/* --- 全局重置与变量 (保持一致性) --- */
:root {
  --bg-color: #0f1012;
  --card-bg: #151618;
  /* 比背景稍亮一点 */
  --text-main: #ffffff;
  --text-grey: #8c8c8c;
  --accent-orange: #d99c68;
  --border-color: #333;
  --font-serif: "SimSun", "Songti SC", serif;
  --font-sans: "DengXian", "Microsoft YaHei", sans-serif;
  --font-mono: "Consolas", "Monaco", monospace;
}

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

a {
  text-decoration: none;
  color: inherit;
}

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-sans);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  /* 防止全屏滚动 */
}

/* --- 顶部导航 --- */
header {
  height: 60px;
  padding: 0 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
}

.header-left .back-btn {
  background: none;
  border: none;
  color: #ccc;
  font-size: 14px;
  font-family: var(--font-sans);
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
  transition: color 0.3s ease;
}

.header-left .back-btn:hover {
  color: #ffffff;
}

.logo-area {
  text-align: center;
}

.logo-title {
  font-family: var(--font-serif);
  font-size: 18px;
  letter-spacing: 2px;
  margin-left: 320px;
}

.logo-sub {
  font-size: 10px;
  color: #fff;
  letter-spacing: 3px;
  margin-left: 320px;
}

.nav-menu {
  display: flex;
  gap: 20px;
}

.nav-item {
  font-size: 15px;
  padding: 6px 16px;
  border-radius: 4px;
  color: var(--text-grey);
  transition: all 0.3s;
}


.nav-item.active {
  background-color: var(--accent-orange);
  color: #1e1f21;
  font-weight: bold;
}

.nav-item:hover:not(.active) {
  color: var(--text-main);
}

/* --- 页面主体布局 (左右分栏) --- */
.main-wrapper {
  flex: 1;
  display: flex;
  width: 100%;
  height: calc(100vh - 60px);
  position: relative;
}

.page-container {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 60px 40px 60px;
}

/* 顶部标题区 */
.header-section {
  text-align: center;
  margin-bottom: 30px;
}

/* 左侧内容区 */
.content-side {
  flex: 1;
  padding: 40px 60px 40px 100px;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  z-index: 5;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.content-side::-webkit-scrollbar {
  display: none;
}



.page-header {
  margin-bottom: 50px;
  text-align: center;
}

.page-title {
  font-family: var(--font-serif);
  font-size: 40px;
  font-weight: 800;
  color: var(--accent-orange);
  margin-bottom: 10px;
}

.page-desc {
  font-size: 18px;
  color: #fff;
}

/* --- 时间轴样式 --- */
.timeline-container {
  position: relative;
  padding-left: 20px;
  /* 给圆点留出位置 */
  padding-bottom: 40px;
}


.timeline-line {
  position: absolute;
  top: 5px;
  bottom: 50px;
  left: 24px;
  width: 3px;
  background-color: var(--accent-orange);
  opacity: 0.5;
}

.t-item {
  position: relative;
  margin-bottom: 45px;
  padding-left: 30px;
  /* 文字距离线的距离 */
  opacity: 0;
  /* 初始隐藏，用于JS动画 */
  transform: translateY(20px);
}

/* 时间轴圆点 */
.t-dot {
  position: absolute;
  left: -4px;
  top: 4px;
  width: 18px;
  height: 18px;
  background-color: var(--accent-orange);
  border-radius: 50%;
  border: 3px solid var(--bg-color);
  box-shadow: 0 0 10px rgba(217, 156, 104, 0.3);
  z-index: 2;
}

.t-title {
  font-size: 20px;
  font-weight: bold;
  /* 字重中等偏粗 */
  color: #daae88;
  margin-bottom: 8px;
  letter-spacing: 0.5px;
}

.t-desc {
  font-size: 18px;
  color: var(--text-grey);
  line-height: 1.6;
  max-width: 550px;
  /* 控制文字宽度，防止太长 */
}

/* --- 全局重置与变量 (保持一致性) --- */
:root {
  --bg-color: #0f1012;
  --card-bg: #151618;
  /* 比背景稍亮一点 */
  --text-main: #ffffff;
  --text-grey: #8c8c8c;
  --accent-orange: #d99c68;
  --border-color: #333;
  --font-serif: "SimSun", "Songti SC", serif;
  --font-sans: "DengXian", "Microsoft YaHei", sans-serif;
  --font-mono: "Consolas", "Monaco", monospace;
}

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

a {
  text-decoration: none;
  color: inherit;
}

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-sans);
  height: 100vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  /* 防止全屏滚动 */
}

/* --- 顶部导航 --- */
header {
  height: 60px;
  padding: 0 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-shrink: 0;
}

