/* ============================================
   网络安全互动问答站 — 赛博糖果守护者主题
   守护蓝 · 警报橙 · 能量黄 · 糖果粉
   双层阴影 · 安全粒子 · 圆润果冻质感
   ============================================ */

/* --- 字体（圆润可爱手写涂鸦风） --- */
@import url('https://fonts.googleapis.com/css2?family=ZCOOL+KuaiLe&display=swap');

:root {
  --color-primary: #4A90D9;
  --color-primary-hover: #5da0e6;
  --color-accent: #FF8C42;
  --color-accent-hover: #ffa366;
  --color-pink: #FF6B9D;
  --color-pink-light: rgba(255, 107, 157, 0.12);
  --color-gold: #FFD166;
  --color-gold-light: rgba(255, 209, 102, 0.25);
  --color-bg-start: #0b1a2e;
  --color-bg-mid: #162d50;
  --color-bg-end: #0a1628;
  --color-card-bg: rgba(15, 30, 55, 0.92);
  --color-card-border: rgba(74, 144, 217, 0.25);
  --color-text: #e8edf5;
  --color-text-muted: #8faec9;
  --color-text-bright: #f0f4fa;
  --color-text-dark: #e8edf5;
  --color-text-dark-muted: #b0c8e0;
  --color-success: #55EFC4;
  --color-error: #FF6B6B;
  --color-warning: #FF8C42;
  --radius-card: 24px;
  --radius-btn: 50px;
  --shadow-card: 0 8px 32px rgba(74, 144, 217, 0.25);
  --shadow-hover: 0 16px 48px rgba(74, 144, 217, 0.35);
  --shadow-glow: 0 0 20px rgba(255, 209, 102, 0.25);
  --transition: 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  --font-stack: 'ZCOOL KuaiLe', -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
}

/* --- Reset & Base --- */
*, *::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(160deg, #0b1a2e 0%, #162d50 30%, #1a3a5c 55%, #0f2840 80%, #0a1628 100%);
  color: var(--color-text);
  min-height: 100vh;
  line-height: 1.7;
  overflow-x: hidden;
  position: relative;
}

/* ===== 深邃星空背景 ===== */
.star-field {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

/* 大星星 — 柔和光晕 */
.bouncing-star {
  position: absolute;
  border-radius: 50%;
  opacity: 0;
  animation: bounceStar var(--dur, 8s) ease-in-out infinite;
  animation-delay: var(--delay, 0s);
  pointer-events: none;
  box-shadow: 0 0 6px currentColor, 0 0 12px currentColor;
}

@keyframes bounceStar {
  0%   { transform: translate(0, 0) scale(0.3); opacity: 0; }
  15%  { opacity: 0.6; }
  50%  { transform: translate(calc(var(--dx, 80px) * 0.6), calc(var(--dy, -60px) * 0.6)) scale(1); opacity: 0.8; }
  80%  { opacity: 0.4; }
  100% { transform: translate(calc(var(--dx, 120px) * 1.2), calc(var(--dy, -80px) * 1.2)) scale(0.2); opacity: 0; }
}

/* 小星星 — 闪烁 */
.twinkle-star {
  position: fixed;
  border-radius: 50%;
  pointer-events: none;
  z-index: 0;
  animation: twinkle var(--dur, 4s) ease-in-out infinite alternate;
  animation-delay: var(--delay, 0s);
  box-shadow: 0 0 3px currentColor, 0 0 8px currentColor;
}

@keyframes twinkle {
  0%   { opacity: 0.1; transform: scale(0.6); }
  50%  { opacity: 0.5; transform: scale(1.1); }
  100% { opacity: 0.15; transform: scale(0.7); }
}

/* --- 渐变标题 --- */
.gradient-title {
  font-size: 2.4rem;
  font-weight: 400;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.5rem;
  text-shadow: none;
  position: relative;
  z-index: 1;
}

