14px; color: var(--color-graphite); line-height: 1.6; }
.tok-card-cta { border-style: dashed; }
.tok-card-cta h4, .tok-card-cta p { color: var(--color-obsidian); }

/* ---------- Industry stack ---------- */
.stack { border: 1px solid var(--color-hairline); border-radius: var(--radius-card); overflow: hidden; }
.layer-row {
  display: grid; grid-template-columns: 160px 1fr; align-items: center;
  padding: var(--sp-16) var(--sp-24);
}
.layer-row + .layer-row { border-top: 1px solid var(--color-hairline); }
.layer-name { font-size: 14px; font-weight: 600; letter-spacing: -0.01em; }
.layer-items { display: flex; flex-wrap: wrap; gap: var(--sp-8); }
.layer-items span {
  font-size: 13px; color: var(--color-graphite);
  border: 1px solid var(--color-hairline); border-radius: var(--radius-pill);
  padding: 3px 12px; white-space: nowrap;
}
.layer-row:nth-child(odd) { background: rgba(0,0,0,.015); }

.badges3 { margin-top: var(--sp-16); }
.badge-card {
  border: 1px dashed var(--color-hairline); border-radius: var(--radius-card);
  padding: var(--sp-16) var(--sp-24); display: flex; align-items: baseline; gap: var(--sp-12);
}
.badge-card h4 { font-size: 15px; font-weight: 600; white-space: nowrap; }
.badge-card p { font-size: 14px; color: var(--color-graphite); }

.scene-card .scene-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: var(--sp-16); }
.scene-card h4 { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; margin-bottom: var(--sp-8); }
.scene-card p { font-size: 15px; color: var(--color-graphite); line-height: 1.65; }
.scene-metric { margin-top: var(--sp-16); padding-top: var(--sp-16); border-top: 1px solid var(--color-hairline); }
.scene-metric strong { font-size: 24px; font-weight: 500; letter-spacing: -0.02em; margin-right: 10px; font-variant-numeric: tabular-nums; }
.scene-metric span { font-size: 13px; color: var(--color-graphite); }

/* ---------- Cases ---------- */
.feature-case {
  display: grid; grid-template-columns: 1.05fr 1fr; gap: var(--sp-40);
  align-items: start; margin-bottom: var(--sp-64);
}
.feature-media { margin: 0; position: relative; }
.feature-media img { border-radius: var(--radius-card); border: 1px solid var(--color-hairline); width: 100%; }
.feature-media figcaption { font-size: 13px; color: var(--color-smoke); margin-top: var(--sp-8); }
.feature-body h3 { font-size: 28px; font-weight: 600; letter-spacing: -0.02em; line-height: 1.25; margin-bottom: var(--sp-16); }
.feature-desc { font-size: 16px; color: var(--color-graphite); line-height: 1.65; margin-bottom: var(--sp-24); }
.feature-metrics { display: flex; gap: var(--sp-40); padding: var(--sp-20) 0; border-top: 1px solid var(--color-hairline); border-bottom: 1px solid var(--color-hairline); margin-bottom: var(--sp-20); }
.fmetric strong { display: block; font-size: 28px; font-weight: 500; letter-spacing: -0.03em; line-height: 1.2; font-variant-numeric: tabular-nums; }
.fmetric span { font-size: 13px; color: var(--color-graphite); }
.feature-list li { font-size: 14px; }

.case-card { padding: 0; overflow: hidden; display: flex; flex-direction: column; }
.case-media { margin: 0; aspect-ratio: 16 / 8.4; overflow: hidden; border-bottom: 1px solid var(--color-hairline); }
.case-media img { width: 100%; height: 100%; object-fit: cover; object-position: top; transition: transform .4s ease; }
.case-card:hover .case-media img { transform: scale(1.025); }
.case-body { padding: var(--sp-20) var(--sp-24) var(--sp-24); display: flex; flex-direction: column; flex: 1; }
.case-body-full { padding: var(--sp-24); }
.case-card h4 { font-size: 18px; font-weight: 600; letter-spacing: -0.01em; margin-bottom: var(--sp-8); }
.case-desc { font-size: 15px; color: var(--color-graphite); line-height: 1.6; }
.case-metric { margin-top: auto; padding-top: var(--sp-16); }
.case-metric strong { font-size: 22px; font-weight: 500; letter-spacing: -0.02em; margin-right: 10px; font-variant-numeric: tabular-nums; }
.case-metric span { font-size: 13px; color: var(--color-graphite); }

