:root {
    /* Modern Palette */
    --primary-hue: 220;
    --primary-color: hsl(var(--primary-hue), 90%, 56%);
    --secondary-color: hsl(260, 90%, 60%);
    --accent-color: hsl(30, 90%, 60%);

    --text-color: #1a1a2e;
    --text-muted: #586b85;

    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --glass-bg: rgba(255, 255, 255, 0.65);
    --glass-border: rgba(255, 255, 255, 0.4);
    --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.1);

    --sidebar-bg: rgba(255, 255, 255, 0.75);
    --code-bg: rgba(240, 240, 250, 0.8);
    --border-color: rgba(255, 255, 255, 0.6);

    --header-height: 70px;
    --sidebar-width: 280px;
    --radius-md: 16px;
    --radius-sm: 8px;
}

[data-theme="dark"] {
    --text-color: #e2e8f0;
    --text-muted: #94a3b8;

    --bg-gradient: linear-gradient(135deg, #0f172a 0%, #1e1b4b 100%);
    --glass-bg: rgba(30, 41, 59, 0.65);
    --glass-border: rgba(255, 255, 255, 0.08);
    --glass-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.3);

    --sidebar-bg: rgba(15, 23, 42, 0.75);
    --code-bg: rgba(15, 23, 42, 0.6);
    --border-color: rgba(255, 255, 255, 0.05);
}

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

ul {
    list-style-type: none;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-color);
    background: var(--bg-gradient);
    background-attachment: fixed;
    line-height: 1.7;
    min-height: 100vh;
}

/* Glass Header */
.site-header {
    height: var(--header-height);
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
}

.brand {
    font-weight: 800;
    font-size: 1.4rem;
    background: linear-gradient(120deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
    letter-spacing: -0.5px;
}

.header-controls {
    display: flex;
    gap: 1rem;
    align-items: center;
}

/* Glass Sidebar */
.site-sidebar {
    width: var(--sidebar-width);
    background: var(--sidebar-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-right: 1px solid var(--glass-border);
    position: fixed;
    top: var(--header-height);
    bottom: 0;
    left: 0;
    overflow-y: auto;
    padding: 2rem 0;
    z-index: 40;
    box-shadow: 4px 0 24px rgba(0, 0, 0, 0.02);
}

.nav-group {
    margin-bottom: 1.5rem;
}

.nav-group-title {
    padding: 0 2rem;
    font-size: 0.7rem;
    text-transform: uppercase;
    color: var(--text-muted);
    letter-spacing: 1px;
    font-weight: 700;
    margin-bottom: 0.75rem;
    margin-top: 1.5rem;
}

.nav-link {
    display: flex;
    align-items: center;
    padding: 0.6rem 2rem;
    color: var(--text-color);
    text-decoration: none;
    font-size: 0.95rem;
    border-left: 3px solid transparent;
    transition: all 0.2s ease;
    opacity: 0.8;
}

.nav-link:hover {
    background: linear-gradient(90deg, rgba(var(--primary-hue), 100%, 80%, 0.1) 0%, transparent 100%);
    opacity: 1;
    padding-left: 2.2rem;
}

.nav-link.active {
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    background: linear-gradient(90deg, rgba(59, 130, 246, 0.1) 0%, transparent 100%);
    font-weight: 600;
    opacity: 1;
}

/* Main Content */
.site-main {
    margin-left: var(--sidebar-width);
    margin-top: var(--header-height);
    padding: 3rem;
    max-width: 1400px;
}

.content-wrapper {
    max-width: 900px;
    margin: 0 auto;
    background: var(--glass-bg);
    padding: 3rem;
    border-radius: var(--radius-md);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    backdrop-filter: blur(8px);
}

/* Cards & Elements */
.card,
.alert,
blockquote {
    background: rgba(255, 255, 255, 0.4);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
    backdrop-filter: blur(4px);
}

[data-theme="dark"] .card {
    background: rgba(0, 0, 0, 0.2);
}

h1 {
    font-size: 2.5rem;
    letter-spacing: -1px;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, var(--text-color), var(--text-muted));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

h2 {
    font-size: 1.8rem;
    margin-top: 2.5rem;
    color: var(--text-color);
}

h3 {
    font-size: 1.3rem;
    margin-top: 2rem;
    color: var(--text-color);
}

hr {
    border: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
    margin: 2.5rem 0;
}

pre {
    background: var(--code-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.05);
    padding: 1rem;
    overflow-x: auto;
    margin: 1.5rem 0;
}

pre code {
    background: transparent;
    padding: 0;
}

code {
    background-color: var(--code-bg);
    padding: 0.2em 0.4em;
    border-radius: 4px;
    font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: 0.9em;
}

.search-container {
    position: relative;
}

.search-container input {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid var(--glass-border);
    color: var(--text-color);
    border-radius: 20px;
    padding: 0.5rem 1.2rem;
    backdrop-filter: blur(4px);
    transition: all 0.3s ease;
    width: 220px;
}

.search-container input:focus {
    width: 280px;
    background: rgba(255, 255, 255, 0.3);
    outline: none;
    box-shadow: 0 0 0 2px var(--primary-color);
}

.btn {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 0.6rem 1.2rem;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}

.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
    text-decoration: none;
}

/* Mobile Toggle */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-color);
    cursor: pointer;
}

/* Responsive */
@media (max-width: 768px) {
    .site-main {
        padding: 1rem;
        margin-left: 0;
    }

    .content-wrapper {
        padding: 1.5rem;
    }

    .site-sidebar {
        transform: translateX(-100%);
        width: 260px;
    }

    .site-sidebar.show {
        transform: translateX(0);
        box-shadow: 50px 0 100px rgba(0, 0, 0, 0.5);
    }

    .mobile-menu-toggle {
        display: block;
    }

    .site-header {
        padding: 0 1rem;
    }
}