.gradient-title-sm {
  font-size: 1.6rem;
  font-weight: 400;
  background: linear-gradient(135deg, var(--color-accent), var(--color-primary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 0.4rem;
}

/* --- 导航栏（半透明果冻质感） --- */
.nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.8rem 2rem;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(74, 144, 217, 0.12);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-bar .logo {
  font-size: 1.3rem;
  font-weight: 400;
  color: var(--color-text-bright);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  text-shadow: 0 0 12px rgba(74, 144, 217, 0.2);
}

.nav-bar .logo:hover {
  color: var(--color-primary);
}

.nav-links {
  display: flex;
  gap: 0.4rem;
  list-style: none;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.65);
  text-decoration: none;
  font-size: 0.9rem;
  padding: 0.4rem 1rem;
  border-radius: 30px;
  transition: var(--transition);
  position: relative;
}

.nav-links a:hover {
  color: var(--color-text-bright);
  background: rgba(255, 255, 255, 0.08);
}

.nav-links a.active {
  color: #fff;
  background: rgba(74, 144, 217, 0.25);
  box-shadow: 0 0 20px rgba(74, 144, 217, 0.15);
}

/* --- 主容器 --- */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  position: relative;
  z-index: 1;
}

/* ===== 魔法糖纸卡片 ===== */
.card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 2rem;
  box-shadow: var(--shadow-card), 0 0 20px rgba(255, 159, 67, 0.06);
  transition: var(--transition);
  backdrop-filter: blur(8px);
  position: relative;
  overflow: hidden;
  color: var(--color-text-dark);
}

/* 卡片边缘发光光晕 */
.card::before {
  content: '';
  position: absolute;
  top: -1px; left: -1px;
  right: -1px; bottom: -1px;
  border-radius: var(--radius-card);
  background: linear-gradient(135deg, rgba(74, 144, 217, 0.15), transparent 40%, transparent 60%, rgba(255, 140, 66, 0.1));
  pointer-events: none;
  z-index: -1;
  opacity: 0.6;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover), 0 0 30px rgba(74, 144, 217, 0.12);
  border-color: rgba(74, 144, 217, 0.3);
}

/* 卡片内文字 */
.card p {
  line-height: 1.8;
  color: var(--color-text-dark);
}

.card h2,
.card .card-title {
  color: var(--color-text-dark);
}

/* 卡片内高亮信息用阳光金 */
.card .highlight {
  color: var(--color-gold);
  text-shadow: 0 0 12px rgba(255, 217, 61, 0.3);
}

/* --- 卡片网格 --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.8rem;
  margin-top: 1.8rem;
}

/* ===== 果冻星星按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 2rem;
  border: none;
  border-radius: var(--radius-btn);
  font-size: 1rem;
  font-weight: 400;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  color: var(--color-text-bright);
  position: relative;
  overflow: hidden;
  letter-spacing: 0.3px;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), #5da0e6);
  color: #fff;
  box-shadow: 0 4px 20px rgba(74, 144, 217, 0.35), 0 0 12px rgba(74, 144, 217, 0.15);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: 0 8px 32px rgba(74, 144, 217, 0.5), 0 0 24px rgba(255, 209, 102, 0.25);
}

/* 果冻Q弹按下效果 */
.btn-primary:active {
  transform: scale(0.92);
  box-shadow: 0 2px 8px rgba(74, 144, 217, 0.3);
  transition-duration: 0.08s;
}

/* 金色星星粒子（用伪元素模拟） */
.btn-primary::after {
  content: '✦ ✧ ✦';
  position: absolute;
  top: -10px;
  right: -10px;
  font-size: 0.6rem;
  color: var(--color-gold);
  opacity: 0;
  transition: var(--transition);
  pointer-events: none;
}

.btn-primary:active::after {
  opacity: 1;
  top: -20px;
  right: -5px;
  animation: starBurst 0.4s ease-out forwards;
}

