/* ==========================================================================
   OSTD 官网 — 样式表（复刻 Next.js 版视觉）
   ========================================================================== */

:root {
  --brand-50: #ECFEFF;
  --brand-100: #CFFAFE;
  --brand-200: #A5F3FC;
  --brand-300: #67E8F9;
  --brand-400: #22D3EE;
  --brand-500: #06B6D4;
  --brand-600: #0891B2;
  --brand-700: #0E7490;
  --brand-800: #155E75;

  --navy-50: #EEF4FB;
  --navy-700: #103A63;
  --navy-800: #0B2A4A;
  --navy-900: #071A30;

  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-400: #94a3b8;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;

  --shadow-card: 0 10px 30px -12px rgba(11, 42, 74, .18);
  --radius: 16px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: #f8fafc;
  color: #0f172a;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
    "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  line-height: 1.6;
}

img { max-width: 100%; display: block; }
a { color: inherit; }
h1, h2, h3, h4, p, ul { margin: 0; }
ul { padding: 0; list-style: none; }

.container-page {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 16px;
}
@media (min-width: 640px) { .container-page { padding: 0 24px; } }
@media (min-width: 1024px) { .container-page { padding: 0 32px; } }

/* ---------------- 按钮 ---------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 0;
  border-radius: 10px;
  padding: 10px 22px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: background-color .2s, color .2s, transform .2s, box-shadow .2s;
}
.btn:focus-visible { outline: 2px solid var(--brand-400); outline-offset: 2px; }
.btn-brand { background: var(--brand-500); color: #fff; }
.btn-brand:hover { background: var(--brand-400); }
.btn-primary { background: var(--brand-600); color: #fff; box-shadow: 0 1px 2px rgba(0,0,0,.08); }
.btn-primary:hover { background: var(--brand-700); }
.btn-ghost { border: 1px solid var(--brand-600); color: var(--brand-700); background: transparent; }
.btn-ghost:hover { background: var(--brand-50); }
.btn-outline-light { border: 1px solid rgba(255,255,255,.4); color: #fff; background: transparent; }
.btn-outline-light:hover { background: rgba(255,255,255,.1); }
.btn-sm { padding: 8px 16px; font-size: 13px; }
.btn-block { width: 100%; }

/* ---------------- 版块 ---------------- */
.section { padding: 64px 0; }
@media (min-width: 640px) { .section { padding: 80px 0; } }
.bg-white { background: #fff; }
.bg-slate-50 { background: #f8fafc; }

.section-head { max-width: 42rem; }
.section-head.center { margin: 0 auto; text-align: center; }
.section-eyebrow {
  display: inline-block;
  margin-bottom: 12px;
  border-radius: 999px;
  background: var(--brand-50);
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--brand-700);
}
.section-title { font-size: 28px; font-weight: 700; color: var(--navy-800); line-height: 1.25; }
@media (min-width: 640px) { .section-title { font-size: 36px; } }
.section-sub { margin-top: 12px; font-size: 16px; color: var(--slate-600); }
.mt-12 { margin-top: 48px; }
.mt-10 { margin-top: 40px; }
.text-center { text-align: center; }
.grid-3 { display: grid; gap: 24px; }
@media (min-width: 768px) { .grid-3 { grid-template-columns: repeat(3, 1fr); } }
.grid-4 { display: grid; gap: 24px; }
@media (min-width: 640px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .grid-4 { grid-template-columns: repeat(4, 1fr); } }

/* ---------------- 顶部导航 ---------------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  color: #fff;
  background: transparent;
  transition: transform .3s ease-out, background-color .3s ease, box-shadow .3s ease;
}
.site-header.solid {
  background: rgba(7, 26, 48, .95);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255,255,255,.1);
  box-shadow: 0 12px 30px -18px rgba(0,0,0,.7);
}
.site-header.bar-hidden { transform: translateY(-100%); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.brand { display: flex; align-items: center; text-decoration: none; }
.logo { height: 30px; width: auto; color: #fff; }
.logo-footer { height: 34px; }

.nav-desktop { display: none; align-items: center; gap: 28px; font-size: 14px; }
@media (min-width: 768px) { .nav-desktop { display: flex; } }
.nav-link { color: rgba(255,255,255,.8); text-decoration: none; transition: color .2s; }
.nav-link:hover { color: #fff; }
.nav-link.active { color: var(--brand-300); font-weight: 600; }

