/* ============================================================
   泰联成网络科技有限公司 — 商务深色主题
   配色：深海军蓝底 + 商务蓝强调 + 冷灰文字
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  /* 背景层次 */
  --bg:            #080c16;   /* 页面最底层 */
  --bg-elevated:   #0d1322;   /* 区块/卡片底 */
  --bg-card:       #111a2e;   /* 卡片内底 */
  --bg-hover:      #162138;   /* 悬停态 */

  /* 文字 */
  --text:          #e6ebf5;   /* 主标题/正文 */
  --text-dim:      #8b95ab;   /* 次级说明 */
  --text-muted:    #5a6478;   /* 弱化/辅助 */

  /* 强调色 — 商务蓝 */
  --accent:        #5b9dff;
  --accent-hover:  #7ab3ff;
  --accent-soft:   rgba(91, 157, 255, 0.10);
  --accent-border: rgba(91, 157, 255, 0.25);

  /* 边框与分割 */
  --border:        #1c2740;
  --border-light:  #263350;

  /* 功能色 */
  --success:       #4ade80;
  --warning:       #fbbf24;

  /* 排版 */
  --font-sans:   'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-serif:  'Playfair Display', Georgia, 'Times New Roman', serif;
  --font-mono:   'SF Mono', 'JetBrains Mono', 'Fira Code', Consolas, monospace;

  /* 布局 */
  --wrap-max:    1180px;
  --radius:      12px;
  --radius-sm:   8px;
  --transition:  0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- Reset & 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: 16px;
  line-height: 1.7;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-hover); }

img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
ul { list-style: none; }

::selection { background: var(--accent); color: #fff; }

/* ---------- 背景装饰层 ---------- */
.bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}

/* 网格底纹 */
.bg__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(91, 157, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(91, 157, 255, 0.035) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
}

/* 顶部蓝色光晕 */
.bg__glow {
  position: absolute;
  top: -20%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(ellipse, rgba(91, 157, 255, 0.10) 0%, rgba(91, 157, 255, 0.03) 40%, transparent 70%);
  filter: blur(40px);
}

/* 噪点纹理（用SVG data URI模拟） */
.bg__noise {
  position: absolute;
  inset: 0;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- 通用容器 ---------- */
.wrap {
  max-width: var(--wrap-max);
  margin: 0 auto;
  padding: 0 32px;
}

.mono {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.eyebrow {
  display: inline-block;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 16px;
}

/* ---------- 滚动显现动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}
.js .reveal { /* JS 启用时才隐藏，无JS降级显示 */ }
html:not(.js) .reveal { opacity: 1; transform: none; }

/* ---------- 顶部导航 ---------- */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  background: rgba(8, 12, 22, 0.75);
  border-bottom: 1px solid var(--border);
}

.header__inner {
  max-width: var(--wrap-max);
  margin: 0 auto;
  padding: 0 32px;
  height: 72px;
  display: flex;
  align-items: center;
  gap: 32px;
}

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}
.brand:hover { color: inherit; }

.brand__mark {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--accent) 0%, #3b7dd8 100%);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  box-shadow: 0 4px 16px rgba(91, 157, 255, 0.3);
}

.brand__text { display: flex; flex-direction: column; line-height: 1.3; }
.brand__name { font-size: 0.95rem; font-weight: 600; color: var(--text); }
.brand__sub { font-size: 0.72rem; color: var(--text-muted); font-family: var(--font-mono); letter-spacing: 0.05em; }

/* 导航链接 */
.nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}
.nav__link {
  position: relative;
  padding: 8px 14px;
  font-size: 0.9rem;
  color: var(--text-dim);
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
}
.nav__link:hover { color: var(--text); background: var(--accent-soft); }
.nav__link.is-active { color: var(--accent); }
.nav__link.is-active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--accent);
}

/* 语言切换 */
.lang {
  display: flex;
  align-items: center;
  gap: 2px;
  padding: 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-elevated);
}
.lang__btn {
  padding: 5px 10px;
  font-size: 0.78rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  border-radius: 5px;
  transition: all var(--transition);
}
.lang__btn:hover { color: var(--text-dim); }
.lang__btn.is-active {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

/* 汉堡菜单（移动端） */
.burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
}
.burger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-dim);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ---------- Hero 首屏 ---------- */
.hero {
  padding: 100px 0 80px;
  position: relative;
}

.hero__head { margin-bottom: 48px; }

.hero__title {
  font-family: var(--font-serif);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.01em;
}
.hero__title .l1 {
  display: block;
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  color: var(--text);
}
.hero__title .l2 {
  display: block;
  font-size: clamp(1.6rem, 3.5vw, 2.6rem);
  background: linear-gradient(120deg, var(--accent) 0%, #8ec5ff 50%, var(--accent) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-top: 8px;
}

.hero__grid {
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 48px;
  align-items: start;
}