.flow { display: flex; align-items: center; gap: var(--sp-8); margin: var(--sp-16) 0; flex-wrap: wrap; }
.flow span {
  font-size: 13px; font-weight: 500;
  border: 1px solid var(--color-hairline); border-radius: var(--radius-pill);
  padding: 4px 14px;
}
.flow .icon-sm { color: var(--color-smoke); }

/* ---------- About ---------- */
.about-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: var(--sp-52); align-items: start; }
.about-block + .about-block { margin-top: var(--sp-40); }
.about-block h3 { font-size: 20px; font-weight: 600; letter-spacing: -0.015em; margin-bottom: var(--sp-4); }
.about-note { font-size: 15px; color: var(--color-graphite); line-height: 1.65; margin-top: var(--sp-12); }
.about-map { margin: 0; border: 1px solid var(--color-hairline); border-radius: var(--radius-card); overflow: hidden; }
.about-map img { width: 100%; }
.about-map figcaption { font-size: 13px; color: var(--color-graphite); padding: var(--sp-12) var(--sp-16); border-top: 1px solid var(--color-hairline); }

/* ---------- Contact ---------- */
.section-contact { padding-bottom: var(--sp-120); }
.contact-card { text-align: left; }
.contact-card h3 { font-size: 22px; font-weight: 600; letter-spacing: -0.015em; margin-bottom: var(--sp-16); }
.contact-line {
  display: flex; align-items: center; gap: 10px;
  font-size: 16px; margin-top: var(--sp-8); font-variant-numeric: tabular-nums;
}
.contact-line a { border-bottom: 1px solid transparent; transition: border-color .15s ease; }
.contact-line a:hover { border-bottom-color: #000; }
.contact-line .icon-sm { color: var(--color-smoke); }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--color-hairline); margin-top: var(--sp-40); }
.footer-grid {
  display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: var(--sp-32);
  padding-top: var(--sp-64); padding-bottom: var(--sp-52);
}
.footer-tag { font-size: 14px; color: var(--color-graphite); line-height: 1.7; margin-top: var(--sp-16); }
.footer-col h5 { font-size: 13px; font-weight: 600; letter-spacing: .02em; margin-bottom: var(--sp-16); }
.footer-col a {
  display: block; font-size: 14px; font-weight: 500; color: var(--color-graphite);
  margin-bottom: var(--sp-12); word-break: break-all;
  transition: color .15s ease;
}
.footer-col a:hover { color: var(--color-obsidian); }
.footer-bar {
  display: flex; justify-content: space-between; gap: var(--sp-16); flex-wrap: wrap;
  border-top: 1px solid var(--color-hairline);
  padding-top: var(--sp-20); padding-bottom: var(--sp-32);
  font-size: 13px; color: var(--color-smoke);
}
.footer-bar p { line-height: 1.9; }
.footer-bar a { color: var(--color-smoke); text-decoration: none; transition: color .15s ease; }
.footer-bar a:hover { color: var(--color-obsidian); }

