/* ==================== 设计系统：Notion 风格 ==================== */
/*
 * 核心理念：暖纸笔记本在午后阳光下
 * - 暖纸画布 #f6f5f4，纯白卡片，1px 细线无阴影
 * - 文字层次靠 alpha（100/90/60/40%），不用多色
 * - 仅一个蓝色 CTA，其余 ghost/text
 * - 轮换强调色做彩色卡片背景
 * - Inter 主导 + Songti SC 衬线点缀
 */

:root {
  /* === 色彩 === */
  --blue: #0075de;
  --blue-hover: #0066c4;
  --paper: #f6f5f4;
  --white: #ffffff;
  --ink: #000000;
  --graphite: #615d59;
  --stone: #757575;
  --slate: #696969;
  --sky-tint: #e6f3fe;
  --marigold: #ffb110;
  --coral: #f64932;
  --signal-blue: #097fe8;
  --sky-wash: #62aef0;
  --midnight: #02093a;
  --border: rgba(0, 0, 0, 0.08);
  --border-light: rgba(0, 0, 0, 0.05);

  /* === 字体 === */
  --font-sans: "Inter", "PingFang SC", "Microsoft YaHei", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-editorial: "Songti SC", "STSong", "SimSun", "Noto Serif SC", serif;

  /* === 字号 === */
  --text-caption: 0.75rem;   /* 12px */
  --text-sm: 0.875rem;       /* 14px */
  --text-base: 1rem;         /* 16px */
  --text-lg: 1.125rem;       /* 18px */
  --text-xl: 1.25rem;        /* 20px */
  --text-heading-sm: 1.375rem; /* 22px */
  --text-heading: 2.5rem;    /* 40px */
  --text-heading-lg: 3rem;   /* 48px */
  --text-display-sm: 3.375rem; /* 54px */
  --text-display: 4.5rem;    /* 72px */

  /* === 行高 === */
  --leading-caption: 1.33;
  --leading-sm: 1.43;
  --leading-base: 1.5;
  --leading-lg: 1.56;
  --leading-heading-sm: 1.27;
  --leading-heading: 1.5;
  --leading-display-sm: 1.04;
  --leading-display: 1.21;

  /* === 字间距（大标题紧缩） === */
  --tracking-display: -0.028em;
  --tracking-display-sm: -0.02em;
  --tracking-heading: -0.01em;
  --tracking-caption: 0.01em;

  /* === 间距（4px 基准） === */
  --sp-4: 0.25rem;
  --sp-8: 0.5rem;
  --sp-12: 0.75rem;
  --sp-16: 1rem;
  --sp-20: 1.25rem;
  --sp-24: 1.5rem;
  --sp-28: 1.75rem;
  --sp-32: 2rem;
  --sp-36: 2.25rem;
  --sp-64: 4rem;
  --sp-80: 5rem;

  /* === 圆角 === */
  --radius-sm: 4px;
  --radius: 8px;
  --radius-lg: 12px;
  --radius-full: 9999px;

  /* === 阴影（仅导航栏使用） === */
  --shadow-nav: 0 0.7px 1.46px rgba(0,0,0,0.015), 0 3px 9px rgba(0,0,0,0.03);
  --shadow-ui: 0 4px 12px rgba(0,0,0,0.1);

  /* === 过渡 === */
  --ease: 0.2s ease;

  /* === 布局 === */
  --max-width: 1200px;
}

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

html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: 400;
  line-height: var(--leading-base);
  color: var(--ink);
  background: var(--paper);
  min-height: 100vh;
}

a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; cursor: pointer; }
input, select, textarea { font-family: inherit; font-size: inherit; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--sp-24);
}

/* ==================== 按钮 ==================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-8);
  padding: 6px 15px;
  border: none;
  border-radius: var(--radius);
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: var(--leading-sm);
  cursor: pointer;
  transition: all var(--ease);
  white-space: nowrap;
}

/* 唯一填充按钮 — 蓝色 CTA */
.btn-primary {
  background: var(--blue);
  color: var(--white);
}
.btn-primary:hover {
  background: var(--blue-hover);
}

/* Ghost 按钮 — 浅蓝底色 */
.btn-ghost {
  background: var(--sky-tint);
  color: var(--blue);
}
.btn-ghost:hover {
  background: #d6e9fc;
}

/* 纯文字按钮 */
.btn-text {
  background: transparent;
  color: rgba(0,0,0,0.9);
}
.btn-text:hover {
  background: rgba(0,0,0,0.04);
}

/* Outline 按钮 — 带边框（登录/注册小按钮） */
.btn-outline {
  background: transparent;
  color: rgba(0,0,0,0.9);
  border: 1px solid rgba(0,0,0,0.15);
}
.btn-outline:hover {
  background: rgba(0,0,0,0.04);
  border-color: rgba(0,0,0,0.25);
}

.btn-sm { padding: 5px 12px; font-size: var(--text-caption); border-radius: var(--radius-sm); }
.btn-lg { padding: 8px 20px; font-size: var(--text-base); border-radius: var(--radius); }
.btn-full { width: 100%; }

/* ==================== 导航 ==================== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-nav);
}
.header-inner {
  display: flex;
  align-items: center;
  height: 60px;
  gap: var(--sp-32);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--sp-8);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--ink);
  letter-spacing: var(--tracking-heading);
}
.logo-icon-img { width: 28px; height: 28px; border-radius: var(--radius-sm); object-fit: cover; }

.nav { display: flex; gap: 0; }
.nav-link {
  padding: var(--sp-12) var(--sp-16);
  border-radius: var(--radius);
  font-size: var(--text-sm);
  font-weight: 500;
  color: rgba(0,0,0,0.54);
  transition: color var(--ease);
}
.nav-link:hover { color: var(--ink); background: none; }
.nav-link.active { color: var(--ink); background: none; }

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--sp-12);
  margin-left: auto;
}

.points-badge {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  background: rgba(0,0,0,0.04);
  border-radius: var(--radius-full);
  font-size: var(--text-caption);
  font-weight: 500;
  color: var(--graphite);
}
.points-value { font-weight: 700; font-size: var(--text-sm); }

.header-avatar {
  width: 32px; height: 32px; border-radius: 50%;
  background: var(--border); display: inline-block; flex-shrink: 0;
}
.header-user-name {
  font-size: var(--text-sm); font-weight: 500; color: var(--ink); max-width: 80px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}

/* ==================== Hero ==================== */
.hero {
  padding: var(--sp-80) 0;
  text-align: center;
}

