/* ===== CSS 变量 ===== */
:root {
  --bg-base: #0c0d0f;
  --bg-elevated: #14161a;
  --bg-card: #1a1c22;
  --border: rgba(255, 255, 255, 0.08);
  --text-primary: #f0f2f5;
  --text-secondary: #8b92a0;
  --text-muted: #5c6370;
  --accent: #00d4aa;
  --accent-dim: rgba(0, 212, 170, 0.15);
  --accent-hover: #00e6b8;
  --font-display: "Outfit", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.2s ease;
  --focus-ring: 3px solid var(--accent);
  --focus-offset: 2px;
}

/* ===== 跳过链接（无障碍） ===== */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 200;
  padding: 0.75rem 1rem;
  background: var(--accent);
  color: var(--bg-base);
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 1rem;
  outline: 3px solid var(--accent-hover);
  outline-offset: 2px;
}

/* ===== 重置与基础 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-display);
  background: var(--bg-base);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* 背景层次 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(0, 212, 170, 0.12), transparent);
  pointer-events: none;
  z-index: 0;
}

/* 噪点叠加层 */
.noise-overlay {
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 10;
}

/* ===== 导航 ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.25rem 2rem;
  backdrop-filter: blur(12px);
  background: rgba(12, 13, 15, 0.7);
  border-bottom: 1px solid var(--border);
}

.nav {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  gap: 2rem;
  align-items: center;
}

.nav-link {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color var(--transition);
  cursor: pointer;
}

.nav-link:hover {
  color: var(--accent);
}

.nav-link:focus-visible {
  outline: var(--focus-ring);
  outline-offset: var(--focus-offset);
  border-radius: 4px;
}

/* ===== Hero ===== */
.hero {
  position: relative;
  padding: 8rem 2rem 5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.hero-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  line-height: 1.15;
}

.hero-desc {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 520px;
}

/* ===== 软件列表 ===== */
.releases {
  position: relative;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem 4rem;
}

.section-title {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  font-family: var(--font-mono);
}

.release-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.release-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color var(--transition), box-shadow var(--transition);
  cursor: default;
}

.release-card:focus-within {
  border-color: rgba(0, 212, 170, 0.3);
  box-shadow: 0 0 0 1px rgba(0, 212, 170, 0.08);
}

.release-card:hover {
  border-color: rgba(0, 212, 170, 0.3);
  box-shadow: 0 0 0 1px rgba(0, 212, 170, 0.08);
}

.release-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.75rem;
}

.release-icon {
  color: var(--accent);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.release-icon svg {
  width: 16px;
  height: 16px;
}

.release-name {
  font-size: 1.15rem;
  font-weight: 600;
}

.release-version {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
  background: rgba(255, 255, 255, 0.06);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  margin-left: auto;
}

.release-desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  line-height: 1.5;
}

.release-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.release-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 0.5rem 1rem;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition), border-color var(--transition);
  cursor: pointer;
}

.btn:focus-visible {
  outline: var(--focus-ring);
  outline-offset: var(--focus-offset);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-base);
  border: 1px solid var(--accent);
}

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

.btn-primary:focus-visible {
  outline-color: var(--accent-hover);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--text-muted);
  background: rgba(255, 255, 255, 0.04);
}

.btn-secondary:focus-visible {
  outline-color: var(--text-primary);
}

/* ===== 页脚 ===== */
.footer {
  text-align: center;
  padding: 3rem 2rem;
  border-top: 1px solid var(--border);
}

.footer p {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .header {
    padding: 1rem 1.25rem;
  }

  .hero {
    padding: 6rem 1.25rem 4rem;
  }

  .releases {
    padding: 0 1.25rem 3rem;
  }

  .release-grid {
    grid-template-columns: 1fr;
  }
}

/* 尊重用户偏好：减少动画 */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}