/* =========================================================
   AntMessenger — Official Website Stylesheet (Light Blue Theme)
   ========================================================= */

/* ---------- Design Tokens ---------- */
:root {
  --blue-900: #16324F;   /* 深色文字 / 页脚 */
  --blue-800: #1E4A7A;
  --blue-700: #2B5C99;
  --blue-600: #2563EB;   /* 主按钮 hover */
  --blue-500: #3B82F6;   /* 主按钮 */
  --blue-400: #60A5FA;
  --blue-200: #BFDBFE;
  --blue-100: #DBEAFE;
  --blue-50:  #EFF6FF;
  --sky-surface:  #E3EEFB; /* 浅蓝区块背景 */
  --sky-surface-2:#D6E6F8;
  --bg: #F7FAFD;
  --bg-soft: #EEF4FB;
  --card: #FFFFFF;
  --text: #0F2944;
  --text-muted: #5A7391;
  --border: #D6E4F2;
  --shadow-sm: 0 2px 8px rgba(30, 74, 122, 0.08);
  --shadow-md: 0 10px 30px rgba(30, 74, 122, 0.12);
  --shadow-lg: 0 24px 60px rgba(30, 74, 122, 0.18);
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --maxw: 1200px;
  --font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: var(--blue-600); text-decoration: none; transition: color .2s; }
a:hover { color: var(--blue-500); }
h1, h2, h3, h4 { line-height: 1.25; color: var(--text); margin: 0 0 .6em; font-weight: 700; }
h1 { font-size: clamp(2rem, 4.5vw, 3.2rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.6rem, 3vw, 2.3rem); letter-spacing: -0.01em; }
h3 { font-size: 1.25rem; }
p { margin: 0 0 1em; }
.container { 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; border: none; cursor: pointer;
  transition: transform .15s ease, box-shadow .2s ease, background .2s, color .2s;
  white-space: nowrap;
}
.btn-primary { background: var(--blue-500); color: #fff; box-shadow: 0 8px 20px rgba(59, 130, 246, .35); }
.btn-primary:hover { background: var(--blue-600); color: #fff; transform: translateY(-2px); }
.btn-ghost { background: transparent; color: var(--blue-700); border: 1.5px solid var(--blue-300, #93C5FD); }
.btn-ghost:hover { border-color: var(--blue-500); color: var(--blue-600); }
.btn-dark { background: var(--blue-600); color: #fff; }
.btn-dark:hover { background: var(--blue-700); color: #fff; }
.btn-amber { background: var(--blue-500); color: #fff; box-shadow: 0 8px 20px rgba(59, 130, 246, .3); }
.btn-amber:hover { background: var(--blue-600); color: #fff; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(240, 247, 255, .88);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.nav-wrap {
  display: flex; align-items: center; justify-content: space-between;
  height: 68px; max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
}
.brand { display: flex; align-items: center; gap: 10px; color: var(--blue-900); font-weight: 700; font-size: 18px; }
.brand img { width: 34px; height: 34px; border-radius: 8px; }
.nav-links { display: flex; align-items: center; gap: 28px; list-style: none; margin: 0; padding: 0; }
.nav-links a { color: var(--blue-800); font-size: 15px; font-weight: 500; }
.nav-links a:hover, .nav-links a.active { color: var(--blue-600); }
.nav-cta { display: flex; align-items: center; gap: 12px; }
.nav-cta .btn { padding: 9px 20px; font-size: 14px; }
.hamburger {
  display: none; background: none; border: none; cursor: pointer;
  width: 40px; height: 40px; flex-direction: column; justify-content: center; gap: 5px;
}
.hamburger span { display: block; height: 2px; background: var(--blue-900); border-radius: 2px; transition: .3s; }

