/* ===== 基础变量 ===== */
:root {
  --bg: #060a18;
  --bg-soft: #0b1124;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-hover: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.09);
  --text: #eef2ff;
  --text-dim: #9aa6c4;
  --primary: #4f8cff;
  --accent: #7c5cff;
  --cyan: #2ad8d8;
  --radius: 16px;
  --max: 1140px;
  font-synthesis: none;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

a { color: inherit; text-decoration: none; }

/* ===== 背景装饰 ===== */
.bg-grid {
  position: fixed; inset: 0; z-index: -2;
  background-image:
    linear-gradient(rgba(79, 140, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(79, 140, 255, 0.05) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at 50% 0%, #000 30%, transparent 80%);
}
.bg-glow {
  position: fixed; top: -200px; left: 50%; transform: translateX(-50%);
  width: 900px; height: 900px; z-index: -1;
  background: radial-gradient(circle, rgba(124, 92, 255, 0.22), transparent 60%);
  filter: blur(40px); pointer-events: none;
}

/* ===== 导航栏 ===== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  transition: background .3s, backdrop-filter .3s, border-color .3s;
  border-bottom: 1px solid transparent;
}
.navbar.scrolled {
  background: rgba(6, 10, 24, 0.8);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--border);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 70px; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.logo-mark {
  width: 38px; height: 38px; border-radius: 10px;
  display: grid; place-items: center; font-size: 20px; font-weight: 800; color: #fff;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: 0 4px 18px rgba(79, 140, 255, .4);
}
.logo-text { display: flex; flex-direction: column; line-height: 1.1; font-size: 18px; }
.logo-text small { font-size: 11px; font-weight: 500; color: var(--text-dim); letter-spacing: 1px; }

.nav-links { display: flex; gap: 30px; }
.nav-links a { color: var(--text-dim); font-size: 15px; font-weight: 500; transition: color .2s; position: relative; }
.nav-links a:hover { color: var(--text); }
.nav-links a::after {
  content: ""; position: absolute; left: 0; bottom: -6px; width: 0; height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent)); transition: width .25s;
}
.nav-links a:hover::after { width: 100%; }

.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; }
.nav-toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: .3s; }

/* ===== 按钮 ===== */
.btn {
  display: inline-block; padding: 13px 28px; border-radius: 12px;
  font-weight: 600; font-size: 15px; cursor: pointer; transition: transform .2s, box-shadow .2s, background .2s; border: 0;
}
.btn-primary {
  color: #fff; background: linear-gradient(135deg, var(--primary), var(--accent));
  box-shadow: 0 8px 24px rgba(79, 140, 255, .35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 12px 30px rgba(124, 92, 255, .45); }
.btn-ghost { color: var(--text); background: var(--surface); border: 1px solid var(--border); }
.btn-ghost:hover { background: var(--surface-hover); transform: translateY(-2px); }

/* ===== Hero ===== */
.hero { padding: 170px 0 110px; text-align: center; }
.hero-inner { display: flex; flex-direction: column; align-items: center; }
.hero-badge {
  display: inline-block; padding: 7px 16px; border-radius: 999px; font-size: 13px;
  color: var(--cyan); background: rgba(42, 216, 216, .08);
  border: 1px solid rgba(42, 216, 216, .25); margin-bottom: 28px; letter-spacing: .5px;
}
.hero-title { font-size: clamp(34px, 6vw, 62px); font-weight: 800; line-height: 1.15; letter-spacing: -1px; }
.gradient-text {
  background: linear-gradient(110deg, var(--primary), var(--accent) 50%, var(--cyan));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-sub { max-width: 680px; margin: 28px auto 0; color: var(--text-dim); font-size: 18px; }
.hero-actions { display: flex; gap: 16px; margin-top: 40px; flex-wrap: wrap; justify-content: center; }

.hero-stats { display: flex; gap: 56px; margin-top: 70px; flex-wrap: wrap; justify-content: center; }
.stat { display: flex; flex-direction: column; align-items: center; }
.stat strong { font-size: 40px; font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--cyan)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.stat span { color: var(--text-dim); font-size: 14px; margin-top: 4px; }