.hero__lead { max-width: 560px; }

.hero__sub {
  font-size: 1.1rem;
  color: var(--text-dim);
  line-height: 1.8;
  margin-bottom: 32px;
}

.hero__actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-size: 0.92rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-light);
  color: var(--text);
  background: var(--bg-elevated);
  transition: all var(--transition);
}
.btn:hover {
  border-color: var(--accent-border);
  background: var(--bg-hover);
  color: var(--accent);
  transform: translateY(-1px);
}

.btn--primary {
  background: linear-gradient(135deg, var(--accent) 0%, #3b7dd8 100%);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 4px 20px rgba(91, 157, 255, 0.25);
}
.btn--primary:hover {
  background: linear-gradient(135deg, var(--accent-hover) 0%, #4a8de8 100%);
  color: #fff;
  box-shadow: 0 6px 28px rgba(91, 157, 255, 0.35);
}

/* ---------- 信息面板 ---------- */
.panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  backdrop-filter: blur(8px);
}
.panel__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 16px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.panel__head .dot {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 22px;
  border-radius: 4px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.7rem;
}
.panel__row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  padding: 10px 0;
}
.panel__row + .panel__row { border-top: 1px solid rgba(28, 39, 64, 0.5); }
.panel__k {
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-shrink: 0;
  min-width: 72px;
}
.panel__v {
  font-size: 0.88rem;
  color: var(--text);
  text-align: right;
  line-height: 1.5;
}

/* ---------- 通用区块 ---------- */
.section {
  padding: 80px 0;
  position: relative;
}
.section + .section { border-top: 1px solid var(--border); }

/* 区块标题 */
.sec-head {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  margin-bottom: 48px;
}
.sec-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  padding-top: 6px;
  flex-shrink: 0;
}
.sec-head__meta { flex: 1; }
.sec-title {
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
  letter-spacing: -0.01em;
}

/* 简介区块 */
.intro { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: start; }
.intro__body .lede {
  font-size: 1rem;
  color: var(--text-dim);
  line-height: 1.9;
}

.lede {
  font-size: 1.05rem;
  color: var(--text-dim);
  line-height: 1.9;
}

/* ---------- 卡片网格（核心优势） ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: all var(--transition);
  overflow: hidden;
}
.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  opacity: 0;
  transition: opacity var(--transition);
}
.card:hover {
  border-color: var(--accent-border);
  background: var(--bg-hover);
  transform: translateY(-3px);
  box-shadow: 0 12px 32px rgba(0, 0, 0, 0.3);
}
.card:hover::before { opacity: 1; }

.card__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  display: block;
  margin-bottom: 16px;
}
.card__title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
  line-height: 1.4;
}
.card__desc {
  font-size: 0.88rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* ---------- 关于我们 ---------- */
.about { margin-bottom: 40px; }
.about .lede { margin-bottom: 32px; max-width: 820px; }

.mv {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.mv__item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 24px;
}
.mv__k {
  display: block;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 10px;
}
.mv__v {
  font-size: 0.95rem;
  color: var(--text-dim);
  line-height: 1.7;
}

/* 价值观 */
.values {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 24px 0;
  border-top: 1px solid var(--border);
}
.values__k { flex-shrink: 0; color: var(--text-muted); }
.values__list { display: flex; gap: 12px; flex-wrap: wrap; }
.values__list li {
  padding: 6px 16px;
  font-size: 0.85rem;
  color: var(--text-dim);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 100px;
  transition: all var(--transition);
}
.values__list li:hover {
  color: var(--accent);
  border-color: var(--accent-border);
  background: var(--accent-soft);
}

/* ---------- 业务板块 ---------- */
.note {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-bottom: 32px;
  padding: 10px 16px;
  background: var(--accent-soft);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius-sm);
  display: inline-block;
}

.rows { display: flex; flex-direction: column; gap: 1px; }
.row {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 32px;
  padding: 32px 0;
  border-bottom: 1px solid var(--border);
  transition: background var(--transition);
}
.row:last-child { border-bottom: none; }
.row:hover { background: rgba(91, 157, 255, 0.02); }

.row__num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  padding-top: 4px;
}
.row__title {
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 4px;
}
.row__name {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  letter-spacing: 0.06em;
  margin-bottom: 12px;
}
.row__desc {
  font-size: 0.95rem;
  color: var(--text-dim);
  line-height: 1.8;
  max-width: 780px;
}

/* ---------- 技术能力 ---------- */
.tech {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.tech__item {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: all var(--transition);
}
.tech__item:hover {
  border-color: var(--accent-border);
  background: var(--bg-hover);
}
.tech__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}
.tech__num {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.08em;
}
.tech__plus {
  width: 24px;
  height: 24px;
  position: relative;
  opacity: 0.4;
  transition: opacity var(--transition), transform var(--transition);
}
.tech__plus::before,
.tech__plus::after {
  content: '';
  position: absolute;
  background: var(--accent);
  border-radius: 2px;
}
.tech__plus::before { top: 50%; left: 0; right: 0; height: 2px; transform: translateY(-50%); }
.tech__plus::after { left: 50%; top: 0; bottom: 0; width: 2px; transform: translateX(-50%); }
.tech__item:hover .tech__plus { opacity: 1; transform: rotate(90deg); }

