/* =========================================================================
   DeepSeek Harness 产品体系 — 共享基础样式
   风格：干净、专业、开发者工具风（非 AI 风）
   ========================================================================= */

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

:root {
  --bg: #0C0F1A;
  --bg-card: #131726;
  --bg-card-hover: #1A1F32;
  --border: #1E2338;
  --border-hover: #2A3050;
  --text: #E4E8F0;
  --text-dim: #8892A8;
  --text-muted: #546074;
  --accent: #3B82F6;
  --accent-dim: #2563EB;
  --accent-light: #60A5FA;
  --green: #22C55E;
  --amber: #F59E0B;
  --purple: #8B5CF6;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --radius: 10px;
  --radius-sm: 6px;
  --container: 1080px;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

a { color: var(--accent-light); text-decoration: none; transition: color 0.15s; }
a:hover { color: #fff; }

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

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(12, 15, 26, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  gap: 24px;
}

.nav-links a {
  font-size: 14px;
  color: var(--text-dim);
  font-weight: 500;
}

/* --- Sections --- */
.section {
  padding: 80px 0;
  border-top: 1px solid var(--border);
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  color: #fff;
  letter-spacing: -0.02em;
  text-align: center;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16px;
  color: var(--text-dim);
  text-align: center;
  max-width: 560px;
  margin: 0 auto 48px;
  line-height: 1.7;
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
}

.footer-grid {
  display: flex;
  gap: 60px;
  justify-content: center;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 12px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col a {
  font-size: 14px;
  color: var(--text-dim);
}

.footer-col a:hover {
  color: #fff;
}

.footer-copy {
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
}

/* --- Selection --- */
::selection {
  background: rgba(59, 130, 246, 0.25);
  color: #fff;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .container { padding: 0 16px; }
  .section { padding: 50px 0; }
  .section-title { font-size: 22px; }
  .section-desc { font-size: 14px; margin-bottom: 32px; }
  .footer-grid { gap: 32px; flex-direction: column; align-items: center; text-align: center; }
}