/* ========== 深色模式（默认） ========== */
:root {
  --bg-start: #071029;
  --bg-end: #0b1220;
  --card-bg: rgba(255,255,255,0.03);
  --text: #ffffff;
  --text-muted: #94a3b8;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --border: rgba(255,255,255,0.08);
  --shadow: rgba(0,0,0,0.3);
  --btn-shadow: rgba(59,130,246,0.4);
}

/* ========== 亮色模式 ========== */
[data-theme="light"] {
  --bg-start: #f0f4f8;
  --bg-end: #e2e8f0;
  --card-bg: rgba(0,0,0,0.03);
  --text: #1e293b;
  --text-muted: #475569;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --border: rgba(0,0,0,0.1);
  --shadow: rgba(0,0,0,0.1);
  --btn-shadow: rgba(37,99,235,0.3);
}

* {
  box-sizing: border-box;
  transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background: linear-gradient(180deg, var(--bg-start) 0%, var(--bg-end) 100%);
  color: var(--text);
  line-height: 1.5;
}

.container { max-width: 1000px; margin: 0 auto; padding: 1rem; }

.site-header {
  .site-header {
  background: rgba(7, 16, 41, 0.8);
}
[data-theme="light"] .site-header {
  background: rgba(240, 244, 248, 0.9);
}
}
/* 因为背景色使用了变量，需要额外定义 RGB 值用于透明背景，但为了简化，直接使用背景色变量加透明度 */
[data-theme="light"] .site-header {
  background: rgba(240, 244, 248, 0.9);
}
[data-theme="dark"] .site-header {
  background: rgba(7, 16, 41, 0.8);
}

.site-header .container { display: flex; align-items: center; gap: 1rem; }
.logo { font-weight: 700; color: var(--text); text-decoration: none; }
.main-nav { margin-left: auto; display: flex; gap: 1rem; align-items: center; }
.main-nav a { color: var(--text-muted); text-decoration: none; }
.nav-toggle { display: none; background: transparent; border: 0; color: var(--text); font-size: 1.2rem; cursor: pointer; }

/* 主题切换按钮 */
.theme-toggle {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 30px;
  padding: 0.3rem 0.7rem;
  cursor: pointer;
  font-size: 1.1rem;
  color: var(--text);
  transition: all 0.2s;
}
.theme-toggle:hover {
  background: var(--card-bg);
  transform: scale(1.02);
}

.hero {
  padding: 4rem 0;
  background: linear-gradient(135deg, rgba(59,130,246,0.12), transparent 40%);
  border-radius: var(--radius, 10px);
  margin: 1rem 0;
}
.hero h1 { font-size: 2rem; margin: 0 0 0.5rem; }

.btn {
  display: inline-block;
  background: var(--accent);
  color: white;
  padding: 0.6rem 1rem;
  border-radius: 8px;
  text-decoration: none;
  margin-top: 0.5rem;
  transition: all 0.2s ease;
}
.btn:hover {
  background: var(--accent-hover);
  transform: scale(1.02);
  box-shadow: 0 4px 12px var(--btn-shadow);
}

.section { margin: 2rem 0; padding: 0.5rem; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; }
.card {
  background: var(--card-bg);
  padding: 1rem;
  border-radius: 8px;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}
.card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 24px var(--shadow);
}
.card .btn:hover {
  transform: translateY(-2px);
}

label { display: block; margin: 0.5rem 0; }
input, textarea {
  width: 100%;
  padding: 0.5rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
}
input:invalid, textarea:invalid { border-color: #f87171; }
.form-msg { margin-top: 0.5rem; color: #d1fae5; }

.site-footer {
  padding: 1rem 0;
  border-top: 1px solid var(--border);
  margin-top: 2rem;
  text-align: center;
  color: var(--text-muted);
}

/* 移动端导航 */
@media (max-width: 700px) {
  .main-nav {
    position: absolute;
    right: 1rem;
    top: 56px;
    background: var(--card-bg);
    backdrop-filter: blur(12px);
    padding: 0.5rem;
    border-radius: 8px;
    flex-direction: column;
    display: none;
    gap: 0.5rem;
    border: 1px solid var(--border);
  }
  .main-nav.show { display: flex; }
  .nav-toggle { display: block; }
  .theme-toggle {
    margin-left: auto;
    order: 2;
  }
}

/* 打字机光标 */
#typed-title::after {
  content: "|";
  animation: blink 0.8s step-end infinite;
  margin-left: 2px;
  opacity: 0.8;
}
@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.comment-input {
  width: 100%;
  margin-bottom: 0.5rem;
  padding: 0.4rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
}
#comment-status {
  margin-bottom: 1rem;
}
#comments-list .card {
  background: var(--card-bg);
  padding: 0.8rem;
  border-radius: 8px;
  margin-bottom: 1rem;
}
.delete-comment-btn {
  background: none;
  border: none;
  color: #f87171;
  cursor: pointer;
  font-size: 0.8rem;
  padding: 0;
}
.delete-comment-btn:hover {
  text-decoration: underline;
}