/* ---------- Knowledge base (article cards) ---------- */
.kb-list {
  display: flex; flex-direction: column; gap: var(--sp-24);
  max-width: 920px; margin: 0 auto;
}
.kb-row {
  display: flex; align-items: stretch;
  border-radius: 12px;
  background: var(--color-paper);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04), 0 8px 24px rgba(0, 0, 0, 0.07);
  overflow: hidden; cursor: pointer;
  transition: box-shadow .2s ease, transform .2s ease;
}
.kb-row:hover {
  transform: translateY(-2px);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05), 0 14px 36px rgba(0, 0, 0, 0.11);
}
.kb-row:focus-visible { outline: 2px solid #000; outline-offset: 3px; }
.kb-thumb {
  flex: 0 0 260px; display: flex; align-items: center; justify-content: center;
  background-color: var(--color-ash);
  background-image: radial-gradient(circle, rgba(0, 0, 0, 0.08) 1px, transparent 1px);
  background-size: 18px 18px;
}
.kb-thumb .icon { width: 44px; height: 44px; stroke-width: 1.2; opacity: .8; transition: opacity .2s ease; }
.kb-main { flex: 1; padding: var(--sp-32) var(--sp-40); min-width: 0; display: flex; flex-direction: column; justify-content: center; }
.kb-cat { font-size: 13px; font-weight: 500; color: var(--color-graphite); margin-bottom: var(--sp-8); }
.kb-title {
  font-size: 21px; font-weight: 600; letter-spacing: -0.015em;
  line-height: 1.35; margin-bottom: var(--sp-8);
}
.kb-desc { font-size: 15px; color: var(--color-graphite); line-height: 1.7; }
.kb-side {
  flex: 0 0 150px; display: flex; flex-direction: column;
  align-items: center; justify-content: center; gap: var(--sp-8);
  padding: var(--sp-24); border-left: 1px solid var(--color-hairline);
}
.kb-cta { display: inline-flex; align-items: center; gap: 6px; font-size: 13px; font-weight: 500; color: var(--color-graphite); transition: color .15s ease; }
.kb-cta .icon-sm { width: 14px; height: 14px; transition: transform .18s ease; }
.kb-row:hover .kb-cta { color: var(--color-obsidian); }
.kb-row:hover .kb-cta .icon-sm { transform: translateX(3px); }
.kb-row:hover .kb-thumb .icon { opacity: 1; }

@media (max-width: 900px) {
  .kb-thumb { flex-basis: 180px; }
  .kb-main { padding: var(--sp-24); }
  .kb-side { flex-basis: 120px; padding: var(--sp-16); }
}
@media (max-width: 768px) {
  .kb-list { gap: var(--sp-16); }
  .kb-row { flex-direction: column; }
  .kb-thumb { flex: none; width: 100%; height: 140px; }
  .kb-main { padding: var(--sp-20); }
  .kb-title { font-size: 18px; }
  .kb-side {
    flex: none; flex-direction: row; width: 100%;
    align-items: center; justify-content: center;
    padding: 0 var(--sp-20) var(--sp-20);
    border-left: 0;
  }
}

/* ---------- Standalone knowledge page ---------- */
.kb-page { padding-bottom: var(--sp-80); }
.kb-page .section { padding-top: calc(var(--nav-h) + var(--sp-40)); }
.kb-page .sec-head { margin-bottom: var(--sp-40); }
.kb-page .nav-links a[href="knowledge.html"] { color: var(--color-obsidian); }