/* 装饰标记行 */
.hero-marks {
  display: flex;
  justify-content: center;
  gap: var(--sp-16);
  margin-bottom: var(--sp-28);
}
.hero-mark-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  animation: markFloat 3s ease-in-out infinite;
}
.hero-mark {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--white);
  border: 2px solid var(--mark-color, var(--border));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  transition: transform 0.2s ease;
}
.hero-mark:hover {
  transform: translateY(-3px);
}
.hero-mark-label {
  font-size: 11px;
  font-weight: 500;
  color: var(--stone);
  letter-spacing: 0.02em;
}

.hero-eyebrow {
  font-size: var(--text-caption);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--stone);
  margin-bottom: var(--sp-20);
}

.hero-title {
  font-family: var(--font-sans);
  font-size: var(--text-display);
  font-weight: 600;
  color: var(--ink);
  line-height: var(--leading-display);
  letter-spacing: var(--tracking-display);
  margin-bottom: var(--sp-20);
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

/* 标题中高亮 pill */
.hero-pill {
  display: inline-block;
  background: #f6d5b8;
  border-radius: var(--radius-full);
  padding: 4px var(--sp-24);
  color: var(--ink);
}

.hero-subhead {
  font-family: var(--font-editorial);
  font-size: var(--text-lg);
  font-weight: 400;
  color: var(--graphite);
  line-height: var(--leading-lg);
  max-width: 560px;
  margin: 0 auto var(--sp-32);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: var(--sp-12);
  margin-bottom: var(--sp-64);
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-32);
}

.stat-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.stat-number {
  font-family: var(--font-sans);
  font-size: var(--text-heading);
  font-weight: 600;
  color: var(--ink);
  letter-spacing: var(--tracking-heading);
  line-height: var(--leading-heading);
}
.stat-suffix {
  color: var(--blue);
  font-weight: 500;
}
.stat-label {
  font-size: var(--text-caption);
  font-weight: 500;
  color: var(--stone);
  letter-spacing: var(--tracking-caption);
}

.stat-divider {
  width: 1px;
  height: 36px;
  background: var(--border);
}

/* ==================== SPA 页面切换 ==================== */
.page-section { display: none; }
.page-section.active {
  display: block;
  animation: pageIn 0.4s ease both;
}

@keyframes pageIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* 子页面内容错落入场 */
.page-section.active .reveal-item {
  opacity: 0; transform: translateY(20px);
  transition: opacity 0.45s ease, transform 0.45s ease;
}
.page-section.active .reveal-item.visible {
  opacity: 1; transform: translateY(0);
}
/* 错开延迟 */
.page-section.active .reveal-stagger > *:nth-child(1) { transition-delay: 0.05s; }
.page-section.active .reveal-stagger > *:nth-child(2) { transition-delay: 0.12s; }
.page-section.active .reveal-stagger > *:nth-child(3) { transition-delay: 0.19s; }
.page-section.active .reveal-stagger > *:nth-child(4) { transition-delay: 0.26s; }
.page-section.active .reveal-stagger > *:nth-child(5) { transition-delay: 0.33s; }
.page-section.active .reveal-stagger > *:nth-child(6) { transition-delay: 0.40s; }

/* ==================== 通用区块 ==================== */
.section-title {
  font-family: var(--font-sans);
  font-size: var(--text-heading);
  font-weight: 600;
  text-align: center;
  letter-spacing: var(--tracking-heading);
  color: var(--ink);
  line-height: var(--leading-heading);
  margin-bottom: var(--sp-8);
}
.section-desc {
  text-align: center;
  color: var(--graphite);
  margin-bottom: var(--sp-36);
  font-size: var(--text-base);
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-24);
  flex-wrap: wrap;
  gap: var(--sp-16);
}
.section-header .section-title { margin-bottom: 0; text-align: left; font-size: var(--text-heading-sm); }

/* ==================== 页面头部（非首页） ==================== */
.page-header {
  text-align: center;
  padding: var(--sp-64) 0 var(--sp-36);
}
.page-title {
  font-size: var(--text-heading-lg);
  font-weight: 600;
  letter-spacing: var(--tracking-heading);
  color: var(--ink);
  line-height: var(--leading-heading);
  margin-bottom: var(--sp-8);
}
.page-desc {
  color: var(--graphite);
  font-size: var(--text-base);
}

/* ==================== 内容区块间距 ==================== */
#page-resources, #page-upload, #page-rules, #page-about {
  padding: 0 0 var(--sp-80);
}

/* ==================== 学科卡片（彩色强调背景） ==================== */
.subjects-inline { margin-bottom: var(--sp-32); }
.subjects-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--sp-16);
}

.subject-row {
  display: flex;
  align-items: center;
  gap: var(--sp-16);
  margin-bottom: var(--sp-16);
}
.subject-row:last-child { margin-bottom: 0; }
.subject-row-label {
  width: 80px; flex-shrink: 0;
  font-size: var(--text-sm); font-weight: 600; color: var(--stone);
  text-align: right; letter-spacing: 0.03em;
}
.subject-row-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-16);
  flex: 1;
}
.subject-row:last-child .subject-row-cards {
  grid-template-columns: 1fr;
  max-width: calc(33.333% - 11px);
}

.subject-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--sp-8);
  padding: var(--sp-24) var(--sp-16);
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--ease);
}
.subject-card:hover { border-color: rgba(0,0,0,0.15); transform: translateY(-2px); }
.subject-card:nth-child(5n+1):hover { background: #fff8e7; }
.subject-card:nth-child(5n+2):hover { background: #fff0ed; }
.subject-card:nth-child(5n+3):hover { background: var(--sky-tint); }
.subject-card:nth-child(5n+4):hover { background: #f0f0ff; }
.subject-card:nth-child(5n+5):hover { background: #e8f8f0; }
.subject-icon { font-size: 32px; }
.subject-name { font-size: var(--text-base); font-weight: 600; color: var(--ink); }
.subject-count { font-size: var(--text-caption); font-weight: 500; color: var(--stone); }

/* ==================== 学科分类（pill 风格） ==================== */
.subjects-section { margin-bottom: var(--sp-36); }
.subjects-section-header {
  display: flex; align-items: baseline; gap: var(--sp-12);
  margin-bottom: var(--sp-20);
}
.subjects-section-title {
  font-size: var(--text-heading-sm); font-weight: 600; color: var(--ink);
  letter-spacing: var(--tracking-heading);
}
.subjects-section-hint { font-size: var(--text-caption); color: var(--stone); }

