/* ============================================================
   杭州恒传信息技术有限公司 · 企业官网
   简约大气 · 统一视觉规范
   ============================================================ */

:root {
  --brand: #1d4ed8;
  --brand-dark: #1e3a8a;
  --brand-light: #3b82f6;
  --ink: #0f172a;
  --text: #1e293b;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-soft: #f8fafc;
  --bg-deep: #0b1220;
  --accent: #38bdf8;
  --ai: #8b5cf6;
  --ai-2: #6366f1;
  --radius: 14px;
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, .08), 0 1px 2px rgba(15, 23, 42, .04);
  --shadow-md: 0 10px 30px rgba(15, 23, 42, .10);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, .16);
  --maxw: 1180px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system,
    BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

/* 防止横向溢出（clip 不会破坏 sticky 头部） */
html, body { overflow-x: clip; }

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
ul { list-style: none; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------------- Buttons ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease, color .2s ease;
  white-space: nowrap;
}
.btn-primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
  color: #fff;
  box-shadow: 0 8px 20px rgba(29, 78, 216, .30);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 30px rgba(29, 78, 216, .38); }
.btn-ghost {
  background: rgba(255, 255, 255, .12);
  color: #fff;
  border-color: rgba(255, 255, 255, .35);
}
.btn-ghost:hover { background: rgba(255, 255, 255, .22); }
.btn-outline {
  background: transparent;
  color: var(--brand);
  border-color: var(--brand);
}
.btn-outline:hover { background: var(--brand); color: #fff; }

/* ---------------- Header ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, .82);
  backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 800;
  font-size: 18px;
  color: var(--ink);
  letter-spacing: .3px;
}
.brand .logo {
  height: 38px;
  width: auto;
  object-fit: contain;
  display: block;
}

.nav-links { display: flex; align-items: center; gap: 28px; }
.nav-links a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text);
  position: relative;
  padding: 6px 0;
  transition: color .2s ease;
}
.nav-links a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -2px;
  width: 0; height: 2px;
  background: var(--brand);
  transition: width .25s ease;
}
.nav-links a:hover, .nav-links a.active { color: var(--brand); }
.nav-links a.active::after, .nav-links a:hover::after { width: 100%; }

.nav-actions { display: flex; align-items: center; gap: 12px; }
.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle span { display: block; width: 22px; height: 2px; background: var(--ink); margin: 4px 0; border-radius: 2px; }

.user-chip {
  display: none;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text);
}
.user-chip .avatar {
  width: 32px; height: 32px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  color: #fff; display: grid; place-items: center; font-weight: 700; font-size: 14px;
}

/* ---------------- Hero ---------------- */
.hero {
  position: relative;
  color: #fff;
  overflow: hidden;
  background:
    radial-gradient(1200px 600px at 80% -10%, rgba(56, 189, 248, .35), transparent 60%),
    radial-gradient(900px 500px at 10% 110%, rgba(29, 78, 216, .45), transparent 55%),
    linear-gradient(135deg, var(--brand-dark), #0b1220);
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(circle at 50% 30%, #000 30%, transparent 75%);
  opacity: .5;
}
.hero-inner { position: relative; padding: 110px 0 120px; }
.hero .eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; letter-spacing: 2px; text-transform: uppercase;
  color: var(--accent); font-weight: 600; margin-bottom: 22px;
  border: 1px solid rgba(56,189,248,.4); padding: 6px 14px; border-radius: 999px;
}
.hero h1 {
  font-size: 52px;
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -.5px;
  margin-bottom: 22px;
  max-width: none;
  overflow-wrap: anywhere;
}
.hero h1 .grad {
  background: linear-gradient(120deg, #7dd3fc, #38bdf8);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero p.lead {
  font-size: 19px;
  color: rgba(226, 232, 240, .88);
  max-width: 920px;
  margin-bottom: 36px;
  overflow-wrap: anywhere;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: flex; gap: 48px; margin-top: 64px; flex-wrap: wrap;
}
.hero-stats .stat .num { font-size: 38px; font-weight: 800; color: #fff; }
.hero-stats .stat .label { font-size: 14px; color: rgba(226,232,240,.7); }

/* ---------------- Sections ---------------- */
.section { padding: 96px 0; }
.section.soft { background: var(--bg-soft); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-head .tag {
  color: var(--brand); font-weight: 700; letter-spacing: 2px; font-size: 13px;
  text-transform: uppercase;
}
.section-head h2 {
  font-size: 38px; font-weight: 800; color: var(--ink); margin: 12px 0 14px;
  letter-spacing: -.5px;
}
.section-head p { color: var(--muted); font-size: 17px; }

