/* ===== 小赵官网 · 星空银河风（暗色默认 + 亮色主题） ===== */
:root {
  --bg: #050816;
  --bg-deep: #030512;
  --text: #e8ecff;
  --text-dim: #9aa3c7;
  --primary: #7c8cff;
  --accent: #b78cff;
  --accent2: #6ee7ff;
  --glass: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.09);
  --radius: 16px;

  /* 主题相关（暗色默认值） */
  --page-grad: linear-gradient(180deg, var(--bg-deep) 0%, var(--bg) 55%, #0a0f2e 100%);
  --nav-bg: rgba(5, 8, 22, 0.65);
  --nav-bg-solid: rgba(5, 8, 22, 0.85);
  --nav-bg-drop: rgba(5, 8, 22, 0.97);
  --hero-grad: linear-gradient(100deg, #ffffff 0%, var(--primary) 45%, var(--accent) 80%, var(--accent2) 100%);
  --aurora-opacity: 1;
}

/* 亮色主题 */
:root[data-theme="light"] {
  --bg: #f4f6ff;
  --bg-deep: #e9edff;
  --text: #1b2140;
  --text-dim: #5a6388;
  --glass: rgba(255, 255, 255, 0.66);
  --glass-border: rgba(27, 33, 64, 0.10);
  --page-grad: linear-gradient(180deg, #e9edff 0%, #f4f6ff 55%, #dbe4ff 100%);
  --nav-bg: rgba(244, 246, 255, 0.72);
  --nav-bg-solid: rgba(244, 246, 255, 0.92);
  --nav-bg-drop: rgba(244, 246, 255, 0.97);
  --hero-grad: linear-gradient(100deg, #1b2140 0%, #4a5cf0 45%, #8a5cf0 80%, #1f9ec9 100%);
  --aurora-opacity: 0.45;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  transition: background-color 0.45s ease, color 0.45s ease;
}

/* ===== 星空画布 ===== */
#stars {
  position: fixed;
  inset: 0;
  z-index: -2;
  background: var(--page-grad);
  transition: background 0.45s ease;
}

/* 极光光晕 */
.aurora {
  position: fixed;
  inset: -20% -20% auto;
  height: 70vh;
  z-index: -1;
  background:
    radial-gradient(40% 55% at 20% 30%, rgba(124, 140, 255, 0.16), transparent 70%),
    radial-gradient(35% 50% at 80% 25%, rgba(183, 140, 255, 0.14), transparent 70%),
    radial-gradient(30% 45% at 60% 60%, rgba(110, 231, 255, 0.10), transparent 70%);
  opacity: var(--aurora-opacity);
  transition: opacity 0.45s ease;
  pointer-events: none;
}

/* ===== 导航栏 ===== */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: var(--nav-bg);
  border-bottom: 1px solid var(--glass-border);
  transition: background-color 0.45s ease;
}
.nav.scrolled { background: var(--nav-bg-solid); }

.nav-inner {
  max-width: 1040px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: 20px;
  font-weight: 800;
  color: var(--text);
  text-decoration: none;
  letter-spacing: 1px;
}
.nav-logo span {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.nav-links { list-style: none; display: flex; align-items: center; gap: 28px; }
.nav-links a {
  color: var(--text-dim);
  text-decoration: none;
  font-size: 15px;
  transition: color 0.25s;
}
.nav-links a:hover { color: var(--text); }

/* ===== 导航右侧按钮组（汉堡） ===== */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* 主题切换按钮（菜单尾项：桌面在"联系"后，移动端在展开菜单最后） */
.nav-theme-item {
  display: flex;
  align-items: center;
  margin-left: 2px;
}

.theme-toggle {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 15px;
  line-height: 1;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.25s, background-color 0.3s, border-color 0.3s;
}
.theme-toggle:hover {
  transform: translateY(-2px) rotate(12deg);
  border-color: rgba(124, 140, 255, 0.45);
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 120px 24px 60px;
  position: relative;
}

.hero-eyebrow {
  color: var(--accent2);
  font-size: 15px;
  letter-spacing: 6px;
  margin-bottom: 18px;
}

.hero-name {
  font-size: clamp(52px, 9vw, 92px);
  font-weight: 900;
  letter-spacing: 14px;
  background: var(--hero-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 0 60px rgba(124, 140, 255, 0.25);
  margin-bottom: 22px;
}

.hero-title {
  font-size: clamp(19px, 3.4vw, 26px);
  font-weight: 600;
  color: var(--text-dim);
  min-height: 2.2em;
}

.typewriter {
  color: var(--text);
  border-bottom: 2px solid var(--accent2);
}

.cursor {
  color: var(--accent2);
  animation: blink 0.85s step-end infinite;
  font-weight: 300;
}
@keyframes blink { 50% { opacity: 0; } }

.hero-desc {
  margin-top: 20px;
  color: var(--text-dim);
  font-size: 15.5px;
  max-width: 600px;
}

.hero-actions { margin-top: 36px; display: flex; gap: 16px; flex-wrap: wrap; justify-content: center; }

