/* ============================================================
 * style.css — LINK99 官方网站
 * 设计：科技 / 大气 / 国际化（深海军蓝 + 电光青）
 * 纯静态、零第三方依赖、完全响应式
 * ============================================================ */

/* ---------- 设计变量 ---------- */
:root {
  --navy: #0A2540;          /* 主色：深海军蓝 */
  --navy-deep: #061226;     /* 深色底：Hero / 页脚 / 数据墙 */
  --navy-2: #0E2E52;
  --accent: #16C8FF;        /* 点缀：电光青 */
  --accent-2: #2D7FF9;      /* 辅助：科技蓝 */
  --bg: #FFFFFF;            /* 页面底色 */
  --bg-alt: #F4F7FB;        /* 交替内容区 */
  --text: #0F1B2D;          /* 主文字 */
  --muted: #5B6B7F;         /* 次级文字 */
  --light: #C9D6E5;         /* 深色区文字 */
  --border: #E3EAF2;        /* 描边 */
  --maxw: 1160px;
  --radius: 14px;
  --header-h: 68px;

  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
          Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "微软雅黑", sans-serif;
}

/* ---------- 基础重置 ---------- */
* { margin: 0; padding: 0; box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-h);   /* 锚点不被固定顶栏遮挡 */
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a { color: inherit; text-decoration: none; }
img, svg { display: block; max-width: 100%; }

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

/* 各区块滚动锚点偏移 */
section[id], header[id] { scroll-margin-top: var(--header-h); }

/* ============================================================
 * 1. 顶栏导航
 * ============================================================ */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  z-index: 1000;
  background: rgba(6, 18, 38, 0.82);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: background 0.25s ease;
}
.site-header.scrolled { background: rgba(6, 18, 38, 0.96); }

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

/* 品牌标识 */
.brand { display: flex; flex-direction: column; line-height: 1.1; }
.brand-mark {
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 1px;
  color: #FFFFFF;
}
.brand-accent { color: var(--accent); }
.brand-sub {
  font-size: 11px;
  color: var(--light);
  opacity: 0.8;
  letter-spacing: 0.5px;
}

/* 桌面导航 */
.nav-desktop { display: flex; gap: 28px; }
.nav-desktop a {
  font-size: 14px;
  color: var(--light);
  position: relative;
  transition: color 0.2s ease;
}
.nav-desktop a:hover { color: var(--accent); }

/* 语言切换 */
.lang-switch {
  display: flex;
  gap: 4px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 999px;
  padding: 3px;
}
.lang-btn {
  font-family: var(--font);
  font-size: 12px;
  font-weight: 600;
  color: var(--light);
  background: transparent;
  border: none;
  border-radius: 999px;
  padding: 5px 12px;
  cursor: pointer;
  transition: all 0.2s ease;
}
.lang-btn:hover { color: #fff; }
.lang-btn.is-active {
  background: var(--accent);
  color: #04121f;
}

/* 汉堡按钮（移动端） */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px; height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  width: 22px; height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.25s ease, opacity 0.25s ease;
}
.nav-toggle.is-active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.is-active span:nth-child(2) { opacity: 0; }
.nav-toggle.is-active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 移动端下拉菜单 */
.nav-mobile {
  display: none;
  flex-direction: column;
  position: absolute;
  top: 100%; left: 0; right: 0;
  background: var(--navy-deep);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.nav-mobile.is-open { display: flex; }
.nav-mobile a {
  padding: 14px 24px;
  font-size: 15px;
  color: var(--light);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.nav-mobile a:hover { color: var(--accent); }