/* Cards */
.grid { display: grid; gap: 26px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px 28px;
  transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: transparent; }
.card .icon {
  width: 54px; height: 54px; border-radius: 14px;
  background: linear-gradient(135deg, var(--brand-dark), var(--brand-light));
  display: grid; place-items: center; color: #fff; margin-bottom: 20px;
  box-shadow: 0 10px 22px rgba(29,78,216,.28);
}
.card h3 { font-size: 20px; color: var(--ink); margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }

/* Feature split */
.split { display: grid; grid-template-columns: 1.05fr .95fr; gap: 64px; align-items: center; }
.split .visual {
  border-radius: 20px; overflow: hidden;
  background:
    linear-gradient(135deg, rgba(11,18,32,.35), rgba(30,58,138,.15)),
    url('../images/about-photo.jpg') center/cover no-repeat;
  aspect-ratio: 4 / 3; position: relative;
  box-shadow: var(--shadow-lg);
}
.split .visual::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.07) 1px, transparent 1px);
  background-size: 38px 38px;
  mask-image: radial-gradient(circle at 70% 30%, #000 20%, transparent 70%);
}
.split .visual .badge {
  position: absolute; left: 26px; bottom: 26px;
  background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.25);
  color: #fff; padding: 12px 18px; border-radius: 12px; backdrop-filter: blur(6px);
  font-size: 14px;
}
.split h2 { font-size: 34px; color: var(--ink); margin-bottom: 16px; letter-spacing: -.4px; }
.split p { color: var(--muted); font-size: 16px; margin-bottom: 22px; }
.checklist li {
  display: flex; align-items: flex-start; gap: 12px; margin-bottom: 14px;
  color: var(--text); font-size: 16px;
}
.checklist li svg { flex-shrink: 0; margin-top: 3px; color: var(--brand); }

/* Values */
.value-num {
  font-size: 15px; font-weight: 800; color: var(--brand);
  width: 40px; height: 40px; border-radius: 10px; border: 1px solid var(--line);
  display: grid; place-items: center; margin-bottom: 16px;
  background: var(--bg-soft);
}

/* Steps / timeline */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.step { position: relative; padding-top: 28px; }
.step .dot {
  width: 44px; height: 44px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  color: #fff; font-weight: 800; display: grid; place-items: center;
  box-shadow: var(--shadow-sm); margin-bottom: 14px;
}
.step h4 { color: var(--ink); font-size: 17px; margin-bottom: 6px; }
.step p { color: var(--muted); font-size: 14px; }

/* CTA band */
.cta-band {
  background: linear-gradient(135deg, var(--brand-dark), var(--brand));
  color: #fff; border-radius: 22px; padding: 56px 48px;
  display: flex; align-items: center; justify-content: space-between; gap: 32px;
  flex-wrap: wrap; box-shadow: var(--shadow-lg);
}
.cta-band h2 { font-size: 30px; margin-bottom: 8px; }
.cta-band p { color: rgba(226,232,240,.9); }

/* ---------------- Footer ---------------- */
.site-footer {
  background: var(--bg-deep);
  color: rgba(226, 232, 240, .75);
  padding: 64px 0 28px;
  margin-top: 0;
}
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 40px; }
.site-footer .brand { color: #fff; margin-bottom: 16px; }
.site-footer p { font-size: 14px; margin-bottom: 18px; max-width: 320px; }
.site-footer h4 { color: #fff; font-size: 15px; margin-bottom: 16px; }
.site-footer ul li { margin-bottom: 10px; font-size: 14px; }
.site-footer ul li a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.1);
  margin-top: 44px; padding-top: 22px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px;
  font-size: 13px; color: rgba(226,232,240,.55);
}

/* ---------------- Forms ---------------- */
.field { margin-bottom: 20px; }
.field label { display: block; font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.field input, .field textarea, .field select {
  width: 100%; padding: 13px 16px; border: 1px solid var(--line);
  border-radius: 10px; font-size: 15px; font-family: inherit; color: var(--text);
  background: #fff; transition: border-color .2s ease, box-shadow .2s ease;
}
.field input:focus, .field textarea:focus, .field select:focus {
  outline: none; border-color: var(--brand);
  box-shadow: 0 0 0 4px rgba(29, 78, 216, .12);
}
.field textarea { resize: vertical; min-height: 130px; }
.form-note { font-size: 13px; color: var(--muted); margin-top: 6px; }
.alert { padding: 12px 16px; border-radius: 10px; font-size: 14px; margin-bottom: 18px; display: none; }
.alert.show { display: block; }
.alert.error { background: #fef2f2; color: #b91c1c; border: 1px solid #fecaca; }
.alert.success { background: #f0fdf4; color: #15803d; border: 1px solid #bbf7d0; }

