/* ========================================
   用户增长博客 - User Growth Styles
   ======================================== */

:root {
  --primary-start: #047857;
  --primary-end: #10b981;
  --primary-gradient: linear-gradient(135deg, #047857 0%, #10b981 100%);
  --accent: #059669;
  --accent-light: #34d399;
  --accent-dark: #047857;
  --bg-primary: #022c22;
  --bg-secondary: #064e3b;
  --bg-card: #064e3b;
  --text-primary: #f8fafc;
  --text-secondary: #a7f3d0;
  --text-muted: #6ee7b7;
  --text-light: #f8fafc;
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-hover: 0 12px 32px rgba(16, 185, 129, 0.3);
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background-color: var(--bg-primary); color: var(--text-primary); line-height: 1.7; font-size: 16px; }
a { text-decoration: none; color: inherit; transition: color var(--transition-fast); }
ul, ol { list-style: none; }
img { max-width: 100%; height: auto; display: block; }

.navbar { background: var(--primary-gradient); padding: 1rem 2rem; position: fixed; top: 0; left: 0; right: 0; z-index: 1000; box-shadow: var(--shadow-md); }
.nav-container { max-width: 1200px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; }
.nav-logo { display: flex; align-items: center; gap: 0.75rem; font-size: 1.5rem; font-weight: 700; color: var(--text-light); }
.nav-logo .logo-icon { font-size: 1.75rem; }
.nav-logo:hover { transform: scale(1.02); }
.nav-links { display: flex; gap: 2rem; }
.nav-links a { color: var(--text-light); font-weight: 500; padding: 0.5rem 1rem; border-radius: var(--border-radius-sm); transition: all var(--transition-fast); }
.nav-links a:hover { background: rgba(255, 255, 255, 0.15); }
.nav-toggle { display: none; flex-direction: column; cursor: pointer; gap: 5px; }
.nav-toggle span { width: 25px; height: 3px; background: var(--text-light); border-radius: 2px; }

.hero { background: var(--primary-gradient); padding: 8rem 2rem 4rem; text-align: center; color: var(--text-light); position: relative; overflow: hidden; }
.hero::before { content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E"); opacity: 0.5; }
.hero-content { position: relative; z-index: 1; max-width: 800px; margin: 0 auto; }
.hero-icon { font-size: 4rem; margin-bottom: 1.5rem; display: inline-block; animation: float 3s ease-in-out infinite; }
@keyframes float { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }
.hero h1 { font-size: 3rem; font-weight: 800; margin-bottom: 1rem; text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2); }
.hero p { font-size: 1.25rem; opacity: 0.95; margin-bottom: 2rem; line-height: 1.8; }
.hero-stats { display: flex; justify-content: center; gap: 3rem; margin-top: 2rem; }
.stat-item { display: flex; flex-direction: column; align-items: center; }
.stat-icon { font-size: 1.5rem; margin-bottom: 0.5rem; }
.stat-number { font-size: 2rem; font-weight: 700; }
.stat-label { font-size: 0.875rem; opacity: 0.9; }
.hero-tags { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 24px; }
.tag { display: inline-block; padding: 6px 14px; background: rgba(255, 255, 255, 0.15); color: #ffffff; border-radius: 20px; font-size: 0.85rem; border: 1px solid rgba(255, 255, 255, 0.2); }

.container { max-width: 1200px; margin: 0 auto; padding: 3rem 2rem; }

.section-title { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 2rem; padding-bottom: 1rem; border-bottom: 2px solid var(--primary-start); font-size: 1.75rem; color: var(--text-primary); font-weight: 700; }
.section-title::before { content: '◆'; color: var(--accent); font-size: 1.5rem; }
.section-icon { font-size: 1.75rem; }

