/* ══════════════════════════════════════════════════════════════
   DigiCave 官网 — 全局样式
   品牌：数洞·数字像素引擎
   ══════════════════════════════════════════════════════════════ */

:root {
  --bg: #0d0d0d;
  --bg-alt: #111115;
  --card: #1a1a1f;
  --card-hover: #1f1f26;
  --border: #252530;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #4fc3f7;
  --accent-dim: #2b7a9e;
  --green: #4CAF50;
  --orange: #ed7d31;
  --red: #D95555;
  --purple: #9b6fc0;
  --gradient-hero: linear-gradient(135deg, #0d0d0d 0%, #0a1628 50%, #0d1020 100%);
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
  --radius: 10px;
}

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

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

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

/* ── 导航栏 ──────────────────────────────────────────────── */

.nav {
  background: rgba(13,13,13,0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
}
.nav-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between; height: 60px;
}
.nav-brand {
  font-size: 1.2rem; font-weight: 700; color: var(--text);
  display: flex; align-items: center; gap: 10px;
}
.nav-brand .logo {
  width: 32px; height: 32px; background: var(--accent);
  border-radius: 8px; display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; color: var(--bg);
}
.nav-links { display: flex; gap: 28px; list-style: none; }
.nav-links a { color: var(--text-muted); font-size: 0.92rem; transition: color 0.2s; }
.nav-links a:hover { color: var(--accent); text-decoration: none; }
.nav-links a.active { color: var(--accent); }

/* ── Hero ────────────────────────────────────────────────── */

.hero {
  background: var(--gradient-hero);
  text-align: center; padding: 80px 24px 64px;
  border-bottom: 1px solid var(--border);
}
.hero h1 {
  font-size: 2.8rem; font-weight: 700; letter-spacing: -0.01em;
  background: linear-gradient(135deg, var(--accent), var(--purple));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero .subtitle {
  font-size: 1.15rem; color: var(--text-muted); margin: 16px 0 32px;
  max-width: 560px; margin-left: auto; margin-right: auto;
}
.hero .cta-group { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ── 按钮 ────────────────────────────────────────────────── */

.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 28px; border-radius: 8px; font-size: 0.95rem;
  font-weight: 600; cursor: pointer; border: none;
  transition: all 0.2s; text-decoration: none;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }

.btn-primary {
  background: var(--accent); color: var(--bg);
}
.btn-primary:hover { box-shadow: 0 4px 20px rgba(79,195,247,0.35); }

.btn-outline {
  background: transparent; color: var(--accent);
  border: 1.5px solid var(--accent-dim);
}
.btn-outline:hover { border-color: var(--accent); background: rgba(79,195,247,0.08); }

.btn-lg { padding: 14px 36px; font-size: 1rem; }

/* ── 容器 ────────────────────────────────────────────────── */

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

.section { padding: 64px 0; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-header h2 {
  font-size: 1.8rem; font-weight: 700; color: var(--text); margin-bottom: 8px;
}
.section-header p { color: var(--text-muted); font-size: 1.05rem; }

/* ── 特性卡片 ────────────────────────────────────────────── */

.features-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.feature-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px 24px;
  transition: border-color 0.2s, transform 0.2s;
}
.feature-card:hover { border-color: var(--accent-dim); transform: translateY(-2px); }
.feature-card .icon { font-size: 2rem; margin-bottom: 12px; }
.feature-card h3 { font-size: 1.1rem; margin-bottom: 8px; color: var(--text); }
.feature-card p { color: var(--text-muted); font-size: 0.92rem; line-height: 1.65; }

/* ── 表格 ────────────────────────────────────────────────── */

.table-wrap { overflow-x: auto; margin: 24px 0; }
table {
  width: 100%; border-collapse: collapse;
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
}
th, td { border-bottom: 1px solid var(--border); padding: 12px 16px; text-align: left; }
th { background: var(--bg-alt); color: var(--text-muted); font-weight: 600; font-size: 0.85rem; }
td { font-size: 0.92rem; }
tr:last-child td { border-bottom: none; }

/* ── 脚注 ────────────────────────────────────────────────── */

.footer {
  border-top: 1px solid var(--border); text-align: center;
  padding: 32px 24px; color: var(--text-muted); font-size: 0.85rem;
}
.footer a { color: var(--text-muted); }
.footer a:hover { color: var(--accent); }

/* ── 表单（激活页） ──────────────────────────────────────── */

.form-group { margin-bottom: 20px; }
.form-group label {
  display: block; color: var(--text-muted); font-size: 0.85rem;
  font-weight: 600; margin-bottom: 6px;
}
.form-input {
  width: 100%; max-width: 420px; padding: 12px 16px;
  background: var(--bg-alt); border: 1px solid var(--border);
  border-radius: 8px; color: var(--text); font-size: 0.95rem;
  font-family: "Consolas", "Source Code Pro", monospace;
  transition: border-color 0.2s;
}
.form-input:focus { outline: none; border-color: var(--accent); }
.form-input::placeholder { color: #555; }

.form-hint { font-size: 0.82rem; color: var(--text-muted); margin-top: 4px; }

.alert {
  padding: 14px 18px; border-radius: 8px; margin: 16px 0; font-size: 0.9rem;
  display: flex; align-items: center; gap: 10px;
}
.alert-success { background: rgba(76,175,80,0.12); border: 1px solid rgba(76,175,80,0.3); color: var(--green); }
.alert-error { background: rgba(217,85,85,0.12); border: 1px solid rgba(217,85,85,0.3); color: var(--red); }
.alert-info { background: rgba(79,195,247,0.1); border: 1px solid rgba(79,195,247,0.25); color: var(--accent); }

/* ── 步骤条 ──────────────────────────────────────────────── */

.steps { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin: 32px 0; }
.step-item {
  display: flex; align-items: center; gap: 12px;
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 16px 24px;
}
.step-num {
  background: var(--accent); color: var(--bg); font-weight: 700;
  width: 32px; height: 32px; min-width: 32px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center; font-size: 0.9rem;
}
.step-body { font-size: 0.9rem; }
.step-body strong { color: var(--accent); }

/* ── 响应式 ──────────────────────────────────────────────── */

@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .hero .subtitle { font-size: 1rem; }
  .nav-links { gap: 16px; }
  .features-grid { grid-template-columns: 1fr; }
  .steps { flex-direction: column; align-items: center; }
}