/* 新创投商学 - 学员端设计系统（深藏青 + 鎏金） */
:root {
  --primary: #1B2A4A;      /* 深藏青 */
  --primary-light: #2A3D66;
  --gold: #C9A24B;          /* 鎏金 */
  --gold-light: #E3C878;
  --dark: #0F1E3D;
  --text: #3A3F4B;
  --gray: #8A8F99;
  --bg: #F7F6F3;
  --card: #FFFFFF;
  --border: #EAE7E0;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary); text-decoration: none; }
a:hover { opacity: 0.85; }

/* ===== 顶部导航 ===== */
.nav {
  background: var(--primary);
  padding: 0 20px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;                      /* logo 与导航之间留白，避免贴死 */
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 8px rgba(15,30,61,0.25);
}
/* ⚠️ 手机上这里踩过坑：logo 没设 nowrap，"新创投商学"被挤成两行，
   flex 布局随之把金色副标签顶上去盖住「首页」，右侧「注册」也被裁掉。
   导航类元素一律禁止换行，挤不下时靠缩字号/隐藏副标签解决，绝不换行。 */
.nav .logo {
  font-size: 19px; font-weight: 700; color: #fff; letter-spacing: 1px;
  display: flex; align-items: center; gap: 10px;
  white-space: nowrap; flex-shrink: 0;
}
.nav .logo .badge {
  background: var(--gold);
  color: var(--dark);
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 4px;
  letter-spacing: 0;
  font-weight: 600;
  white-space: nowrap;
}
.nav .links { display: flex; align-items: center; white-space: nowrap; flex-shrink: 0; }
.nav .links a {
  margin-left: 20px;
  font-size: 14px;
  color: rgba(255,255,255,0.85);
  white-space: nowrap;
}
.nav .links a:hover { color: var(--gold-light); }
.nav .links a.active { color: var(--gold-light); font-weight: 600; }
.nav .links a.btn-nav {
  background: var(--gold);
  color: var(--dark);
  padding: 7px 18px;
  border-radius: 20px;
  font-weight: 600;
}

/* 移动端导航适配 */
@media (max-width: 768px) {
  .nav { padding: 0 10px; height: 52px; gap: 8px; }
  .nav .logo { font-size: 15px; gap: 6px; letter-spacing: 0; }
  .nav .logo .badge { font-size: 9px; padding: 1px 5px; border-radius: 3px; }
  .nav .links a { margin-left: 9px; font-size: 12.5px; }
  .nav .links a.btn-nav { padding: 5px 10px; font-size: 12.5px; }
}
/* 多数手机竖屏（≤480px）：隐藏 logo 上的金色副标签，把横向空间全让给导航。
   不隐藏的话 logo+5个导航项会超宽，"注册"按钮会被切掉。
   品牌信息不丢——首屏大标题和页脚都有"新创投商学 · 玖块玖学园"。 */
@media (max-width: 480px) {
  .nav .logo .badge { display: none; }
  .nav .links a { margin-left: 8px; font-size: 12px; }
  .nav .links a.btn-nav { padding: 5px 9px; font-size: 12px; }
}
/* 极窄屏（≤360px，如 iPhone SE）再收一档 */
@media (max-width: 360px) {
  .nav { padding: 0 8px; }
  .nav .logo { font-size: 13.5px; }
  .nav .links a { margin-left: 6px; font-size: 11.5px; }
  .nav .links a.btn-nav { padding: 4px 8px; font-size: 11.5px; }
}

