/* 基础样式与主题变量 */
:root {
  --bg: #0b0c10;
  --panel: #111217;
  --text: #e8ecf1;
  --muted: #9aa4af;
  --brand: #5aa9e6;
  --brand-2: #7dcfb6;
  --danger: #ff5c5c;
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.2);
  --radius: 14px;
}

[data-theme="light"] {
  --bg: #f7f9fb;
  --panel: #ffffff;
  --text: #0a0c10;
  --muted: #56606b;
  --brand: #2f6feb;
  --brand-2: #14b8a6;
  --shadow: 0 6px 24px rgba(0, 0, 0, 0.1);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: ui-sans-serif, -apple-system, Segoe UI, PingFang SC, Microsoft YaHei, Helvetica, Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 600px at 10% -10%, rgba(90, 169, 230, 0.1), transparent 60%),
              radial-gradient(900px 500px at 90% 10%, rgba(125, 207, 182, 0.08), transparent 60%),
              var(--bg);
  line-height: 1.6;
}

/* 容器与布局 */
.container {
  width: min(1160px, 92vw);
  margin: 0 auto;
}

.section {
  padding: 96px 0 80px;
}

.section.alt {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), rgba(0, 0, 0, 0.06));
}

.two-col {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
}

.two-col.gap-lg { gap: 64px; }

.grid {
  display: grid;
  gap: 24px;
}
.cards-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

/* 头部导航 */
.site-header {
  position: sticky;
  top: 0; inset-inline: 0;
  z-index: 20;
  background: rgba(11, 12, 16, 0.5);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { text-decoration: none; display: flex; align-items: center; }
.logo img { height: 32px; width: auto; }

.nav-list { display: flex; gap: 20px; align-items: center; margin: 0; padding: 0; list-style: none; }
.nav-link { color: var(--muted); text-decoration: none; padding: 8px 10px; border-radius: 8px; }
.nav-link:hover { color: var(--text); background: rgba(255,255,255,0.04); }

.header-actions { display: flex; align-items: center; gap: 10px; }
.theme-toggle { background: transparent; border: 1px solid rgba(255, 255, 255, 0.14); color: var(--text); border-radius: 10px; padding: 8px 10px; cursor: pointer; }
.hamburger { display: none; background: transparent; border: none; cursor: pointer; padding: 8px; }
.hamburger span { display: block; width: 22px; height: 2px; background: var(--text); margin: 5px 0; border-radius: 2px; }

/* Hero */
.hero-inner { display: grid; grid-template-columns: 1.2fr 1fr; align-items: center; gap: 56px; }
.hero-title { font-size: clamp(28px, 4.5vw, 44px); margin: 0 0 12px; }
.hero-subtitle { color: var(--muted); margin: 0 0 20px; }
.cta-group { display: flex; gap: 12px; margin: 24px 0; }

.button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 18px; border-radius: 12px; border: 1px solid rgba(255,255,255,0.14); color: var(--text); text-decoration: none; background: transparent; transition: transform .08s ease, background .2s; }
.button:hover { transform: translateY(-1px); background: rgba(255,255,255,0.05); }
.button.primary { background: linear-gradient(45deg, var(--brand), var(--brand-2)); border: none; color: #fff; box-shadow: var(--shadow); }
.button.ghost { background: transparent; }
.cta-inline { display: flex; gap: 12px; margin-top: 18px; flex-wrap: wrap; }

.hero-metrics { display: grid; grid-template-columns: repeat(3, auto); gap: 18px 28px; padding: 0; list-style: none; margin: 28px 0 0; }
.hero-metrics li { display: flex; flex-direction: column; }
.hero-metrics strong { font-size: 22px; }
.hero-metrics span { color: var(--muted); font-size: 13px; }

.img-frame { border-radius: var(--radius); overflow: hidden; background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.06); min-height: 240px; display: grid; place-items: center; }
.img-frame img { width: 100%; height: 100%; object-fit: cover; display: block; }
.img-frame.placeholder { position: relative; }
.img-frame.placeholder::after { content: "替换为你的图片"; color: var(--muted); font-size: 14px; }