/* ---------- Hero (light blue) ---------- */
.hero {
  background:
    radial-gradient(1200px 600px at 80% 20%, rgba(59,130,246,.18), transparent 60%),
    radial-gradient(800px 400px at 10% 90%, rgba(96,165,250,.15), transparent 60%),
    linear-gradient(180deg, #E3EEFB 0%, #F0F7FF 100%);
  color: var(--text);
  overflow: hidden;
}
.hero-grid {
  display: grid; grid-template-columns: 1.05fr 1fr; gap: 48px; align-items: center;
  padding: 80px 0 90px;
}
.hero .eyebrow {
  display: inline-block; padding: 6px 14px; border-radius: 999px;
  background: var(--blue-100); color: var(--blue-700);
  font-size: 13px; font-weight: 600; letter-spacing: .04em; margin-bottom: 20px;
}
.hero h1 { color: var(--blue-900); }
.hero h1 .accent { color: var(--blue-500); }
.hero p.lead { font-size: 18px; color: var(--text-muted); max-width: 540px; margin-bottom: 32px; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 36px; }
.hero-stats { display: flex; gap: 36px; flex-wrap: wrap; }
.hero-stats .stat b { display: block; font-size: 26px; color: var(--blue-900); font-weight: 700; }
.hero-stats .stat span { font-size: 13px; color: var(--text-muted); }
.hero-media { position: relative; }
.hero-media img { border-radius: var(--radius-lg); box-shadow: var(--shadow-lg); width: 100%; height: auto; }

/* ---------- Sections ---------- */
.section { padding: 90px 0; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-head .eyebrow {
  color: var(--blue-600); font-weight: 600; font-size: 14px;
  letter-spacing: .08em; text-transform: uppercase;
}
.section-head p { color: var(--text-muted); font-size: 17px; }

/* ---------- Feature grid ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.feature-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius-md); overflow: hidden;
  transition: transform .25s, box-shadow .25s;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-md); }
.feature-card .thumb { aspect-ratio: 4/3; overflow: hidden; background: var(--blue-50); }
.feature-card .thumb img { width: 100%; height: 100%; object-fit: cover; }
.feature-card .body { padding: 24px; }
.feature-card h3 { margin-bottom: 8px; }
.feature-card p { color: var(--text-muted); margin: 0; font-size: 15px; }

/* ---------- Split rows (text + image) ---------- */
.split {
  display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center;
  padding: 60px 0;
}
.split.reverse > .split-media { order: 2; }
.split-media img { border-radius: var(--radius-md); box-shadow: var(--shadow-md); width: 100%; height: auto; }
.split h2 { margin-bottom: 16px; }
.split ul.checks { list-style: none; padding: 0; margin: 20px 0 0; }
.split ul.checks li {
  padding-left: 30px; position: relative; margin-bottom: 12px; color: var(--text-muted);
}
.split ul.checks li::before {
  content: ""; position: absolute; left: 0; top: 7px;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--blue-100) url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%232563EB' stroke-width='3'><polyline points='20 6 9 17 4 12'/></svg>") center/12px no-repeat;
}

/* ---------- CTA band (light blue) ---------- */
.cta-band {
  background: linear-gradient(135deg, #D6E6F8 0%, #E3EEFB 100%);
  border: 1px solid var(--blue-200);
  border-radius: var(--radius-lg);
  padding: 60px; color: var(--blue-900); text-align: center;
}
.cta-band h2 { color: var(--blue-900); }
.cta-band p { color: var(--text-muted); max-width: 560px; margin: 0 auto 28px; }
.cta-band .actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ---------- Platform / Download cards ---------- */
.platform-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.platform-card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 28px; text-align: center; transition: .25s;
}
.platform-card:hover { border-color: var(--blue-400); box-shadow: var(--shadow-md); transform: translateY(-4px); }
.platform-card .icon {
  width: 56px; height: 56px; margin: 0 auto 16px; border-radius: 14px;
  background: var(--blue-100); display: flex; align-items: center; justify-content: center;
}
.platform-card .icon svg { width: 30px; height: 30px; fill: var(--blue-600); }
.platform-card h3 { font-size: 18px; }
.platform-card .ver { color: var(--text-muted); font-size: 13px; margin-bottom: 16px; }
.platform-card .btn { width: 100%; justify-content: center; padding: 10px; font-size: 14px; }

