/**
 * 🌸 大程地理实验室 · 大程课堂 V1.0 全局手账视觉主题规范
 * 
 * 核心设计语言：
 * 浅粉 + 奶油白 + 纸张纹理感 + 柔和手账边框 + 浮雕微光晕 + 精致教学感
 * 严禁使用黑色或深蓝作为主背景。
 */

:root {
  /* 基础主色板 */
  --bg-main: #FFF8FA;
  --bg-cream: #FFFDFD;
  --bg-card: #FFFFFF;
  --bg-card-subtle: #FFF4F7;
  --bg-tag-pink: #FFE6EC;
  --bg-tape: #FFD4DF;

  /* 品牌粉色调 */
  --color-pink-primary: #FF7B90;
  --color-pink-deep: #E65C73;
  --color-pink-light: #FF9EAE;
  --color-pink-border: #FFCCD6;
  --color-pink-border-subtle: #F6E2E6;

  /* 文字颜色 */
  --text-title: #3A2E39;
  --text-body: #55444E;
  --text-muted: #8C7883;
  --text-light: #B3A1AA;

  /* 辅助考纲色 */
  --color-vol1: #FF7B90;      /* 自然地理 · 必修一 */
  --color-vol2: #38A3A5;      /* 人文地理 · 必修二 */
  --color-sel1: #F77F00;      /* 地球运动 · 选必一 */
  --color-sel2: #0077B6;      /* 区域发展 · 选必二 */
  --color-sel3: #2B9348;      /* 资源安全 · 选必三 */
  --color-gaokao: #9D4EDD;    /* 高考专题 */

  /* 阴影与手账质感 */
  --shadow-soft: 0 4px 16px rgba(255, 123, 144, 0.08);
  --shadow-hover: 0 8px 24px rgba(255, 123, 144, 0.16);
  --shadow-card: 0 2px 10px rgba(90, 60, 70, 0.04), 0 1px 3px rgba(255, 123, 144, 0.06);
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 8px;
  --radius-pill: 999px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-main);
  color: var(--text-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}

/* 嵌套于主站 iframe 时，自动由主站 DualNavBar 统一托管，杜绝双导航栏 */
body.in-iframe nav.global-back-nav {
  display: none !important;
}

body.in-iframe header.classroom-header-banner {
  margin-top: 16px;
}

body.in-iframe .lesson-page-layout {
  margin-top: 16px;
}

body.in-iframe .in-iframe-breadcrumb {
  display: block !important;
}

/* 顶部全站标准返回手账胶囊 */
.global-back-nav {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(255, 248, 250, 0.92);
  backdrop-filter: blur(12px);
  padding: 12px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--color-pink-border-subtle);
}

.back-btn-capsule {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 18px;
  background: #FFFFFF;
  border: 1.5px solid var(--color-pink-primary);
  border-radius: var(--radius-pill);
  color: var(--color-pink-deep);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(255, 123, 144, 0.12);
  transition: all 0.25s ease;
  cursor: pointer;
}

.back-btn-capsule:hover {
  background: var(--color-pink-primary);
  color: #FFFFFF;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(255, 123, 144, 0.25);
}

.nav-brand-area {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-title);
  letter-spacing: 0.5px;
}

.brand-badge {
  background: var(--bg-tag-pink);
  color: var(--color-pink-deep);
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-pink-border);
}

/* 手账风格化顶部 Banner */
.classroom-header-banner {
  max-width: 1280px;
  margin: 24px auto 0;
  padding: 0 32px;
}

.banner-card {
  background: linear-gradient(135deg, #FFF0F4 0%, #FFFFFF 60%, #FFF5F7 100%);
  border: 2px dashed var(--color-pink-border);
  border-radius: var(--radius-lg);
  padding: 36px 48px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.banner-card::before {
  content: "";
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  width: 120px;
  height: 24px;
  background: rgba(255, 212, 223, 0.7);
  border-radius: 4px;
  transform: translateX(-50%) rotate(-1deg);
  box-shadow: 0 1px 4px rgba(0,0,0,0.05);
}

.banner-title-group {
  position: relative;
  z-index: 2;
}

.banner-main-title {
  font-size: 34px;
  font-weight: 800;
  color: var(--text-title);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.banner-main-title .cherry {
  font-size: 32px;
  animation: floatCherry 3s ease-in-out infinite alternate;
}

