/* ===== 宁夏之韵 — 共享样式 ===== */
:root {
  --nx-primary: #f97316;       /* 暖橙 — 宁夏枸杞色 */
  --nx-primary-light: #fb923c;
  --nx-primary-dark: #ea580c;
  --nx-accent: #fbbf24;        /* 亮黄 */
  --nx-bg-start: #0f172a;      /* 深空蓝黑 */
  --nx-bg-end: #1e293b;
  --nx-card-bg: rgba(255, 255, 255, 0.06);
  --nx-card-border: rgba(255, 255, 255, 0.1);
  --nx-text: #e2e8f0;
  --nx-text-dim: #94a3b8;
  --nx-glow: 0 0 20px rgba(249, 115, 22, 0.3);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

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

/* ===== 导航栏 ===== */
header.site-header {
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--nx-card-border);
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 100;
}

nav {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

nav .logo {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(90deg, var(--nx-primary), var(--nx-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
}

nav .nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
}

nav .nav-links a {
  color: var(--nx-text-dim);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: 8px;
  font-size: 0.9rem;
  transition: all 0.25s;
}

nav .nav-links a:hover,
nav .nav-links a.active {
  color: var(--nx-primary-light);
  background: rgba(249, 115, 22, 0.1);
}

/* ===== 主容器 ===== */
main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

/* ===== 标题渐变文字 ===== */
h1.gradient-title {
  font-size: 2.8rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--nx-primary), var(--nx-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
}

h2 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--nx-text);
}

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 20px;
  margin: 32px 0;
}

.card {
  background: var(--nx-card-bg);
  border: 1px solid var(--nx-card-border);
  border-radius: 16px;
  padding: 24px;
  text-decoration: none;
  color: var(--nx-text);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--nx-primary), var(--nx-accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s ease;
}

.card:hover {
  transform: translateY(-6px);
  border-color: var(--nx-primary);
  box-shadow: var(--nx-glow);
}

.card:hover::before {
  transform: scaleX(1);
}

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

.card .card-icon {
  font-size: 2.4rem;
  margin-bottom: 12px;
  display: block;
}

.card h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.card p {
  color: var(--nx-text-dim);
  font-size: 0.88rem;
  line-height: 1.5;
}

/* ===== 内容区卡片 (非链接) ===== */
.content-card {
  background: var(--nx-card-bg);
  border: 1px solid var(--nx-card-border);
  border-radius: 16px;
  padding: 28px;
  margin: 24px 0;
  transition: border-color 0.3s;
}

.content-card:hover {
  border-color: rgba(249, 115, 22, 0.3);
}

.content-card h3 {
  font-size: 1.2rem;
  margin-bottom: 12px;
  color: var(--nx-primary-light);
}

.content-card p {
  color: var(--nx-text-dim);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 8px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  padding: 10px 24px;
  background: linear-gradient(135deg, var(--nx-primary), var(--nx-primary-dark));
  color: #fff;
  border: none;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.25s;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(249, 115, 22, 0.4);
}

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

/* ===== 图片 ===== */
img.responsive-img {
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  display: block;
  margin: 16px 0;
}

/* ===== 页脚 ===== */
footer {
  text-align: center;
  padding: 32px 24px;
  color: var(--nx-text-dim);
  font-size: 0.82rem;
  border-top: 1px solid var(--nx-card-border);
}

/* ===== 粒子画布 (特效) ===== */
#particle-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
  pointer-events: none;
}

/* ===== AI 问答区 ===== */
.qa-section {
  margin: 32px 0;
  padding: 24px;
  background: var(--nx-card-bg);
  border: 1px solid var(--nx-card-border);
  border-radius: 16px;
}
.qa-section h3 {
  margin-bottom: 4px;
}
.qa-hint {
  color: var(--nx-text-dim);
  font-size: 14px;
  margin-bottom: 16px;
}
.qa-messages {
  max-height: 300px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 14px;
  padding: 8px;
  background: rgba(0,0,0,0.2);
  border-radius: 10px;
}
.qa-q {
  align-self: flex-end;
  background: var(--nx-primary);
  color: #fff;
  padding: 8px 14px;
  border-radius: 14px 14px 4px 14px;
  max-width: 80%;
  font-size: 14px;
}
.qa-a {
  align-self: flex-start;
  background: rgba(255,255,255,0.1);
  color: var(--nx-text);
  padding: 8px 14px;
  border-radius: 14px 14px 14px 4px;
  max-width: 80%;
  font-size: 14px;
  line-height: 1.5;
}
.qa-input-row {
  display: flex;
  gap: 10px;
}
.qa-input-row input {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--nx-card-border);
  border-radius: 10px;
  background: rgba(255,255,255,0.08);
  color: var(--nx-text);
  font-size: 14px;
  outline: none;
}
.qa-input-row input:focus {
  border-color: var(--nx-primary);
  box-shadow: 0 0 0 2px rgba(249, 115, 22, 0.2);
}
.qa-input-row .btn {
  padding: 10px 20px;
  border: none;
  border-radius: 10px;
}
.qa-input-row .btn:hover {
  transform: none; /* 消除按钮悬停缩放, 避免变形 */
}