@keyframes starBurst {
  0%   { opacity: 1; transform: scale(0.5) rotate(0deg); }
  50%  { opacity: 0.8; transform: scale(1.5) rotate(180deg); }
  100% { opacity: 0; transform: scale(2) rotate(360deg) translateY(-20px); }
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(74, 144, 217, 0.2);
  color: var(--color-primary);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateY(-3px);
  box-shadow: 0 0 20px rgba(74, 144, 217, 0.12);
}

.btn-secondary:active {
  transform: scale(0.92);
}

.btn-success {
  background: linear-gradient(135deg, var(--color-accent), #ffa366);
  color: #fff;
  box-shadow: 0 4px 20px rgba(255, 140, 66, 0.35);
}

.btn-success:hover {
  transform: translateY(-3px) scale(1.04);
  box-shadow: 0 8px 32px rgba(255, 140, 66, 0.5);
}

.btn-success:active {
  transform: scale(0.92);
}

.btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

/* --- 徽章 / 标签（糖果色） --- */
.badge {
  display: inline-block;
  padding: 0.25rem 0.9rem;
  border-radius: 20px;
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.3px;
}

.badge-primary {
  background: rgba(74, 144, 217, 0.15);
  color: var(--color-primary);
  box-shadow: 0 0 8px rgba(74, 144, 217, 0.1);
}

.badge-success {
  background: rgba(85, 239, 196, 0.2);
  color: #00b894;
}

.badge-warning {
  background: rgba(255, 140, 66, 0.2);
  color: var(--color-accent);
}

/* --- 进度条（薄荷绿渐变果冻条） --- */
.progress-bar {
  width: 100%;
  height: 10px;
  background: rgba(255, 255, 255, 0.3);
  border-radius: 10px;
  overflow: hidden;
  margin: 0.5rem 0;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.06);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-success), #00b894);
  border-radius: 10px;
  transition: width 0.6s ease;
  box-shadow: 0 0 12px rgba(85, 239, 196, 0.3);
}

/* --- 弹幕容器 --- */
.danmaku-area {
  position: relative;
  width: 100%;
  height: 300px;
  overflow: hidden;
  background: rgba(255, 245, 230, 0.5);
  border-radius: var(--radius-card);
  border: 1px solid rgba(255, 159, 67, 0.15);
  box-shadow: inset 0 0 40px rgba(255, 159, 67, 0.08);
}

.danmaku-item {
  position: absolute;
  white-space: nowrap;
  padding: 0.3rem 1rem;
  border-radius: 20px;
  font-size: 0.9rem;
  animation: danmaku-scroll 8s linear forwards;
  pointer-events: none;
  backdrop-filter: blur(4px);
}

@keyframes danmaku-scroll {
  from { transform: translateX(100%); }
  to   { transform: translateX(-100%); }
}

/* --- 选项按钮 (闯关用) --- */
.option-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: 0.9rem 1.2rem;
  margin: 0.5rem 0;
  background: rgba(74, 144, 217, 0.12);
  border: 2px solid rgba(74, 144, 217, 0.25);
  border-radius: 16px;
  color: #fff;
  font-size: 1rem;
  font-family: var(--font-stack);
  cursor: pointer;
  transition: var(--transition);
}

.option-btn:hover {
  background: rgba(74, 144, 217, 0.22);
  border-color: var(--color-primary);
  transform: translateX(6px);
  box-shadow: 0 0 20px rgba(74, 144, 217, 0.2);
}

.option-btn.correct {
  background: rgba(85, 239, 196, 0.2);
  border-color: var(--color-success);
  color: #00b894;
  box-shadow: 0 0 20px rgba(85, 239, 196, 0.15);
}

.option-btn.wrong {
  background: rgba(255, 107, 107, 0.2);
  border-color: var(--color-error);
  color: var(--color-error);
}