.subjects-pill-grid {
  display: grid; grid-template-columns: repeat(5, 1fr); gap: var(--sp-12);
}
.type-pill .subject-pill-name {
  display: block; text-align: justify; text-align-last: justify; width: 100%;
}
.subject-pill {
  display: flex; align-items: center; gap: var(--sp-12);
  padding: var(--sp-12) var(--sp-16);
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--radius-lg); cursor: pointer;
  transition: all var(--ease); text-align: left;
}
.subject-pill:hover {
  border-color: rgba(0,0,0,0.2); transform: translateY(-2px);
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.subject-pill-icon { font-size: 28px; flex-shrink: 0; }
.subject-pill-info { display: flex; flex-direction: column; gap: 1px; min-width: 0; }
.subject-pill-name { font-size: var(--text-sm); font-weight: 600; color: var(--ink); }
.subject-pill-count { font-size: var(--text-caption); color: var(--stone); }

/* ==================== 资源筛选 ==================== */
.filter-panel {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--sp-24);
  margin-bottom: var(--sp-32);
}
.filter-bar {
  padding: 0;
  margin-bottom: 0;
}
.filter-row {
  display: flex;
  gap: var(--sp-16);
  align-items: flex-end;
  flex-wrap: wrap;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}
.filter-group label {
  font-size: var(--text-caption);
  color: var(--stone);
  font-weight: 500;
  letter-spacing: var(--tracking-caption);
}

.filter-group select,
.filter-group input {
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--ink);
  background: var(--page);
  min-width: 140px;
  transition: border-color var(--ease);
}
.filter-group select:focus,
.filter-group input:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(0,117,222,0.1);
}
.filter-search { flex: 1; min-width: 200px; }
.filter-search input { width: 100%; }

.empty-state {
  text-align: center;
  padding: var(--sp-64) 0;
  color: var(--stone);
  font-size: var(--text-base);
}

.resource-count-info {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: var(--sp-20);
}
.resource-count-label {
  font-size: var(--text-sm); font-weight: 500; color: var(--graphite);
}

/* ==================== 资源列表（白卡片，1px 边框无阴影） ==================== */
.resource-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-20);
}

.resource-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--sp-24);
  transition: border-color var(--ease), transform var(--ease);
}
.resource-card.reveal-item {
  opacity: 0; transform: translateY(16px);
}
.resource-card.reveal-item.visible {
  opacity: 1; transform: translateY(0);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
.resource-card:hover {
  border-color: rgba(0,0,0,0.15);
  transform: translateY(-2px);
}

.resource-type-tag {
  display: inline-block;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  font-size: var(--text-caption);
  font-weight: 500;
  margin-bottom: var(--sp-12);
}

.tag-lesson_plan { background: var(--sky-tint); color: var(--blue); }
.tag-courseware  { background: #fde8ec; color: var(--coral); }
.tag-exam        { background: #fff2e5; color: #c2701e; }
.tag-exercise    { background: #e6f0fa; color: #2e6ab0; }
.tag-summary     { background: #f0e8f6; color: #6b3fa0; }
.tag-mindmap             { background: #e8f5e9; color: #2e7d32; }
.tag-core_literacy       { background: #e3f2fd; color: #1565c0; }
.tag-teaching_reflection { background: #fff3e0; color: #e65100; }
.tag-learning_analysis   { background: #fce4ec; color: #c62828; }
.tag-other               { background: rgba(0,0,0,0.04); color: var(--stone); }

.resource-title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--sp-8);
  line-height: 1.4;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.resource-meta {
  font-size: var(--text-caption);
  font-weight: 500;
  color: var(--stone);
  display: flex;
  gap: var(--sp-16);
  margin-bottom: var(--sp-16);
}

.resource-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--sp-12);
  border-top: 1px solid var(--border-light);
}

.resource-uploader { font-size: var(--text-caption); color: var(--stone); }
.resource-btn { padding: 4px 14px; font-size: var(--text-caption); }

/* ==================== 资源页 Tabs ==================== */
.section-tabs { display: flex; gap: var(--sp-8); }
.tab-btn {
  padding: 5px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  background: var(--white);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--stone);
  cursor: pointer;
  transition: all var(--ease);
}
.tab-btn.active {
  background: var(--ink);
  color: var(--white);
  border-color: var(--ink);
}
.tab-btn:hover:not(.active) {
  border-color: rgba(0,0,0,0.2);
  color: var(--ink);
}

/* ==================== 首页最新资源 ==================== */
.latest-resources { padding: var(--sp-64) 0 var(--sp-80); }

/* ==================== 上传表单 ==================== */
.upload-section { padding: var(--sp-64) 0; }
.upload-form { max-width: 680px; margin: 0 auto; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-20); }

.form-group { margin-bottom: var(--sp-20); }
.form-group label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  margin-bottom: var(--sp-8);
  color: var(--ink);
}
.form-group label .required {
  color: #d64045;
  margin-left: 2px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--ink);
  background: var(--white);
  transition: border-color var(--ease);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(0,117,222,0.1);
}
.form-group textarea { resize: vertical; min-height: 80px; }

.file-upload-box {
  border: 2px dashed var(--border);
  border-radius: var(--radius-lg);
  padding: var(--sp-32);
  text-align: center;
  cursor: pointer;
  transition: all var(--ease);
  background: rgba(0,0,0,0.01);
}
.file-upload-box:hover,
.file-upload-box.dragover {
  border-color: var(--blue);
  background: var(--sky-tint);
}
.file-upload-icon { font-size: 36px; margin-bottom: var(--sp-8); }
.file-upload-box p { font-size: var(--text-sm); font-weight: 400; color: var(--graphite); }
.file-hint { font-size: var(--text-caption); color: var(--stone); margin-top: 4px; }
.upload-submit { margin-top: var(--sp-8); }

.upload-image-btn {
  width: 80px; height: 80px; border: 2px dashed var(--border); border-radius: var(--radius);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  cursor: pointer; transition: all var(--ease); gap: 2px; color: var(--stone);
  background: var(--page);
}
.upload-image-btn:hover { border-color: var(--blue); color: var(--blue); background: var(--sky-tint); }
.upload-image-preview { width: 80px; height: 80px; border-radius: var(--radius); object-fit: cover; border: 1px solid var(--border); }
.upload-image-wrap { position: relative; display: inline-block; }
.upload-image-remove {
  position: absolute; top: -6px; right: -6px; width: 20px; height: 20px;
  border-radius: 50%; background: var(--ink); color: #fff; border: none;
  font-size: 12px; cursor: pointer; display: flex; align-items: center; justify-content: center;
}