.container { max-width: 1080px; margin: 0 auto; padding: 0 18px; }

/* ===== Hero 区 ===== */
.hero {
  background: linear-gradient(135deg, #0F1E3D 0%, #1B2A4A 55%, #2A3D66 100%);
  color: #fff;
  padding: 60px 18px 50px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: '';
  position: absolute;
  right: -80px; top: -80px;
  width: 300px; height: 300px;
  border: 1px solid rgba(201,162,75,0.25);
  border-radius: 50%;
}
.hero .eyebrow {
  display: inline-block;
  border: 1px solid var(--gold);
  color: var(--gold-light);
  padding: 4px 16px;
  border-radius: 20px;
  font-size: 13px;
  letter-spacing: 2px;
  margin-bottom: 18px;
}
.hero h1 {
  font-size: 40px;
  font-weight: 700;
  letter-spacing: 3px;
  margin-bottom: 10px;
}
.hero h1 .gold { color: var(--gold-light); }
.hero .slogan { font-size: 17px; color: rgba(255,255,255,0.8); letter-spacing: 1px; margin-bottom: 28px; }
.hero .metrics {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}
.hero .metric .num { font-size: 28px; font-weight: 700; color: var(--gold-light); }
.hero .metric .label { font-size: 13px; color: rgba(255,255,255,0.7); margin-top: 2px; }

/* ===== Hero 区 · 移动端适配 =====
   原来这块完全没有媒体查询，直接沿用桌面尺寸，390px 手机上会：
   ① 徽标里 "新创投商学 · XINCHUANGTOU BUSINESS SCHOOL" 约 422px 宽 → 被迫折成两行
   ② 标题 40px + 字距 3px → 约 298px，塞得下但顶到屏幕两边
   ③ 数据区 flex + gap 48px，4 个约需 424px → 第 4 个"100节"掉到第二行，孤零零居中
   下面逐条收掉。 */
@media (max-width: 768px) {
  /* 上半屏是"第一印象"，挤压感比信息量更值得避免，整体收紧留白 */
  .hero { padding: 40px 16px 36px; }

  /* 徽标：隐藏超长的英文副标（装饰性，中文品牌已够），只留中文，单行不折 */
  .hero .eyebrow { font-size: 11.5px; letter-spacing: 1px; padding: 4px 12px; margin-bottom: 14px; }
  .hero .eyebrow .en { display: none; }

  /* 标题：40px→31px，字距 3px→1px，两侧留出呼吸（390px 下约 236px 宽） */
  .hero h1 { font-size: 31px; letter-spacing: 1px; line-height: 1.32; }

  /* 副标题同步收一档，行高放开，避免与标题挤在一起 */
  .hero .slogan { font-size: 14.5px; letter-spacing: 0; line-height: 1.7; margin-bottom: 24px; }

  /* 数据区：flex 换成 2×2 网格。数字保住 24px 仍醒目，且不会出现"3+1"孤儿 */
  .hero .metrics { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px 10px; }
  .hero .metric .num { font-size: 24px; }
  .hero .metric .label { font-size: 12px; }
}
/* 极窄屏再收一档（iPhone SE 等 320~360px） */
@media (max-width: 360px) {
  .hero { padding: 34px 14px 30px; }
  .hero h1 { font-size: 27px; }
  .hero .metric .num { font-size: 22px; }
}

/* ===== 区块标题 ===== */
.section { padding: 40px 0; }
.section-title { text-align: center; margin-bottom: 28px; }
.section-title h2 { font-size: 26px; color: var(--gold); font-weight: 700; letter-spacing: 1px; }
.section-title .en { font-size: 12px; color: var(--gold); letter-spacing: 3px; text-transform: uppercase; margin-bottom: 6px; }
.section-title .line {
  width: 40px; height: 3px; background: var(--gold); margin: 12px auto 0; border-radius: 2px;
}