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

/* --- 案例卡片 --- */
.case-card {
  background: var(--color-card-bg);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-card);
  padding: 1.8rem;
  margin: 1rem 0;
  box-shadow: var(--shadow-card);
  transition: var(--transition);
  cursor: pointer;
  backdrop-filter: blur(8px);
  position: relative;
  color: var(--color-text-dark);
}

.case-card::before {
  content: '';
  position: absolute;
  top: -1px; left: -1px;
  right: -1px; bottom: -1px;
  border-radius: var(--radius-card);
  background: linear-gradient(135deg, rgba(74, 144, 217, 0.15), transparent 40%, transparent 60%, rgba(255, 140, 66, 0.1));
  pointer-events: none;
  z-index: -1;
  opacity: 0.5;
}

.case-card:hover {
  transform: translateY(-6px) scale(1.01);
  box-shadow: var(--shadow-hover), 0 0 30px rgba(74, 144, 217, 0.1);
  border-color: rgba(74, 144, 217, 0.3);
}

.case-card .case-tag {
  display: inline-block;
  padding: 0.15rem 0.6rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 400;
  margin-bottom: 0.5rem;
}

.case-card p {
  color: var(--color-text-dark-muted);
}

.case-card .case-title {
  color: var(--color-text-dark);
}

.case-card .case-brief {
  color: var(--color-text-dark-muted);
}

/* --- Toast 提示（糖果色） --- */
.toast {
  position: fixed;
  top: 1.5rem;
  right: 1.5rem;
  padding: 0.8rem 1.5rem;
  border-radius: 16px;
  font-weight: 400;
  z-index: 999;
  animation: toast-in 0.3s ease, toast-out 0.3s ease 2.5s forwards;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(8px);
  font-size: 0.95rem;
}

.toast-success {
  background: rgba(85, 239, 196, 0.92);
  color: #1a3a2a;
}

.toast-error {
  background: rgba(255, 107, 107, 0.92);
  color: #fff;
}

@keyframes toast-in {
  from { opacity: 0; transform: translateX(60px); }
  to   { opacity: 1; transform: translateX(0); }
}

@keyframes toast-out {
  from { opacity: 1; }
  to   { opacity: 0; transform: translateX(60px); }
}

/* --- 呼吸光晕图标（所有导航图标、功能图标） --- */
.icon-glow {
  display: inline-block;
  animation: breathe 3s ease-in-out infinite;
  filter: drop-shadow(0 0 6px rgba(255, 107, 107, 0.2));
}

@keyframes breathe {
  0%   { transform: scale(1); filter: drop-shadow(0 0 6px rgba(255, 107, 107, 0.15)); }
  50%  { transform: scale(1.08); filter: drop-shadow(0 0 14px rgba(255, 107, 107, 0.4)); }
  100% { transform: scale(1); filter: drop-shadow(0 0 6px rgba(255, 107, 107, 0.15)); }
}

/* --- 页脚 --- */
.footer {
  text-align: center;
  padding: 2rem;
  color: rgba(255, 255, 255, 0.4);
  font-size: 0.85rem;
  border-top: 1px solid rgba(74, 144, 217, 0.1);
  margin-top: 3rem;
  position: relative;
  z-index: 1;
}

/* --- 响应式 --- */
@media (max-width: 768px) {
  .nav-bar {
    flex-direction: column;
    gap: 0.6rem;
    padding: 0.6rem 1rem;
    background: rgba(255, 255, 255, 0.15);
  }
  .nav-links {
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.3rem;
  }
  .nav-links a {
    font-size: 0.8rem;
    padding: 0.3rem 0.8rem;
  }
  .container { padding: 1.2rem 1rem; }
  .gradient-title { font-size: 1.6rem; }
  .card-grid { grid-template-columns: 1fr; gap: 1.2rem; }
  .card { padding: 1.4rem; }
  .shield-row { gap: 0.5rem; }
  .shield-item { padding: 0.4rem 0.7rem; font-size: 0.7rem; }
  .shield-item .shield-icon { font-size: 1.2rem; }
  .card-footer-deco { font-size: 0.65rem; }
  .case-card { padding: 1.2rem; }
}

