:root {
    --bg-color: #1a1a1d;
    --surface-color: #2c2f33;
    --primary-color: #4a90e2;
    --text-color: #f0f0f0;
    --text-muted-color: #a9a9a9;
    --border-color: #444;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    display: flex;
    min-height: 100vh;
    overflow: hidden;
}

html {
    scrollbar-width: thin;
    scrollbar-color: var(--border-color) var(--surface-color);
    font-size: 16px;
}

.main-view {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    height: 100vh;
    min-width: 0;
    transition: transform 0.3s ease-in-out;
}

header {
    background-color: var(--surface-color);
    padding: 1rem 1.5rem;
    border-bottom: 2px solid var(--border-color);
    text-align: left;
    flex-shrink: 0;
    z-index: 1000;
}

header h1 {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.8rem;
}

#sidebar {
    width: 300px;
    flex-shrink: 0;
    background-color: var(--surface-color);
    padding: 1.5rem;
    height: 100vh;
    overflow-y: auto;
    border-right: 2px solid var(--border-color);
    transition: transform 0.3s ease-in-out;
}

#content {
    flex-grow: 1;
    padding: 2rem 3rem;
    overflow-y: scroll;
    min-width: 0;
}

.content-wrapper {
    overflow-wrap: break-word;
    word-wrap: break-word;
}

#sidebar ul {
    list-style: none;
}

#sidebar ul li a {
    display: block;
    color: var(--text-muted-color);
    text-decoration: none;
    padding: 0.75rem 1rem;
    border-radius: 6px;
    transition: background-color 0.2s ease, color 0.2s ease;
    font-weight: 500;
}

#sidebar ul li a:hover {
    background-color: rgba(74, 144, 226, 0.1);
    color: var(--primary-color);
}

#sidebar ul li a.active {
    background-color: var(--primary-color);
    color: #fff;
}

#content h1, #content h2, #content h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    margin-top: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

#content h1 { font-size: 2.2rem; }
#content h2 { font-size: 1.8rem; }
#content h3 { font-size: 1.5rem; }
#content p { margin-bottom: 1rem; }

#content ul, #content ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
    overflow-wrap: break-word;
}

#content a {
    color: var(--primary-color);
    text-decoration: none;
}

#content a:hover {
    text-decoration: underline;
}

#content pre {
    background-color: #23241f;
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    overflow-x: auto;
    font-family: "Fira Code", SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    font-size: 0.9rem;
}

#content code {
    background-color: rgba(74, 144, 226, 0.2);
    color: var(--primary-color);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-family: "Fira Code", SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
    overflow-wrap: break-word;
    word-wrap: break-word;
    white-space: normal;
}

#content pre code {
    background-color: transparent;
    color: inherit;
    padding: 0;
    white-space: pre;
    overflow-wrap: normal;
    word-wrap: normal;
}

#content img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 1.5rem 0;
    border-radius: 8px;
}

#content table {
    width: 100%;
    max-width: 100%;
    border-collapse: collapse;
    margin-bottom: 1.5rem;
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

#content table th,
#content table td {
    padding: 0.8rem 1rem;
    border: 1px solid var(--border-color);
    text-align: left;
    vertical-align: top;
    white-space: normal;
    overflow-wrap: break-word;
}

#content table th {
    background-color: var(--surface-color);
    color: var(--primary-color);
    font-weight: 600;
}

#content table tr:nth-child(even) {
    background-color: rgba(74, 144, 226, 0.05);
}

#content blockquote {
    border-left: 4px solid var(--primary-color);
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    background-color: rgba(74, 144, 226, 0.08);
    color: var(--text-color);
    border-radius: 6px;
}

#content blockquote p:last-child { margin-bottom: 0; }
#content hr {
    border: none;
    border-top: 1px solid var(--border-color);
    margin: 2rem 0;
}

#content strong, #content b {
    color: var(--primary-color);
    font-weight: 700;
}

#content em, #content i { font-style: italic; }
#content s, #content del {
    text-decoration: line-through;
    color: var(--text-muted-color);
}