/* Auth page */
.auth-wrap { min-height: calc(100vh - 70px); display: grid; grid-template-columns: 1fr 1fr; }
.auth-aside {
  background: linear-gradient(135deg, var(--brand-dark), #0b1220);
  color: #fff; padding: 64px 56px; display: flex; flex-direction: column; justify-content: center;
  position: relative; overflow: hidden;
}
.auth-aside::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 40px 40px; opacity: .4;
  mask-image: radial-gradient(circle at 30% 30%, #000, transparent 70%);
}
.auth-aside h2 { font-size: 34px; margin-bottom: 16px; position: relative; }
.auth-aside p { color: rgba(226,232,240,.85); position: relative; max-width: 380px; }
.auth-aside .qmark { font-size: 120px; font-weight: 800; color: rgba(255,255,255,.08); position: absolute; right: 30px; bottom: -20px; }
.auth-main { display: grid; place-items: center; padding: 40px 24px; }
.auth-card { width: 100%; max-width: 400px; }
.auth-card h1 { font-size: 28px; color: var(--ink); margin-bottom: 6px; }
.auth-card .sub { color: var(--muted); margin-bottom: 28px; }
.auth-switch { text-align: center; margin-top: 22px; font-size: 14px; color: var(--muted); }
.auth-switch a { color: var(--brand); font-weight: 600; }
.auth-tabs { display: flex; gap: 0; margin-bottom: 26px; border: 1px solid var(--line); border-radius: 10px; padding: 4px; background: var(--bg-soft); }
.auth-tabs button {
  flex: 1; padding: 10px; border: 0; background: transparent; cursor: pointer;
  border-radius: 8px; font-weight: 600; color: var(--muted); font-size: 15px; font-family: inherit;
}
.auth-tabs button.active { background: #fff; color: var(--brand); box-shadow: var(--shadow-sm); }

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1.1fr; gap: 56px; align-items: start; }
.info-item { display: flex; gap: 16px; margin-bottom: 26px; }
.info-item .ic {
  width: 46px; height: 46px; border-radius: 12px; flex-shrink: 0;
  background: var(--bg-soft); display: grid; place-items: center; color: var(--brand);
  border: 1px solid var(--line);
}
.info-item h4 { font-size: 15px; color: var(--ink); margin-bottom: 4px; }
.info-item p { color: var(--muted); font-size: 15px; }
.contact-form-card { background: #fff; border: 1px solid var(--line); border-radius: var(--radius); padding: 36px; box-shadow: var(--shadow-sm); }

/* Sub page hero */
.page-hero {
  background: linear-gradient(135deg, var(--brand-dark), #0b1220);
  color: #fff; padding: 76px 0 80px; position: relative; overflow: hidden;
}
.page-hero::before {
  content: ""; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(circle at 80% 20%, #000, transparent 70%);
}
.page-hero .container { position: relative; }
.page-hero .crumb { color: rgba(226,232,240,.7); font-size: 13px; margin-bottom: 14px; letter-spacing: 1px; }
.page-hero h1 { font-size: 42px; font-weight: 800; letter-spacing: -.5px; }
.page-hero p { color: rgba(226,232,240,.85); margin-top: 12px; font-size: 17px; max-width: 640px; }

/* Reveal animation */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------------- AI 元素 ---------------- */
/* AI 主题色已在 :root 中定义 --ai / --ai-2 */

/* Hero 神经网络动效 */
.hero-nn {
  position: absolute; right: -80px; top: 50%; transform: translateY(-50%);
  width: 540px; height: 540px; opacity: .22; pointer-events: none; z-index: 0;
}
.hero-nn .node {
  transform-box: fill-box; transform-origin: center;
  animation: nnPulse 3.4s ease-in-out infinite;
}
.hero-nn .edge { stroke-dasharray: 5 9; animation: nnFlow 5s linear infinite; }
@keyframes nnPulse { 0%,100% { opacity: .45; } 50% { opacity: 1; } }
@keyframes nnFlow { to { stroke-dashoffset: -56; } }
.hero-inner { position: relative; z-index: 1; }
.eyebrow.ai { color: #c4b5fd; border-color: rgba(139,92,246,.5); background: rgba(139,92,246,.12); }

