/* =============================================
   Zijiao (Daisy) Zheng - 个人网站样式表
   风格：暗色复古 · 温润典雅 · 学术气质
   配色：深棕#2C1810 / 暖金#D4A574 / 奶油#F5E6D3 / 墨绿#1A3C34
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Playfair+Display:wght@400;600;700&family=Source+Serif+4:wght@300;400;600&display=swap');

:root {
  --bg: #1A1410;
  --bg-card: #231D16;
  --bg-elevated: #2C241C;
  --bg-input: #1E1812;
  --text: #E8DDD0;
  --text-secondary: #B5A590;
  --text-muted: #7A6E5E;
  --accent: #D4A574;
  --accent-hover: #E0BC90;
  --accent-dim: #8B6F52;
  --gold: #C9A96E;
  --cream: #F5E6D3;
  --green: #5C8D7A;
  --green-light: #7BAA95;
  --red: #C46767;
  --border: #3D3226;
  --border-light: #4D4032;
  --shadow: 0 2px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.4);
  --radius: 4px;
  --radius-lg: 8px;
  --max-width: 1100px;
  --nav-height: 72px;
  --font-display: 'Playfair Display', 'Noto Serif SC', serif;
  --font-body: 'Source Serif 4', 'Noto Serif SC', serif;
}

/* 基础 */
*, *::before, *::after { margin:0; padding:0; box-sizing:border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.8;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; transition: color 0.3s; }
a:hover { color: var(--accent-hover); }
img { max-width: 100%; display: block; }

/* 导航栏 - 暗色复古 */
.navbar {
  position: fixed; top:0; left:0; right:0; z-index: 1000;
  height: var(--nav-height);
  background: rgba(26, 20, 16, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center;
}
.nav-container {
  max-width: var(--max-width); margin:0 auto; padding:0 24px;
  width: 100%; display: flex; justify-content: space-between; align-items: center;
}
.nav-logo { font-family: var(--font-display); font-size: 1.3em; font-weight: 600; color: var(--accent); }
.nav-right { display: flex; align-items: center; gap: 24px; }
.nav-links { display: flex; list-style: none; gap: 28px; }
.nav-links a {
  color: var(--text-secondary); font-size: 0.9em; font-weight: 400;
  transition: color 0.3s; padding: 8px 0; position: relative; font-family: var(--font-body);
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); }
.nav-links a::after {
  content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 1px;
  background: var(--accent); transition: width 0.3s;
}
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

/* 语言切换 */
.lang-switch {
  background: transparent; border: 1px solid var(--border-light); color: var(--text-secondary);
  padding: 6px 14px; border-radius: 3px; cursor: pointer; font-family: var(--font-body);
  font-size: 0.85em; transition: all 0.3s;
}
.lang-switch:hover { border-color: var(--accent); color: var(--accent); }

/* 通用 */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }
section { padding: 100px 0; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-header h2 {
  font-family: var(--font-display); font-size: 2.4em; color: var(--cream);
  margin-bottom: 12px; position: relative; display: inline-block;
}
.section-header h2::after {
  content: ''; position: absolute; bottom: -8px; left: 50%; transform: translateX(-50%);
  width: 40px; height: 2px; background: var(--accent);
}
.section-header .subtitle { font-size: 1em; color: var(--text-muted); font-style: italic; }

/* 装饰线 */
.ornament { text-align: center; color: var(--accent-dim); font-size: 1.2em; letter-spacing: 8px; margin: 16px 0; }