/* ===== 通用 Section ===== */
.section { padding: 100px 0; }
.section-alt { background: var(--bg-soft); border-block: 1px solid var(--border); }
.section-head { text-align: center; margin-bottom: 60px; }
.eyebrow { color: var(--primary); font-size: 14px; font-weight: 600; letter-spacing: 2px; text-transform: uppercase; }
.section-head h2 { font-size: clamp(28px, 4vw, 40px); font-weight: 800; margin-top: 10px; }
.section-desc { color: var(--text-dim); margin-top: 12px; font-size: 17px; }

/* ===== 关于我们 ===== */
.about-grid { display: grid; grid-template-columns: 1.3fr 1fr; gap: 50px; align-items: start; }
.about-text p { color: var(--text-dim); font-size: 17px; margin-bottom: 18px; }
.about-text strong { color: var(--text); }
.about-list { list-style: none; margin-top: 26px; display: flex; flex-direction: column; gap: 12px; }
.about-list li { padding-left: 24px; position: relative; color: var(--text-dim); font-size: 15px; }
.about-list li::before { content: ""; position: absolute; left: 0; top: 11px; width: 8px; height: 8px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent)); }
.about-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 12px 28px; }
.about-card-row { padding: 22px 0; border-bottom: 1px solid var(--border); }
.about-card-row:last-child { border-bottom: 0; }
.about-card-row span { color: var(--cyan); font-size: 14px; font-weight: 600; }
.about-card-row p { margin-top: 6px; color: var(--text); font-size: 16px; }

/* ===== 卡片网格 ===== */
.cards-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 32px 28px; transition: transform .25s, border-color .25s, background .25s;
}
.card:hover { transform: translateY(-6px); border-color: rgba(79, 140, 255, .45); background: var(--surface-hover); }
.card-icon { font-size: 30px; width: 58px; height: 58px; border-radius: 14px; display: grid; place-items: center;
  background: rgba(79, 140, 255, .1); border: 1px solid var(--border); margin-bottom: 18px; }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { color: var(--text-dim); font-size: 15px; }

/* ===== 核心优势 ===== */
.advantage-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.advantage-item { padding: 28px 24px; border-radius: var(--radius); border: 1px solid var(--border);
  background: linear-gradient(160deg, var(--surface), transparent); transition: transform .25s; }
.advantage-item:hover { transform: translateY(-6px); }
.adv-num { font-size: 34px; font-weight: 800; color: rgba(124, 92, 255, .55); }
.advantage-item h3 { margin: 10px 0 8px; font-size: 18px; }
.advantage-item p { color: var(--text-dim); font-size: 14px; }

/* ===== 联系我们 ===== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; }
.contact-row { display: flex; flex-direction: column; gap: 4px; padding: 18px 0; border-bottom: 1px solid var(--border); }
.contact-label { color: var(--cyan); font-size: 13px; font-weight: 600; letter-spacing: 1px; }
.contact-info span:last-child { color: var(--text); font-size: 16px; }
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.contact-form input, .contact-form textarea {
  width: 100%; padding: 14px 16px; border-radius: 12px; font-size: 15px; font-family: inherit;
  background: var(--surface); border: 1px solid var(--border); color: var(--text); transition: border-color .2s;
  resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--primary); }
.contact-form input::placeholder, .contact-form textarea::placeholder { color: #5f6b88; }
.form-hint { font-size: 14px; color: var(--cyan); min-height: 20px; }

/* ===== 页脚 ===== */
.footer { padding: 40px 0; border-top: 1px solid var(--border); }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 12px; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 10px; font-weight: 600; }
.footer-copy { color: var(--text-dim); font-size: 14px; }

/* ===== 滚动出现动画 ===== */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity .6s ease, transform .6s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 900px) {
  .about-grid, .contact-grid { grid-template-columns: 1fr; }
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .advantage-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .nav-links {
    position: fixed; top: 70px; right: 0; width: 70%; height: calc(100vh - 70px);
    flex-direction: column; gap: 0; padding: 20px;
    background: rgba(6, 10, 24, .97); backdrop-filter: blur(14px);
    border-left: 1px solid var(--border); transform: translateX(100%); transition: transform .3s;
  }
  .nav-links.open { transform: none; }
  .nav-links a { padding: 16px 0; border-bottom: 1px solid var(--border); }
  .nav-toggle { display: flex; }
  .cards-grid, .advantage-grid { grid-template-columns: 1fr; }
  .hero-stats { gap: 36px; }
  .form-row { grid-template-columns: 1fr; }
}