/* ============================================================
 * 2. Hero 首屏
 * ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #061226 0%, #0A2540 55%, #0E3A66 100%);
  overflow: hidden;
  padding: calc(var(--header-h) + 40px) 0 60px;
}
/* 科技网格 + 光晕 */
.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(22, 200, 255, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(22, 200, 255, 0.07) 1px, transparent 1px);
  background-size: 46px 46px;
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 40%, #000 30%, transparent 75%);
          mask-image: radial-gradient(ellipse 80% 70% at 50% 40%, #000 30%, transparent 75%);
}
.hero::after {
  content: "";
  position: absolute;
  top: -10%; right: -5%;
  width: 520px; height: 520px;
  background: radial-gradient(circle, rgba(22, 200, 255, 0.25), transparent 60%);
  filter: blur(20px);
  pointer-events: none;
}
.hero-inner {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 860px;
  margin: 0 auto;
}
.hero-badge {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.5px;
  color: var(--accent);
  background: rgba(22, 200, 255, 0.10);
  border: 1px solid rgba(22, 200, 255, 0.35);
  border-radius: 999px;
  padding: 7px 16px;
  margin-bottom: 22px;
}
.hero-title {
  font-size: clamp(2.2rem, 5.2vw, 3.6rem);
  font-weight: 800;
  line-height: 1.12;
  color: #FFFFFF;
  letter-spacing: -0.5px;
}
.hero-sub {
  font-size: clamp(1rem, 1.6vw, 1.12rem);
  color: var(--light);
  max-width: 660px;
  margin: 22px auto 0;
}
.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-top: 34px;
  flex-wrap: wrap;
}
.hero-stats {
  display: flex;
  justify-content: center;
  gap: clamp(28px, 6vw, 64px);
  margin-top: 56px;
  flex-wrap: wrap;
}
.hero-stat { text-align: center; }
.hero-stat-num {
  display: block;
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  font-weight: 800;
  color: var(--accent);
}
.hero-stat-label {
  font-size: 13px;
  color: var(--light);
  opacity: 0.85;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-block;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 600;
  padding: 13px 28px;
  border-radius: 9px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;
}
.btn-primary {
  background: var(--accent);
  color: #04121f;
  box-shadow: 0 8px 24px rgba(22, 200, 255, 0.35);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 30px rgba(22, 200, 255, 0.5);
}
.btn-ghost {
  background: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}
.btn-ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: rgba(22, 200, 255, 0.08);
}

/* ============================================================
 * 3. 通用区块
 * ============================================================ */
.section { padding: clamp(64px, 9vw, 110px) 0; }
.section-alt { background: var(--bg-alt); }

.section-head { text-align: center; max-width: 720px; margin: 0 auto 52px; }
.eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--accent-2);
  margin-bottom: 12px;
}
.section-title {
  font-size: clamp(1.6rem, 3.4vw, 2.4rem);
  font-weight: 800;
  color: var(--navy);
  line-height: 1.2;
}
.section-sub {
  color: var(--muted);
  font-size: 1.02rem;
  margin-top: 14px;
}

/* ---------- 关于我们 ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.45fr 1fr;
  gap: 52px;
  align-items: center;
}
.about-text p {
  color: var(--muted);
  margin-bottom: 16px;
  font-size: 1rem;
  line-height: 1.75;
}
.about-text p:first-of-type { color: var(--text); font-size: 1.04rem; }

.about-facts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.fact {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 22px 20px;
  transition: border-color 0.2s ease, transform 0.2s ease;
}
.fact:hover { border-color: var(--accent); transform: translateY(-3px); }
.fact-num {
  display: block;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-2);
  line-height: 1.1;
}
.fact-label {
  font-size: 0.85rem;
  color: var(--muted);
  margin-top: 6px;
  display: block;
}

/* ---------- 解决方案卡片 ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 22px;
}
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px 26px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}
.card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: 0 16px 36px rgba(10, 37, 64, 0.12);
}
.card-icon {
  width: 50px; height: 50px;
  border-radius: 12px;
  background: rgba(22, 200, 255, 0.12);
  color: var(--accent);
  display: grid;
  place-items: center;
  margin-bottom: 18px;
}
.card-icon svg { width: 26px; height: 26px; }
.card h3 {
  font-size: 1.16rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 10px;
}
.card p { color: var(--muted); font-size: 0.95rem; line-height: 1.65; }