/* ==================== 关于我们 ==================== */
.about-section { padding: var(--sp-64) 0; }
.about-content { display: flex; gap: var(--sp-64); align-items: flex-start; }
.about-text { flex: 1; }
.about-text p {
  margin-bottom: var(--sp-16);
  color: var(--graphite);
  line-height: var(--leading-base);
}
.about-qrcode { text-align: center; flex-shrink: 0; }
.about-qrcode p { margin-top: var(--sp-8); font-size: var(--text-caption); color: var(--stone); }
.qrcode-img {
  width: 180px;
  height: 180px;
  object-fit: contain;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
}
.about-contact { margin-top: var(--sp-24); }
.about-contact h4 {
  font-family: var(--font-editorial);
  font-size: var(--text-lg);
  font-weight: 400;
  color: var(--ink);
  margin-bottom: var(--sp-16);
}
.contact-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-16);
  margin-bottom: var(--sp-16);
}
.contact-card {
  display: flex;
  align-items: center;
  gap: var(--sp-12);
  padding: var(--sp-16);
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.contact-icon { font-size: 22px; }
.contact-card p { margin-bottom: 2px; font-size: var(--text-sm); font-weight: 400; color: var(--graphite); }
.contact-card p strong { color: var(--ink); font-weight: 600; }
.contact-email { color: var(--stone); font-size: var(--text-caption); }

/* ==================== 用户中心 ==================== */
.profile-layout {
  display: flex; max-width: var(--max-width); margin: 0 auto; min-height: calc(100vh - 60px);
}

/* 左侧栏 */
.profile-sidebar {
  width: 240px; flex-shrink: 0;
  background: var(--white); border-right: 1px solid var(--border);
  padding: var(--sp-32) var(--sp-24); text-align: center;
  position: sticky; top: 60px; height: calc(100vh - 60px); overflow-y: auto;
}
.profile-avatar-wrap {
  position: relative; width: 72px; height: 72px; margin: 0 auto var(--sp-12);
}
.profile-level-badge {
  position: absolute; top: -4px; left: -4px;
  width: 26px; height: 26px; border-radius: 50%;
  background: var(--white); border: 1.5px solid var(--border);
  display: flex; align-items: center; justify-content: center;
  font-size: 14px; z-index: 1; box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

.profile-avatar-large {
  width: 72px; height: 72px; border-radius: 50%;
  background: var(--border); margin: 0 auto var(--sp-12);
  background-size: cover; background-position: center;
  cursor: pointer; transition: opacity var(--ease);
  position: relative;
}
.profile-avatar-large:hover { opacity: 0.8; }
.profile-avatar-large::after {
  content: '📷'; position: absolute; bottom: 0; right: 0;
  width: 24px; height: 24px; border-radius: 50%;
  background: var(--white); border: 1px solid var(--border);
  font-size: 12px; display: flex; align-items: center; justify-content: center;
}
.profile-sidebar-name {
  font-size: var(--text-lg); font-weight: 600; color: var(--ink); margin-bottom: 2px;
}
.profile-sidebar-role { font-size: var(--text-caption); color: var(--stone); margin-bottom: var(--sp-20); }
.profile-sidebar-stat {
  padding: var(--sp-12) 0; border-top: 1px solid var(--border-light);
}
.profile-sidebar-stat-num {
  display: block; font-size: var(--text-heading-sm); font-weight: 700; color: var(--ink);
  letter-spacing: var(--tracking-heading);
}
.profile-sidebar-stat-label { font-size: var(--text-caption); color: var(--stone); }

/* 右侧 */
.profile-main { flex: 1; min-width: 0; padding: var(--sp-36); background: var(--paper); }
.profile-section {
  background: var(--white); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: var(--sp-28); margin-bottom: var(--sp-24);
}
.profile-section-title {
  font-size: var(--text-lg); font-weight: 600; color: var(--ink);
  letter-spacing: var(--tracking-heading); margin-bottom: var(--sp-20);
}
.profile-form-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-16);
}
.profile-input {
  width: 100%; padding: 9px 12px; border: 1px solid var(--border); border-radius: var(--radius);
  font-size: var(--text-sm); color: var(--ink); background: var(--white); transition: border-color var(--ease);
}
.profile-input:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(0,117,222,0.1); }
.profile-input:disabled { background: rgba(0,0,0,0.02); color: var(--stone); }

/* 积分规则网格 */
.profile-points-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--sp-8);
}
.profile-points-item {
  text-align: center; padding: var(--sp-12); border-radius: var(--radius);
  font-size: var(--text-sm); color: var(--graphite);
  background: rgba(0,0,0,0.02);
}
.profile-points-item span {
  display: block; font-size: var(--text-lg); font-weight: 700; margin-bottom: 2px;
}
.profile-points-item.earn span { color: #2d6a4f; }
.profile-points-item.spend span { color: #d64045; }

/* 签到日历 */
.checkin-calendar {
  font-size: var(--text-caption);
}
.cal-header {
  display: grid; grid-template-columns: repeat(7, 1fr); gap: 2px;
  text-align: center; color: var(--stone); margin-bottom: 4px;
  font-weight: 500;
}
.cal-grid {
  display: grid; grid-template-columns: repeat(7, 1fr); gap: 2px;
  text-align: center;
}
.cal-grid span {
  padding: 4px 0; border-radius: 4px; font-size: 11px;
}
.cal-grid span.checked {
  background: #e8f0ec; color: #2d6a4f; font-weight: 600;
}
.cal-grid span.today {
  box-shadow: inset 0 0 0 1.5px var(--blue); color: var(--blue); font-weight: 600;
}
.cal-grid span.today.checked {
  background: #e8f0ec; color: #2d6a4f; box-shadow: inset 0 0 0 1.5px #2d6a4f;
}

/* 积分明细日志 */
.profile-log-row {
  display: flex; justify-content: space-between; align-items: center;
  padding: 8px 0; border-bottom: 1px solid var(--border-light);
  font-size: var(--text-sm);
}
.profile-log-row:last-child { border-bottom: none; }
.profile-log-amount { font-weight: 600; }
.profile-log-amount.plus { color: #2d6a4f; }
.profile-log-amount.minus { color: #d64045; }

/* 上传记录表 */
.profile-table-wrap { overflow-x: auto; }
.profile-table { width: 100%; border-collapse: collapse; font-size: var(--text-sm); }
.profile-table th {
  text-align: left; padding: 8px var(--sp-12); font-weight: 600; color: var(--ink);
  border-bottom: 2px solid var(--ink); font-size: var(--text-caption); letter-spacing: 0.03em;
}
.profile-table td {
  padding: 10px var(--sp-12); border-bottom: 1px solid var(--border-light); color: var(--graphite);
}
.profile-table tr:hover td { background: rgba(0,0,0,0.01); }
.profile-empty { text-align: center; color: var(--stone); padding: var(--sp-32) 0 !important; }

