/* --------------------------------
 * 核心样式 (style.css)
 * 目标: 简洁、专业、易于截图
 * -------------------------------- */

/* 1. 基础重置与全局设置 */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans GB", "Microsoft YaHei", "WenQuanYi Micro Hei", sans-serif;
    background-color: #F8F9FA;
    color: #333;
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    box-sizing: border-box;
}

/* 2. 幻灯片容器 (核心布局) */
.slide-container {
    width: 1280px;
    height: 720px;
    background-color: #FFFFFF;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    border: 1px solid #E0E0E0;
    border-top: 6px solid #007AFF;
    padding: 50px 60px;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
}

/* 封面页专用布局 */
.cover-page .slide-container {
    justify-content: center;
    text-align: center;
}

/* 3. 索引页专用样式 */
.index-page h1 {
    text-align: left;
    border-bottom: 2px solid #007AFF;
    padding-bottom: 15px;
}
.index-page ol {
    padding-left: 20px;
    font-size: 1.4rem;
    line-height: 2.2;
}
.index-page li a {
    text-decoration: none;
    color: #007AFF;
    transition: color 0.2s;
}
.index-page li a:hover {
    color: #0056b3;
    text-decoration: underline;
}

/* 4. 通用排版 */
h1, h2, h3, h4 {
    color: #1A1A1A;
    margin: 0 0 20px 0;
    font-weight: 600;
}
h1 {
    font-size: 3.5rem;
    color: #007AFF;
}
h2 {
    font-size: 2.5rem;
    font-weight: 400;
    color: #555;
    margin-top: -10px;
}
h3 {
    font-size: 2rem;
    color: #007AFF;
    border-left: 5px solid #007AFF;
    padding-left: 15px;
    margin-bottom: 30px;
}
p, li {
    font-size: 1.25rem;
    line-height: 1.8;
}
ul, ol {
    margin: 0;
    padding-left: 40px;
}

/* 页脚样式 */
.slide-container footer {
    margin-top: auto;
    padding-top: 20px;
    font-size: 1.1rem;
    color: #777;
    text-align: right;
}
.cover-page footer {
    text-align: center;
    font-size: 1.25rem;
    color: #555;
    margin-top: 60px;
}

/* 针对特定内容的局部样式覆盖 */

/* 学习目标页的 flex 布局 */
.target-layout {
    display: flex;
    justify-content: space-around;
    align-items: flex-start;
    padding: 20px 0;
}
.target-column {
    width: 30%;
}
.target-column h4 {
    font-size: 1.6rem;
    color: #333;
    font-weight: 600;
    border-bottom: 2px solid #EEE;
    padding-bottom: 10px;
    margin-bottom: 20px;
}
.target-column ul {
    padding-left: 25px;
}
.target-column li {
    font-size: 1.15rem;
    line-height: 1.9;
    color: #444;
}

/* 准备工作页的两列布局 */
.prep-list {
    padding-left: 0;
    list-style-type: none;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
}
.prep-list li {
    font-size: 1.2rem;
    line-height: 1.8;
    color: #333;
    width: 48%;
    margin-bottom: 25px;
    display: flex;
    align-items: flex-start;
}
.prep-list .icon {
    font-size: 1.5rem;
    margin-right: 15px;
    min-width: 30px;
    text-align: center;
}
.prep-list strong {
    color: #111;
    font-size: 1.3rem;
    margin-bottom: 5px;
    display: block;
}
.prep-list .full-width {
    width: 100%;
}

/* 注意事项页的有序列表 */
.notes-list {
    padding-left: 20px;
    list-style-type: decimal;
}
.notes-list li {
    font-size: 1.35rem;
    line-height: 2.2;
    color: #333;
    margin-bottom: 15px;
    padding-left: 10px;
}

/* 卧位概念页的定义列表 */
.concept-list {
    padding-left: 0;
    list-style-type: none;
}
.concept-list li {
    font-size: 1.3rem;
    line-height: 1.9;
    color: #333;
    margin-bottom: 30px;
    padding-left: 10px;
    border-left: 4px solid #E0E0E0;
}
.concept-list strong {
    font-size: 1.5rem;
    color: #007AFF;
    font-weight: 600;
    margin-right: 10px;
}

/* 卧位种类页的复杂列表 */
.position-list {
    padding-left: 0;
    list-style-type: none;
}
.position-list > li {
    margin-bottom: 25px;
}
.position-list h4 {
    font-size: 1.7rem;
    color: #333;
    font-weight: 600;
    margin: 0 0 10px 0;
}
.position-list ul {
    list-style-type: none;
    padding-left: 20px;
}
.position-list ul li {
    font-size: 1.15rem;
    line-height: 1.8;
    margin-bottom: 15px;
    border-left: 3px solid #E0E0E0;
    padding-left: 15px;
}
.position-list ul strong {
    color: #007AFF;
    font-weight: 600;
}
.position-list > li > p {
    font-size: 1.15rem;
    line-height: 1.8;
    margin: 0;
    padding-left: 20px;
}

/* --- 变更点: 操作要点页的新样式 --- */
.operation-section {
    padding-left: 0; /* 移除外层列表的默认缩进 */
    list-style-type: none; /* 移除外层列表的项目符号 */
}

/* 通用要点 (黑色项目符号) */
.operation-section > li {
    font-size: 1.25rem; /* 20px */
    line-height: 1.8;
    margin-bottom: 15px; /* 间隔 */
    padding-left: 0;
    position: relative; /* 用于自定义项目符号 */
}
.operation-section > li::before {
    content: '•'; /* 自定义圆点 */
    color: #333;
    font-size: 1.5em;
    position: absolute;
    left: -25px; /* 调整位置 */
    top: -5px;
}

/* 主操作流程标题 (红色数字) */
.operation-section h4 {
    font-size: 1.6rem; /* 26px */
    color: #D9534F; /* 红色系 */
    font-weight: 600;
    margin: 30px 0 15px 0; /* 上下间距 */
    padding-left: 0;
    position: relative; /* 用于自定义数字 */
}
.operation-section h4::before {
    counter-increment: op-counter; /* 计数器递增 */
    content: counter(op-counter) '.'; /* 显示数字和点 */
    color: #D9534F;
    font-size: 1.1em; /* 比标题文字略大 */
    font-weight: bold;
    position: absolute;
    left: -35px; /* 调整位置 */
    top: 0;
}
.operation-section ol { /* 重置有序列表的计数器 */
    counter-reset: op-counter;
}

/* 操作流程内部的子项 (黑色项目符号) */
.operation-section ul {
    list-style-type: none; /* 移除默认圆点 */
    padding-left: 20px; /* 内部缩进 */
}
.operation-section ul li {
    font-size: 1.2rem; /* 19px */
    line-height: 2.0;
    margin-bottom: 10px;
    position: relative;
    padding-left: 20px; /* 留出位置给自定义项目符号 */
}
.operation-section ul li::before {
    content: '•'; /* 自定义圆点 */
    color: #333;
    font-size: 1.3em;
    position: absolute;
    left: 0px; /* 调整位置 */
    top: -3px;
}
.operation-section ul li strong {
    color: #111;
    font-weight: 600;
}