/* 首页 Hero */
.hero {
  min-height: 100vh; display: flex; align-items: center;
  background: radial-gradient(ellipse at 50% 30%, #2C1E14 0%, var(--bg) 70%);
  padding-top: var(--nav-height);
}
.hero-content {
  display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center;
}
.hero-text h1 { font-family: var(--font-display); font-size: 3.4em; line-height: 1.2; margin-bottom: 8px; color: var(--cream); }
.hero-text h1 .hi { display: block; font-size: 0.35em; color: var(--text-muted); font-weight: 400; margin-bottom: 8px; }
.hero-text h1 .name { color: var(--accent); }
.hero-text .tagline { font-size: 1.1em; color: var(--text-secondary); margin-bottom: 28px; line-height: 1.7; }
.hero-text .tagline .highlight { color: var(--accent); font-weight: 600; }
.hero-btns { display: flex; gap: 16px; }
.btn {
  display: inline-block; padding: 14px 32px; border-radius: 3px;
  font-size: 0.95em; font-weight: 600; text-align: center; cursor: pointer;
  transition: all 0.3s; border: none; font-family: var(--font-body); letter-spacing: 0.5px;
}
.btn-primary { background: var(--accent); color: var(--bg); }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-2px); box-shadow: var(--shadow); }
.btn-outline { background: transparent; color: var(--accent); border: 1px solid var(--accent); }
.btn-outline:hover { background: rgba(212,165,116,0.1); transform: translateY(-2px); }
.hero-image { display: flex; justify-content: center; align-items: center; }
.avatar-frame {
  width: 300px; height: 300px; border-radius: 50%;
  border: 3px solid var(--accent);
  padding: 4px; overflow: hidden;
}
.avatar-frame img { width: 100%; height: 100%; object-fit: cover; border-radius: 50%; }

/* 卡片 */
.card {
  background: var(--bg-card); border: 1px solid var(--border);
  overflow: hidden; transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--border-light); }
.card-body { padding: 24px; }
.card-title { font-family: var(--font-display); font-size: 1.15em; font-weight: 600; margin-bottom: 8px; color: var(--cream); }
.card-text { color: var(--text-secondary); font-size: 0.9em; line-height: 1.7; }

/* 统计卡片 */
.stats-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: 40px; }
.stat-card {
  text-align: center; padding: 28px 16px; border: 1px solid var(--border);
  background: var(--bg-card);
}
.stat-number { font-family: var(--font-display); font-size: 2.2em; font-weight: 700; color: var(--accent); }
.stat-label { color: var(--text-muted); font-size: 0.85em; margin-top: 6px; }

/* 页面横幅 */
.page-banner {
  padding: 130px 0 70px;
  background: radial-gradient(ellipse at center, #2C1E14 0%, var(--bg) 70%);
  text-align: center; border-bottom: 1px solid var(--border);
}
.page-banner h1 { font-family: var(--font-display); font-size: 2.8em; color: var(--cream); margin-bottom: 12px; }
.page-banner p { font-size: 1.05em; color: var(--text-muted); font-style: italic; }

/* 时间线 */
.timeline { position: relative; padding-left: 44px; }
.timeline::before {
  content: ''; position: absolute; left: 16px; top: 0; bottom: 0;
  width: 1px; background: var(--border-light);
}
.timeline-item { position: relative; margin-bottom: 36px; }
.timeline-item::before {
  content: ''; position: absolute; left: -34px; top: 6px;
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--bg); border: 2px solid var(--accent);
}
.timeline-year { font-size: 0.85em; color: var(--accent); font-weight: 600; letter-spacing: 1px; text-transform: uppercase; }
.timeline-title { font-family: var(--font-display); font-size: 1.1em; font-weight: 600; margin: 4px 0; color: var(--cream); }
.timeline-desc { color: var(--text-secondary); font-size: 0.9em; }

/* 技能条 */
.skills-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; margin-top: 40px; }
.skill-category h3 { font-family: var(--font-display); font-size: 1.2em; margin-bottom: 20px; color: var(--cream); }
.skill-bar { margin-bottom: 18px; }
.skill-bar .label { display: flex; justify-content: space-between; margin-bottom: 6px; font-size: 0.85em; color: var(--text-secondary); }
.skill-bar .bar-bg { height: 6px; background: var(--bg-input); border-radius: 3px; overflow: hidden; }
.skill-bar .bar-fill { height: 100%; border-radius: 3px; transition: width 1.5s ease; }
.bar-fill.gold { background: var(--accent); }
.bar-fill.green { background: var(--green); }
.bar-fill.cream { background: var(--cream); }

