/* ============================================================
   「文化桥」—— 面向中俄留学生的跨文化适应智能匹配与知识服务平台
   公共样式：桥梁主题（中国红 · 深蓝 · 米白）
   ============================================================ */
:root {
  --red: #C8102E;          /* 中国红 */
  --red-dark: #9C0C24;
  --blue: #1B2A4A;         /* 深蓝（俄式/智慧） */
  --blue-light: #2E4A75;
  --cream: #F7F3EC;        /* 米白背景 */
  --cream-2: #FBF9F4;
  --ink: #23252B;          /* 主文字 */
  --ink-2: #5B6070;        /* 次级文字 */
  --line: #E5DFD3;
  --white: #FFFFFF;
  --gold: #D9A441;         /* 桥梁金色点缀 */
  --shadow: 0 6px 24px rgba(27,42,74,0.08);
  --shadow-lg: 0 14px 40px rgba(27,42,74,0.14);
  --radius: 16px;
  --font: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Segoe UI", system-ui, -apple-system, sans-serif;
  --font-ru: "Segoe UI", "Noto Sans", system-ui, sans-serif;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--cream);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
body.lang-ru { font-family: var(--font-ru); }
img { max-width: 100%; display: block; }
a { color: var(--blue); text-decoration: none; }
a:hover { color: var(--red); }
.container { width: min(1120px, 92%); margin: 0 auto; }
section { padding: 72px 0; }

/* ---------- 顶部导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 66px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 20px; color: var(--ink); }
.brand svg { width: 32px; height: 32px; }
.brand:hover { color: var(--ink); }
.brand small { display: block; font-size: 11px; font-weight: 500; color: var(--ink-2); letter-spacing: .06em; }
.nav-links { display: flex; gap: 6px; align-items: center; }
.nav-links a {
  padding: 8px 14px; border-radius: 999px; font-size: 15px; color: var(--ink-2);
  transition: all .2s;
}
.nav-links a:hover { color: var(--red); background: rgba(200,16,46,.06); }
.nav-links a.active { color: var(--white); background: var(--red); font-weight: 600; }
.lang-switch {
  display: inline-flex; margin-left: 10px; border: 1px solid var(--line); border-radius: 999px; overflow: hidden;
}
.lang-switch button {
  border: 0; background: transparent; padding: 6px 12px; cursor: pointer; font-size: 13px; color: var(--ink-2); font-family: inherit;
}
.lang-switch button.active { background: var(--blue); color: #fff; }
.menu-btn { display: none; background: none; border: 0; font-size: 22px; cursor: pointer; color: var(--ink); padding: 6px; }
@media (max-width: 860px) {
  .menu-btn { display: block; }
  .nav-links {
    display: none; position: absolute; top: 66px; left: 0; right: 0; flex-direction: column;
    background: #fff; padding: 14px 5%; border-bottom: 1px solid var(--line); gap: 4px; align-items: stretch;
  }
  .nav-links.open { display: flex; }
  .nav-links a { border-radius: 10px; }
  .lang-switch { margin-left: 0; align-self: flex-start; }
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 26px; border-radius: 999px; font-size: 15px; font-weight: 600;
  border: 0; cursor: pointer; transition: all .2s; font-family: inherit;
}
.btn-primary { background: var(--red); color: #fff; box-shadow: 0 6px 18px rgba(200,16,46,.28); }
.btn-primary:hover { background: var(--red-dark); transform: translateY(-2px); color: #fff; }
.btn-blue { background: var(--blue); color: #fff; }
.btn-blue:hover { background: var(--blue-light); transform: translateY(-2px); color: #fff; }
.btn-ghost { background: transparent; color: var(--blue); border: 1.5px solid var(--blue); }
.btn-ghost:hover { background: rgba(27,42,74,.06); color: var(--red); border-color: var(--red); }
.btn-lg { padding: 14px 34px; font-size: 16px; }
.btn-sm { padding: 8px 18px; font-size: 13px; }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden;
  background: linear-gradient(135deg, #1B2A4A 0%, #24406E 55%, #1B2A4A 100%);
  color: #fff;
}
.hero::before {
  content: ""; position: absolute; inset: 0;
  background:
    radial-gradient(900px 400px at 85% -10%, rgba(217,164,65,.18), transparent 60%),
    radial-gradient(700px 360px at -10% 110%, rgba(200,16,46,.32), transparent 55%);
}
.hero-inner { position: relative; padding: 96px 0 120px; max-width: 780px; }
.hero .badge {
  display: inline-block; background: rgba(255,255,255,.12); border: 1px solid rgba(255,255,255,.25);
  padding: 6px 16px; border-radius: 999px; font-size: 13px; letter-spacing: .08em; margin-bottom: 22px;
}
.hero h1 { font-size: clamp(34px, 5.4vw, 56px); line-height: 1.18; font-weight: 800; letter-spacing: .01em; }
.hero h1 .accent { color: #F0C36A; }
.hero .sub { font-size: clamp(15px, 2vw, 18px); color: rgba(255,255,255,.82); margin: 22px 0 12px; max-width: 640px; }
.hero .sub2 { font-size: 14px; color: rgba(255,255,255,.6); margin-bottom: 34px; }
.hero .cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-wave { position: absolute; bottom: -1px; left: 0; width: 100%; }
.hero-stats { display: flex; gap: 36px; margin-top: 48px; flex-wrap: wrap; }
.hero-stats .num { font-size: 30px; font-weight: 800; color: #F0C36A; }
.hero-stats .lab { font-size: 13px; color: rgba(255,255,255,.7); }

