:root {
    --bg-color: #0b1329;
    --card-bg: #131e3a;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --accent: #38bdf8;
    --success: #4ade80;
    --warning: #fbbf24;
    --error: #f87171;
    --accent-glow: rgba(56, 189, 248, 0.15);
    --border-color: #1e293b;
    --row-hover-bg: rgba(24, 37, 70, 0.8);
    --radial-glow-1: rgba(56, 189, 248, 0.05);
    --radial-glow-2: rgba(139, 92, 246, 0.03);
    
    /* Alert Colors (Dark Mode) */
    --note-bg: rgba(56, 189, 248, 0.1);
    --note-border: rgba(56, 189, 248, 0.3);
    --tip-bg: rgba(74, 222, 128, 0.1);
    --tip-border: rgba(74, 222, 128, 0.3);
    --important-bg: rgba(167, 139, 250, 0.1);
    --important-border: rgba(167, 139, 250, 0.3);
    --warning-bg: rgba(251, 191, 36, 0.1);
    --warning-border: rgba(251, 191, 36, 0.3);
    --caution-bg: rgba(248, 113, 113, 0.1);
    --caution-border: rgba(248, 113, 113, 0.3);
}

body.light-mode {
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #475569;
    --accent: #0284c7;
    --success: #16a34a;
    --warning: #d97706;
    --error: #dc2626;
    --accent-glow: rgba(2, 132, 199, 0.1);
    --border-color: #e2e8f0;
    --row-hover-bg: rgba(241, 245, 249, 0.9);
    --radial-glow-1: rgba(2, 132, 199, 0.03);
    --radial-glow-2: rgba(79, 70, 229, 0.02);

    /* Alert Colors (Light Mode) */
    --note-bg: #f0f9ff;
    --note-border: #bae6fd;
    --tip-bg: #f0fdf4;
    --tip-border: #bbf7d0;
    --important-bg: #f5f3ff;
    --important-border: #ddd6fe;
    --warning-bg: #fffbeb;
    --warning-border: #fde68a;
    --caution-bg: #fef2f2;
    --caution-border: #fca5a5;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    background-image: radial-gradient(circle at top right, var(--radial-glow-1), transparent 400px),
        radial-gradient(circle at bottom left, var(--radial-glow-2), transparent 400px);
    color: var(--text-main);
    line-height: 1.6;
    padding: 3rem 2rem;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
}

/* Top navigation and back button */
.nav-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

.back-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-muted);
    text-decoration: none;
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
    font-size: 1rem;
    transition: color 0.2s ease;
}

.back-btn:hover {
    color: var(--accent);
}

.back-btn svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    stroke-width: 2;
    fill: none;
}

/* Theme Toggle Button */
.theme-toggle-btn {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 0.6rem;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.theme-toggle-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    box-shadow: 0 0 10px var(--accent-glow);
}

.theme-toggle-btn svg {
    width: 20px;
    height: 20px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2;
}

/* Sun icon configuration */
.theme-toggle-btn .sun {
    display: block;
}

.theme-toggle-btn .moon {
    display: none;
}

body.light-mode .theme-toggle-btn .sun {
    display: none;
}

body.light-mode .theme-toggle-btn .moon {
    display: block;
}

/* Markdown Rendering Styles */
.content-area {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 3rem;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

/* Loader */
.loader {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 5rem 0;
    color: var(--text-muted);
    font-family: 'Outfit', sans-serif;
    font-weight: 500;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(56, 189, 248, 0.1);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s infinite linear;
    margin-bottom: 1rem;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Markdown elements formatting */
.markdown-body h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.25;
    color: var(--text-main);
}

.markdown-body h2 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.75rem;
    font-weight: 700;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    padding-bottom: 0.3rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
}

.markdown-body h3 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.35rem;
    font-weight: 600;
    margin-top: 2rem;
    margin-bottom: 0.75rem;
    color: var(--text-main);
}

.markdown-body p {
    margin-bottom: 1.2rem;
    color: var(--text-main);
    opacity: 0.9;
}

.markdown-body ul, .markdown-body ol {
    margin-bottom: 1.2rem;
    padding-left: 2rem;
}

.markdown-body li {
    margin-bottom: 0.5rem;
}

.markdown-body a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 500;
}

.markdown-body a:hover {
    text-decoration: underline;
}

/* Responsive, beautiful images */
.markdown-body img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    margin: 1.5rem 0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    display: block;
}

/* horizontal rules */
.markdown-body hr {
    height: 1px;
    background-color: var(--border-color);
    border: none;
    margin: 2.5rem 0;
}

/* Inline code styling */
.markdown-body :not(pre) > code {
    font-family: 'Courier New', Courier, monospace;
    background-color: rgba(255, 255, 255, 0.07);
    color: var(--accent);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
    font-weight: 600;
}

body.light-mode .markdown-body :not(pre) > code {
    background-color: rgba(0, 0, 0, 0.05);
}

