/* ============================================
   溺水救援问答游戏 — 共享样式表
   暗色海洋主题 · 卡片式 UI · 微动效 · 响应式
   ============================================ */

/* --- CSS 自定义属性（主题色） --- */
:root {
  --color-bg-start: #0a0e27;
  --color-bg-end: #1a1040;
  --color-primary: #00d4ff;
  --color-primary-dim: #0099cc;
  --color-accent: #ff6b6b;
  --color-accent-gold: #ffd700;
  --color-success: #4ade80;
  --color-warning: #fbbf24;
  --color-danger: #ef4444;
  --color-text: #e0e0e0;
  --color-text-dim: #a0a0b0;
  --color-card-bg: rgba(255, 255, 255, 0.06);
  --color-card-border: rgba(255, 255, 255, 0.1);
  --color-card-hover: rgba(255, 255, 255, 0.12);
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --transition: 0.25s 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", "Helvetica Neue", 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: 0;
  -webkit-font-smoothing: antialiased;
}

/* --- 渐变标题 --- */
.gradient-title {
  font-size: 2.2rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent-gold));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
}

.gradient-title-sm {
  font-size: 1.6rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent-gold));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* --- 容器 --- */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 1.5rem 1rem;
}

/* --- 导航栏 --- */
nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.75rem 1rem;
  background: rgba(0, 0, 0, 0.3);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-card-border);
}

nav .logo {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--color-primary);
  text-decoration: none;
}

nav .nav-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

nav .nav-links a {
  color: var(--color-text-dim);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  transition: background var(--transition), color var(--transition);
}

nav .nav-links a:hover {
  background: var(--color-card-bg);
  color: var(--color-primary);
}

/* --- 卡片 --- */
.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  backdrop-filter: blur(4px);
  transition: transform var(--transition), box-shadow var(--transition),
              background var(--transition);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  background: var(--color-card-hover);
}

.card:active {
  transform: translateY(-1px);
}

/* --- 按钮 --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition),
              background var(--transition), opacity var(--transition);
  text-decoration: none;
  color: #fff;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 212, 255, 0.3);
}

.btn:active {
  transform: translateY(0);
  box-shadow: none;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dim));
  color: #000;
}

.btn-success {
  background: linear-gradient(135deg, var(--color-success), #22c55e);
  color: #000;
}

.btn-danger {
  background: linear-gradient(135deg, var(--color-danger), #dc2626);
}

.btn-gold {
  background: linear-gradient(135deg, var(--color-accent-gold), #f59e0b);
  color: #000;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: #000;
}

/* --- 选项按钮（游戏用） --- */
.option-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: 1rem 1.25rem;
  margin-bottom: 0.75rem;
  background: var(--color-card-bg);
  border: 2px solid var(--color-card-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 1rem;
  cursor: pointer;
  transition: all var(--transition);
}

.option-btn:hover {
  border-color: var(--color-primary);
  background: rgba(0, 212, 255, 0.08);
  transform: translateX(4px);
}

.option-btn.correct {
  border-color: var(--color-success);
  background: rgba(74, 222, 128, 0.15);
  color: var(--color-success);
}

.option-btn.wrong {
  border-color: var(--color-danger);
  background: rgba(239, 68, 68, 0.15);
  color: var(--color-danger);
}

.option-btn:disabled {
  cursor: default;
  transform: none !important;
}

/* --- 进度条 --- */
.progress-bar {
  width: 100%;
  height: 8px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 4px;
  overflow: hidden;
  margin: 1rem 0;
}

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

/* --- 徽章 --- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 600;
}

.badge-primary {
  background: rgba(0, 212, 255, 0.2);
  color: var(--color-primary);
}

.badge-gold {
  background: rgba(255, 215, 0, 0.2);
  color: var(--color-accent-gold);
}

/* --- 反馈区域 --- */
.feedback-box {
  padding: 1.25rem;
  border-radius: var(--radius-sm);
  margin: 1rem 0;
  border-left: 4px solid;
}

