/* ========== 全局基础 ========== */

:root {
  --bit-blue: #005bac;
  --bit-blue-light: #4ea3ff;
  --bit-blue-dark: #003b70;
  --bit-gold: #d8b15a;
  --text-main: #f3f6fb;
  --text-secondary: #c7d3e3;
  --text-dim: #92a4bb;
  --bg-main: #0b1020;
  --bg-panel: #111a2e;
  --bg-panel-2: #0f1730;
  --line-soft: rgba(255,255,255,0.10);
  --line-strong: rgba(78,163,255,0.45);
}

/* 整体背景 */
.reveal {
  background:
    radial-gradient(circle at top right, rgba(0,91,172,0.18), transparent 28%),
    radial-gradient(circle at left bottom, rgba(78,163,255,0.12), transparent 24%),
    linear-gradient(180deg, #0a0f1d 0%, #0c1326 100%);
  color: var(--text-main);
  font-family:
    "Helvetica Neue",
    "PingFang SC",
    "Hiragino Sans GB",
    "Microsoft YaHei",
    "Noto Sans CJK SC",
    sans-serif;
  font-size: 36px;
  font-weight: 400;
}

/* 页面内容区域 */
.reveal .slides section {
  text-align: left;
  padding: 55px 95px 70px 95px;
  box-sizing: border-box;
}

/* ========== 标题层级 ========== */

.reveal h1,
.reveal h2,
.reveal h3,
.reveal h4 {
  font-family:
    "Helvetica Neue",
    "PingFang SC",
    "Microsoft YaHei",
    sans-serif;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.01em;
  text-transform: none;
  margin-bottom: 0.45em;
  color: var(--text-main);
}

.reveal h1 {
  font-size: 1.65em;
  color: #ffffff;
}

.reveal h2 {
  font-size: 1.18em;
  color: var(--bit-blue-light);
}

.reveal h3 {
  font-size: 0.88em;
  color: #dbe9ff;
}

.reveal h4 {
  font-size: 0.72em;
  color: var(--text-secondary);
}

/* 一级标题下方蓝线 */
.reveal h1::after,
.reveal h2:first-child::after {
  content: "";
  display: block;
  width: 120px;
  height: 4px;
  margin-top: 14px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--bit-blue), var(--bit-blue-light));
}

/* ========== 正文与列表 ========== */

.reveal p,
.reveal li,
.reveal div,
.reveal span {
  color: var(--text-main);
  line-height: 1.62;
}

.reveal p {
  margin: 0.35em 0 0.55em 0;
  font-size: 0.88em;
}

.reveal ul,
.reveal ol {
  display: block;
  margin: 0.4em 0 0.6em 1.1em;
  padding-left: 0.2em;
}

.reveal li {
  margin: 0.34em 0;
  font-size: 0.88em;
}

.reveal strong {
  color: #ffffff;
  font-weight: 700;
}

.reveal em {
  color: #d6e8ff;
}

/* ========== 链接 ========== */

.reveal a {
  color: #79b8ff;
  text-decoration: none;
  border-bottom: 1px solid rgba(121,184,255,0.35);
}

.reveal a:hover {
  color: #a9d2ff;
  border-bottom-color: rgba(169,210,255,0.8);
}

/* ========== 代码 ========== */

.reveal code {
  font-family:
    "SFMono-Regular",
    "Menlo",
    "Consolas",
    monospace;
  font-size: 0.78em;
  color: #d8ecff;
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 6px;
  padding: 0.10em 0.32em;
}

.reveal pre {
  width: 100%;
  margin: 0.7em 0;
  box-shadow: none;
  border-radius: 12px;
  border: 1px solid rgba(78,163,255,0.22);
  background: rgba(9,13,26,0.92);
}

.reveal pre code {
  display: block;
  padding: 1em 1.1em;
  line-height: 1.55;
  max-height: 560px;
  overflow: auto;
  background: transparent;
  border: none;
  border-radius: 0;
}

/* ========== 引用块 ========== */

.reveal blockquote {
  width: 100%;
  margin: 0.8em 0;
  padding: 0.75em 1em;
  color: #e6f0ff;
  background: rgba(255,255,255,0.05);
  border-left: 4px solid var(--bit-blue-light);
  box-shadow: none;
  border-radius: 10px;
}

/* ========== 数学公式 ========== */

.reveal .math.display {
  margin: 0.65em 0 !important;
}

.reveal .MathJax,
.reveal mjx-container {
  font-size: 105% !important;
  color: #ffffff !important;
}

/* ========== 表格 ========== */

.reveal table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5em;
  font-size: 0.74em;
}

.reveal table th,
.reveal table td {
  border: 1px solid rgba(255,255,255,0.12);
  padding: 10px 14px;
  text-align: left;
}