.header-actions { display: flex; align-items: center; gap: 14px; }
.lang-switch { display: flex; align-items: center; gap: 5px; font-size: 13px; color: rgba(255,255,255,.45); }
.lang-switch a { color: rgba(255,255,255,.75); text-decoration: none; transition: color .2s; }
.lang-switch a:hover { color: #fff; }
.lang-switch a.on { color: var(--brand-300); font-weight: 700; }

.nav-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px;
  background: none; border: 0; color: #fff; font-size: 18px; cursor: pointer;
}
@media (min-width: 768px) { .nav-toggle { display: none; } }
.hide-sm { display: none; }
@media (min-width: 768px) { .hide-sm { display: inline-flex; } }

.nav-mobile {
  display: none;
  background: rgba(7, 26, 48, .97);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-top: 1px solid rgba(255,255,255,.1);
  padding: 6px 16px 12px;
}
.nav-mobile.open { display: block; }
.nav-mobile a {
  display: block;
  padding: 11px 0;
  color: rgba(255,255,255,.85);
  text-decoration: none;
  font-size: 14px;
  border-bottom: 1px solid rgba(255,255,255,.06);
}
.nav-mobile a.active { color: var(--brand-300); font-weight: 600; }
@media (min-width: 768px) { .nav-mobile { display: none !important; } }

/* ---------------- 首页 Hero ---------------- */
.hero { position: relative; overflow: hidden; background: var(--navy-900); color: #fff; }
.hero-glow {
  position: absolute; right: -8rem; top: -8rem;
  width: 24rem; height: 24rem; border-radius: 50%;
  background: rgba(6, 182, 212, .2); filter: blur(70px); pointer-events: none;
}
.hero-glow2 {
  position: absolute; bottom: -10rem; left: -6rem;
  width: 24rem; height: 24rem; border-radius: 50%;
  background: rgba(34, 211, 238, .1); filter: blur(70px); pointer-events: none;
}
.hero-inner {
  position: relative;
  display: grid;
  gap: 48px;
  padding: 80px 0;
}
@media (min-width: 1024px) {
  .hero-inner { grid-template-columns: 1fr 1fr; padding: 112px 0; align-items: center; }
}
.hero-kicker {
  display: inline-block;
  border-radius: 999px;
  background: rgba(255,255,255,.1);
  padding: 4px 12px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .05em;
  text-transform: uppercase;
  color: var(--brand-200);
}
.hero h1 { margin-top: 20px; font-size: 34px; line-height: 1.15; font-weight: 700; }
@media (min-width: 640px) { .hero h1 { font-size: 48px; } }
.hero-sub { margin-top: 20px; max-width: 36rem; font-size: 17px; line-height: 1.75; color: rgba(255,255,255,.75); }
.hero-actions { margin-top: 32px; display: flex; flex-wrap: wrap; gap: 14px; }

.hero-side { display: none; }
@media (min-width: 1024px) { .hero-side { display: flex; align-items: center; } }
.hero-side-card {
  width: 100%;
  border-radius: var(--radius);
  border: 1px solid rgba(255,255,255,.1);
  background: rgba(255,255,255,.05);
  padding: 32px;
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
}
.hero-side-head { display: flex; align-items: center; gap: 12px; color: var(--brand-200); }
.hero-side-head strong { font-size: 17px; color: #fff; font-weight: 600; }
.hero-side-card > p { margin-top: 16px; font-size: 14px; line-height: 1.7; color: rgba(255,255,255,.7); }
.hero-badges { margin-top: 24px; display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; text-align: center; }
.hero-badges span {
  border-radius: 10px;
  background: rgba(255,255,255,.06);
  padding: 12px 0;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--brand-100);
}

/* ---------------- 统计条 ---------------- */
.stats { background: var(--navy-800); color: #fff; }
.stats-inner { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; padding: 40px 0; }
@media (min-width: 640px) { .stats-inner { grid-template-columns: repeat(4, 1fr); } }
.stat-value { font-size: 30px; font-weight: 700; color: var(--brand-300); }
.stat-label { margin-top: 4px; font-size: 14px; color: rgba(255,255,255,.65); }