/* ==================== 管理后台 ==================== */
.admin-hero {
  margin-bottom: var(--sp-36);
}
.admin-eyebrow {
  font-size: var(--text-caption); font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--stone); margin-bottom: var(--sp-8);
}
.admin-title {
  font-size: var(--text-heading-lg); font-weight: 600; color: var(--ink);
  letter-spacing: var(--tracking-heading); line-height: var(--leading-heading); margin-bottom: var(--sp-8);
}
.admin-subhead {
  font-family: var(--font-editorial); font-size: var(--text-lg); font-weight: 400;
  color: var(--graphite); line-height: var(--leading-lg);
}

/* KPI 卡片 */
.admin-kpi-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--sp-16); margin-bottom: var(--sp-32);
}
.admin-kpi-card {
  background: var(--white); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: var(--sp-28); text-align: center; transition: border-color var(--ease);
}
.admin-kpi-card:hover { border-color: rgba(0,0,0,0.15); }
.admin-kpi-num {
  display: block; font-size: var(--text-heading); font-weight: 700; color: var(--ink);
  letter-spacing: var(--tracking-heading); line-height: var(--leading-heading);
}
.admin-kpi-label {
  font-size: var(--text-caption); color: var(--stone); font-weight: 500; margin-top: 4px;
  letter-spacing: var(--tracking-caption);
}

/* 双列面板 */
.admin-grid-2col {
  display: grid; grid-template-columns: 1fr 1fr; gap: var(--sp-24);
}
.admin-panel {
  background: var(--white); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: var(--sp-28);
}
.admin-panel-title {
  font-size: var(--text-lg); font-weight: 600; color: var(--ink);
  letter-spacing: var(--tracking-heading); margin-bottom: var(--sp-20);
}

/* 柱状图 */
.admin-chart-area { min-height: 200px; }
.admin-bar-row {
  display: flex; align-items: center; gap: var(--sp-12); margin-bottom: 6px;
}
.admin-bar-label-col {
  width: 48px; font-size: var(--text-caption); color: var(--stone); text-align: right; flex-shrink: 0;
}
.admin-bar-track {
  flex: 1; height: 22px; background: rgba(0,0,0,0.03); border-radius: 4px; overflow: hidden;
}
.admin-bar-fill {
  height: 100%; border-radius: 4px; transition: width 0.5s ease;
  display: flex; align-items: center; padding-left: 8px;
}
.admin-bar-fill span {
  font-size: 11px; font-weight: 600; color: #fff;
}

/* 活动时间线 */
.admin-activity-feed {
  display: flex; flex-direction: column; gap: 0;
}
.admin-activity-item {
  display: flex; align-items: center; gap: var(--sp-12); padding: 12px 0;
  border-bottom: 1px solid var(--border-light);
}
.admin-activity-item:last-child { border-bottom: none; }
.admin-activity-dot {
  width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0;
}
.admin-activity-dot.upload { background: var(--blue); }
.admin-activity-dot.download { background: #2d6a4f; }
.admin-activity-info { flex: 1; min-width: 0; }
.admin-activity-info .name {
  font-size: var(--text-sm); font-weight: 500; color: var(--ink);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.admin-activity-info .meta {
  font-size: var(--text-caption); color: var(--stone); margin-top: 1px;
}
.admin-activity-status {
  font-size: var(--text-caption); font-weight: 500; padding: 2px 10px;
  border-radius: var(--radius-full); white-space: nowrap;
}
.admin-activity-status.success { background: #e8f0ec; color: #2d6a4f; }
.admin-activity-status.pending { background: #fff8e7; color: #e89d01; }
.admin-activity-status.rejected { background: #fde8ec; color: #d64045; }

@media (max-width: 768px) {
  .profile-layout { flex-direction: column; }
  .profile-sidebar {
    position: static; width: 100%; height: auto; border-right: none;
    border-bottom: 1px solid var(--border); display: flex; flex-wrap: wrap;
    gap: var(--sp-16); align-items: center; justify-content: center; padding: var(--sp-20);
  }
  .profile-sidebar-stat { border-top: none; padding: 0 var(--sp-12); }
  .profile-main { padding: var(--sp-20); }
  .profile-form-grid { grid-template-columns: 1fr; }
  .profile-points-grid { grid-template-columns: repeat(2, 1fr); }

  .admin-kpi-grid { grid-template-columns: repeat(2, 1fr); }
  .admin-grid-2col { grid-template-columns: 1fr; }
}

/* ==================== 页脚 ==================== */
.footer {
  background: var(--paper);
  border-top: 1px solid var(--border);
  color: var(--stone);
  padding: var(--sp-32) 0;
  text-align: center;
  font-size: var(--text-sm);
}
.footer-beian {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-12);
  flex-wrap: wrap;
  margin-bottom: var(--sp-8);
}
.beian-link {
  font-size: var(--text-caption);
  color: var(--stone);
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: color var(--ease);
}
.beian-link:hover { color: rgba(0,0,0,0.8); }
.beian-divider { color: var(--border); }
.gongan-icon { width: 14px; height: 14px; opacity: 0.5; }
.footer-copyright { font-size: var(--text-caption); color: rgba(0,0,0,0.4); }

/* ==================== 客服助手 ==================== */
.chat-widget { position: fixed; right: var(--sp-24); bottom: var(--sp-24); z-index: 200; }
.chat-toggle {
  width: 48px;
  height: 48px;
  border: none;
  border-radius: 50%;
  background: var(--ink);
  color: var(--white);
  font-size: 20px;
  cursor: pointer;
  box-shadow: var(--shadow-ui);
  transition: transform var(--ease);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.chat-toggle:hover { transform: scale(1.06); }
.chat-toggle-icon { font-size: 20px; }
.chat-toggle-text { font-size: 8px; font-weight: 600; letter-spacing: 0.04em; }

.chat-panel {
  position: absolute;
  bottom: 64px;
  right: 0;
  width: 360px;
  height: 460px;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-ui);
  border: 1px solid var(--border);
  display: none;
  flex-direction: column;
  overflow: hidden;
}
.chat-panel.open { display: flex; }

.chat-header {
  background: var(--ink);
  color: var(--white);
  padding: var(--sp-16) var(--sp-20);
  position: relative;
}
.chat-header h3 { font-size: var(--text-base); font-weight: 600; }
.chat-header p { font-size: var(--text-caption); opacity: 0.6; margin-top: 2px; font-weight: 400; }