/* ---------- 区块标题 ---------- */
.sec-head { text-align: center; margin-bottom: 48px; }
.sec-head .tag {
  display: inline-block; font-size: 13px; color: var(--red); font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase; margin-bottom: 10px;
}
.sec-head h2 { font-size: clamp(26px, 3.6vw, 38px); font-weight: 800; }
.sec-head p { color: var(--ink-2); margin-top: 10px; max-width: 640px; margin-inline: auto; }

/* ---------- 卡片通用 ---------- */
.card {
  background: var(--white); border-radius: var(--radius); padding: 28px;
  box-shadow: var(--shadow); border: 1px solid var(--line); transition: all .25s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }

/* ---------- 首页三大模块 ---------- */
.modules { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.mod-card { position: relative; overflow: hidden; }
.mod-card .icon {
  width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center; margin-bottom: 18px;
}
.mod-card .icon svg { width: 30px; height: 30px; }
.mod-card h3 { font-size: 20px; font-weight: 700; margin-bottom: 8px; }
.mod-card .phase {
  display: inline-block; font-size: 12px; padding: 3px 10px; border-radius: 999px;
  background: #FDEBEC; color: var(--red); font-weight: 600; margin-bottom: 10px;
}
.mod-card ul { list-style: none; margin: 12px 0 18px; }
.mod-card li { font-size: 14px; color: var(--ink-2); padding: 4px 0 4px 22px; position: relative; }
.mod-card li::before { content: "✓"; position: absolute; left: 0; color: var(--red); font-weight: 700; }
.mod-card .more { font-weight: 600; font-size: 14px; }
@media (max-width: 900px) { .modules { grid-template-columns: 1fr; } }

/* ---------- 特点区 ---------- */
.feats { background: var(--white); border-block: 1px solid var(--line); }
.feat-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; }
.feat { display: flex; gap: 16px; }
.feat .n { font-size: 30px; font-weight: 800; color: var(--gold); line-height: 1; }
.feat h4 { font-size: 17px; margin-bottom: 6px; }
.feat p { font-size: 14px; color: var(--ink-2); }
@media (max-width: 900px) { .feat-grid { grid-template-columns: 1fr; } }

/* ---------- 楼层 / 流程 ---------- */
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.step { text-align: center; position: relative; }
.step .dot {
  width: 52px; height: 52px; margin: 0 auto 14px; border-radius: 50%; display: grid; place-items: center;
  background: var(--blue); color: #fff; font-weight: 800; font-size: 18px;
}
.step h4 { font-size: 16px; margin-bottom: 6px; }
.step p { font-size: 13.5px; color: var(--ink-2); }
.step::after { content: "→"; position: absolute; right: -14px; top: 12px; color: var(--gold); font-weight: 700; font-size: 20px; }
.step:last-child::after { display: none; }
@media (max-width: 900px) { .steps { grid-template-columns: repeat(2, 1fr); } .step::after { display: none; } }

/* ---------- 页脚 ---------- */
footer { background: var(--blue); color: rgba(255,255,255,.75); padding: 56px 0 0; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 36px; padding-bottom: 40px; }
.footer-grid h5 { color: #fff; font-size: 15px; margin-bottom: 14px; }
.footer-grid a { display: block; color: rgba(255,255,255,.7); font-size: 14px; padding: 4px 0; }
.footer-grid a:hover { color: #F0C36A; }
.footer-brand p { font-size: 14px; margin-top: 10px; color: rgba(255,255,255,.6); max-width: 320px; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.14); padding: 18px 0; text-align: center; font-size: 13px; color: rgba(255,255,255,.5); }
.footer-bottom a { color: rgba(255,255,255,.75); }
@media (max-width: 900px) { .footer-grid { grid-template-columns: 1fr 1fr; } }