::-webkit-scrollbar { width: 12px; }
::-webkit-scrollbar-track { background: var(--surface-color); }
::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 20px;
    border: 3px solid var(--surface-color);
}
::-webkit-scrollbar-thumb:hover { background-color: var(--text-muted-color); }

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

#version-selector-container {
    position: relative;
    display: inline-block;
    min-width: 180px;
}

.version-selected {
    background-color: var(--surface-color);
    color: var(--text-color);
    padding: 0.5rem 2.5rem 0.5rem 1rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: background-color 0.2s ease;
    user-select: none;
    position: relative;
}

.version-selected:hover { background-color: #3a3d40; }
.version-selected::after {
    content: '▼';
    font-size: 0.8rem;
    color: var(--text-muted-color);
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    transition: transform 0.3s ease;
}

.version-options.is-open + .version-selected::after {
    transform: translateY(-50%) rotate(180deg);
}

.version-options {
    position: absolute;
    top: calc(100% + 5px);
    left: 0;
    right: 0;
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    z-index: 100;
    max-height: 300px;
    overflow-y: auto;
    transform-origin: top;
    transform: scaleY(0);
    opacity: 0;
    visibility: hidden;
    transition: transform 0.25s ease, opacity 0.25s ease, visibility 0.25s;
}

.version-options.is-open {
    transform: scaleY(1);
    opacity: 1;
    visibility: visible;
}

.version-option {
    padding: 0.75rem 1rem;
    color: var(--text-muted-color);
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease;
    font-size: 0.9rem;
}

.version-option:hover {
    background-color: rgba(74, 144, 226, 0.1);
    color: var(--primary-color);
}

.version-option.is-selected {
    background-color: var(--primary-color);
    color: #fff;
    font-weight: 500;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    z-index: 2001;
}

.menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 5px 0;
    transition: all 0.3s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeOut {
    from { opacity: 1; transform: translateY(0); }
    to { opacity: 0; transform: translateY(15px); }
}

.content-wrapper.content-fade-in {
    animation: fadeIn 0.3s ease-out forwards;
}

.content-wrapper.content-fade-out {
    animation: fadeOut 0.25s ease-in forwards;
}

@media (max-width: 768px) {
    body {
        flex-direction: column;
        height: 100vh;
        overflow-y: auto;
        overflow-x: hidden;
    }

    body.sidebar-is-open {
        overflow: hidden;
    }

    .main-view {
        height: 100%;
        padding-top: 60px;
    }

    header {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        padding: 0 1rem;
        height: 60px;
        display: flex;
        align-items: center;
    }

    .header-content {
        display: grid;
        grid-template-columns: auto 1fr auto;
        gap: 1rem;
        align-items: center;
        width: 100%;
    }

    header h1 {
        font-size: 1.5rem;
        text-align: center;
        margin: 0;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        min-width: 0;
    }

    .menu-toggle {
        display: block;
        order: 0;
    }

    #version-selector-container {
        order: 0;
        min-width: 140px;
    }

    #sidebar {
        position: fixed;
        top: 0;
        left: 0;
        width: 280px;
        height: 100%;
        transform: translateX(-100%);
        border-right: 2px solid var(--border-color);
        z-index: 2000;
        padding-top: 4rem;
        border-bottom: none;
    }

    body.sidebar-is-open #sidebar {
        transform: translateX(0);
        box-shadow: 5px 0 15px rgba(0,0,0,0.2);
    }

    #sidebar ul li a {
        padding: 0.5rem 0.75rem;
    }

    #content {
        padding: 1.5rem;
        height: auto;
        flex-grow: 1;
    }

    #content .content-wrapper > *:first-child {
        margin-top: 0;
    }

    #content h1 { font-size: 1.8rem; }
    #content h2 { font-size: 1.5rem; }
    #content h3 { font-size: 1.3rem; }
    #content pre {
        padding: 1rem;
        font-size: 0.85rem;
    }
}

body.error-page .main-view {
    width: 100%;
}

body.error-page main#content {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    height: calc(100vh - 60px);
    padding: 2rem;
}