.chat-close {
  position: absolute;
  right: var(--sp-12);
  top: var(--sp-12);
  background: none;
  border: none;
  color: rgba(255,255,255,0.6);
  font-size: 22px;
  cursor: pointer;
  line-height: 1;
  transition: color var(--ease);
}
.chat-close:hover { color: var(--white); }

.chat-body {
  flex: 1;
  padding: var(--sp-16);
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: var(--sp-12);
  background: rgba(0,0,0,0.01);
}
.chat-msg { display: flex; gap: var(--sp-8); align-items: flex-start; }
.chat-msg.user { flex-direction: row-reverse; }
.msg-avatar { font-size: 26px; flex-shrink: 0; width: 36px; height: 36px; border-radius: 50%; overflow: hidden; }
.avatar-img { width: 100%; height: 100%; object-fit: cover; display: block; }
.msg-bubble {
  background: var(--white);
  border: 1px solid var(--border);
  padding: 10px 14px;
  border-radius: var(--radius-lg);
  border-top-left-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 400;
  max-width: 82%;
  line-height: var(--leading-sm);
  color: var(--ink);
}
.chat-msg.user .msg-bubble {
  background: var(--ink);
  color: var(--white);
  border-color: var(--ink);
  border-top-left-radius: var(--radius-lg);
  border-top-right-radius: var(--radius-sm);
}

.chat-input-area { border-top: 1px solid var(--border); background: var(--white); }
.quick-questions { display: flex; flex-wrap: wrap; gap: 6px; padding: var(--sp-12); }
.quick-btn {
  padding: 4px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  background: var(--white);
  font-size: var(--text-caption);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--ease);
  color: var(--stone);
}
.quick-btn:hover { background: rgba(0,0,0,0.04); color: var(--ink); border-color: rgba(0,0,0,0.15); }
.chat-input-row { display: flex; gap: var(--sp-8); padding: var(--sp-12); }
.chat-input {
  flex: 1;
  padding: 8px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 400;
  outline: none;
  background: rgba(0,0,0,0.02);
  color: var(--ink);
  transition: border-color var(--ease);
}
.chat-input:focus { border-color: var(--blue); }

/* ==================== 弹窗 ==================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.4);
  z-index: 300;
  display: flex;
  align-items: center;
  justify-content: center;
}
.modal {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: var(--sp-32);
  width: 400px;
  max-width: 90vw;
  position: relative;
  box-shadow: var(--shadow-ui);
  border: 1px solid var(--border);
}
.modal h3 {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--sp-24);
  letter-spacing: var(--tracking-heading);
}
.modal-close {
  position: absolute;
  top: var(--sp-12);
  right: var(--sp-16);
  background: none;
  border: none;
  font-size: 22px;
  cursor: pointer;
  color: var(--stone);
  transition: color var(--ease);
}
.modal-close:hover { color: var(--ink); }
.modal .form-group { margin-bottom: var(--sp-16); }
.modal .btn-full { margin-top: var(--sp-8); }

.modal-switch {
  margin-top: var(--sp-16);
  text-align: center;
  font-size: var(--text-sm);
  color: var(--graphite);
}
.modal-switch a {
  color: var(--blue);
  font-weight: 500;
  cursor: pointer;
}
.modal-switch a:hover { text-decoration: underline; }
.auth-inline-err { display: block; font-size: 12px; color: #d64045; margin-top: 4px; min-height: 18px; }
.auth-input.error { border-color: #d64045; }

/* ==================== Hero → 功能区 分隔线 ==================== */
.hero-divider {
  width: 100%;
  height: 40px;
  background: linear-gradient(to bottom, var(--white) 0%, var(--paper) 100%);
}

/* ==================== 滚动揭示动画 ==================== */
.reveal-item {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.reveal-item.visible {
  opacity: 1;
  transform: translateY(0);
}

/* 错开延迟（stagger） */
.reveal-stagger .reveal-item:nth-child(1) { transition-delay: 0s; }
.reveal-stagger .reveal-item:nth-child(2) { transition-delay: 0.08s; }
.reveal-stagger .reveal-item:nth-child(3) { transition-delay: 0.16s; }
.reveal-stagger .reveal-item:nth-child(4) { transition-delay: 0.24s; }
.reveal-stagger .reveal-item:nth-child(5) { transition-delay: 0.32s; }
.reveal-stagger .reveal-item:nth-child(6) { transition-delay: 0.40s; }

/* Hero 中的 reveal 元素立即显示 */
.hero .reveal-item,
.hero .reveal-stagger .reveal-item {
  opacity: 1;
  transform: none;
}

/* ==================== Hero 标记浮动动画 ==================== */
.hero-mark-item:nth-child(1) { animation-delay: 0s; }
.hero-mark-item:nth-child(2) { animation-delay: 0.15s; }
.hero-mark-item:nth-child(3) { animation-delay: 0.3s; }
.hero-mark-item:nth-child(4) { animation-delay: 0.45s; }
.hero-mark-item:nth-child(5) { animation-delay: 0.6s; }
.hero-mark-item:nth-child(6) { animation-delay: 0.75s; }
.hero-mark-item:nth-child(7) { animation-delay: 0.9s; }
.hero-mark-item:nth-child(8) { animation-delay: 1.05s; }
.hero-mark-item:nth-child(9) { animation-delay: 1.2s; }

@keyframes markFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-6px); }
}

/* ==================== 首页推广模块 ==================== */
.home-section {
  padding: var(--sp-80) 0;
}

.home-section-title {
  font-size: var(--text-heading);
  font-weight: 600;
  color: var(--ink);
  text-align: center;
  letter-spacing: var(--tracking-heading);
  line-height: var(--leading-heading);
  margin-bottom: var(--sp-8);
}
.home-section-sub {
  font-family: var(--font-editorial);
  font-size: var(--text-lg);
  font-weight: 400;
  color: var(--graphite);
  text-align: center;
  line-height: var(--leading-lg);
  margin-bottom: var(--sp-36);
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

