html {
    scroll-behavior: smooth;
}

:root {
    --bg-body: #f8f9fa;
    --bg-nav: #ffffff;
    --bg-card: #ffffff;
    --bg-sidebar: #f1f3f5;
    --border-color: #e0e0e0;
    --border-light: #f0f0f0;
    --text-main: #212529;
    --text-dim: #6c757d;
    --text-title: #1a1a1a;
    --primary: #0077cc;
    --secondary: #6543c7;
    --scrollbar-thumb: #c0c0c0;
    --scrollbar-hover: #999999;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { 
    font-family: 'Inter', system-ui, sans-serif; 
    background-color: var(--bg-body); 
    color: var(--text-main); 
    line-height: 1.6; 
    min-height: 100vh;
}
.glass-nav { 
    display: flex; justify-content: space-between; align-items: center; 
    padding: 1rem 2rem; 
    background: var(--bg-nav); 
    border-bottom: 1px solid var(--border-color);
    position: sticky; top: 0; z-index: 100; 
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}
.logo { 
    font-size: 1.5rem; font-weight: 800; letter-spacing: 2px; 
    color: var(--primary); 
}
nav a { 
    color: var(--text-dim); text-decoration: none; margin-left: 2rem; 
    font-weight: 500; transition: 0.3s; 
}
nav a:hover, nav a.active { color: var(--primary); }

.container { max-width: 1200px; margin: 0 auto; padding: 4rem 2rem; }
.hero { text-align: center; margin-bottom: 4rem; }
.hero h1 { 
    font-size: 3rem; 
    background: linear-gradient(90deg, var(--primary), var(--secondary)); 
    -webkit-background-clip: text; -webkit-text-fill-color: transparent; 
    margin-left: auto;
    margin-right: auto; 
}
.grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); 
    gap: 2rem; 
}
.theme-btn {
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: #0077cc;
    padding: 6px 12px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.3s ease;
}

.theme-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #ffffff;
}
.card { 
    max-width: 560px;
    width: 100%;
    background: var(--bg-card); 
    border: 1px solid var(--border-color); 
    border-radius: 12px; 
    padding: 2rem; 
    text-decoration: none; 
    color: var(--text-main); 
    transition: 0.3s; 
    box-shadow: 0 4px 12px rgba(0,0,0,0.05);
}
.card:hover { 
    transform: translateY(-5px); 
    box-shadow: 0 8px 20px rgba(0,0,0,0.1); 
    border-color: var(--primary); 
}
.card h3 { margin-bottom: 0.5rem; color: var(--text-title); }
.card p { font-size: 0.9rem; color: var(--text-dim); margin-bottom: 1rem; }
.tag { 
    display: inline-block; padding: 4px 10px; font-size: 0.75rem; 
    border-radius: 20px; 
    background: rgba(101, 67, 199, 0.1); 
    color: var(--secondary); 
    border: 1px solid rgba(101, 67, 199, 0.3); 
}

.doc-layout { 
    display: flex; max-width: 1200px; margin: 0 auto; 
    padding: 3rem 2rem; gap: 3rem; 
}
.sidebar { 
    width: 250px; flex-shrink: 0; position: sticky; top: 100px; 
    height: fit-content; max-height: calc(100vh - 150px); 
    overflow-y: auto; 
    background: var(--bg-sidebar);
    padding: 1rem; 
    border-radius: 12px; 
    border: 1px solid var(--border-color); 
}
.sidebar h4 { 
    color: var(--primary); margin-bottom: 1rem; text-transform: uppercase; 
    letter-spacing: 1px; font-size: 0.8rem; 
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.5rem;
}
.sidebar ul { list-style: none; }
.sidebar li { margin-bottom: 0.5rem; }
.sidebar a { 
    color: var(--text-dim); text-decoration: none; font-size: 0.9rem; 
    display: block; padding: 4px 8px; border-radius: 6px; transition: 0.3s; 
}
.sidebar a:hover { 
    color: var(--primary); 
    background: rgba(0, 119, 204, 0.1); 
    padding-left: 12px; 
}
.content { flex: 1; max-width: 800px; }
.content h1, .content h2 { margin-top: 2rem; margin-bottom: 1rem; color: var(--text-title); }
.content p { margin-bottom: 1rem; color: var(--text-dim); }
.content code { 
    background: rgba(0,0,0,0.05); 
    padding: 2px 6px; 
    border-radius: 4px; 
    font-family: monospace; 
    color: var(--primary); 
}

.content h1, 
.content h2, 
.content h3, 
.content h4 {
    scroll-margin-top: 80px; 
}

::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--border-light); }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--scrollbar-hover); }
* { scrollbar-width: thin; scrollbar-color: var(--scrollbar-thumb) var(--border-light); }

@media (max-width: 768px) { 
    .doc-layout { flex-direction: column; } 
    .sidebar { width: 100%; margin-bottom: 1rem; } 
}