@keyframes floatCherry {
  0% { transform: rotate(0deg) translateY(0); }
  100% { transform: rotate(8deg) translateY(-4px); }
}

.banner-subtitle {
  font-size: 16px;
  color: var(--text-muted);
  font-weight: 500;
  letter-spacing: 0.5px;
}

.banner-stats-bar {
  display: flex;
  gap: 20px;
  margin-top: 20px;
}

.stat-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--text-body);
  background: rgba(255, 255, 255, 0.8);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-pink-border-subtle);
}

.stat-tag .stat-num {
  font-weight: 700;
  color: var(--color-pink-deep);
}

/* 主内容容器 */
.classroom-container {
  max-width: 1280px;
  margin: 28px auto 60px;
  padding: 0 32px;
}

/* 手账风分类导航 Tab */
.volume-nav-strip {
  display: flex;
  gap: 12px;
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: 24px;
}

.volume-tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background: #FFFFFF;
  border: 1.5px solid var(--color-pink-border);
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 600;
  color: var(--text-body);
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.volume-tab:hover {
  border-color: var(--color-pink-primary);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(255, 123, 144, 0.15);
}

.volume-tab.active {
  background: var(--color-pink-primary);
  border-color: var(--color-pink-primary);
  color: #FFFFFF;
  box-shadow: 0 4px 14px rgba(255, 123, 144, 0.3);
}

.volume-tab .tab-badge {
  font-size: 11px;
  padding: 1px 6px;
  border-radius: 10px;
  background: rgba(0, 0, 0, 0.06);
}

.volume-tab.active .tab-badge {
  background: rgba(255, 255, 255, 0.25);
}

/* 课程卡片网格 */
.lessons-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 24px;
}

.lesson-card {
  background: var(--bg-card);
  border: 1.5px solid var(--color-pink-border-subtle);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-card);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  position: relative;
  overflow: hidden;
  text-decoration: none;
  color: inherit;
}

.lesson-card:hover {
  transform: translateY(-4px);
  border-color: var(--color-pink-primary);
  box-shadow: var(--shadow-hover);
}

.card-top-tape {
  position: absolute;
  top: 0;
  left: 32px;
  width: 60px;
  height: 8px;
  background: var(--bg-tape);
  border-radius: 0 0 4px 4px;
}

.card-badge-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  padding-top: 4px;
}

.lesson-vol-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: var(--bg-tag-pink);
  color: var(--color-pink-deep);
}

.lesson-time-badge {
  font-size: 12px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
}

.lesson-card-title {
  font-size: 19px;
  font-weight: 700;
  color: var(--text-title);
  margin-bottom: 8px;
  line-height: 1.4;
}

.lesson-card-subtitle {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.cross-link-icons {
  display: flex;
  align-items: center;
  gap: 8px;
  padding-top: 14px;
  border-top: 1px dashed var(--color-pink-border-subtle);
  margin-top: auto;
}

.cross-badge-pill {
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  background: #FFF5F7;
  color: var(--color-pink-deep);
  border: 1px solid var(--color-pink-border-subtle);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* 通用弹窗与提示层 */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(58, 46, 57, 0.4);
  backdrop-filter: blur(6px);
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.modal-overlay.active {
  display: flex;
}

.modal-box {
  background: #FFFFFF;
  border: 2px solid var(--color-pink-primary);
  border-radius: var(--radius-lg);
  max-width: 580px;
  width: 100%;
  padding: 28px;
  box-shadow: 0 12px 36px rgba(255, 123, 144, 0.25);
  position: relative;
  animation: modalPop 0.25s ease-out;
}

@keyframes modalPop {
  0% { transform: scale(0.92); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  border-bottom: 1.5px dashed var(--color-pink-border);
  padding-bottom: 12px;
}

.modal-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-title);
  display: flex;
  align-items: center;
  gap: 8px;
}

.modal-close-btn {
  background: none;
  border: none;
  font-size: 22px;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
}

.modal-close-btn:hover {
  color: var(--color-pink-deep);
}

.modal-body {
  font-size: 14px;
  color: var(--text-body);
  line-height: 1.6;
}

.modal-footer {
  margin-top: 20px;
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

.btn-primary {
  background: var(--color-pink-primary);
  color: #FFFFFF;
  border: none;
  padding: 8px 20px;
  border-radius: var(--radius-pill);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary:hover {
  background: var(--color-pink-deep);
}