/* 卡片 */
.card {
  background: var(--panel);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow);
}
.card .icon { font-size: 24px; }
.card h3 { margin: 8px 0; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }

.product { padding: 0; overflow: hidden; }
.product img { width: 100%; height: 160px; object-fit: cover; display: block; }
.product-body { padding: 16px 18px 20px; }

/* 上云方案 */
.checklist { list-style: none; padding-left: 0; margin: 0; display: grid; gap: 10px; }
.checklist li { position: relative; padding-left: 28px; }
.checklist li::before { content: "✔"; position: absolute; left: 0; top: 0; color: var(--brand-2); }

.plan { display: grid; gap: 16px; }
.plan-step { display: grid; grid-template-columns: auto 1fr; gap: 14px; align-items: start; background: var(--panel); border: 1px solid rgba(255,255,255,0.08); border-radius: var(--radius); padding: 14px 16px; }
.step-index { width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center; background: linear-gradient(45deg, var(--brand), var(--brand-2)); color: #fff; font-weight: 700; }
.step-body h3 { margin: 2px 0 6px; font-size: 16px; }
.step-body p { margin: 0; color: var(--muted); }

.compare { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 14px; }
.compare-col { background: var(--panel); border: 1px solid rgba(255,255,255,0.08); border-radius: var(--radius); padding: 16px; }
.compare-col h4 { margin: 4px 0 10px; }
.compare-col ul { margin: 0; padding-left: 18px; color: var(--muted); }

/* About */
.timeline { list-style: none; padding-left: 0; margin-top: 12px; display: grid; gap: 10px; }
.timeline li { display: grid; grid-template-columns: 64px 1fr; gap: 10px; align-items: baseline; }
.timeline span { color: var(--brand); font-weight: 700; }

/* Contact */
.contact { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin: 16px 0 8px; }
.contact-card { background: var(--panel); border: 1px solid rgba(255,255,255,0.06); border-radius: var(--radius); padding: 16px; }

.contact-form { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-top: 12px; }
.contact-form label { display: grid; gap: 6px; }
.contact-form label.full { grid-column: 1 / -1; }
.contact-form input, .contact-form textarea { width: 100%; background: rgba(255,255,255,0.04); color: var(--text); border: 1px solid rgba(255,255,255,0.12); border-radius: 10px; padding: 10px 12px; outline: none; }
.contact-form input:focus, .contact-form textarea:focus { border-color: var(--brand); box-shadow: 0 0 0 3px rgba(90,169,230,0.2); }
.contact-form .button { grid-column: 1 / -1; width: max-content; }

/* 页脚与全局控件 */
.footer { border-top: 1px solid rgba(255,255,255,0.06); background: rgba(255,255,255,0.02); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }

.back-to-top { position: fixed; right: 14px; bottom: 18px; width: 40px; height: 40px; border-radius: 10px; border: none; cursor: pointer; background: linear-gradient(45deg, var(--brand), var(--brand-2)); color: #fff; box-shadow: var(--shadow); display: none; align-items: center; justify-content: center; }
.back-to-top.show { display: inline-flex; }

/* 动效 */
.reveal { opacity: 0; transform: translateY(10px); transition: opacity .4s ease, transform .4s ease; }
.reveal.show { opacity: 1; transform: none; }

/* 响应式 */
@media (max-width: 980px) {
  .two-col, .hero-inner { grid-template-columns: 1fr; }
  .hero-inner { gap: 28px; }
  .cards-3 { grid-template-columns: 1fr 1fr; }
  .contact { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  .nav { position: fixed; inset: 64px 12px auto 12px; background: var(--panel); border: 1px solid rgba(255,255,255,0.08); border-radius: 12px; padding: 12px; display: none; }
  .nav.open { display: block; }
  .nav-list { flex-direction: column; align-items: stretch; }
  .hamburger { display: inline-block; }
  .cards-3 { grid-template-columns: 1fr; }
  .contact { grid-template-columns: 1fr; }
  .contact-form { grid-template-columns: 1fr; }
}