/*
 * BT Platform Child - Tutorials Styles
 * Extracted from page-tutorials.php
 */

.bt-tutorial-page {
    display: flex;
    gap: 24px;
    max-width: 1200px;
    margin: 40px auto;
    padding: 0 24px;
    min-height: 60vh;
}

/* 左侧导航 */
.bt-tutorial-nav {
    width: 240px;
    flex-shrink: 0;
    position: sticky;
    top: 80px;
    align-self: flex-start;
    max-height: calc(100vh - 100px);
    overflow-y: auto;
    background: var(--bt-card-bg, #fff);
    border-radius: 12px;
    border: 1px solid var(--bt-border-color, #e5e7eb);
    padding: 16px 0;
}

.bt-tutorial-nav-title {
    font-size: 14px;
    font-weight: 700;
    color: var(--bt-text-secondary, #6b7280);
    padding: 0 16px 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.bt-tutorial-nav a {
    display: block;
    padding: 10px 16px;
    font-size: 14px;
    color: var(--bt-text-primary, #1f2937);
    text-decoration: none;
    border-left: 3px solid transparent;
    transition: all 0.2s;
}

.bt-tutorial-nav a:hover {
    background: var(--bt-bg-hover, #f3f4f6);
    color: var(--bt-primary, #3b82f6);
}

.bt-tutorial-nav a.active {
    border-left-color: var(--bt-primary, #3b82f6);
    background: var(--bt-primary-light, #eff6ff);
    color: var(--bt-primary, #3b82f6);
    font-weight: 600;
}

/* 父级导航 */
.bt-tutorial-nav-parent {
    font-weight: 600 !important;
    color: var(--bt-text-primary, #1f2937) !important;
    font-size: 15px !important;
    margin-top: 4px;
    display: flex !important;
    align-items: center;
    gap: 10px;
    padding-left: 14px !important;
}

.bt-tutorial-nav-arrow {
    font-size: 18px;
    line-height: 1;
    transition: transform 0.25s ease;
    flex-shrink: 0;
    color: var(--bt-text-secondary, #9ca3af);
}

.bt-tutorial-nav-parent.collapsed .bt-tutorial-nav-arrow {
    transform: rotate(-90deg);
}

/* 子导航容器 */
.bt-tutorial-nav-children {
    padding-left: 12px;
    overflow: hidden;
    max-height: 500px;
    transition: max-height 0.3s ease, opacity 0.25s ease;
    opacity: 1;
}

.bt-tutorial-nav-children.collapsed {
    max-height: 0;
    opacity: 0;
}

.bt-tutorial-nav-children a {
    font-size: 13px;
    padding: 6px 16px 6px 20px;
    border-left-width: 2px;
}

/* 右侧内容 */
.bt-tutorial-content {
    flex: 1;
    min-width: 0;
}

.bt-tutorial-section {
    background: var(--bt-card-bg, #fff);
    border-radius: 12px;
    border: 1px solid var(--bt-border-color, #e5e7eb);
    padding: 32px;
    margin-bottom: 24px;
}

.bt-tutorial-section h2 {
    font-size: 22px;
    font-weight: 700;
    margin: 0 0 20px;
    color: var(--bt-text-primary, #1f2937);
}

.bt-tutorial-section h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 32px 0 12px;
    padding-top: 8px;
    color: var(--bt-text-primary, #1f2937);
}

.bt-tutorial-section hr {
    border: none;
    border-top: 1px solid var(--bt-border-color, #e5e7eb);
    margin: 32px 0;
}

.bt-tutorial-section h4 {
    font-size: 16px;
    font-weight: 600;
    margin: 20px 0 8px;
    color: var(--bt-text-primary, #1f2937);
}

.bt-tutorial-section p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--bt-text-secondary, #4b5563);
    margin: 0 0 16px;
}

.bt-tutorial-section ul,
.bt-tutorial-section ol {
    padding-left: 24px;
    margin: 0 0 16px;
}

.bt-tutorial-section li {
    font-size: 15px;
    line-height: 1.8;
    color: var(--bt-text-secondary, #4b5563);
    margin-bottom: 4px;
}

.bt-tutorial-section code {
    background: var(--bt-bg-code, #f3f4f6);
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 13px;
    font-family: 'SF Mono', 'Fira Code', monospace;
}

.bt-tutorial-section pre {
    background: #1e293b;
    color: #e2e8f0;
    padding: 16px 20px;
    border-radius: 8px;
    overflow-x: auto;
    font-size: 13px;
    line-height: 1.6;
    margin: 0 0 16px;
}

.bt-tutorial-section pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.bt-tutorial-section table {
    width: 100%;
    border-collapse: collapse;
    margin: 0 0 16px;
    font-size: 14px;
}

.bt-tutorial-section th,
.bt-tutorial-section td {
    padding: 10px 14px;
    border: 1px solid var(--bt-border-color, #e5e7eb);
    text-align: left;
}

.bt-tutorial-section th {
    background: var(--bt-bg-hover, #f9fafb);
    font-weight: 600;
    color: var(--bt-text-primary, #1f2937);
}

/* 快捷键 kbd 标签 */
.bt-tutorial-section kbd {
    display: inline-block;
    padding: 2px 7px;
    font-size: 12px;
    font-family: 'SF Mono', 'Consolas', 'Monaco', monospace;
    background: var(--bt-bg-hover, #f3f4f6);
    border: 1px solid var(--bt-border-color, #d1d5db);
    border-radius: 4px;
    box-shadow: 0 1px 0 var(--bt-border-color, #d1d5db);
    color: var(--bt-text-primary, #1f2937);
    white-space: nowrap;
    line-height: 1.6;
}

/* 快捷键速查表 */
.bt-shortcut-table td:first-child {
    white-space: nowrap;
    width: 200px;
}

/* Bilibili 视频嵌入 */
.bt-tutorial-video {
    position: relative;
    width: 100%;
    padding-bottom: 56.25%;
    margin: 0 0 20px;
    border-radius: 8px;
    overflow: hidden;
    background: #000;
}

.bt-tutorial-video iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: none;
}

/* 响应式 */
@media (max-width: 768px) {
    .bt-tutorial-page {
        flex-direction: column;
        padding: 0 16px;
        margin: 20px auto;
    }
    .bt-tutorial-nav {
        width: 100%;
        position: static;
        max-height: none;
        display: flex;
        flex-wrap: wrap;
        gap: 4px;
        padding: 12px;
    }
    .bt-tutorial-nav-title {
        width: 100%;
        padding-bottom: 8px;
    }
    .bt-tutorial-nav a {
        padding: 6px 12px;
        border-left: none;
        border-radius: 6px;
        font-size: 13px;
    }
    .bt-tutorial-nav a.active {
        background: var(--bt-primary, #3b82f6);
        color: #fff;
    }
    .bt-tutorial-section {
        padding: 20px;
    }
}