/* 作品集 */
.portfolio-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.portfolio-card .card-image {
  height: 160px; display: flex; align-items: center; justify-content: center;
  font-size: 2.8em; border-bottom: 1px solid var(--border);
}
.card-image.math { background: linear-gradient(135deg, #2C1E14, #1A2C24); }
.card-image.research { background: linear-gradient(135deg, #1E2420, #1A2C24); }
.card-image.art { background: linear-gradient(135deg, #2C1E1E, #1E1A24); }
.card-image.tech { background: linear-gradient(135deg, #1E2428, #1A2430); }
.card-image.volunteer { background: linear-gradient(135deg, #241E1C, #2C241C); }
.card-image.sport { background: linear-gradient(135deg, #1E2020, #1A2424); }
.tag {
  display: inline-block; padding: 3px 10px; border: 1px solid var(--border-light);
  font-size: 0.75em; color: var(--text-muted); margin-right: 6px; margin-bottom: 6px;
  font-family: var(--font-body); letter-spacing: 0.5px;
}

/* 博客 */
.blog-list { max-width: 800px; margin: 0 auto; }
.blog-item {
  display: grid; grid-template-columns: 160px 1fr; gap: 28px;
  padding: 28px; margin-bottom: 20px;
  border: 1px solid var(--border); background: var(--bg-card);
  transition: border-color 0.3s, transform 0.3s;
}
.blog-item:hover { border-color: var(--border-light); transform: translateY(-2px); }
.blog-date-box {
  width: 100%; height: 90px; display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  border: 1px solid var(--border); color: var(--accent);
}
.blog-date-box .day { font-family: var(--font-display); font-size: 2em; line-height: 1; }
.blog-date-box .month { font-size: 0.8em; color: var(--text-muted); margin-top: 2px; }
.blog-info h3 { font-family: var(--font-display); font-size: 1.1em; margin-bottom: 8px; color: var(--cream); }
.blog-info p { color: var(--text-secondary); font-size: 0.9em; margin-bottom: 10px; }
.blog-info .read-more { font-size: 0.85em; font-weight: 600; color: var(--accent); letter-spacing: 0.5px; }

/* 联系 */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: start; }
.contact-info h3 { font-family: var(--font-display); font-size: 1.4em; margin-bottom: 24px; color: var(--cream); }
.contact-item {
  display: flex; align-items: center; gap: 16px; margin-bottom: 16px;
  padding: 14px 18px; border: 1px solid var(--border); background: var(--bg-card);
}
.contact-icon { font-size: 1.3em; color: var(--accent); }
.contact-item .label { font-weight: 600; font-size: 0.9em; color: var(--cream); }
.contact-item .value { color: var(--text-muted); font-size: 0.85em; }
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.contact-form input, .contact-form textarea {
  padding: 14px 18px; border: 1px solid var(--border); background: var(--bg-input);
  color: var(--text); font-size: 0.95em; font-family: var(--font-body);
  transition: border-color 0.3s;
}
.contact-form input:focus, .contact-form textarea:focus {
  outline: none; border-color: var(--accent);
}
.contact-form textarea { min-height: 140px; resize: vertical; }
.form-msg { margin-top: 8px; font-size: 0.9em; min-height: 1.4em; color: var(--accent); }

/* 页脚 */
.footer {
  padding: 36px 0; text-align: center;
  color: var(--text-muted); font-size: 0.85em;
  border-top: 1px solid var(--border);
  font-style: italic;
}

/* 动画 */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(24px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate { animation: fadeInUp 0.7s ease forwards; }
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }

/* 响应式 */
@media (max-width: 768px) {
  .hero-content { grid-template-columns: 1fr; text-align: center; }
  .hero-text h1 { font-size: 2.2em; }
  .hero-btns { justify-content: center; }
  .portfolio-grid { grid-template-columns: 1fr; }
  .skills-grid { grid-template-columns: 1fr; }
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .blog-item { grid-template-columns: 1fr; }
  .nav-links { gap: 14px; font-size: 0.85em; }
}