/* ---------- 技术优势 ---------- */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 26px;
}
.feature { padding: 4px; }
.feature-icon {
  width: 46px; height: 46px;
  border-radius: 50%;
  background: rgba(45, 127, 249, 0.10);
  color: var(--accent-2);
  display: grid;
  place-items: center;
  margin-bottom: 16px;
}
.feature-icon svg { width: 24px; height: 24px; }
.feature h3 { font-size: 1.1rem; font-weight: 700; color: var(--navy); margin-bottom: 8px; }
.feature p { color: var(--muted); font-size: 0.95rem; line-height: 1.65; }

/* ---------- 应用场景 ---------- */
.ind-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}
.ind-card {
  background: #fff;
  border: 1px solid var(--border);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 26px 24px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.ind-card:hover { transform: translateY(-4px); box-shadow: 0 16px 36px rgba(10, 37, 64, 0.12); }
.ind-card h3 { font-size: 1.12rem; font-weight: 700; color: var(--navy); margin-bottom: 10px; }
.ind-card p { color: var(--muted); font-size: 0.93rem; line-height: 1.6; }

/* ---------- 数据墙 ---------- */
.stats-band {
  background: linear-gradient(135deg, #061226 0%, #0A2540 100%);
  padding: 58px 0;
}
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}
.stat-num {
  display: block;
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  color: var(--accent);
}
.stat-label { color: var(--light); font-size: 0.92rem; letter-spacing: 0.3px; }

/* ============================================================
 * 8. 联系我们
 * ============================================================ */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  max-width: 560px;
  margin: 0 auto;
  align-items: start;
}
.info-item { margin-bottom: 24px; }
.info-label {
  display: block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--accent-2);
  margin-bottom: 6px;
}
.info-item p { color: var(--text); font-size: 1rem; }
.info-item a:hover { color: var(--accent-2); }

.contact-form .field { margin-bottom: 16px; }
.contact-form label {
  display: block;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 6px;
}
.contact-form input,
.contact-form textarea {
  width: 100%;
  font-family: var(--font);
  font-size: 1rem;
  color: var(--text);
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 9px;
  padding: 12px 14px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.contact-form input:focus,
.contact-form textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(22, 200, 255, 0.15);
}
.contact-form textarea { resize: vertical; }
.form-note { color: var(--accent-2); font-size: 0.92rem; margin-top: 12px; font-weight: 600; }

/* ============================================================
 * 9. 页脚
 * ============================================================ */
.site-footer {
  background: var(--navy-deep);
  color: var(--light);
  padding: 56px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 36px;
}
.footer-tag { color: var(--muted); font-size: 0.92rem; margin-top: 12px; max-width: 300px; line-height: 1.6; }
.footer-col h4 { color: #fff; font-size: 1rem; margin-bottom: 16px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 9px; }
.footer-col a, .footer-col p { color: var(--light); opacity: 0.85; font-size: 0.92rem; }
.footer-col a:hover { color: var(--accent); opacity: 1; }
.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  margin-top: 40px;
  padding-top: 20px;
  text-align: center;
  color: var(--muted);
  font-size: 0.82rem;
}

/* ============================================================
 * 响应式
 * ============================================================ */
@media (max-width: 980px) {
  .nav-desktop { display: none; }
  .nav-toggle { display: flex; }
  .brand-sub { display: none; }

  .about-grid { grid-template-columns: 1fr; gap: 36px; }
  .contact-grid { grid-template-columns: 1fr; gap: 36px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 32px 16px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
  .footer-brand { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  .container { padding: 0 18px; }
  .hero-stats { gap: 24px 36px; }
  .hero-actions .btn { width: 100%; max-width: 280px; }
  .about-facts { grid-template-columns: 1fr 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; }
  .lang-btn { padding: 5px 10px; }
}