/* ---------- 子页 Hero ---------- */
.page-hero { background: var(--blue); color: #fff; padding: 56px 0 64px; position: relative; overflow: hidden; }
.page-hero::before {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(700px 300px at 90% -20%, rgba(217,164,65,.2), transparent 60%);
}
.page-hero .container { position: relative; }
.page-hero h1 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; }
.page-hero p { color: rgba(255,255,255,.78); margin-top: 10px; max-width: 680px; }

/* ---------- 匹配页 ---------- */
.match-layout { display: grid; grid-template-columns: 400px 1fr; gap: 28px; align-items: start; }
.match-form .card { position: sticky; top: 86px; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 8px; }
.form-group .hint { font-size: 12px; color: var(--ink-2); margin-left: 8px; font-weight: 400; }
.form-group input[type=text], .form-group select {
  width: 100%; padding: 11px 14px; border: 1.5px solid var(--line); border-radius: 10px; font-size: 14px; font-family: inherit;
  background: var(--cream-2);
}
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--red); background: #fff; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  padding: 7px 14px; border-radius: 999px; border: 1.5px solid var(--line); font-size: 13px; cursor: pointer;
  background: var(--cream-2); transition: all .15s; user-select: none;
}
.chip:hover { border-color: var(--blue); }
.chip.sel { background: var(--blue); color: #fff; border-color: var(--blue); font-weight: 600; }
.match-results .empty { text-align: center; padding: 60px 20px; color: var(--ink-2); }
.match-results .empty svg { width: 64px; height: 64px; opacity: .5; margin-bottom: 14px; }
.people { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 20px; }
.person { text-align: center; }
.person .avatar {
  width: 74px; height: 74px; border-radius: 50%; margin: 0 auto 12px; display: grid; place-items: center;
  color: #fff; font-size: 26px; font-weight: 800;
}
.person h4 { font-size: 17px; }
.person .city { font-size: 13px; color: var(--ink-2); margin: 2px 0 10px; }
.person .tags { display: flex; flex-wrap: wrap; gap: 6px; justify-content: center; margin-bottom: 10px; }
.person .tags span { font-size: 12px; background: #FDEBEC; color: var(--red); padding: 3px 9px; border-radius: 999px; }
.person p.desc { font-size: 13px; color: var(--ink-2); }
.manual {
  margin-top: 24px; background: #FEF6E7; border: 1.5px dashed var(--gold); color: #6B5522;
}
.manual h4 { color: #6B5522; }

/* ---------- 指南页 ---------- */
.tabs { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; margin-bottom: 36px; }
.tab-btn {
  padding: 9px 20px; border-radius: 999px; border: 1.5px solid var(--line); background: #fff; font-size: 14px; cursor: pointer;
  font-family: inherit; color: var(--ink-2); transition: all .15s;
}
.tab-btn.active { background: var(--red); color: #fff; border-color: var(--red); font-weight: 600; }
.guide-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 22px; }
.guide-card { overflow: hidden; cursor: pointer; padding: 0; }
.guide-card .cover {
  height: 148px; display: grid; place-items: center; color: #fff; font-size: 40px; font-weight: 800;
  background-size: cover; position: relative;
}
.guide-card .ctype {
  position: absolute; top: 12px; left: 12px; font-size: 12px; padding: 4px 12px; border-radius: 999px;
  background: rgba(0,0,0,.35); color: #fff; backdrop-filter: blur(4px);
}
.guide-card .cover .emoji { font-size: 44px; }
.guide-card .body { padding: 18px 20px 20px; }
.guide-card h4 { font-size: 16px; margin: 6px 0 4px; }
.guide-card .meta { font-size: 12px; color: var(--ink-2); display: flex; gap: 14px; margin-bottom: 8px; }
.guide-card p { font-size: 13.5px; color: var(--ink-2); }