.back-btn {
  font-size: 14px;
  color: var(--text-main);
  cursor: pointer;
  opacity: 0.8;
  display: flex;
  gap: 8px;
}

.back-btn:hover {
  opacity: 1;
}

.logo-area {
  text-align: center;
}

.logo-title {
  font-family: var(--font-serif);
  font-size: 18px;
  letter-spacing: 2px;
}

.logo-sub {
  font-size: 10px;
  color: var(--text-grey);
  letter-spacing: 3px;
}

.nav-menu {
  display: flex;
  gap: 20px;
}

.nav-item {
  font-size: 14px;
  padding: 6px 16px;
  border-radius: 4px;
  color: var(--text-grey);
  transition: all 0.3s;
}

.nav-item.active {
  background-color: var(--accent-orange);
  color: #1e1f21;
  font-weight: bold;
}

.nav-item:hover:not(.active) {
  color: var(--text-main);
}



/* 与其他页面统一的背景装饰层*/
.bg-layer {
  position: fixed;
  top: 55%;
  right: 0;
  transform: translateY(-50%);
  /* 垂直居中 */

  width: 50vw;
  height: 80vh;

  /* 青铜器素材图片 */
  background-image: url('./素材补充/未标题-2.png');
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center right;

  pointer-events: none;
  /* 鼠标穿透 */
  z-index: 0;
  opacity: 0.9;

  mask-image: linear-gradient(to left, rgba(0, 0, 0, 1), rgba(0, 0, 0, 0.2));
  -webkit-mask-image: linear-gradient(to left, rgba(0, 0, 0, 1), rgba(0, 0, 0, 0.2));

  /* 呼吸动感动画 */
  animation: pulseGlow 10s infinite alternate;
}

@keyframes pulseGlow {
  0% {
    transform: translateY(-50%) scale(1);
    opacity: 0.6;
  }

  100% {
    transform: translateY(-50%) scale(1.1);
    opacity: 0.9;
  }
}

.page-container {
  display: flex;
  flex-direction: column;
  height: calc(100vh - 60px);
  overflow: hidden;
  position: relative;
  z-index: 1;
  /* 确保文字在背景上层 */
}

.content-side {
  flex: 1;
  overflow-y: auto;
  max-width: 800px;
  margin-left: -100px;
  /* 整体居左留白 */
  padding-right: 20px;

  /* 隐藏滚动条但保留功能 */
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.content-side::-webkit-scrollbar {
  display: none;
}

/* 响应式适配：手机端隐藏大背景图 */
@media (max-width: 900px) {
  .bg-layer {
    display: none;
  }

  .content-side {
    max-width: 100%;
    margin-left: 20px;
  }
}


@media (max-width: 768px) {

  /* 1. 取消全屏锁定，允许页面垂直滚动 */
  body {
    height: auto;
    overflow-y: auto;
    overflow-x: hidden;
  }

  /* 2. 导航栏改造：分两行显示 */
  header {
    height: auto;
    flex-direction: column;
    padding: 15px 15px 10px 15px;
    gap: 15px;
    position: relative;
  }

  .header-left {
    position: absolute;
    left: 15px;
    top: 20px;
  }

  .logo-title,
  .logo-sub {
    margin-left: 0;
    text-align: center;
  }

  .nav-menu {
    width: 100%;
    justify-content: center;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 5px;
  }

  .nav-item {
    font-size: 12px;
    padding: 6px 10px;
    white-space: nowrap;
  }

  .page-container {
    height: auto;
    overflow: visible;
    padding: 15px;
    /* 缩小全局边距 */
  }

  .header-section {
    margin-top: 10px;
    margin-bottom: 25px;
  }

  .page-title {
    font-size: 24px;
    margin-bottom: 8px;
  }

  .page-desc {
    font-size: 13px;
  }

  .content-side {
    max-width: 100%;
    margin-left: 0;
    padding: 0 10px 20px 10px;
    /* 清除原本巨大的左右内边距 */
    overflow-y: visible;
    /* 取消内部滚动条 */
  }

  .timeline-container {
    padding-left: 5px;
  }

  .timeline-line {
    left: -4px;
    /* 调整线条靠近左侧 */
    width: 2px;
  }

  .t-item {
    padding-left: 20px;
    /* 减小文字距离线条的空隙 */
    margin-bottom: 35px;
  }

  .t-dot {
    left: -15px;
    /* 重新对齐圆点中心到线条 */
    width: 14px;
    height: 14px;
    top: 2px;
    border-width: 2px;
  }

  /* 调整时间轴文字 */
  .t-title {
    font-size: 16px;
    margin-bottom: 6px;
  }

  .t-desc {
    font-size: 13px;
  }

  .visual-side {
    display: none;
  }
}