/* ===== 全局基础 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

:root {
  --bg: #eaf3fb;
  --bg-grad-1: #f2f8ff;
  --bg-grad-2: #dbeafb;
  --card: #ffffff;
  --primary: #2f80ed;
  --primary-dark: #1c64d4;
  --text: #1f2d3d;
  --text-sub: #5b6b7e;
  --shadow: 0 6px 20px rgba(47, 128, 237, 0.12);
  --radius: 16px;
}

html, body {
  height: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, var(--bg-grad-1) 0%, var(--bg-grad-2) 100%);
  background-attachment: fixed;
  color: var(--text);
  line-height: 1.75;
  min-height: 100vh;
  padding: env(safe-area-inset-top) 0 env(safe-area-inset-bottom);
}

/* ===== 顶部 Logo + 标题 ===== */
.header {
  text-align: center;
  padding: 28px 20px 18px;
}

.header .logo {
  width: 88px;
  height: 88px;
  object-fit: contain;
  border-radius: 50%;
  background: #fff;
  box-shadow: var(--shadow);
  padding: 8px;
}

.header h1 {
  margin-top: 14px;
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--primary-dark);
}

.header .subtitle {
  margin-top: 6px;
  font-size: 14px;
  color: var(--text-sub);
}

/* ===== 通用容器 ===== */
.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 0 18px 40px;
}

/* ===== 宫格菜单 ===== */
.grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  margin-top: 10px;
}

.grid-item {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 26px 12px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-decoration: none;
  color: var(--text);
  transition: transform 0.18s ease, box-shadow 0.18s ease;
}

.grid-item:active {
  transform: scale(0.96);
}

.grid-item .icon {
  width: 56px;
  height: 56px;
  object-fit: contain;
}

.grid-item .label {
  font-size: 16px;
  font-weight: 600;
  text-align: center;
}

/* ===== 视频控件 ===== */
.video-wrap {
  background: #000;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  margin-top: 10px;
}

.video-wrap video {
  width: 100%;
  display: block;
}

/* ===== 摘要 / 正文区块 ===== */
.section-title {
  margin: 26px 0 10px;
  font-size: 18px;
  font-weight: 700;
  color: var(--primary-dark);
  border-left: 4px solid var(--primary);
  padding-left: 10px;
}

.summary p {
  font-size: 15px;
  color: var(--text);
}

.summary img,
.article-img {
  width: 100%;
  border-radius: 12px;
  margin: 14px 0;
  box-shadow: var(--shadow);
  display: block;
}

/* ===== 图文文章（公众号风格） ===== */
.article p {
  font-size: 16px;
  margin: 14px 0;
  color: var(--text);
}

.article h2 {
  font-size: 19px;
  margin: 24px 0 8px;
  color: var(--primary-dark);
}

.article ul {
  margin: 12px 0 12px 20px;
}

.article li {
  margin: 8px 0;
  font-size: 16px;
}

.note {
  background: #e8f1ff;
  border-radius: 12px;
  padding: 14px 16px;
  margin: 16px 0;
  font-size: 15px;
  color: var(--text-sub);
}

/* ===== 返回按钮 ===== */
.back-bar {
  max-width: 640px;
  margin: 0 auto;
  padding: 16px 18px 0;
}

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--primary-dark);
  text-decoration: none;
  font-size: 15px;
  font-weight: 600;
}

.back-btn:active {
  opacity: 0.6;
}

/* ===== 底部提示 ===== */
.footer {
  text-align: center;
  font-size: 12px;
  color: var(--text-sub);
  padding: 24px 0 30px;
}