:root {
    --bg-primary: #F8FAFC;
    --bg-secondary: #FFFFFF;
    --bg-tertiary: #F1F5F9;
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --accent-color: #2563EB;
    --accent-hover: #1D4ED8;
    --border-color: #E2E8F0;
    --code-bg: #1E293B;
    --code-text: #E2E8F0;
    --code-border: #334155;
    --radius-md: 12px;
    --radius-lg: 16px;
    --shadow-soft: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 2rem;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
}

/* Layout Wrapper */
.layout-wrapper {
    display: flex;
    min-height: 100vh;
    max-width: 1400px;
    margin: 0 auto;
}

/* Sidebar */
.sidebar {
    width: 280px;
    position: sticky;
    top: 0;
    height: 100vh;
    padding: 2rem 1.5rem;
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    flex-shrink: 0;
    overflow-y: auto;
}

.sidebar-header h2 {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-color), #2DD4BF);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 2rem;
}

.toc ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toc-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    display: block;
    padding: 0.5rem 0.75rem;
    border-radius: 8px;
    transition: all 0.2s ease;
}

.toc-link:hover {
    background-color: var(--bg-tertiary);
    color: var(--text-primary);
}

.toc-link.active {
    background-color: var(--bg-primary);
    color: var(--accent-color);
    font-weight: 600;
}

/* Main Content */
.content {
    flex-grow: 1;
    padding: 3rem 4rem 6rem;
    max-width: 1000px;
}

.hero {
    margin-bottom: 3.5rem;
}

.hero h1 {
    font-size: 2.75rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.hero p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 700px;
}

/* Sections */
.section-block {
    margin-bottom: 4rem;
    padding-top: 1.5rem;
}

.mt-0 {
    margin-top: 0;
    padding-top: 0;
}

.section-header {
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 1rem;
}

.section-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1.05rem;
}

/* Grid & Cards */
.steps-grid {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.step-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    padding-top: 1.75rem;
    box-shadow: var(--shadow-soft);
    position: relative;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.step-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

.step-badge {
    position: absolute;
    top: -12px;
    left: 20px;
    background-color: var(--text-primary);
    color: white;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 20px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.highlight-card {
    background-color: #EFF6FF;
    border-color: #BFDBFE;
}

.step-obs {
    margin-top: 0.75rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* Lists */
.data-list {
    list-style: none;
    margin-top: 1rem;
    display: grid;
    gap: 0.5rem;
}

.data-list li {
    font-size: 0.95rem;
    background: rgba(255, 255, 255, 0.5);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.data-list code {
    background: #DBEAFE;
    color: #1E3A8A;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 0.85rem;
}

/* Code Blocks */
.code-block {
    position: relative;
    margin-top: 1rem;
    background-color: var(--code-bg);
    border-radius: 8px;
    border: 1px solid var(--code-border);
    overflow: hidden;
}

.code-block pre {
    margin: 0;
    padding: 1.25rem 1.5rem;
    overflow-x: auto;
}

.code-block code {
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    font-size: 0.9rem;
    color: var(--code-text);
}

.copy-btn {
    position: absolute;
    top: 8px;
    right: 8px;
    background: rgba(255, 255, 255, 0.1);
    color: #94A3B8;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    backdrop-filter: blur(4px);
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.copy-btn.copied {
    background-color: #10B981;
    color: white;
    border-color: #10B981;
}

/* Alerts */
.info-alert {
    display: flex;
    gap: 1rem;
    background-color: #FEF2F2;
    border: 1px solid #FECACA;
    padding: 1.5rem;
    border-radius: var(--radius-md);
    color: #7F1D1D;
}

.info-alert svg {
    flex-shrink: 0;
    color: #DC2626;
    margin-top: 2px;
}

.info-alert h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.info-alert p {
    font-size: 0.95rem;
    line-height: 1.5;
}

.info-alert code {
    background-color: white;
    padding: 2px 6px;
    border-radius: 4px;
    border: 1px solid #FECACA;
    font-size: 0.85rem;
}

/* Footer */
.app-footer {
    margin-top: 4rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 1024px) {
    .content {
        padding: 2rem;
    }
}

@media (max-width: 768px) {
    .layout-wrapper {
        flex-direction: column;
    }
    
    .sidebar {
        width: 100%;
        height: auto;
        position: relative;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: 1.5rem;
    }
    
    .toc ul {
        flex-direction: row;
        flex-wrap: wrap;
    }
    
    .content {
        padding: 2rem 1.5rem;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
}