/* ==================== 变量 ==================== */
:root {
  --bg: #0b1117;
  --bg-alt: #101823;
  --card: #141d29;
  --card-hover: #1a2534;
  --border: #223047;
  --text: #dce6f2;
  --text-dim: #8296ad;
  --accent: #1890ff;
  --accent-hover: #40a9ff;
  --success: #52c41a;
  --warning: #faad14;
  --radius: 12px;
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', Roboto, Arial, sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

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

/* ==================== 顶部导航 ==================== */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(11, 17, 23, 0.75);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s;
}
.site-header.scrolled { border-bottom-color: var(--border); }

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 1px;
}
.logo span { color: var(--accent); font-weight: 500; }

.nav { display: flex; gap: 28px; }
.nav a {
  font-size: 14px;
  color: var(--text-dim);
  transition: color 0.2s;
}
.nav a:hover { color: var(--text); }

/* ==================== 首屏 ==================== */
.hero {
  position: relative;
  min-height: 92vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

/* 网格 + 光晕背景 */
.hero-grid-bg {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, rgba(0,0,0,0.55), transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, rgba(0,0,0,0.55), transparent 75%);
  opacity: 0.6;
}
.hero::after {
  content: '';
  position: absolute;
  top: -20%; left: 50%;
  width: 720px; height: 720px;
  transform: translateX(-50%);
  background: radial-gradient(circle, rgba(24, 144, 255, 0.14) 0%, transparent 60%);
  pointer-events: none;
}

.hero-inner { position: relative; text-align: center; padding-top: 60px; }

.hero-eyebrow {
  font-size: 13px;
  letter-spacing: 6px;
  color: var(--accent);
  margin-bottom: 18px;
}

.hero h1 {
  font-size: clamp(44px, 8vw, 76px);
  font-weight: 800;
  letter-spacing: 4px;
  margin-bottom: 14px;
}

.hero-sub {
  font-size: clamp(15px, 2.4vw, 19px);
  color: var(--text-dim);
  margin-bottom: 38px;
}

/* ==================== 按钮 ==================== */
.btn {
  display: inline-block;
  padding: 11px 30px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 500;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  transition: all 0.2s;
}
.btn:hover { background: var(--card-hover); border-color: var(--accent); }

.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); }

.btn-sm { padding: 8px 18px; font-size: 13.5px; border-radius: 6px; }

/* ==================== 区块通用 ==================== */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }

.section-title {
  font-size: 30px;
  font-weight: 700;
  margin-bottom: 8px;
}
.section-title::after {
  content: '';
  display: block;
  width: 44px; height: 3px;
  background: var(--accent);
  border-radius: 2px;
  margin-top: 12px;
}

.section-desc { color: var(--text-dim); margin: 18px 0 40px; }

/* ==================== 项目卡片 ==================== */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 22px;
}

.project-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: transform 0.22s, border-color 0.22s, background 0.22s;
}
.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  background: var(--card-hover);
}

.project-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}
.project-name { font-size: 19px; font-weight: 700; }
.project-en { font-size: 12px; color: var(--text-dim); letter-spacing: 1px; }

.badge {
  font-size: 11.5px;
  padding: 3px 10px;
  border-radius: 999px;
  white-space: nowrap;
  border: 1px solid;
}
.badge-dev { color: var(--warning); border-color: var(--warning); background: rgba(250, 173, 20, 0.08); }
.badge-ok  { color: var(--success); border-color: var(--success); background: rgba(82, 196, 26, 0.08); }

.project-desc {
  font-size: 14px;
  color: var(--text-dim);
  flex: 1;
}

.tag-row { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
  font-size: 11.5px;
  padding: 3px 10px;
  border-radius: 5px;
  background: rgba(24, 144, 255, 0.10);
  color: var(--accent-hover);
}

.link-row { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 4px; }

/* 占位卡片 */
.project-card.ghost {
  align-items: center;
  justify-content: center;
  border-style: dashed;
  opacity: 0.55;
  min-height: 220px;
  text-align: center;
}
.project-card.ghost:hover { transform: none; background: var(--card); border-color: var(--border); }
.ghost-title { font-size: 17px; font-weight: 600; color: var(--text-dim); }
.ghost-sub { font-size: 13px; color: var(--text-dim); margin-top: 4px; }

/* ==================== 关于 ==================== */
.about-text { max-width: 640px; color: var(--text); }
.about-text.muted { color: var(--text-dim); margin-top: 10px; font-size: 14px; }

/* ==================== 页脚 ==================== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
  text-align: center;
  font-size: 13px;
  color: var(--text-dim);
}

/* ==================== 移动端 ==================== */
@media (max-width: 640px) {
  .hero { min-height: 80vh; }
  .section { padding: 72px 0; }
  .nav { gap: 18px; }
}