/* ---------------- 卡片通用 ---------------- */
.card {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--slate-200);
  background: #fff;
  padding: 24px;
  box-shadow: var(--shadow-card);
  height: 100%;
}
.card-inner { position: relative; display: flex; flex-direction: column; height: 100%; }
.card-halo {
  position: absolute; right: -32px; top: -32px;
  width: 112px; height: 112px; border-radius: 50%;
  background: var(--brand-50);
  transition: transform .5s ease;
}
.card-title { font-size: 17px; font-weight: 700; color: var(--navy-800); }
.card-desc { margin-top: 8px; font-size: 14px; line-height: 1.7; color: var(--slate-600); }

.icon-tile {
  display: inline-flex; align-items: center; justify-content: center;
  width: 48px; height: 48px; border-radius: 12px;
  margin-bottom: 16px;
  flex: none;
}
.icon-tile.gradient {
  background: linear-gradient(135deg, var(--brand-500), var(--brand-600));
  color: #fff;
  box-shadow: 0 6px 16px -6px rgba(6, 182, 212, .55);
}
.icon-tile.navy { background: var(--navy-800); color: var(--brand-300); }
.icon-tile.soft { background: var(--brand-50); color: var(--brand-600); }

.ico { width: 24px; height: 24px; }
.ico-sm { width: 16px; height: 16px; flex: none; }
.ico-xs { width: 12px; height: 12px; flex: none; }
.ico-lg { width: 40px; height: 40px; }

/* 服务卡片（卡片有动效，文字保持静态） */
.svc-card { transition: transform .5s ease, box-shadow .5s ease, border-color .5s ease; }
.svc-card:hover { transform: translateY(-4px); border-color: var(--brand-200); box-shadow: 0 20px 40px -20px rgba(11,42,74,.35); }
.svc-card:hover .card-halo { transform: scale(1.25); }
.svc-card:hover .icon-tile { transform: scale(1.1) rotate(3deg); }
.svc-card .icon-tile { transition: transform .5s ease; }
.card-topbar {
  position: absolute; top: 0; left: 0; right: 0; height: 4px;
  background: linear-gradient(90deg, var(--brand-500), var(--brand-400));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform .5s ease;
}
.svc-card:hover .card-topbar { transform: scaleX(1); }

.check-list { margin-top: 20px; padding-top: 16px; border-top: 1px solid var(--slate-100); font-size: 14px; }
.check-list li { display: flex; align-items: flex-start; gap: 10px; padding: 6px 0; }
.check-badge {
  display: inline-flex; align-items: center; justify-content: center;
  width: 20px; height: 20px; border-radius: 50%;
  background: var(--brand-100); color: var(--brand-600);
  flex: none; margin-top: 2px;
}
.check-list li > span:last-child { color: var(--slate-700); line-height: 1.6; }

/* 区域卡片（可点击，保留交互反馈） */
.region-card { transition: transform .5s ease, box-shadow .5s ease, border-color .5s ease; }
.region-card:hover { transform: translateY(-4px); border-color: var(--brand-200); box-shadow: 0 20px 40px -20px rgba(11,42,74,.35); }
.region-card:hover .card-halo { transform: scale(1.25); }
.region-card:hover .icon-tile { background: var(--brand-600); color: #fff; }
.region-card .icon-tile { transition: background-color .5s ease, color .5s ease; }

.link-list { margin-top: 16px; padding-top: 12px; border-top: 1px solid var(--slate-100); font-size: 14px; }
.link-row {
  display: flex; align-items: center; gap: 10px;
  margin: 0 -8px;
  padding: 8px;
  border-radius: 10px;
  text-decoration: none;
  transition: background-color .3s ease;
}
a.link-row:hover { background: var(--brand-50); }
.arrow-badge {
  display: inline-flex; align-items: center; justify-content: center;
  width: 20px; height: 20px; border-radius: 50%;
  background: var(--brand-100); color: var(--brand-600);
  flex: none;
  transition: background-color .3s ease, color .3s ease;
}
a.link-row:hover .arrow-badge { background: var(--brand-500); color: #fff; }
a.link-row:hover .arrow-badge .ico-xs { transform: translateX(2px); }
.arrow-badge .ico-xs { transition: transform .3s ease; }
.link-text { flex: 1; font-weight: 500; color: var(--navy-800); transition: color .3s ease; }
a.link-row:hover .link-text { color: var(--brand-700); }
.link-row.muted { color: var(--slate-400); }
.link-row.muted .arrow-badge { background: var(--slate-100); color: var(--slate-300); }
.link-row.muted .link-text { font-weight: 400; color: var(--slate-400); }