/* ===== 响应式 ===== */
/* ===== 问答页 ===== */
.quiz-container {
  max-width: 700px;
  margin: 0 auto;
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 12px;
}

.quiz-progress {
  font-size: 0.9rem;
  color: var(--nx-text-dim);
}

.quiz-score {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--nx-accent);
  background: rgba(251, 191, 36, 0.1);
  padding: 6px 16px;
  border-radius: 20px;
}

.quiz-card {
  background: var(--nx-card-bg);
  border: 1px solid var(--nx-card-border);
  border-radius: 16px;
  padding: 32px;
  margin-bottom: 20px;
  transition: all 0.3s;
}

.quiz-card.correct {
  border-color: #22c55e;
  box-shadow: 0 0 20px rgba(34, 197, 94, 0.2);
}

.quiz-card.wrong {
  border-color: #ef4444;
  box-shadow: 0 0 20px rgba(239, 68, 68, 0.2);
}

.quiz-question {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 20px;
  line-height: 1.6;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-option {
  padding: 14px 20px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--nx-card-border);
  border-radius: 12px;
  color: var(--nx-text);
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.25s;
  text-align: left;
}

.quiz-option:hover:not(.disabled) {
  background: rgba(249, 115, 22, 0.15);
  border-color: var(--nx-primary);
  transform: translateX(4px);
}

.quiz-option.selected {
  border-color: var(--nx-primary);
  background: rgba(249, 115, 22, 0.2);
}

.quiz-option.correct-answer {
  border-color: #22c55e;
  background: rgba(34, 197, 94, 0.15);
  color: #bbf7d0;
}

.quiz-option.wrong-answer {
  border-color: #ef4444;
  background: rgba(239, 68, 68, 0.15);
  color: #fca5a5;
}

.quiz-option.disabled {
  cursor: default;
  opacity: 0.7;
}

.quiz-feedback {
  margin-top: 16px;
  padding: 14px 20px;
  border-radius: 12px;
  font-size: 0.95rem;
  line-height: 1.6;
  display: none;
}

.quiz-feedback.show {
  display: block;
  animation: fadeSlideIn 0.3s ease;
}

.quiz-feedback.correct {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.3);
  color: #bbf7d0;
}

.quiz-feedback.wrong {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: #fca5a5;
}

.quiz-btn-group {
  display: flex;
  gap: 12px;
  justify-content: center;
  margin-top: 24px;
  flex-wrap: wrap;
}

/* 结果面板 */
.quiz-result {
  text-align: center;
  padding: 40px 24px;
}

.quiz-result .result-icon {
  font-size: 4rem;
  margin-bottom: 16px;
}

.quiz-result h2 {
  font-size: 1.8rem;
  margin-bottom: 12px;
}

.quiz-result p {
  color: var(--nx-text-dim);
  font-size: 1.05rem;
  margin-bottom: 8px;
}

.quiz-result .score-big {
  font-size: 3rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--nx-primary), var(--nx-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 16px 0;
}

@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(10px); }
  to   { opacity: 1; transform: translateY(0); }
}

.quiz-restart-btn {
  margin-top: 20px;
}

@media (max-width: 768px) {
  h1.gradient-title {
    font-size: 1.8rem;
  }

  h2 {
    font-size: 1.3rem;
  }

  main {
    padding: 24px 16px 60px;
  }

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

  nav {
    flex-direction: column;
    height: auto;
    padding: 12px 0;
    gap: 8px;
  }

  nav .nav-links {
    flex-wrap: wrap;
    justify-content: center;
  }
}