/* =============================================
   地震安全小卫士 — 共享样式表
   面向 8-15 岁中小学生
   ============================================= */

/* --- CSS 自定义属性（主题色） --- */
:root {
  --color-primary: #f59e0b;       /* 橙黄 — 主色调 */
  --color-primary-light: #fbbf24; /* 浅橙黄 */
  --color-secondary: #60a5fa;     /* 暖蓝 — 辅助色 */
  --color-secondary-light: #93c5fd;
  --color-bg-start: #0f172a;      /* 深蓝黑渐变起始 */
  --color-bg-end: #1e293b;        /* 深蓝黑渐变结束 */
  --color-card-bg: rgba(30, 41, 59, 0.85);
  --color-card-border: rgba(96, 165, 250, 0.2);
  --color-text: #e2e8f0;          /* 主文字 */
  --color-text-muted: #94a3b8;    /* 辅助文字 */
  --color-text-bright: #f8fafc;   /* 亮白文字 */
  --color-success: #34d399;       /* 正确/安全绿 */
  --color-danger: #f87171;        /* 错误/危险红 */
  --color-shadow: rgba(0, 0, 0, 0.3);
  --radius-card: 16px;
  --radius-btn: 12px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
}

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

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
               "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: linear-gradient(135deg, var(--color-bg-start), var(--color-bg-end));
  color: var(--color-text);
  min-height: 100vh;
  line-height: 1.6;
  padding: 20px;
}

/* --- 渐变标题 --- */
.gradient-title {
  font-size: 2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
  margin-bottom: 8px;
}

.gradient-subtitle {
  text-align: center;
  color: var(--color-text-muted);
  font-size: 1rem;
  margin-bottom: 24px;
}

/* --- 导航栏 --- */
.nav-bar {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 32px;
  padding: 12px 0;
}

.nav-bar a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 6px 16px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.05);
  transition: var(--transition-fast);
}

.nav-bar a:hover {
  color: var(--color-text-bright);
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-1px);
}

/* --- 卡片容器 --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  max-width: 960px;
  margin: 0 auto;
}

.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 24px;
  backdrop-filter: blur(8px);
  box-shadow: 0 4px 20px var(--color-shadow);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
  cursor: pointer;
  text-decoration: none;
  color: var(--color-text);
  display: block;
}

.card:hover {
  transform: translateY(-6px) scale(1.02);
  box-shadow: 0 8px 30px var(--color-shadow);
}

.card:active {
  transform: translateY(-2px) scale(0.98);
}

.card-icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
  display: block;
}

.card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--color-text-bright);
}

.card p {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* --- 按钮 --- */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border: none;
  border-radius: var(--radius-btn);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  text-decoration: none;
  text-align: center;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  color: #1e293b;
}

.btn-secondary {
  background: linear-gradient(135deg, var(--color-secondary), var(--color-secondary-light));
  color: #1e293b;
}

.btn-success {
  background: linear-gradient(135deg, var(--color-success), #6ee7b7);
  color: #1e293b;
}

.btn-danger {
  background: linear-gradient(135deg, var(--color-danger), #fca5a5);
  color: #1e293b;
}

.btn-back {
  background: rgba(255, 255, 255, 0.08);
  color: var(--color-text-muted);
  padding: 8px 20px;
  font-size: 0.85rem;
}

.btn-back:hover {
  background: rgba(255, 255, 255, 0.15);
  color: var(--color-text-bright);
}

/* --- 关卡页面容器 --- */
.level-container {
  max-width: 720px;
  margin: 0 auto;
  padding: 20px 0;
}

/* --- 场景描述框 --- */
.scene-box {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 24px;
  margin-bottom: 20px;
  backdrop-filter: blur(8px);
  box-shadow: 0 4px 20px var(--color-shadow);
}

.scene-box .scene-icon {
  font-size: 3rem;
  text-align: center;
  display: block;
  margin-bottom: 12px;
}

.scene-box p {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text);
}

/* --- 选项列表 --- */
.choices {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 20px 0;
}