/* ---------- Payment modal ---------- */
.modal { position: fixed; inset: 0; z-index: 200; display: flex; align-items: center; justify-content: center; padding: var(--sp-20); }
.modal[hidden] { display: none; }
.modal-overlay { position: absolute; inset: 0; background: rgba(0, 0, 0, 0.44); opacity: 0; transition: opacity .18s ease; }
.modal-dialog {
  position: relative; background: var(--color-paper);
  border: 1px solid var(--color-hairline); border-radius: var(--radius-card);
  max-width: 400px; width: 100%; max-height: calc(100vh - 40px); overflow: auto;
  padding: var(--sp-32); text-align: center;
  opacity: 0; transform: translateY(10px) scale(.98);
  transition: opacity .18s ease, transform .18s ease;
}
.modal.show .modal-overlay { opacity: 1; }
.modal.show .modal-dialog { opacity: 1; transform: none; }
.modal-close {
  position: absolute; top: var(--sp-12); right: var(--sp-12);
  width: 32px; height: 32px; border-radius: var(--radius-pill);
  border: 1px solid var(--color-hairline); background: var(--color-paper);
  display: flex; align-items: center; justify-content: center;
  color: var(--color-graphite); transition: background .15s ease, color .15s ease;
}
.modal-close:hover { background: var(--color-whisper); color: var(--color-obsidian); }
.modal-qr img {
  width: 280px; max-width: 100%; margin: 0 auto;
  border: 1px solid var(--color-hairline); border-radius: var(--radius-card);
}
.modal-steps { text-align: left; margin-top: var(--sp-20); padding-top: var(--sp-20); border-top: 1px solid var(--color-hairline); counter-reset: step; list-style: none; }
.modal-steps li {
  position: relative; padding-left: 28px;
  font-size: 14px; color: var(--color-graphite); line-height: 1.6;
  margin-top: var(--sp-8); counter-increment: step;
}
.modal-steps li:first-child { margin-top: 0; }
.modal-steps li::before {
  content: counter(step);
  position: absolute; left: 0; top: .18em;
  width: 18px; height: 18px; border-radius: var(--radius-pill);
  background: var(--color-obsidian); color: #fff;
  font-size: 11px; font-weight: 500; line-height: 18px; text-align: center;
}
.modal-steps .pay-amount { color: var(--color-obsidian); font-weight: 600; font-variant-numeric: tabular-nums; }
.modal-steps a { border-bottom: 1px solid var(--color-hairline); padding-bottom: 1px; }
.modal-steps a:hover { border-bottom-color: #000; }
html.noanim .modal-overlay, html.noanim .modal-dialog { transition: none !important; }

@media (max-width: 480px) {
  .modal-dialog { padding: var(--sp-24); }
  .modal-qr img { width: 240px; }
}

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .55s ease, transform .55s ease; }
.reveal.in { opacity: 1; transform: none; }
html.noanim .reveal, html.noanim .count { opacity: 1 !important; transform: none !important; transition: none !important; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .site-media img, .case-media img { transition: none; }
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-title { font-size: 52px; }
  .sec-title { font-size: 40px; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .sites { grid-template-columns: repeat(2, 1fr); }
  .site-card, .site-featured { grid-column: span 1; }
  .feature-case { grid-template-columns: 1fr; gap: var(--sp-24); }
  .about-grid { grid-template-columns: 1fr; gap: var(--sp-40); }
}

@media (max-width: 820px) {
  .nav-links {
    position: fixed; top: var(--nav-h); left: 0; right: 0;
    background: var(--color-paper); border-bottom: 1px solid var(--color-hairline);
    flex-direction: column; align-items: flex-start; gap: 0;
    padding: var(--sp-8) var(--sp-32) var(--sp-16);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { font-size: 16px; padding: 12px 0; width: 100%; border-bottom: 1px solid var(--color-whisper); }
  .nav-toggle { display: block; }
  .nav-actions { margin-left: auto; }
  .nav-actions .btn { display: none; }
}

@media (max-width: 768px) {
  .container { padding: 0 var(--sp-20); }
  .hero { padding-top: calc(var(--nav-h) + var(--sp-52)); }
  .hero-title { font-size: 40px; }
  .hero-sub { font-size: 17px; }
  .section { padding-top: var(--sp-80); }
  .sec-title { font-size: 32px; }
  .sub-title { font-size: 24px; }
  .stats { grid-template-columns: repeat(2, 1fr); row-gap: var(--sp-24); }
  .stat + .stat { border-left: 0; }
  .stat:nth-child(even) { border-left: 1px solid var(--color-hairline); }
  .stat-num { font-size: 30px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .sites { grid-template-columns: 1fr; }
  .feature-metrics { gap: var(--sp-24); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-bar { flex-direction: column; gap: var(--sp-4); }
}

@media (max-width: 480px) {
  .hero-title { font-size: 32px; }
  .hero-cta { flex-direction: column; align-items: center; }
  .sec-title { font-size: 28px; }
  .stat-num { font-size: 26px; }
  .feature-metrics { flex-direction: column; gap: var(--sp-16); }
}