/* ---------- 问答页 ---------- */
.ask-hero { background: linear-gradient(135deg, #1B2A4A, #2E4A75); }
.ask-box { max-width: 800px; margin: 0 auto; }
.ask-input-wrap {
  display: flex; gap: 0; background: #fff; border-radius: 999px; padding: 6px 6px 6px 22px;
  box-shadow: var(--shadow-lg); border: 1.5px solid var(--line); align-items: center;
}
.ask-input-wrap input {
  flex: 1; border: 0; outline: 0; font-size: 15px; font-family: inherit; background: transparent; padding: 10px 0;
}
.quick { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; margin-top: 16px; }
.quick button {
  font-size: 13px; padding: 7px 14px; border-radius: 999px; border: 1px solid rgba(255,255,255,.3);
  background: rgba(255,255,255,.08); color: rgba(255,255,255,.85); cursor: pointer; font-family: inherit;
}
.quick button:hover { background: rgba(255,255,255,.2); }
.chat { margin-top: 28px; display: flex; flex-direction: column; gap: 18px; }
.msg { display: flex; gap: 12px; }
.msg .bubble { max-width: 82%; background: #fff; padding: 16px 20px; border-radius: 16px; box-shadow: var(--shadow); }
.msg.user { flex-direction: row-reverse; }
.msg.user .bubble { background: var(--blue); color: #fff; }
.msg .who { font-size: 12px; color: var(--ink-2); margin-bottom: 4px; }
.msg.user .who { text-align: right; }
.msg p { font-size: 15px; }
.srcbox {
  margin-top: 12px; background: var(--cream-2); border: 1px solid var(--line); border-left: 3px solid var(--gold);
  border-radius: 10px; padding: 10px 14px; font-size: 13px; color: var(--ink-2);
}
.srcbox b { color: var(--gold); }
.disclaim {
  margin-top: 40px; text-align: center; font-size: 13px; color: var(--ink-2);
  background: #FEF6E7; border: 1px dashed var(--gold); border-radius: 12px; padding: 14px 20px;
}
.typing { display: inline-flex; gap: 4px; padding: 6px 0; }
.typing i { width: 7px; height: 7px; border-radius: 50%; background: var(--ink-2); animation: blink 1.2s infinite; }
.typing i:nth-child(2) { animation-delay: .2s; } .typing i:nth-child(3) { animation-delay: .4s; }
@keyframes blink { 0%,80%,100% { opacity: .25; } 40% { opacity: 1; } }

/* ---------- 关于页 ---------- */
.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 56px; }
.stat { text-align: center; background: var(--white); border-radius: var(--radius); padding: 30px 16px; box-shadow: var(--shadow); }
.stat .v { font-size: 34px; font-weight: 800; color: var(--red); }
.stat .l { font-size: 13.5px; color: var(--ink-2); margin-top: 6px; }
@media (max-width: 900px) { .stat-row { grid-template-columns: repeat(2, 1fr); } }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; }
@media (max-width: 900px) { .two-col { grid-template-columns: 1fr; } }
.about-section-title { font-size: 22px; font-weight: 800; margin: 8px 0 22px; display: flex; align-items: center; gap: 10px; }
.about-section-title .bar { width: 6px; height: 24px; border-radius: 3px; background: var(--red); display: inline-block; }
.recruit ul { list-style: none; }
.recruit li { padding: 10px 0 10px 26px; position: relative; border-bottom: 1px dashed var(--line); font-size: 14.5px; }
.recruit li::before { content: "●"; position: absolute; left: 6px; color: var(--red); font-size: 11px; top: 14px; }
.recruit .role { font-weight: 700; }
.recruit .tag-pri { font-size: 11px; background: #FDEBEC; color: var(--red); padding: 2px 8px; border-radius: 999px; font-weight: 600; }
table.mini { width: 100%; border-collapse: collapse; font-size: 14px; }
table.mini th, table.mini td { border: 1px solid var(--line); padding: 10px 12px; text-align: left; }
table.mini th { background: var(--blue); color: #fff; font-weight: 600; }
table.mini tr:nth-child(even) td { background: var(--cream-2); }

/* ---------- 通用 ---------- */
.center { text-align: center; }
.mt24 { margin-top: 24px; }
.mt40 { margin-top: 40px; }
.muted { color: var(--ink-2); }
.notice {
  background: #FEF6E7; border: 1px solid #EFD9A7; color: #6B5522; padding: 12px 18px;
  border-radius: 12px; font-size: 13.5px; margin: 20px 0;
}
.phase-badge { display: inline-block; font-size: 12px; padding: 3px 10px; border-radius: 999px; font-weight: 600; }
.phase-p1 { background: #FDEBEC; color: var(--red); }
.phase-p2 { background: #E7EFFA; color: var(--blue-light); }