/* ---------------- 新闻卡片 ---------------- */
.news-card {
  display: block;
  overflow: hidden;
  border-radius: var(--radius);
  border: 1px solid var(--slate-200);
  background: #fff;
  box-shadow: var(--shadow-card);
  text-decoration: none;
  transition: transform .35s ease, box-shadow .35s ease;
}
.news-card:hover { transform: translateY(-4px); box-shadow: 0 22px 45px -22px rgba(11,42,74,.35); }
.news-cover {
  display: flex; align-items: center; justify-content: center;
  aspect-ratio: 16 / 9;
  background: linear-gradient(135deg, var(--brand-50), var(--navy-50));
  color: var(--brand-200);
}
.news-cover img { width: 100%; height: 100%; object-fit: cover; }
.news-body { padding: 20px; }
.news-meta { display: flex; align-items: center; gap: 8px; font-size: 12px; margin-bottom: 8px; }
.tag { border-radius: 4px; background: var(--brand-50); padding: 2px 8px; font-weight: 500; color: var(--brand-700); }
.date { color: var(--slate-400); }
.news-title { font-size: 16px; font-weight: 700; color: var(--navy-800); transition: color .25s; }
.news-card:hover .news-title { color: var(--brand-600); }
.news-excerpt {
  margin-top: 8px; font-size: 14px; color: var(--slate-600);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ---------------- 子页 banner ---------------- */
.page-hero { position: relative; overflow: hidden; background: var(--navy-800); color: #fff; }
.page-hero-inner { position: relative; padding: 128px 0 64px; }
.page-hero h1 { font-size: 28px; font-weight: 700; line-height: 1.25; }
@media (min-width: 640px) { .page-hero h1 { font-size: 36px; } }
.page-hero p { margin-top: 12px; max-width: 42rem; color: rgba(255,255,255,.7); font-size: 16px; }

/* ---------------- 认证列表 ---------------- */
.cert-group { margin-top: 40px; }
.cert-group-title {
  font-size: 20px; font-weight: 700; color: var(--navy-800);
  display: flex; align-items: center; gap: 10px;
}
.cert-list { margin-top: 16px; display: grid; gap: 16px; }
@media (min-width: 768px) { .cert-list { grid-template-columns: repeat(2, 1fr); } }
.cert-item {
  display: block;
  border-radius: var(--radius);
  border: 1px solid var(--slate-200);
  background: #fff;
  padding: 22px 24px;
  text-decoration: none;
  box-shadow: var(--shadow-card);
  transition: transform .3s ease, border-color .3s ease, box-shadow .3s ease;
}
.cert-item:hover { transform: translateY(-3px); border-color: var(--brand-200); box-shadow: 0 20px 40px -22px rgba(11,42,74,.32); }
.cert-item h3 { font-size: 16px; font-weight: 700; color: var(--navy-800); display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.cert-item p { margin-top: 8px; font-size: 14px; color: var(--slate-600); line-height: 1.7; }
.cert-more { font-size: 13px; font-weight: 600; color: var(--brand-600); white-space: nowrap; }

/* ---------------- 富文本内容 ---------------- */
.rich-content { font-size: 15px; line-height: 1.85; color: var(--slate-700); }
.rich-content h3 { margin: 1.4em 0 .5em; font-size: 17px; font-weight: 700; color: #0c3059; }
.rich-content h3:first-child { margin-top: 0; }
.rich-content p { margin: .7em 0; }
.rich-content ul { list-style: disc; padding-left: 1.4em; margin: .6em 0; }
.rich-content ol { list-style: decimal; padding-left: 1.4em; margin: .6em 0; }
.rich-content li { margin: .3em 0; }
.rich-content img { max-width: 100%; height: auto; border-radius: 10px; margin: .8em 0; }
.rich-content a { color: var(--brand-700); text-decoration: underline; }
.rich-content em { color: var(--slate-500); }
.rich-content strong { color: var(--navy-800); }