.choice-btn {
  display: block;
  width: 100%;
  padding: 16px 20px;
  background: var(--color-card-bg);
  border: 2px solid var(--color-card-border);
  border-radius: var(--radius-btn);
  color: var(--color-text);
  font-size: 1rem;
  text-align: left;
  cursor: pointer;
  transition: var(--transition-fast);
}

.choice-btn:hover {
  border-color: var(--color-primary);
  background: rgba(245, 158, 11, 0.1);
  transform: translateX(4px);
}

.choice-btn:active {
  transform: translateX(2px);
}

.choice-btn.selected-correct {
  border-color: var(--color-success);
  background: rgba(52, 211, 153, 0.15);
}

.choice-btn.selected-wrong {
  border-color: var(--color-danger);
  background: rgba(248, 113, 113, 0.15);
}

/* --- 反馈框 --- */
.feedback {
  border-radius: var(--radius-card);
  padding: 20px;
  margin: 16px 0;
  display: none;
  animation: fadeSlideIn 0.4s ease;
}

.feedback.show {
  display: block;
}

.feedback.correct {
  background: rgba(52, 211, 153, 0.12);
  border: 1px solid rgba(52, 211, 153, 0.3);
}

.feedback.wrong {
  background: rgba(248, 113, 113, 0.12);
  border: 1px solid rgba(248, 113, 113, 0.3);
}

.feedback h4 {
  font-size: 1.1rem;
  margin-bottom: 8px;
}

.feedback.correct h4 { color: var(--color-success); }
.feedback.wrong h4 { color: var(--color-danger); }

.feedback p {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text);
}

.feedback .safety-tip {
  margin-top: 12px;
  padding: 12px;
  background: rgba(245, 158, 11, 0.1);
  border-left: 3px solid var(--color-primary);
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--color-primary-light);
}

/* --- 进度条 --- */
.progress-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 24px;
}

.progress-track {
  flex: 1;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  overflow: hidden;
}

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

.progress-text {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  white-space: nowrap;
}

/* --- 安全标语横幅 --- */
.safety-banner {
  text-align: center;
  padding: 16px;
  margin: 24px 0;
  background: rgba(245, 158, 11, 0.08);
  border-radius: var(--radius-card);
  border: 1px dashed rgba(245, 158, 11, 0.3);
}

.safety-banner p {
  font-size: 0.95rem;
  color: var(--color-primary-light);
  font-weight: 600;
}

/* --- 知识卡片（关卡完成页） --- */
.knowledge-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 24px;
  margin: 16px 0;
}

.knowledge-card h4 {
  color: var(--color-secondary-light);
  margin-bottom: 12px;
  font-size: 1.1rem;
}

.knowledge-card ul {
  list-style: none;
  padding: 0;
}

.knowledge-card li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
  font-size: 0.95rem;
  color: var(--color-text);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.knowledge-card li:last-child {
  border-bottom: none;
}

.knowledge-card li::before {
  content: "⭐";
  position: absolute;
  left: 0;
  top: 8px;
  font-size: 0.8rem;
}

/* --- 完成页面庆祝 --- */
.celebration {
  text-align: center;
  padding: 40px 20px;
}

.celebration .big-icon {
  font-size: 4rem;
  margin-bottom: 16px;
}

.celebration h2 {
  font-size: 1.8rem;
  color: var(--color-text-bright);
  margin-bottom: 12px;
}

.celebration p {
  color: var(--color-text-muted);
  margin-bottom: 24px;
}

/* --- 动画 --- */
@keyframes fadeSlideIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.fade-in {
  animation: fadeIn 0.5s ease;
}

/* --- 响应式 --- */
@media (max-width: 600px) {
  body {
    padding: 12px;
  }

  .gradient-title {
    font-size: 1.5rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .card {
    padding: 18px;
  }

  .scene-box {
    padding: 18px;
  }

  .choice-btn {
    padding: 14px 16px;
    font-size: 0.95rem;
  }

  .nav-bar {
    gap: 8px;
  }

  .nav-bar a {
    font-size: 0.8rem;
    padding: 4px 12px;
  }
}