.articles-section { margin-bottom: 4rem; }
.articles-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 2rem; }
.article-card { background: var(--bg-card); border-radius: var(--border-radius); overflow: hidden; box-shadow: var(--shadow-sm); transition: all var(--transition-normal); cursor: pointer; border: 1px solid rgba(16, 185, 129, 0.2); }
.article-card:hover { transform: translateY(-8px); box-shadow: var(--shadow-lg); border-color: var(--accent); }
.article-image { height: 200px; background: var(--primary-gradient); position: relative; overflow: hidden; }
.article-image-icon { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); font-size: 4rem; opacity: 0.3; }
.article-content { padding: 1.5rem; }
.article-category { display: inline-block; padding: 0.25rem 0.75rem; background: var(--accent); color: var(--text-light); border-radius: 20px; font-size: 0.75rem; font-weight: 600; text-transform: uppercase; margin-bottom: 0.75rem; }
.article-card h3 { font-size: 1.25rem; margin-bottom: 0.75rem; color: var(--text-primary); line-height: 1.4; }
.article-card h3:hover { color: var(--accent); }
.article-excerpt { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 1rem; line-height: 1.7; }
.article-meta { display: flex; justify-content: space-between; align-items: center; color: var(--text-muted); font-size: 0.875rem; }
.article-date { display: flex; align-items: center; gap: 0.5rem; }
.article-read-time { display: flex; align-items: center; gap: 0.5rem; }

.categories-section { margin-bottom: 4rem; }
.categories-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 20px; }
.category-card { background: var(--bg-card); border-radius: var(--border-radius); padding: 24px; box-shadow: var(--shadow-sm); transition: all var(--transition-normal); cursor: pointer; text-decoration: none; display: block; border: 1px solid transparent; }
.category-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); border-color: var(--accent); }
.category-card h3 { font-size: 1.15rem; font-weight: 600; margin-bottom: 8px; color: var(--text-primary); }
.category-card p { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.6; }
.category-count { display: inline-block; padding: 4px 12px; background: rgba(5, 150, 105, 0.2); color: var(--accent); border-radius: 12px; font-size: 0.8rem; margin-top: 12px; }

.links-section { margin-bottom: 4rem; }
.links-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 24px; color: var(--text-primary); display: flex; align-items: center; gap: 12px; }
.links-title::before { content: '◆'; color: var(--accent); }
.links-list { display: flex; flex-wrap: wrap; gap: 12px; }
.link-item { display: inline-block; padding: 8px 16px; background: var(--bg-card); border: 1px solid var(--bg-secondary); color: var(--text-secondary); text-decoration: none; font-size: 0.9rem; border-radius: 20px; transition: all var(--transition-fast); }
.link-item:hover { border-color: var(--accent); color: var(--accent); background: rgba(5, 150, 105, 0.1); }

.footer { background: #011a15; color: var(--text-light); padding: 3rem 2rem 1.5rem; }
.footer-container { max-width: 1200px; margin: 0 auto; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 3rem; margin-bottom: 2rem; }
.footer-brand { max-width: 300px; }
.footer-logo { display: flex; align-items: center; gap: 0.75rem; font-size: 1.5rem; font-weight: 700; margin-bottom: 1rem; }
.footer-logo-icon { font-size: 1.75rem; }
.footer-brand p { color: var(--text-muted); line-height: 1.7; }
.footer-column h4 { font-size: 1.1rem; margin-bottom: 1rem; color: var(--text-light); }
.footer-links { display: flex; flex-direction: column; gap: 0.75rem; }
.footer-links a { color: var(--text-muted); transition: color var(--transition-fast); }
.footer-links a:hover { color: var(--accent); }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.1); padding-top: 1.5rem; text-align: center; color: var(--text-muted); font-size: 0.875rem; }

@media (max-width: 1200px) { .container { padding: 2rem 1.5rem; } .hero h1 { font-size: 2.5rem; } .footer-grid { grid-template-columns: 1fr 1fr; gap: 2rem; } }
@media (max-width: 768px) { .navbar { padding: 1rem; } .nav-links { display: none; position: absolute; top: 100%; left: 0; right: 0; background: var(--primary-end); flex-direction: column; padding: 1rem; gap: 0.5rem; } .nav-links.active { display: flex; } .nav-toggle { display: flex; } .hero { padding: 6rem 1rem 3rem; } .hero h1 { font-size: 2rem; } .hero p { font-size: 1rem; } .hero-stats { flex-direction: column; gap: 1.5rem; } .container { padding: 2rem 1rem; } .articles-grid { grid-template-columns: 1fr; } .footer-grid { grid-template-columns: 1fr; gap: 1.5rem; text-align: center; } .footer-brand { max-width: 100%; } }
@media (max-width: 480px) { .hero h1 { font-size: 1.75rem; } .stat-number { font-size: 1.5rem; } .article-card h3 { font-size: 1.1rem; } }