/* ---------------- 联系页 ---------------- */
.contact-grid { display: grid; gap: 40px; }
@media (min-width: 1024px) { .contact-grid { grid-template-columns: 1fr 1fr; } }
.contact-list { margin-top: 24px; display: flex; flex-direction: column; gap: 20px; }
.contact-row { display: flex; gap: 12px; }
.contact-icon {
  display: flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 10px;
  background: var(--brand-50); color: var(--brand-600); flex: none;
}
.contact-label { font-size: 13px; color: var(--slate-500); }
.contact-value { font-size: 15px; font-weight: 500; color: var(--slate-800); text-decoration: none; }
a.contact-value:hover { color: var(--brand-600); }

.form-card { border-radius: var(--radius); border: 1px solid var(--slate-200); background: #fff; padding: 24px; box-shadow: var(--shadow-card); }
.form-grid { display: grid; gap: 16px; }
@media (min-width: 640px) { .form-grid { grid-template-columns: 1fr 1fr; } }
.field { display: flex; flex-direction: column; }
.field label { margin-bottom: 6px; font-size: 14px; font-weight: 500; color: var(--slate-700); }
.req { color: #ef4444; }
.input {
  width: 100%;
  border: 1px solid var(--slate-300);
  border-radius: 10px;
  background: #fff;
  padding: 10px 14px;
  font-family: inherit;
  font-size: 14px;
  color: var(--slate-800);
  outline: none;
  transition: border-color .2s, box-shadow .2s;
}
.input:focus { border-color: var(--brand-500); box-shadow: 0 0 0 3px rgba(6,182,212,.18); }
textarea.input { min-height: 130px; resize: vertical; }
.form-actions { margin-top: 18px; }
.form-msg { margin-top: 12px; font-size: 14px; }
.form-msg.ok { color: #0f766e; }
.form-msg.err { color: #dc2626; }

/* ---------------- 页脚 ---------------- */
.site-footer { background: var(--navy-900); color: rgba(255,255,255,.8); }
.footer-grid {
  display: grid; gap: 40px; padding: 56px 0;
  grid-template-columns: 1fr;
}
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }
.footer-brand .logo-footer { color: #fff; }
.footer-desc { margin-top: 16px; max-width: 24rem; font-size: 14px; line-height: 1.7; color: rgba(255,255,255,.7); }
.footer-contact { margin-top: 20px; display: flex; flex-direction: column; gap: 10px; font-size: 14px; }
.footer-contact p { display: flex; align-items: center; gap: 8px; color: rgba(255,255,255,.8); }
.footer-contact .ico-sm { color: var(--brand-300); }
.footer-contact a { text-decoration: none; }
.footer-contact a:hover { color: #fff; }
.site-footer h4 { margin-bottom: 16px; font-size: 14px; font-weight: 600; color: #fff; }
.site-footer ul { display: flex; flex-direction: column; gap: 8px; font-size: 14px; }
.site-footer ul a { text-decoration: none; color: rgba(255,255,255,.8); }
.site-footer ul a:hover { color: #fff; }
.footer-bar { border-top: 1px solid rgba(255,255,255,.1); }
.footer-bar .container-page { padding-top: 20px; padding-bottom: 20px; font-size: 12px; color: rgba(255,255,255,.5); }

/* ---------------- 动效 ---------------- */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}
.fade-up { animation: fadeUp .6s ease-out both; }
.d150 { animation-delay: .15s; }

.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s ease-out, transform .7s ease-out; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  .fade-up, .reveal { animation: none !important; transition: none !important; opacity: 1 !important; transform: none !important; }
}

/* ---------------- 其它 ---------------- */
.cta-band { background: linear-gradient(90deg, var(--brand-700), var(--brand-500)); color: #fff; }
.cta-band-inner {
  display: flex; flex-direction: column; gap: 20px;
  align-items: flex-start; justify-content: space-between;
  padding: 48px 0;
}
@media (min-width: 640px) { .cta-band-inner { flex-direction: row; align-items: center; } }
.cta-band h2 { font-size: 22px; font-weight: 700; }
.note-box {
  display: flex; gap: 8px; align-items: flex-start;
  margin-top: 40px; border-radius: 12px;
  background: var(--slate-100); padding: 16px;
  font-size: 14px; color: var(--slate-600);
}
.note-box .ico-sm { color: var(--brand-500); margin-top: 3px; }
.empty { padding: 48px 0; text-align: center; color: var(--slate-400); }
.back-link { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; color: var(--brand-700); text-decoration: none; margin-bottom: 20px; }
.back-link:hover { text-decoration: underline; }
.article-wrap { max-width: 760px; }
.article-meta { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--slate-400); }