.tech__title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}
.tech__desc {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.75;
}

/* ---------- 联系我们 ---------- */
.contact {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}

.info { border-top: 1px solid var(--border); }
.info__row {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}
.info__k {
  font-size: 0.88rem;
  color: var(--text-muted);
  flex-shrink: 0;
  min-width: 80px;
}
.info__v {
  font-size: 0.92rem;
  color: var(--text);
  text-align: right;
  line-height: 1.6;
}
.info__alt {
  display: block;
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-mono);
  margin-top: 2px;
}
.placeholder {
  color: var(--warning);
  font-style: italic;
  opacity: 0.8;
}

/* CTA 卡片 */
.cta-card {
  background: linear-gradient(160deg, var(--bg-card) 0%, var(--bg-elevated) 100%);
  border: 1px solid var(--accent-border);
  border-radius: var(--radius);
  padding: 32px;
  position: relative;
  overflow: hidden;
}
.cta-card::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -30%;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(91, 157, 255, 0.08) 0%, transparent 70%);
  pointer-events: none;
}
.cta-card__title {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text);
  margin: 12px 0 20px;
}
.cta-card__note {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* ---------- 页脚 ---------- */
.footer {
  border-top: 1px solid var(--border);
  background: rgba(8, 12, 22, 0.6);
  padding: 56px 0 28px;
}
.footer__top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border);
}
.footer__brand {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
}
.footer__tagline {
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.7;
  max-width: 360px;
}
.footer__col h4 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-dim);
  margin-bottom: 16px;
  font-family: var(--font-mono);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.footer__list li { margin-bottom: 10px; }
.footer__list a {
  font-size: 0.88rem;
  color: var(--text-muted);
  transition: color var(--transition);
}
.footer__list a:hover { color: var(--accent); }

.footer__bottom {
  display: flex;
  align-items: center;
  gap: 24px;
  padding-top: 24px;
  flex-wrap: wrap;
}
.footer__bottom .mono { color: var(--text-muted); font-size: 0.75rem; }
.footer__legal { margin-left: auto; display: flex; gap: 16px; }
.footer__legal a { color: var(--text-muted); font-size: 0.75rem; }
.footer__legal a:hover { color: var(--accent); }

/* ---------- 法律条款页 ---------- */
.legal { padding: 80px 0 100px; min-height: calc(100vh - 72px - 120px); }
.legal__head { margin-bottom: 40px; }
.legal__title {
  font-family: var(--font-serif);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 700;
  color: var(--text);
  line-height: 1.2;
}
.legal__body {
  max-width: 760px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  margin-bottom: 32px;
}
.legal__body p {
  font-size: 0.98rem;
  color: var(--text-dim);
  line-height: 2;
}
.legal__foot {
  display: flex;
  align-items: center;
}
.back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  font-size: 0.85rem;
  color: var(--text-dim);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}
.back::before { content: '←'; font-size: 0.9rem; }
.back:hover {
  color: var(--accent);
  border-color: var(--accent-border);
  background: var(--accent-soft);
}
.back--next::before { content: ''; }
.back--next::after { content: '→'; font-size: 0.9rem; }

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero__grid { grid-template-columns: 1fr; }
  .cards { grid-template-columns: repeat(2, 1fr); }
  .intro { grid-template-columns: 1fr; gap: 24px; }
  .contact { grid-template-columns: 1fr; }
  .footer__top { grid-template-columns: 1fr 1fr; }
  .footer__brand-col { grid-column: 1 / -1; }
}

@media (max-width: 768px) {
  .wrap, .header__inner { padding: 0 20px; }
  .hero { padding: 60px 0 48px; }
  .section { padding: 56px 0; }
  .nav { display: none; }
  .burger { display: flex; }
  .lang { display: none; }
  .cards { grid-template-columns: 1fr; }
  .tech { grid-template-columns: 1fr; }
  .mv { grid-template-columns: 1fr; }
  .row { grid-template-columns: 1fr; gap: 12px; }
  .values { flex-direction: column; align-items: flex-start; }
  .footer__top { grid-template-columns: 1fr; gap: 32px; }
  .footer__bottom { flex-direction: column; align-items: flex-start; }
  .footer__legal { margin-left: 0; }
  .legal__body { padding: 24px; }
  .sec-head { gap: 16px; }
}

/* 移动端导航展开态 */
.nav.is-open {
  display: flex;
  flex-direction: column;
  position: absolute;
  top: 72px;
  left: 0;
  right: 0;
  background: var(--bg-elevated);
  border-bottom: 1px solid var(--border);
  padding: 16px 20px;
  gap: 4px;
}
.nav.is-open .nav__link { padding: 12px 14px; }