/* ===== 学园架构 ===== */
.org-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
@media (max-width: 768px) { .org-grid { grid-template-columns: repeat(2, 1fr); } }
.org-card {
  background: var(--card);
  border-radius: 14px;
  padding: 26px 18px;
  text-align: center;
  box-shadow: 0 2px 12px rgba(15,30,61,0.06);
  transition: transform .2s, box-shadow .2s;
  border: 1px solid var(--border);
}
.org-card:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(15,30,61,0.12); }
.org-card .icon { font-size: 34px; margin-bottom: 12px; }
.org-card h3 { font-size: 17px; color: var(--dark); margin-bottom: 6px; font-weight: 700; }
.org-card .tag { font-size: 11px; color: var(--gray); margin-bottom: 8px; }
.org-card .desc { font-size: 12px; color: var(--gray); line-height: 1.6; }
.org-card.active {
  border: 2px solid var(--gold);
  position: relative;
  background: linear-gradient(180deg, #FFFDF7, #fff);
}
.org-card.active .active-tag {
  position: absolute; top: -10px; left: 50%; transform: translateX(-50%);
  background: var(--gold); color: var(--dark);
  font-size: 11px; padding: 2px 12px; border-radius: 10px; font-weight: 600;
}
.org-card.soon { opacity: 0.7; }

/* ===== 课程卡片 ===== */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 20px;
}
.course-card {
  background: var(--card);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 2px 12px rgba(15,30,61,0.06);
  transition: transform .2s, box-shadow .2s;
  display: block;
  border: 1px solid var(--border);
}
.course-card:hover { transform: translateY(-4px); box-shadow: 0 10px 28px rgba(15,30,61,0.14); }
.course-cover {
  height: 130px;
  background: linear-gradient(135deg, #1B2A4A, #2A3D66);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--gold-light);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 2px;
  position: relative;
}
.course-cover .price-tag {
  position: absolute; right: 12px; bottom: 12px;
  background: var(--gold); color: var(--dark);
  font-size: 15px; font-weight: 700;
  padding: 2px 12px; border-radius: 6px;
  letter-spacing: 0;
}
.course-info { padding: 16px; }
.course-info h3 { font-size: 16px; color: var(--dark); margin-bottom: 6px; font-weight: 700; }
.course-info .sub { font-size: 13px; color: var(--gray); margin-bottom: 12px; }
.course-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--gray);
  border-top: 1px solid var(--border);
  padding-top: 10px;
}

/* ===== 按钮 ===== */
.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  padding: 12px 28px;
  border-radius: 24px;
  font-size: 15px;
  border: none;
  cursor: pointer;
  text-align: center;
  font-weight: 600;
  letter-spacing: 1px;
  transition: all .2s;
}
.btn:hover { background: var(--primary-light); color: #fff; }
.btn-gold { background: var(--gold); color: var(--dark); }
.btn-gold:hover { background: var(--gold-light); color: var(--dark); }
.btn-block { display: block; width: 100%; }
.btn-outline { background: transparent; color: var(--primary); border: 1px solid var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; }

/* ===== 表单 ===== */
.form-card {
  background: var(--card);
  border-radius: 14px;
  padding: 28px;
  max-width: 400px;
  margin: 30px auto;
  box-shadow: 0 2px 16px rgba(15,30,61,0.08);
}
.form-card h2 { font-size: 22px; color: var(--gold); margin-bottom: 22px; text-align: center; }
.form-group { margin-bottom: 16px; }
.form-group label { display: block; font-size: 14px; margin-bottom: 6px; color: var(--dark); font-weight: 500; }
.form-group input, .form-group textarea, .form-group select {
  width: 100%;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  background: #fff;
}
.form-group input:focus { outline: none; border-color: var(--gold); box-shadow: 0 0 0 3px rgba(201,162,75,0.12); }
.error { color: #c0392b; font-size: 13px; text-align: center; margin-bottom: 12px; }