/* 核心功能卡片网格 */
.home-features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-20);
}
.home-feature-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--sp-28);
  transition: border-color var(--ease), transform var(--ease);
}
.home-feature-card:hover {
  border-color: rgba(0,0,0,0.15);
  transform: translateY(-2px);
}
.home-feature-icon {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--icon-bg, #e6f3fe);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  color: var(--icon-color, #0075de);
  margin-bottom: var(--sp-20);
  transition: transform var(--ease);
}
.home-feature-icon .material-symbols-outlined {
  font-size: 28px;
  font-variation-settings: 'FILL' 0, 'wght' 300, 'GRAD' 0, 'opsz' 24;
  line-height: 1;
}
.home-feature-card:hover .home-feature-icon {
  transform: scale(1.08);
}
.home-feature-card h4 {
  font-size: var(--text-heading-sm);
  font-weight: 600;
  color: var(--ink);
  letter-spacing: var(--tracking-heading);
  margin-bottom: var(--sp-8);
}
.home-feature-card p {
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--graphite);
  line-height: var(--leading-sm);
}

/* 强调色全幅面板 */
.home-accent {
  background: var(--accent-bg, #ffb110);
  color: var(--accent-text, #000000);
  padding: 100px 0;
  border-radius: 0;
}
/* 三步开始 — 单独增加高度 */
#home-steps {
  padding: 100px 0;
}
.home-accent-row {
  display: flex;
  align-items: center;
  gap: var(--sp-64);
}
.home-accent-text { flex: 1; }
.home-accent-eyebrow {
  font-size: var(--text-caption);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  opacity: 0.7;
  margin-bottom: var(--sp-12);
}
.home-accent-title {
  font-size: var(--text-heading-lg);
  font-weight: 600;
  letter-spacing: var(--tracking-heading);
  line-height: var(--leading-heading);
  margin-bottom: var(--sp-16);
}
.home-accent-desc {
  font-size: var(--text-base);
  font-weight: 400;
  line-height: var(--leading-base);
  opacity: 0.85;
  margin-bottom: var(--sp-24);
  max-width: 440px;
}
.home-accent-stats {
  display: flex;
  gap: var(--sp-32);
}
.home-accent-stat {
  display: flex;
  flex-direction: column;
}
.home-accent-stat-num {
  font-size: var(--text-heading);
  font-weight: 700;
  letter-spacing: var(--tracking-heading);
}
.home-accent-stat-label {
  font-size: var(--text-caption);
  font-weight: 500;
  opacity: 0.7;
  margin-top: 2px;
}

.home-accent-visual {
  flex: 0 0 340px;
}
.home-accent-card {
  background: rgba(255,255,255,0.35);
  backdrop-filter: blur(8px);
  border-radius: var(--radius-lg);
  padding: var(--sp-24);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.home-level-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px var(--sp-16);
  background: rgba(255,255,255,0.5);
  border-radius: var(--radius);
  font-size: var(--text-base);
  font-weight: 500;
}
.home-level-row span {
  font-weight: 600;
  opacity: 0.7;
  font-size: var(--text-sm);
}

/* 三步开始 */
.home-steps-row {
  display: flex;
  align-items: flex-start;
  gap: var(--sp-24);
  max-width: 900px;
  margin: 0 auto;
}
.home-step {
  flex: 1;
  text-align: center;
}
.home-step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--ink);
  color: var(--white);
  font-size: var(--text-xl);
  font-weight: 700;
  letter-spacing: var(--tracking-heading);
  margin-bottom: var(--sp-16);
}
.home-step h4 {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--sp-8);
}
.home-step p {
  font-size: var(--text-sm);
  color: var(--graphite);
  line-height: var(--leading-sm);
}
.home-step-arrow {
  font-size: 28px;
  color: var(--border);
  padding-top: 14px;
  flex-shrink: 0;
}

/* 暗色面板 */
.home-dark-inner {
  text-align: center;
}
.home-dark-title {
  font-size: var(--text-heading-lg);
  font-weight: 600;
  letter-spacing: var(--tracking-heading);
  line-height: var(--leading-heading);
  margin-bottom: var(--sp-12);
}
.home-dark-desc {
  font-family: var(--font-editorial);
  font-size: var(--text-lg);
  font-weight: 400;
  opacity: 0.65;
  line-height: var(--leading-lg);
  margin-bottom: var(--sp-36);
}
.home-dark-stats {
  display: flex;
  justify-content: center;
  gap: var(--sp-64);
}
.home-dark-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.home-dark-stat-num {
  font-size: var(--text-display);
  font-weight: 600;
  letter-spacing: var(--tracking-display);
  line-height: var(--leading-display);
}
.home-dark-stat-label {
  font-size: var(--text-caption);
  font-weight: 500;
  opacity: 0.5;
  letter-spacing: var(--tracking-caption);
}

@media (max-width: 768px) {
  .home-section { padding: var(--sp-64) 0; }
  .home-accent { padding: var(--sp-64) 0; }
  .home-section-title { font-size: 1.75rem; }
  .home-features-grid { grid-template-columns: 1fr; }
  .home-accent-row { flex-direction: column; gap: var(--sp-32); }
  .home-accent-visual { flex: 0 0 auto; width: 100%; }
  .home-accent-title { font-size: 2rem; }
  .home-steps-row { flex-direction: column; align-items: center; }
  .home-step-arrow { transform: rotate(90deg); padding-top: 0; }
  .home-dark-stats { flex-direction: column; gap: var(--sp-24); }
  .home-dark-stat-num { font-size: 3rem; }
}

/* ==================== 文档页（飞书风格） ==================== */
.doc-layout {
  display: flex;
  min-height: calc(100vh - 60px);
  max-width: var(--max-width);
  margin: 0 auto;
}

/* 左侧大纲 */
.doc-sidebar {
  width: 260px;
  flex-shrink: 0;
  border-right: 1px solid var(--border);
  background: var(--white);
  position: sticky;
  top: 60px;
  height: calc(100vh - 60px);
  overflow-y: auto;
  padding: var(--sp-24) 0;
}

.doc-sidebar-header {
  padding: 0 var(--sp-20) var(--sp-16);
  border-bottom: 1px solid var(--border-light);
  margin-bottom: var(--sp-12);
}
.doc-sidebar-header h3 {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--ink);
}

/* 大纲列表 */
.doc-outline { padding: 0 var(--sp-12); }

.doc-outline-group {
  margin-bottom: 2px;
}

.doc-outline-parent {
  display: flex;
  align-items: center;
  width: 100%;
  padding: 7px var(--sp-8);
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  transition: background var(--ease);
  text-align: left;
  gap: 4px;
}
.doc-outline-parent:hover { background: rgba(0,0,0,0.04); }

.doc-outline-arrow {
  font-size: 10px;
  width: 16px;
  flex-shrink: 0;
  color: var(--stone);
  transition: transform var(--ease);
  text-align: center;
}
.doc-outline-group.collapsed .doc-outline-arrow {
  transform: rotate(-90deg);
}

