/* ============================================
   牙齿外伤科普小站 — 全局样式
   暗色主题 · 卡片式 · 微动效 · 响应式
   ============================================ */

/* --- CSS 自定义属性（主题色） --- */
:root {
  --color-primary: #4f8cf7;
  --color-primary-light: #7eb8ff;
  --color-accent: #ff9500;
  --color-accent-light: #ffb340;
  --color-bg: #f0f4ff;
  --color-bg-card: #ffffff;
  --color-bg-card-hover: #f8faff;
  --color-text: #2d3748;
  --color-text-muted: #718096;
  --color-border: #e2e8f0;
  --color-success: #48bb78;
  --color-danger: #fc8181;
  --color-info: #63b3ed;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  --font-stack: -apple-system, 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

/* --- 全局重置 --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-stack);
  background: linear-gradient(135deg, #e8f0fe 0%, #f0f4ff 30%, #fef9e7 70%, #e8f0fe 100%);
  color: var(--color-text);
  min-height: 100vh;
  line-height: 1.6;
  padding: 20px;
}

/* --- 容器 --- */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 16px;
}

/* --- 标题渐变文字 --- */
.gradient-text {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

/* --- 卡片 --- */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 32px rgba(0, 0, 0, 0.1);
}

.card-accent {
  border-left: 4px solid var(--color-accent);
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font-stack);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  color: #fff;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  box-shadow: 0 4px 16px rgba(79, 140, 247, 0.25);
}

.btn:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 6px 24px rgba(79, 140, 247, 0.4);
}

.btn:active {
  transform: translateY(0) scale(0.98);
}

.btn-accent {
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-light));
  box-shadow: 0 4px 16px rgba(255, 149, 0, 0.25);
}

.btn-accent:hover {
  box-shadow: 0 6px 24px rgba(255, 149, 0, 0.4);
}

.btn-danger {
  background: linear-gradient(135deg, var(--color-danger), #dc2626);
  box-shadow: 0 4px 16px rgba(239, 68, 68, 0.3);
}

.btn-lg {
  padding: 18px 40px;
  font-size: 1.25rem;
  border-radius: var(--radius);
}

.btn-block {
  width: 100%;
}

/* --- 导航栏 --- */
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  margin-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
}

.navbar-brand {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.navbar-links {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.navbar-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  padding: 6px 12px;
  border-radius: 8px;
  transition: all var(--transition);
  font-size: 0.9rem;
}

.navbar-links a:hover {
  color: var(--color-text);
  background: rgba(79, 140, 247, 0.08);
}

/* --- 返回首页链接 --- */
.back-home {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 16px;
  transition: color var(--transition);
}

.back-home:hover {
  color: var(--color-primary-light);
}

/* --- 网格布局 --- */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.grid-3 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 20px;
}

.grid-4 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  gap: 16px;
}

/* --- 页面标题区 --- */
.page-header {
  text-align: center;
  margin-bottom: 32px;
}

.page-header h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.page-header p {
  color: var(--color-text-muted);
  font-size: 1.05rem;
}

/* --- 徽章 / 标签 --- */
.badge {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}

.badge-primary {
  background: rgba(79, 140, 247, 0.15);
  color: var(--color-primary);
}

.badge-accent {
  background: rgba(255, 149, 0, 0.15);
  color: var(--color-accent);
}

.badge-success {
  background: rgba(72, 187, 120, 0.15);
  color: var(--color-success);
}

/* --- 进度条 --- */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--color-border);
  border-radius: 4px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  border-radius: 4px;
  transition: width 0.5s ease;
}

/* --- 弹窗 / 模态框 --- */
.modal-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.3s ease;
}

.modal-content {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px;
  max-width: 480px;
  width: 90%;
  box-shadow: 0 8px 48px rgba(0, 0, 0, 0.12);
  animation: slideUp 0.3s ease;
}

/* --- Toast 提示 --- */
.toast {
  position: fixed;
  top: 20px;
  right: 20px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 14px 20px;
  box-shadow: var(--shadow);
  z-index: 2000;
  animation: slideIn 0.3s ease;
  max-width: 360px;
  font-size: 0.95rem;
}

.toast-success { border-left: 4px solid var(--color-success); }
.toast-error { border-left: 4px solid var(--color-danger); }
.toast-info { border-left: 4px solid var(--color-info); }

/* --- 动画关键帧 --- */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(40px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

/* --- 响应式 --- */
@media (max-width: 768px) {
  body { padding: 12px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; }
  .page-header h1 { font-size: 1.5rem; }
  .btn-lg { padding: 14px 28px; font-size: 1.1rem; }
  .navbar { flex-direction: column; gap: 10px; }
  .navbar-links { width: 100%; justify-content: center; }
}

@media (max-width: 480px) {
  .card { padding: 16px; }
  .modal-content { padding: 20px; }
}

/* --- 弹跳牙齿（背景装饰） --- */
.bounce-tooth {
  position: fixed;
  width: 48px;
  height: 48px;
  font-size: 40px;
  line-height: 48px;
  text-align: center;
  cursor: grab;
  z-index: 99999;
  user-select: none;
  pointer-events: none;
  filter: drop-shadow(0 2px 8px rgba(99,102,241,0.3));
  transition: none;
}
.bounce-tooth:active {
  cursor: grabbing;
}

/* --- 工具类 --- */
.text-center { text-align: center; }
.mt-8 { margin-top: 8px; }
.mt-16 { margin-top: 16px; }
.mt-24 { margin-top: 24px; }
.mt-32 { margin-top: 32px; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.gap-12 { gap: 12px; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-col { flex-direction: column; }
.hidden { display: none; }