.reveal table th {
  background: rgba(0,91,172,0.22);
  color: #ffffff;
}

.reveal table tr:nth-child(even) td {
  background: rgba(255,255,255,0.03);
}

/* ========== 图片 ========== */

.reveal img {
  border: none;
  box-shadow: none;
  background: transparent;
}

.figure-main {
  display: block;
  margin: 0.4em auto 0 auto;
  max-width: 78%;
  max-height: 560px;
  object-fit: contain;
  border-radius: 10px;
}

.figure-wide {
  display: block;
  margin: 0.4em auto 0 auto;
  max-width: 88%;
  max-height: 520px;
  object-fit: contain;
  border-radius: 10px;
}

.caption {
  margin-top: 0.7em;
  font-size: 0.62em;
  color: var(--text-secondary);
  line-height: 1.5;
  text-align: center;
}

/* ========== 标题页 ========== */

.reveal section:first-of-type h1 {
  margin-top: 0.45em;
  font-size: 1.9em;
  color: #ffffff;
}

.reveal section:first-of-type h2 {
  margin-top: 0.6em;
  color: #b9d9ff;
  font-size: 1.0em;
}

.title-meta {
  margin-top: 2.2em;
  padding: 1.0em 1.2em;
  width: 62%;
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(78,163,255,0.22);
  border-radius: 12px;
}

.title-meta p {
  margin: 0.18em 0;
  color: var(--text-secondary);
  font-size: 0.70em;
}

/* ========== 章节页 ========== */

.section-slide {
  display: flex !important;
  flex-direction: column;
  justify-content: center;
  min-height: 100%;
}

.section-slide h1 {
  font-size: 1.95em;
  margin-bottom: 0.2em;
  color: #ffffff;
}

.section-slide h2,
.section-slide h3 {
  color: #b9d9ff;
}

/* ========== 双栏 ========== */

.columns {
  display: flex;
  gap: 34px;
  align-items: flex-start;
  margin-top: 0.4em;
}

.column {
  flex: 1 1 0;
  min-width: 0;
  background: rgba(255,255,255,0.035);
  border: 1px solid rgba(255,255,255,0.06);
  border-radius: 12px;
  padding: 0.7em 0.9em 0.8em 0.9em;
  box-sizing: border-box;
}


/* ========== 页面编号与底部信息 ========== */

.reveal .slide-number {
  right: 24px !important;
  top: 14px !important;
  font-size: 64px !important;
  color: var(--text-dim, #92a4bb) !important;
  background: transparent !important;
  padding: 0 !important;
  min-width: auto !important;
  z-index: 1000 !important;
}

.footer-left,
.footer-center {
  position: fixed;
  bottom: 12px;
  z-index: 2000;
  font-size: 16px;
  color: #12a0bb;
  letter-spacing: 0.02em;
  pointer-events: none;
}

.footer-left {
  left: 24px;
  text-align: left;
}

.footer-center {
  left: 0;
  right: 0;
  text-align: center;
}
/* ========== 进度条 ========== */

.reveal .progress {
  color: var(--bit-blue);
  height: 4px;
}

/* ========== 分页边界裁切安全 ========== */

.reveal .slides {
  text-shadow: none;
}

/* ========== 小号辅助类 ========== */

.small {
  font-size: 0.72em;
  color: var(--text-secondary);
}

.tiny {
  font-size: 0.60em;
  color: var(--text-secondary);
}

.center {
  text-align: center;
}

/* ========== 针对投影设备的留白优化 ========== */

@media screen and (max-width: 1400px) {
  .reveal .slides section {
    padding: 50px 78px 68px 78px;
  }

  .title-meta {
    width: 72%;
  }

  .figure-main {
    max-width: 82%;
  }

  .figure-wide {
    max-width: 92%;
  }
}

/* ========== figcaption ========== */
.reveal figure figcaption {
  font-size: 18px;
  color: #9aa6b2;
  margin-top: 8px;
}

/* ========== 文本高亮与强调 ========== */

.highlight {
  display: inline-block;
  padding: 0.02em 0.02em;
  border-radius: 5px;
  background: rgba(78, 163, 255, 0.16);
  color: #dff1ff !important;
  border: 1px solid rgba(78, 163, 255, 0.35);
  font-weight: 700;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.03);
}

.keyword {
  color: var(--bit-blue-light) !important;
  font-weight: 700;
}

.emphasis {
  color: #ffffff !important;
  font-weight: 700;
  text-decoration: underline;
  text-decoration-color: rgba(78,163,255,0.70);
  text-underline-offset: 0.12em;
  text-decoration-thickness: 2px;
}

.note {
  color: #b9d9ff !important;
  font-weight: 600;
}

.warning {
  display: inline-block;
  padding: 0.08em 0.38em;
  border-radius: 6px;
  background: rgba(255, 120, 90, 0.14);
  color: #ffd2c7 !important;
  border: 1px solid rgba(255, 120, 90, 0.30);
  font-weight: 700;
}