@media (max-width: 480px) {
  html { font-size: 14px; }
  .card { padding: 1.2rem; }
  .container { padding: 1rem 0.8rem; }
  .btn { padding: 0.6rem 1.4rem; font-size: 0.9rem; }
}

/* --- 卡片双层阴影增强（赛博糖果守护者风格） --- */
.card {
  box-shadow:
    var(--shadow-card),
    0 0 30px rgba(255, 209, 102, 0.08);
}

.card:hover {
  box-shadow:
    var(--shadow-hover),
    0 0 40px rgba(255, 209, 102, 0.15);
}

/* --- 案例卡片增强 --- */
.case-card {
  border-left: 4px solid transparent;
  background-image:
    linear-gradient(var(--color-card-bg), var(--color-card-bg)),
    linear-gradient(135deg, rgba(74, 144, 217, 0.08), transparent 50%, rgba(255, 140, 66, 0.05));
  background-origin: padding-box, border-box;
  background-clip: padding-box, border-box;
  transition: var(--transition);
}

.case-card:hover {
  border-left-color: var(--color-primary);
}

/* --- 筛选按钮增强 --- */
.filter-btn {
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}

.filter-btn::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 20px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  opacity: 0;
  transition: opacity 0.3s ease;
  z-index: -1;
}

.filter-btn.active {
  color: #fff;
  background: linear-gradient(135deg, var(--color-primary), #5da0e6);
  border-color: transparent;
  box-shadow: 0 4px 16px rgba(74, 144, 217, 0.3);
}

.filter-btn.active::after {
  opacity: 1;
}

/* --- 导航栏增强 --- */
.nav-bar {
  background: rgba(255, 255, 255, 0.35);
  box-shadow: 0 2px 20px rgba(74, 144, 217, 0.08);
}

.nav-links a.active {
  background: linear-gradient(135deg, rgba(74, 144, 217, 0.12), rgba(255, 140, 66, 0.08));
  box-shadow: 0 0 20px rgba(74, 144, 217, 0.1);
}

/* --- 进度条增强（能量块效果） --- */
.progress-fill {
  background-image:
    linear-gradient(90deg, var(--color-success), #00b894),
    repeating-linear-gradient(
      90deg,
      transparent,
      transparent 8px,
      rgba(255, 255, 255, 0.2) 8px,
      rgba(255, 255, 255, 0.2) 10px
    );
  background-blend-mode: overlay, normal;
}

/* --- 徽章增强 --- */
.badge {
  font-size: 0.7rem;
  letter-spacing: 0.3px;
  padding: 0.2rem 0.9rem;
}

/* --- 页面标题区增强 --- */
.hero-section {
  position: relative;
}

.hero-section::after {
  content: '🛡️ ✦ 🔒 ✦ ⭐ ✦ 🔐 ✦ 🛡️';
  display: block;
  text-align: center;
  font-size: 0.7rem;
  letter-spacing: 0.8rem;
  opacity: 0.12;
  margin-top: 0.8rem;
  pointer-events: none;
}

/* --- 容器内联间距优化 --- */
.container > section + section {
  margin-top: 1.5rem;
}

/* --- 卡片在深色背景下的增强 --- */
.card, .case-card {
  backdrop-filter: blur(8px);
}

.card p, .case-card p {
  color: var(--color-text);
}

.card .badge, .case-card .badge {
  color: var(--color-text-bright);
  font-weight: 400;
}

/* --- 卡片网格增强 --- */
.card-grid {
  gap: 1.8rem;
}

/* --- 弹幕区域增强 --- */
.danmaku-area {
  box-shadow:
    inset 0 0 40px rgba(255, 159, 67, 0.08),
    0 4px 20px rgba(74, 144, 217, 0.1);
}