.btn {
  padding: 12px 30px;
  border-radius: 999px;
  text-decoration: none;
  font-size: 15px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: linear-gradient(90deg, var(--primary), var(--accent));
  color: #fff;
  box-shadow: 0 8px 28px rgba(124, 140, 255, 0.35);
}
.btn-ghost {
  border: 1px solid var(--glass-border);
  color: var(--text);
  background: var(--glass);
  backdrop-filter: blur(8px);
}

.hero-stats {
  margin-top: 56px;
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
  justify-content: center;
}
.stat { text-align: center; }
.stat strong {
  display: block;
  font-size: 30px;
  font-weight: 800;
  background: linear-gradient(90deg, var(--accent2), var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat span { color: var(--text-dim); font-size: 13px; }

.scroll-hint {
  position: absolute;
  bottom: 26px;
  color: var(--text-dim);
  font-size: 13px;
  letter-spacing: 2px;
  animation: float 2s ease-in-out infinite;
}
@keyframes float { 50% { transform: translateY(8px); } }

/* ===== 通用章节 ===== */
.section {
  max-width: 1040px;
  margin: 0 auto;
  padding: 90px 24px;
}

.section-head { text-align: center; margin-bottom: 52px; }
.section-head h2 {
  font-size: clamp(30px, 5vw, 42px);
  font-weight: 800;
  margin-bottom: 10px;
}
.section-head p { color: var(--text-dim); }

/* ===== 技能卡片 ===== */
.skills-group { margin-bottom: 28px; }
.skills-group-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 3px;
  margin-bottom: 14px;
  padding-left: 12px;
  border-left: 3px solid var(--primary);
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.skill-card {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 26px 24px;
  backdrop-filter: blur(10px);
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
}
.skill-card:hover {
  transform: translateY(-6px);
  border-color: rgba(124, 140, 255, 0.45);
  box-shadow: 0 12px 40px rgba(124, 140, 255, 0.15);
}
.skill-icon { font-size: 30px; display: block; margin-bottom: 12px; }
.skill-card h3 { font-size: 17px; margin-bottom: 8px; }
.skill-card p { color: var(--text-dim); font-size: 14px; }

/* ===== 项目卡片 ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.project-card {
  display: block;
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 28px 26px;
  text-decoration: none;
  color: var(--text);
  position: relative;
  overflow: hidden;
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
}
.project-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(60% 80% at 80% 0%, rgba(124, 140, 255, 0.12), transparent 60%);
  opacity: 0;
  transition: opacity 0.3s;
}
.project-card:hover {
  transform: translateY(-6px);
  border-color: rgba(183, 140, 255, 0.45);
  box-shadow: 0 12px 40px rgba(183, 140, 255, 0.15);
}
.project-card:hover::before { opacity: 1; }

.project-tags { display: flex; gap: 8px; margin-bottom: 14px; flex-wrap: wrap; }
.tag {
  font-size: 12px;
  padding: 3px 10px;
  border-radius: 999px;
  background: rgba(124, 140, 255, 0.12);
  border: 1px solid rgba(124, 140, 255, 0.28);
  color: var(--primary);
}
.project-card h3 { font-size: 19px; margin-bottom: 10px; }
.project-card p { color: var(--text-dim); font-size: 14px; margin-bottom: 16px; }
.project-link { font-size: 14px; color: var(--accent2); font-weight: 600; }

/* ===== 联系卡片 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.contact-card {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 30px;
  text-align: center;
  text-decoration: none;
  color: var(--text);
  backdrop-filter: blur(10px);
  transition: transform 0.3s, border-color 0.3s;
}
.contact-card:hover { transform: translateY(-4px); border-color: rgba(110, 231, 255, 0.4); }
.contact-icon { font-size: 30px; display: block; margin-bottom: 10px; }
.contact-card h3 { font-size: 16px; margin-bottom: 6px; }
.contact-card p { color: var(--text-dim); font-size: 13.5px; }

/* ===== 页脚 ===== */
.footer {
  border-top: 1px solid var(--glass-border);
  padding: 26px;
  text-align: center;
  color: var(--text-dim);
  font-size: 13.5px;
}
.footer a { color: var(--accent2); text-decoration: none; }
.footer .icp { margin-top: 4px; font-size: 12.5px; }

/* ===== 滚动入场动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.visible { opacity: 1; transform: none; }

/* ===== 汉堡菜单按钮 ===== */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 6px;
}
.nav-toggle span {
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .nav-toggle { display: flex; }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--nav-bg-drop);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--glass-border);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease;
  }
  .nav-links.open { max-height: 340px; }
  .nav-links li { width: 100%; text-align: center; }
  .nav-links a { display: block; padding: 16px 0; font-size: 16px; }
  .nav-theme-item { justify-content: center; padding: 14px 0; }
  .theme-toggle { width: 38px; height: 38px; font-size: 18px; }
}

@media (max-width: 640px) {
  .hero-stats { gap: 28px; }
  .section { padding: 64px 20px; }
  .hero-name { letter-spacing: 8px; }
}