.doc-outline-children {
  overflow: hidden;
  transition: max-height 0.25s ease;
}
.doc-outline-group.collapsed .doc-outline-children {
  max-height: 0 !important;
}

.doc-outline-child {
  display: block;
  width: 100%;
  padding: 5px var(--sp-8) 5px var(--sp-32);
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  font-size: var(--text-sm);
  font-weight: 400;
  color: var(--graphite);
  cursor: pointer;
  transition: background var(--ease);
  text-align: left;
}
.doc-outline-child:hover { background: rgba(0,0,0,0.04); color: var(--ink); }
.doc-outline-child.active { color: var(--blue); background: var(--sky-tint); font-weight: 500; }

/* 右侧正文 */
.doc-content {
  flex: 1;
  min-width: 0;
  padding: var(--sp-36) var(--sp-36) var(--sp-80);
  background: var(--paper);
}

.doc-section {
  margin-bottom: var(--sp-64);
}

.doc-h2 {
  font-size: var(--text-heading-sm);
  font-weight: 600;
  color: var(--ink);
  letter-spacing: var(--tracking-heading);
  margin-bottom: var(--sp-24);
  padding-bottom: var(--sp-8);
  border-bottom: 2px solid var(--ink);
}

.doc-h3 {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--ink);
  margin-top: var(--sp-28);
  margin-bottom: var(--sp-12);
}

.doc-content p {
  font-size: var(--text-base);
  color: var(--graphite);
  line-height: var(--leading-base);
  margin-bottom: var(--sp-12);
}

.doc-content ol,
.doc-content ul {
  margin-bottom: var(--sp-16);
  padding-left: var(--sp-24);
  list-style: decimal;
  color: var(--graphite);
  font-size: var(--text-base);
  line-height: var(--leading-base);
}
.doc-content ul { list-style: disc; }
.doc-content li { margin-bottom: var(--sp-8); }
.doc-content li ul,
.doc-content li ol { margin-top: var(--sp-8); margin-bottom: 0; }

.doc-content strong { color: var(--ink); }

/* 提示块 */
.doc-tip {
  background: var(--sky-tint);
  border-radius: var(--radius);
  padding: var(--sp-12) var(--sp-16);
  margin: var(--sp-16) 0;
  font-size: var(--text-sm);
  color: var(--graphite);
  line-height: var(--leading-sm);
}
.doc-tip strong { color: var(--blue); }

/* 功能网格 */
.doc-feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--sp-12);
  margin: var(--sp-16) 0;
}
.doc-feature-item {
  display: flex;
  gap: var(--sp-12);
  padding: var(--sp-16);
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}
.doc-feature-icon { font-size: 28px; flex-shrink: 0; }
.doc-feature-item strong { display: block; margin-bottom: 2px; font-size: var(--text-sm); }
.doc-feature-item p { font-size: var(--text-sm); margin-bottom: 0; color: var(--graphite); }

/* 表格 */
.doc-table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--sp-16) 0;
  font-size: var(--text-sm);
}
.doc-table th,
.doc-table td {
  text-align: left;
  padding: 10px var(--sp-16);
  border: 1px solid var(--border);
}
.doc-table th {
  background: rgba(0,0,0,0.02);
  font-weight: 600;
  color: var(--ink);
  font-size: var(--text-sm);
}
.doc-table td { color: var(--graphite); }
.doc-table tr:hover td { background: rgba(0,0,0,0.01); }
.doc-table td strong { color: var(--ink); }

/* 学科标签 */
.doc-subject-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-8);
  margin: var(--sp-12) 0;
}
.doc-tag {
  display: inline-block;
  padding: 4px 14px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--ink);
}

/* FAQ */
.doc-faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--sp-20);
  margin-bottom: var(--sp-12);
  background: var(--white);
}
.doc-faq-item h4 {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--ink);
  margin-bottom: var(--sp-8);
}
.doc-faq-item p {
  font-size: var(--text-sm);
  color: var(--graphite);
  line-height: var(--leading-sm);
  margin-bottom: 0;
}

/* 移动端侧边栏隐藏 */
@media (max-width: 768px) {
  .doc-layout { flex-direction: column; }
  .doc-sidebar {
    position: static;
    width: 100%;
    height: auto;
    max-height: 40vh;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .doc-content { padding: var(--sp-24) var(--sp-16); }
  .doc-feature-grid { grid-template-columns: 1fr; }
}

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

.hero-marks   { animation: fadeInUp 0.4s var(--ease) both; }
.hero-eyebrow { animation: fadeInUp 0.4s 0.05s var(--ease) both; }
.hero-title   { animation: fadeInUp 0.4s 0.1s var(--ease) both; }
.hero-subhead { animation: fadeInUp 0.4s 0.15s var(--ease) both; }
.hero-actions { animation: fadeInUp 0.4s 0.2s var(--ease) both; }
.hero-stats   { animation: fadeInUp 0.4s 0.25s var(--ease) both; }

/* ==================== 响应式 ==================== */
@media (max-width: 768px) {
  .container { padding: 0 var(--sp-16); }

  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: var(--sp-12) 0;
    gap: var(--sp-12);
  }
  .nav {
    order: 3;
    width: 100%;
    overflow-x: auto;
    gap: 0;
  }
  .nav-link { white-space: nowrap; padding: var(--sp-8) var(--sp-12); }

  .hero {
    padding: var(--sp-64) 0 var(--sp-36);
  }
  .hero-marks {
    gap: var(--sp-4);
    margin-bottom: var(--sp-20);
  }
  .hero-mark {
    width: 36px;
    height: 36px;
    font-size: 14px;
  }
  .hero-title {
    font-size: 2.25rem;
    letter-spacing: -0.01em;
  }
  .hero-pill {
    padding: 2px var(--sp-16);
  }
  .hero-subhead { font-size: var(--text-base); }
  .hero-stats { flex-wrap: wrap; gap: var(--sp-20); }
  .stat-number { font-size: 2rem; }
  .stat-divider { display: none; }

  .subjects-grid { grid-template-columns: repeat(2, 1fr); }
  .subjects-pill-grid { grid-template-columns: repeat(2, 1fr); }
  .resource-list { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .about-content { flex-direction: column; }
  .contact-row { grid-template-columns: 1fr; }
  .chat-panel { width: calc(100vw - 32px); height: 420px; }

  .page-title { font-size: 2rem; }
  .section-title { font-size: 1.75rem; }
}

/* ==================== 可访问性 ==================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 2px;
  border-radius: 2px;
}