/* ===== OPC 网站 - 核心样式 ===== */

/* --- CSS 变量 --- */
:root {
  --bg-primary: #0f0c29;
  --bg-secondary: #0d1117;
  --bg-card: #141316;
  --bg-elevated: #1a1a2e;
  --text-primary: #ffffff;
  --text-secondary: #cbd5e1;
  --text-muted: #64748b;
  --accent-blue: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-indigo: #6366f1;
  --accent-purple: #818cf8;
  --accent-green: #10b981;
  --accent-amber: #f59e0b;
  --accent-pink: #ec4899;
  --accent-orange: #d77757;
  --font-sans: 'Inter', 'Noto Sans SC', 'PingFang SC', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Inter', monospace;
  --font-serif: 'Noto Serif SC', Georgia, serif;
  --nav-height: 64px;
  --max-width: 1200px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-card: 0 4px 20px rgba(0,0,0,0.2);
  --shadow-glow: 0 0 20px rgba(129,140,248,0.15);
  --transition: 0.3s ease;
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: var(--accent-purple); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-cyan); }
img { max-width: 100%; display: block; }
ul { list-style: none; }

/* --- 排版 --- */
h1, h2, h3, h4 { font-weight: 700; line-height: 1.3; }
h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.8rem); }

.section-title {
  text-align: center;
  margin-bottom: 3rem;
}
.section-title h2 {
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.section-title p {
  color: var(--text-muted);
  margin-top: 0.5rem;
  font-size: 1.05rem;
}

/* --- 容器 --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* --- 导航 --- */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-height);
  background: rgba(15,12,41,0.85);
  -webkit-backdrop-filter: blur(16px);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary) !important;
  letter-spacing: -0.5px;
}
.nav-logo span { color: var(--accent-purple); }
.nav-links { display: flex; gap: 0.25rem; align-items: center; }
.nav-links a {
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  transition: var(--transition);
}
.nav-links a:hover, .nav-links a.active {
  color: var(--text-primary);
  background: rgba(255,255,255,0.06);
}
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0; right: 0;
    background: rgba(15,12,41,0.98);
    -webkit-backdrop-filter: blur(16px);
    backdrop-filter: blur(16px);
    flex-direction: column;
    padding: 1rem;
    gap: 0.25rem;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .nav-links.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .nav-links a { width: 100%; padding: 0.75rem 1rem; }
  .nav-toggle { display: block; }
}

/* --- 页脚 --- */
.footer {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 2rem 0;
  margin-top: 4rem;
}
.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer a { color: var(--text-muted); }
.footer a:hover { color: var(--accent-purple); }

/* --- 卡片 --- */
.card {
  background: var(--bg-card);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  transition: var(--transition);
}
.card:hover {
  border-color: rgba(129,140,248,0.2);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  font-family: var(--font-sans);
}
.btn-primary {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-cyan));
  color: #fff;
}
.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(6,182,212,0.3);
}
.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid rgba(255,255,255,0.1);
}
.btn-ghost:hover {
  color: var(--text-primary);
  border-color: rgba(255,255,255,0.2);
}

/* --- 动画 --- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 0%,100% { opacity: 0.4; } 50% { opacity: 1; } }

/* --- 工具类 --- */
.gradient-text {
  background: linear-gradient(135deg, var(--accent-purple), var(--accent-cyan));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 500;
}
.tag-green { background: rgba(16,185,129,0.15); color: var(--accent-green); }
.tag-blue { background: rgba(59,130,246,0.15); color: var(--accent-blue); }
.tag-amber { background: rgba(245,158,11,0.15); color: var(--accent-amber); }
.tag-cyan { background: rgba(6,182,212,0.15); color: var(--accent-cyan); }

/* --- 加载态 --- */
.loading {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60vh;
  flex-direction: column;
  gap: 1rem;
  color: var(--text-muted);
}
.spinner {
  width: 36px; height: 36px;
  border: 3px solid rgba(129,140,248,0.2);
  border-top-color: var(--accent-purple);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* --- 空态/错误态 --- */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted);
}
.empty-state .icon { font-size: 3rem; margin-bottom: 1rem; }
.error-state {
  background: rgba(239,68,68,0.1);
  border: 1px solid rgba(239,68,68,0.2);
  border-radius: var(--radius-md);
  padding: 1rem;
  color: #ef4444;
  margin: 1rem 0;
}