/* ===== 课程详情页 ===== */
.detail-hero {
  background: linear-gradient(135deg, #0F1E3D, #2A3D66);
  color: #fff;
  padding: 44px 18px;
}
.detail-hero .inner { max-width: 1080px; margin: 0 auto; }
.detail-hero .cate { color: var(--gold-light); font-size: 13px; letter-spacing: 2px; margin-bottom: 10px; }
.detail-hero h1 { font-size: 30px; font-weight: 700; margin-bottom: 8px; }
.detail-hero .sub { color: rgba(255,255,255,0.8); font-size: 15px; margin-bottom: 18px; }
.detail-hero .price-row { display: flex; align-items: baseline; gap: 12px; margin-bottom: 20px; }
.detail-hero .price { font-size: 34px; font-weight: 700; color: var(--gold-light); }
.detail-hero .origin { font-size: 16px; color: rgba(255,255,255,0.5); text-decoration: line-through; }
.detail-body { max-width: 1080px; margin: -20px auto 0; padding: 0 18px; }
.detail-card {
  background: var(--card);
  border-radius: 16px;
  padding: 28px;
  box-shadow: 0 4px 20px rgba(15,30,61,0.1);
  margin-bottom: 20px;
}
.detail-card h2 { font-size: 18px; color: var(--gold); margin-bottom: 14px; padding-left: 12px; border-left: 3px solid var(--gold); }
.detail-card .desc { font-size: 14px; color: var(--text); white-space: pre-line; line-height: 1.8; }

.lesson-list { background: var(--card); border-radius: 16px; overflow: hidden; box-shadow: 0 2px 12px rgba(15,30,61,0.06); }
.lesson-item {
  display: flex;
  align-items: center;
  padding: 15px 18px;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
  color: var(--text);
}
.lesson-item:last-child { border-bottom: none; }
.lesson-item .num {
  width: 30px; height: 30px;
  background: #F2EEE5;
  color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 700;
  margin-right: 12px;
  flex-shrink: 0;
}
.lesson-item.locked { color: var(--gray); }
.section-title {
  padding: 9px 18px;
  background: var(--primary);
  color: #fff;
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: 1px;
  border-left: 3px solid var(--gold);
}
.sidebar .section-title { padding: 8px 8px; font-size: 12.5px; }

/* ===== 学习页 ===== */
.learn-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 20px;
  padding: 24px 0;
}
@media (max-width: 768px) { .learn-layout { grid-template-columns: 1fr; } }
.video-box {
  background: #000;
  border-radius: 14px;
  overflow: hidden;
  margin-bottom: 16px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
}
.video-box video { width: 100%; display: block; max-height: 62vh; }
.lesson-title { font-size: 20px; color: var(--gold); font-weight: 700; margin-bottom: 8px; }
.lesson-doc { margin-top: 14px; }
.sidebar {
  background: var(--card);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 2px 12px rgba(15,30,61,0.06);
  height: fit-content;
}
.sidebar h3 { font-size: 15px; color: var(--gold); margin-bottom: 14px; font-weight: 700; }
.sidebar .lesson-item { padding: 11px 8px; border-radius: 8px; cursor: pointer; border-bottom: none; }
.sidebar .lesson-item.active { background: #F2EEE5; color: var(--primary); font-weight: 700; }
.sidebar .lesson-item:hover { background: #FAF8F3; }

/* ===== 兑换码 ===== */
.redeem-box {
  background: var(--card);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 2px 12px rgba(15,30,61,0.06);
  margin-bottom: 20px;
  display: flex;
  gap: 10px;
  align-items: center;
}
.redeem-box input {
  flex: 1;
  padding: 11px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
}

/* ===== 其他 ===== */
.tip {
  background: #FDF7EA;
  color: #8a6d1a;
  padding: 13px 18px;
  border-radius: 10px;
  font-size: 14px;
  margin-bottom: 16px;
  border-left: 3px solid var(--gold);
}
.empty { text-align: center; color: var(--gray); padding: 50px 0; }
.mt16 { margin-top: 16px; }