/* AI 能力板块 */
.ai-section { position: relative; overflow: hidden; }
.ai-section::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(600px 300px at 15% 0%, rgba(139,92,246,.10), transparent 60%),
    radial-gradient(600px 320px at 90% 100%, rgba(56,189,248,.10), transparent 60%);
  pointer-events: none;
}
.ai-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; position: relative; }
.ai-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 30px 28px; transition: transform .25s ease, box-shadow .25s ease, border-color .25s ease;
  display: flex; gap: 18px; align-items: flex-start;
}
.ai-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); border-color: transparent; }
.ai-card .ai-icon {
  flex-shrink: 0; width: 52px; height: 52px; border-radius: 14px;
  background: linear-gradient(135deg, var(--ai), var(--ai-2));
  display: grid; place-items: center; color: #fff;
  box-shadow: 0 10px 22px rgba(99,102,241,.32);
}
.ai-card h3 { font-size: 19px; color: var(--ink); margin-bottom: 8px; }
.ai-card p { color: var(--muted); font-size: 15px; }
.ai-tag {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 12px; font-weight: 700; letter-spacing: 1.5px; color: var(--ai);
  background: rgba(139,92,246,.10); border: 1px solid rgba(139,92,246,.25);
  padding: 5px 12px; border-radius: 999px; text-transform: uppercase;
}

/* 漂浮 AI 助手 */
.ai-fab {
  position: fixed; right: 22px; bottom: 22px; width: 60px; height: 60px;
  border-radius: 50%; border: 0; cursor: pointer; z-index: 60;
  background: linear-gradient(135deg, var(--ai), var(--ai-2)); color: #fff;
  display: grid; place-items: center; box-shadow: 0 12px 30px rgba(99,102,241,.45);
  transition: transform .2s ease;
}
.ai-fab:hover { transform: scale(1.07); }
.ai-fab .pulse {
  position: absolute; inset: 0; border-radius: 50%;
  animation: fabPulse 2.4s ease-out infinite;
}
@keyframes fabPulse {
  0% { box-shadow: 0 0 0 0 rgba(139,92,246,.5); }
  70% { box-shadow: 0 0 0 18px rgba(139,92,246,0); }
  100% { box-shadow: 0 0 0 0 rgba(139,92,246,0); }
}
.ai-panel {
  position: fixed; right: 22px; bottom: 94px; width: 350px; max-width: calc(100vw - 28px);
  background: #fff; border: 1px solid var(--line); border-radius: 18px; overflow: hidden;
  box-shadow: var(--shadow-lg); z-index: 60;
  transform: translateY(18px) scale(.98); opacity: 0; pointer-events: none;
  transition: transform .25s ease, opacity .25s ease;
  display: flex; flex-direction: column; max-height: 70vh;
}
.ai-panel.open { transform: none; opacity: 1; pointer-events: auto; }
.ai-panel header {
  background: linear-gradient(135deg, var(--ai), var(--ai-2)); color: #fff;
  padding: 16px 18px; display: flex; align-items: center; gap: 12px;
}
.ai-panel header .ava {
  width: 38px; height: 38px; border-radius: 10px; background: rgba(255,255,255,.18);
  display: grid; place-items: center; font-weight: 800;
}
.ai-panel header h4 { font-size: 16px; }
.ai-panel header p { font-size: 12px; color: rgba(255,255,255,.85); margin-top: 2px; }
.ai-panel .body { padding: 16px; overflow-y: auto; flex: 1; }
.ai-msg { margin-bottom: 12px; max-width: 88%; }
.ai-msg.bot { background: var(--bg-soft); border: 1px solid var(--line); border-radius: 12px; padding: 10px 13px; font-size: 14px; color: var(--text); }
.ai-msg.user { margin-left: auto; background: linear-gradient(135deg, var(--ai), var(--ai-2)); color: #fff; border-radius: 12px; padding: 10px 13px; font-size: 14px; }
.ai-chips { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }
.ai-chip {
  border: 1px solid var(--line); background: #fff; border-radius: 999px;
  padding: 8px 13px; font-size: 13px; cursor: pointer; color: var(--text);
  transition: border-color .2s ease, color .2s ease, background .2s ease;
}
.ai-chip:hover { border-color: var(--ai); color: var(--ai); background: rgba(139,92,246,.06); }
.ai-foot { padding: 12px 16px; border-top: 1px solid var(--line); font-size: 12px; color: var(--muted); display: flex; align-items: center; justify-content: space-between; }
.ai-foot a { color: var(--ai); font-weight: 600; }