.feedback-box.success {
  background: rgba(74, 222, 128, 0.1);
  border-color: var(--color-success);
  color: var(--color-success);
}

.feedback-box.error {
  background: rgba(239, 68, 68, 0.1);
  border-color: var(--color-danger);
  color: var(--color-danger);
}

.feedback-box.info {
  background: rgba(0, 212, 255, 0.1);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* --- 动态演示图（CSS 动画） --- */
.demo-scene {
  width: 100%;
  max-width: 400px;
  height: 200px;
  margin: 1rem auto;
  border-radius: var(--radius-sm);
  background: linear-gradient(180deg, #0a1628, #0d1f3c);
  position: relative;
  overflow: hidden;
  border: 1px solid var(--color-card-border);
}

/* 波浪动画 */
.wave {
  position: absolute;
  bottom: 0;
  width: 200%;
  height: 60px;
  background: repeating-linear-gradient(
    90deg,
    rgba(0, 212, 255, 0.3) 0px,
    rgba(0, 212, 255, 0.1) 20px,
    transparent 40px
  );
  animation: waveMove 3s linear infinite;
}

@keyframes waveMove {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

/* 小人动画 */
.person-swim {
  position: absolute;
  bottom: 50px;
  left: 50%;
  font-size: 2rem;
  animation: personBob 1.5s ease-in-out infinite;
}

@keyframes personBob {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

/* 救生圈动画 */
.life-ring {
  position: absolute;
  bottom: 70px;
  right: 20%;
  font-size: 2rem;
  animation: ringFloat 2s ease-in-out infinite;
}

@keyframes ringFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-12px) rotate(10deg); }
}

/* --- 证书样式 --- */
.certificate {
  background: linear-gradient(135deg, #1a1a3e, #2a1a4e);
  border: 3px solid var(--color-accent-gold);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  max-width: 500px;
  margin: 2rem auto;
  box-shadow: 0 0 40px rgba(255, 215, 0, 0.15);
}

.certificate .seal {
  font-size: 4rem;
  margin-bottom: 0.5rem;
}

.certificate h2 {
  color: var(--color-accent-gold);
  font-size: 1.8rem;
  margin-bottom: 0.5rem;
}

.certificate .name {
  font-size: 1.4rem;
  color: #fff;
  margin: 0.5rem 0;
}

.certificate .score-line {
  color: var(--color-text-dim);
  font-size: 1rem;
}

/* 动态徽章 */
.dynamic-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  border-radius: 30px;
  background: linear-gradient(135deg, #ffd700, #f59e0b);
  color: #000;
  font-weight: 700;
  font-size: 1.1rem;
  animation: badgePulse 2s ease-in-out infinite;
  box-shadow: 0 0 20px rgba(255, 215, 0, 0.4);
}

@keyframes badgePulse {
  0%, 100% { transform: scale(1); box-shadow: 0 0 20px rgba(255, 215, 0, 0.4); }
  50% { transform: scale(1.05); box-shadow: 0 0 30px rgba(255, 215, 0, 0.7); }
}

/* --- 响应式 --- */
@media (max-width: 600px) {
  html { font-size: 14px; }

  .container { padding: 1rem 0.75rem; }

  .gradient-title { font-size: 1.6rem; }

  .card { padding: 1rem; }

  .btn { padding: 0.6rem 1.2rem; font-size: 0.9rem; }

  nav { flex-direction: column; align-items: flex-start; }

  nav .nav-links { width: 100%; justify-content: center; }

  .certificate { padding: 1.5rem; margin: 1rem; }
}

@media (min-width: 601px) and (max-width: 900px) {
  .container { padding: 1.25rem; }
}

/* --- 工具类 --- */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.flex-center { display: flex; align-items: center; justify-content: center; }
.flex-col { flex-direction: column; }
.gap-1 { gap: 0.5rem; }
.gap-2 { gap: 1rem; }