/* ===== AI 销售陪练场（核心特色 Banner）===== */
.ai-banner-wrap {
  background: linear-gradient(155deg, #0F1E3D 0%, #1B2A4A 50%, #253760 100%);
  padding: 48px 0 52px;
  position: relative;
  overflow: hidden;
}
.ai-banner-wrap::before {
  content: ""; position: absolute; top: -100px; right: -60px;
  width: 340px; height: 340px;
  background: radial-gradient(circle, rgba(201,162,75,0.30) 0%, transparent 68%);
  pointer-events: none;
}
.ai-banner-wrap::after {
  content: ""; position: absolute; bottom: -130px; left: -90px;
  width: 290px; height: 290px;
  border: 1px solid rgba(201,162,75,0.22); border-radius: 50%;
  pointer-events: none;
}
.ai-badge {
  display: inline-block;
  background: rgba(201,162,75,0.16);
  border: 1px solid rgba(201,162,75,0.5);
  color: var(--gold-light);
  font-size: 12.5px; font-weight: 600;
  padding: 5px 14px; border-radius: 20px;
  letter-spacing: 0.5px; margin-bottom: 16px;
}
.ai-title {
  font-size: 34px; font-weight: 800; color: #fff;
  letter-spacing: 2px; line-height: 1.25;
}
.ai-title .g {
  background: linear-gradient(90deg, #E3C878, #C9A24B);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.ai-sub {
  color: #C3CBDE; font-size: 15.5px; margin-top: 12px;
  /* 760px：第一行完整排下「…把课练进肌肉里。学完不等于会，练过才算数。」约 641px，
     留 119px 安全余量。原来 640px 时只差 1px，用户机器上字体略宽就折行。 */
  line-height: 1.75; max-width: 760px;
}
/* 断行策略：
   ① .ln  —— 桌面各自成行（第二行只放"练累了，还有人在。"），手机连成一段自然折行
   ② .nb  —— 核心口号「学完不等于会，练过才算数。」整块不可拆
             （任何宽度下都不会被切成"练过才算"/"数。"，挤不下就整块挪到下一行） */
.ai-sub .ln { display: block; }
.ai-sub .nb { white-space: nowrap; }
@media (max-width: 768px) {
  .ai-sub .ln { display: inline; }
}
.ai-feats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin: 24px 0 26px; }
/* 撑腰是"情绪支撑"，跟另外三个练功模块性质不同 —— 用暖色微微区分，别让它被当成第四个练习功能 */
.ai-feat-warm { background: rgba(185,134,68,0.16); border-color: rgba(227,200,120,0.45); }
.ai-feat {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(201,162,75,0.22);
  border-radius: 12px; padding: 14px 12px;
}
.ai-feat-icon { font-size: 21px; line-height: 1; }
.ai-feat-name { color: var(--gold-light); font-weight: 700; font-size: 14.5px; margin: 6px 0 4px; }
.ai-feat-desc { color: #AEB8CC; font-size: 12px; line-height: 1.55; }
.ai-cta-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
.ai-cta {
  display: inline-block;
  background: linear-gradient(135deg, #E3C878, #C9A24B);
  color: #1B2A4A; font-weight: 800; font-size: 16px;
  padding: 14px 38px; border-radius: 30px;
  box-shadow: 0 6px 22px rgba(201,162,75,0.40);
  transition: transform .15s;
}
.ai-cta:hover { transform: translateY(-2px); opacity: 1; }
.ai-cta-note { color: #9AA5BD; font-size: 13px; }

/* 中等屏幕：4 列会低于约 190px 宽，文字开始挤，退成 2×2
   （注意阈值别设太高——1000px 时很多笔记本窗口会误命中，变成两行） */
@media (max-width: 900px) {
  .ai-feats { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .ai-banner-wrap { padding: 34px 0 38px; }
  .ai-title { font-size: 26px; letter-spacing: 1px; }
  .ai-sub { font-size: 14px; }
  .ai-feats { grid-template-columns: 1fr; gap: 10px; margin: 20px 0 22px; }
  .ai-feat { padding: 14px; display: flex; align-items: center; gap: 12px; }
  .ai-feat-icon { font-size: 24px; }
  .ai-feat-name { margin: 0; font-size: 15px; }
  .ai-feat-desc { font-size: 12.5px; }
  .ai-cta { width: 100%; text-align: center; padding: 13px; }
  .ai-cta-row { gap: 10px; }
}
.footer {
  text-align: center;
  padding: 30px 18px;
  color: var(--gray);
  font-size: 13px;
  margin-top: 20px;
  border-top: 1px solid var(--border);
}