/* --- 全局样式 --- */
:root {
  --bg-color: #121212;
  --surface-color: #1e1e1e;
  --primary-color: #0d6efd; /* 蓝色主题 */
  --secondary-color: #6c757d;
  --text-color: #e0e0e0;
  --text-muted: #aaa;
  --border-color: #333;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
  scroll-behavior: smooth;
}

.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

h1,
h2,
h3 {
  margin-bottom: 1rem;
  color: #fff;
}

h2 {
  font-size: 2.5rem;
  border-bottom: 3px solid var(--primary-color);
  padding-bottom: 10px;
  display: inline-block;
}

section {
  padding: 60px 0;
}

a {
  color: var(--primary-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* --- 头部导航栏 --- */
#navbar {
  background-color: var(--surface-color);
  color: #fff;
  padding: 1rem 0;
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.5);
}

#navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#navbar .logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: #fff;
  text-decoration: none;
}

#navbar ul {
  list-style: none;
  display: flex;
  transition: transform 0.3s ease-in-out;
}

#navbar ul li {
  margin-left: 20px;
}

#navbar ul li a {
  color: #fff;
  padding: 10px;
  transition: color 0.3s;
}

#navbar ul li a:hover {
  color: var(--primary-color);
  text-decoration: none;
}

/* 汉堡菜单按钮样式，默认隐藏 */
.menu-toggle {
  display: none;
  background: none;
  border: none;
  color: #fff;
  font-size: 1.8rem;
  cursor: pointer;
  padding: 10px;
  z-index: 1001;
  line-height: 1;
}

/* --- 英雄(Hero)区域 --- */
#hero {
  padding-top: 150px;
  min-height: 80vh;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

#hero .hero-content {
  max-width: 60%;
}

#hero h1 {
  font-size: 3.5rem;
  margin-bottom: 0.5rem;
}

#hero .subtitle {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: 1.5rem;
}

#hero p {
  font-size: 1.1rem;
  margin-bottom: 2rem;
}

#hero .hero-image {
  max-width: 35%;
  text-align: center;
}

#hero .profile-pic {
  width: 280px;
  height: 280px;
  border-radius: 50%;
  object-fit: cover;
  border: 5px solid var(--surface-color);
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.4);
}

.social-links a {
  font-size: 1.5rem;
  color: var(--text-muted);
  margin-right: 15px;
  transition: color 0.3s;
}

.social-links a:hover {
  color: var(--primary-color);
  text-decoration: none;
}

/* --- 技能(Skills)区域 --- */
.skill-category {
  margin-top: 2.5rem;
}

.skill-category:first-of-type {
  margin-top: 1.5rem;
}

.skill-category h3 {
  font-size: 1.5rem;
  color: var(--primary-color);
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 5px;
}

#skills .skills-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 10px;
}

.skill-tag {
  background-color: var(--surface-color);
  color: var(--text-color);
  padding: 8px 16px;
  border-radius: 5px;
  font-size: 0.95rem;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  cursor: default;
  max-width: 200px;
  /* 技能评级布局 */
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-width: 160px;
  flex-grow: 1;
}

.skill-tag:hover {
  transform: translateY(-3px);
  background-color: var(--primary-color);
  color: #fff;
  border-color: var(--primary-color);
  box-shadow: 0 4px 10px rgba(13, 110, 253, 0.3);
}

/* 技能评级星级样式 */
.stars {
  color: #ffd700; /* 金色星星 */
  margin-left: 12px;
  font-size: 0.9em;
  flex-shrink: 0;
}
.stars span {
  color: #555; /* 空心星的颜色 */
}

/* --- 项目(Projects)区域 --- */
#projects .projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 25px;
  margin-top: 30px;
}

.project-card {
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.3s, box-shadow 0.3s;
}

.project-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.5);
}

.project-card-content {
  padding: 20px;
  flex-grow: 1;
}

.project-card h3 {
  font-size: 1.5rem;
}

.project-tech {
  margin-top: 10px;
}

.tech-tag {
  background: #333;
  color: var(--text-muted);
  padding: 4px 8px;
  border-radius: 4px;
  font-size: 0.8rem;
  margin-right: 5px;
  margin-bottom: 5px;
  display: inline-block;
}

.project-links {
  padding: 20px;
  background: #2a2a2a;
  border-top: 1px solid var(--border-color);
}

.project-links a {
  margin-right: 15px;
  font-weight: bold;
}

/* --- 经历(Experience) & 奖项(Awards) --- */
#experience-awards {
  background: var(--surface-color);
}

.timeline-container {
  display: flex;
  justify-content: space-between;
  gap: 40px;
  margin-top: 30px;
}

.timeline {
  width: 48%;
}

.timeline-item {
  background: var(--bg-color);
  border-left: 4px solid var(--primary-color);
  padding: 20px;
  margin-bottom: 20px;
  border-radius: 0 8px 8px 0;
}

.timeline-item h4 {
  font-size: 1.3rem;
  color: #fff;
}

.timeline-item .date {
  font-style: italic;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 10px;
}

.timeline-item ul {
  list-style: none;
  padding-left: 0;
}

.timeline-item li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 5px;
}

.timeline-item li::before {
  content: "•";
  color: var(--primary-color);
  position: absolute;
  left: 0;
  font-weight: bold;
}

/* --- 页脚(Footer) --- */
#footer {
  text-align: center;
  padding: 40px 0;
  background: #0a0a0a;
  color: var(--text-muted);
  margin-top: 40px;
}

#footer .footer-links {
  margin-bottom: 10px;
}

#footer .footer-links a {
  margin: 0 15px;
  color: var(--text-muted);
  font-size: 1.5rem;
}

#footer .footer-links a:hover {
  color: var(--primary-color);
}

/* --- 动画效果 (新增) --- */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px); /* 从下方滑入 */
  transition: opacity 0.8s ease-out, transform 0.8s ease-out; /* 800ms的平滑过渡 */
}

.animate-on-scroll.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* 针对内部卡片，设置较快的过渡 */
.project-card,
.skill-category,
.timeline-item {
  transition: all 0.5s ease-out;
  opacity: 0;
  transform: translateY(20px);
}

/* --- 响应式设计 --- */
@media (max-width: 768px) {
  h2 {
    font-size: 2rem;
  }

  /* 导航栏在小屏幕上不换行，保持 logo 和按钮在同一行 */
  #navbar .container {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  /* 默认隐藏导航菜单 */
  #navbar ul {
    display: none;
    flex-direction: column;
    width: 100%;
    position: absolute;
    top: 65px;
    left: 0;
    background-color: var(--surface-color);
    padding: 10px 0;
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.5);
  }

  /* 菜单展开时的显示状态 */
  #navbar ul.nav-open {
    display: flex;
  }

  #navbar ul li {
    margin: 5px 0;
    text-align: center;
  }

  #navbar ul li a {
    display: block;
    padding: 12px;
  }

  /* 在小屏幕上显示切换按钮 */
  .menu-toggle {
    display: block;
  }

  #hero {
    flex-direction: column;
    text-align: center;
    padding-top: 200px;
    min-height: 40vh;
  }

  #hero .hero-content {
    max-width: 100%;
  }

  #hero .hero-image {
    max-width: 60%;
    margin-top: 30px;
  }

  #hero .profile-pic {
    width: 200px;
    height: 200px;
  }

  .timeline-container {
    flex-direction: column;
  }
  .timeline {
    width: 100%;
  }
}