/* ---------- FAQ ---------- */
.faq-layout { display: grid; grid-template-columns: 220px 1fr; gap: 40px; align-items: start; }
.faq-cats { position: sticky; top: 90px; }
.faq-cats h4 { font-size: 13px; text-transform: uppercase; letter-spacing: .08em; color: var(--text-muted); margin-bottom: 12px; }
.faq-cats ul { list-style: none; padding: 0; margin: 0; }
.faq-cats li { margin-bottom: 4px; }
.faq-cats a {
  display: block; padding: 9px 14px; border-radius: 8px; color: var(--text); font-size: 15px;
}
.faq-cats a:hover, .faq-cats a.active { background: var(--blue-100); color: var(--blue-600); }
.faq-list { max-width: 820px; }
.faq-search {
  width: 100%; padding: 14px 18px; border-radius: 999px;
  border: 1px solid var(--border); background: #fff; font-size: 15px; margin-bottom: 28px;
  font-family: var(--font);
}
.faq-search:focus { outline: none; border-color: var(--blue-400); }
.faq-item {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-md);
  margin-bottom: 12px; overflow: hidden;
}
.faq-item summary {
  cursor: pointer; padding: 18px 22px; font-weight: 600; list-style: none;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+"; font-size: 22px; color: var(--blue-500); font-weight: 400; transition: transform .2s;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item .answer { padding: 0 22px 20px; color: var(--text-muted); }

/* ---------- Client page (jiqiren) ---------- */
.client-hero {
  background: linear-gradient(180deg, #D6E6F8 0%, #E3EEFB 100%);
  color: var(--text); padding: 80px 0;
}
.client-hero h1 { color: var(--blue-900); }
.client-hero p { color: var(--text-muted); max-width: 640px; font-size: 18px; }
.client-matrix { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 40px; }
.client-tile {
  background: rgba(255,255,255,.7); border: 1px solid var(--blue-200);
  border-radius: var(--radius-md); padding: 28px;
}
.client-tile h3 { color: var(--blue-900); display: flex; align-items: center; gap: 10px; }
.client-tile p { color: var(--text-muted); font-size: 14px; }
.client-tile .tag {
  display: inline-block; font-size: 12px; padding: 3px 10px; border-radius: 999px;
  background: var(--blue-500); color: #fff; margin-left: auto;
}

/* ---------- Footer (light blue) ---------- */
.site-footer {
  background: #D6E6F8; color: var(--blue-800); padding: 60px 0 30px; margin-top: 40px;
  border-top: 1px solid var(--blue-200);
}
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand { display: flex; align-items: center; gap: 10px; color: var(--blue-900); font-weight: 700; margin-bottom: 14px; }
.footer-brand img { width: 32px; height: 32px; border-radius: 7px; }
.site-footer h4 { color: var(--blue-900); font-size: 15px; margin-bottom: 14px; }
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer li { margin-bottom: 8px; }
.site-footer a { color: var(--blue-800); font-size: 14px; }
.site-footer a:hover { color: var(--blue-600); }
.footer-bottom {
  border-top: 1px solid rgba(22, 50, 79, .12); padding-top: 24px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; font-size: 13px; color: var(--blue-700);
}

/* ---------- Misc ---------- */
.badge-new { background: var(--blue-500); color: #fff; font-size: 12px; padding: 2px 8px; border-radius: 999px; font-weight: 600; }
.muted { color: var(--text-muted); }
.mt-0 { margin-top: 0; }
.center { text-align: center; }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-grid, .split { grid-template-columns: 1fr; gap: 36px; padding: 50px 0; }
  .split.reverse > .split-media { order: 0; }
  .feature-grid, .platform-grid, .client-matrix { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .faq-layout { grid-template-columns: 1fr; }
  .faq-cats { position: static; }
}
@media (max-width: 640px) {
  .nav-links {
    position: fixed; top: 68px; left: 0; right: 0;
    background: #F0F7FF; flex-direction: column; padding: 20px; gap: 16px;
    transform: translateY(-120%); transition: transform .3s; border-bottom: 1px solid var(--border);
  }
  .nav-links.open { transform: translateY(0); }
  .hamburger { display: flex; }
  .nav-cta .btn-ghost { display: none; }
  .feature-grid, .platform-grid, .client-matrix, .footer-grid { grid-template-columns: 1fr; }
  .section { padding: 60px 0; }
  .cta-band { padding: 40px 24px; }
}