@media (max-width: 960px) { .ai-grid { grid-template-columns: 1fr; } .hero-nn { opacity: .22; } }
@media (max-width: 640px) { .hero-nn { display: none; } .ai-panel { right: 14px; bottom: 88px; } .ai-fab { right: 14px; bottom: 14px; } }

/* 产品中心 */
.prod-block { margin-top: 54px; }
.prod-block:first-child { margin-top: 0; }
.prod-block > h3 {
  font-size: 19px; color: var(--ink); margin-bottom: 18px;
  display: flex; align-items: center; gap: 10px;
}
.prod-block > h3::before {
  content: ""; width: 5px; height: 20px; border-radius: 3px;
  background: linear-gradient(180deg, var(--brand), var(--brand-light));
}
.prod-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(258px, 1fr)); gap: 16px;
}
.prod-card {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 14px;
  padding: 18px 20px; font-size: 15px; color: var(--text); line-height: 1.5;
  display: flex; align-items: center; gap: 12px;
  transition: transform .2s ease, box-shadow .2s ease, border-color .2s ease;
}
.prod-card:hover {
  transform: translateY(-3px); border-color: var(--brand);
  box-shadow: var(--shadow-md);
}
.prod-card .dot {
  flex: 0 0 auto; width: 9px; height: 9px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
}
.prod-card .sub { color: var(--muted); font-size: 13px; }

/* FAQ */
.faq-list { max-width: 860px; margin: 0 auto; display: grid; gap: 14px; }
.faq {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 14px;
  padding: 4px 22px; transition: border-color .2s ease, box-shadow .2s ease;
}
.faq[open] { border-color: var(--brand); box-shadow: var(--shadow-sm); }
.faq summary {
  cursor: pointer; list-style: none; padding: 18px 0; font-size: 17px; font-weight: 600;
  color: var(--ink); display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; font-size: 22px; font-weight: 400; color: var(--brand); flex: 0 0 auto;
  transition: transform .2s ease;
}
.faq[open] summary::after { content: "\2212"; }
.faq p { color: var(--muted); font-size: 15px; padding: 0 0 20px; line-height: 1.9; }

/* ---------------- Responsive ---------------- */
@media (max-width: 960px) {
  .grid-3, .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: repeat(2, 1fr); }
  .split, .contact-grid { grid-template-columns: 1fr; gap: 36px; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .auth-wrap { grid-template-columns: 1fr; }
  .auth-aside { display: none; }
  .hero h1 { font-size: 40px; }
  .hero-nn { width: 400px; height: 400px; right: -150px; opacity: .16; }
}
@media (max-width: 640px) {
  .nav-links {
    position: fixed; top: 70px; left: 0; right: 0;
    background: #fff; flex-direction: column; gap: 0; padding: 12px 24px 20px;
    border-bottom: 1px solid var(--line); box-shadow: var(--shadow-md);
    transform: translateY(-130%); transition: transform .3s ease; z-index: 49;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 12px 0; width: 100%; border-bottom: 1px solid var(--line); }
  .nav-toggle { display: block; }
  .grid-3, .grid-4, .grid-2, .steps, .footer-grid { grid-template-columns: 1fr; }
  .hero-inner { padding: 72px 0 84px; }
  .hero .eyebrow { font-size: 12px; padding: 5px 12px; letter-spacing: 1px; }
  .hero h1 { font-size: 29px; line-height: 1.28; }
  .hero p.lead { font-size: 16px; max-width: 100%; }
  .hero-actions { gap: 12px; }
  .hero-actions .btn { flex: 1 1 auto; justify-content: center; padding: 13px 18px; }
  .hero-stats {
    display: grid; grid-template-columns: repeat(2, 1fr);
    gap: 26px 12px; margin-top: 48px; text-align: center;
  }
  .hero-stats .stat { min-width: 0; }
  .hero-stats .stat .num { font-size: 30px; }
  .hero-stats .stat .label { font-size: 13px; }
  .section { padding: 64px 0; }
  .section-head h2 { font-size: 28px; }
  .cta-band { padding: 40px 28px; flex-direction: column; text-align: center; gap: 18px; align-items: stretch; }
  .page-hero h1 { font-size: 32px; }
}