/* Preformatted code block wrapper */
.markdown-body pre {
    background-color: #1e293b !important; /* Always dark syntax block */
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.2rem;
    margin-bottom: 1.5rem;
    overflow-x: auto;
    position: relative;
}

.markdown-body pre code {
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.9rem;
    background: transparent;
    padding: 0;
    border-radius: 0;
    color: #f8fafc;
}

/* Tables */
.markdown-body table {
    width: 100%;
    display: block;
    overflow-x: auto;
    border-collapse: collapse;
    margin-bottom: 1.5rem;
    font-size: 0.95rem;
}

.markdown-body th, .markdown-body td {
    padding: 0.75rem 1rem;
    border: 1px solid var(--border-color);
    text-align: left;
}

.markdown-body th {
    background-color: rgba(255, 255, 255, 0.03);
    font-family: 'Outfit', sans-serif;
    font-weight: 600;
}

body.light-mode .markdown-body th {
    background-color: rgba(0, 0, 0, 0.02);
}

.markdown-body tr:nth-child(even) {
    background-color: rgba(255, 255, 255, 0.01);
}

/* Alert blocks styling */
.alert-block {
    border-left: 4px solid transparent;
    border-radius: 6px;
    padding: 1rem 1.25rem;
    margin-bottom: 1.5rem;
}

.alert-block .alert-header {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.alert-block .alert-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.alert-block .alert-icon svg {
    width: 18px;
    height: 18px;
    fill: currentColor;
}

.alert-block .alert-content p:last-child {
    margin-bottom: 0;
}

/* Specific Alert Types */
.alert-block.alert-note {
    background-color: var(--note-bg);
    border-color: var(--accent);
    color: var(--text-main);
}
.alert-block.alert-note .alert-header {
    color: var(--accent);
}

.alert-block.alert-tip {
    background-color: var(--tip-bg);
    border-color: var(--success);
    color: var(--text-main);
}
.alert-block.alert-tip .alert-header {
    color: var(--success);
}

.alert-block.alert-important {
    background-color: var(--important-bg);
    border-color: #a78bfa;
    color: var(--text-main);
}
.alert-block.alert-important .alert-header {
    color: #a78bfa;
}

.alert-block.alert-warning {
    background-color: var(--warning-bg);
    border-color: var(--warning);
    color: var(--text-main);
}
.alert-block.alert-warning .alert-header {
    color: var(--warning);
}

.alert-block.alert-caution {
    background-color: var(--caution-bg);
    border-color: var(--error);
    color: var(--text-main);
}
.alert-block.alert-caution .alert-header {
    color: var(--error);
}

/* Mermaid Diagrams container */
.mermaid {
    background-color: #1e293b;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: center;
    overflow-x: auto;
}

/* Error state formatting */
.error-message {
    text-align: center;
    padding: 4rem 0;
    color: var(--error);
}

.error-message svg {
    width: 48px;
    height: 48px;
    stroke: currentColor;
    stroke-width: 2;
    fill: none;
    margin-bottom: 1rem;
}

.error-message h3 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

/* Responsiveness */
@media (max-width: 768px) {
    body {
        padding: 1.5rem 1rem;
    }

    .content-area {
        padding: 1.5rem;
    }

    .markdown-body h1 {
        font-size: 2rem;
    }

    .markdown-body h2 {
        font-size: 1.45rem;
    }
}

.kicker { font-family: 'Outfit', sans-serif; color: var(--accent); font-weight: 700; text-transform: uppercase; letter-spacing: .05em; font-size: .85rem; margin-bottom: .5rem; }
.article-meta { display: flex; flex-wrap: wrap; gap: .4rem 1rem; color: var(--text-muted); font-size: .9rem; margin: -.5rem 0 2rem; padding-bottom: 1.25rem; border-bottom: 1px solid var(--border-color); }
.article-meta a { color: var(--accent); text-decoration: none; }
.markdown-body .mermaid:not([data-processed]) { visibility: hidden; min-height: 120px; }
.page-nav { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 2.5rem; }
.page-nav a, .related a { display: block; padding: 1rem 1.25rem; border: 1px solid var(--border-color); border-radius: 12px; background: var(--card-bg); color: var(--text-main); text-decoration: none; transition: border-color .2s ease; }
.page-nav a:hover, .related a:hover { border-color: var(--accent); }
.page-nav small, .related small { display: block; color: var(--text-muted); font-size: .8rem; text-transform: uppercase; letter-spacing: .05em; }
.page-nav .next { text-align: right; grid-column: 2; }
.related { margin-top: 2rem; }
.related h2 { font-family: 'Outfit', sans-serif; font-size: 1.2rem; margin-bottom: 1rem; }
.related ul { list-style: none; display: grid; gap: .75rem; padding: 0; }
.site-footer { margin-top: 3rem; padding-top: 1.5rem; border-top: 1px solid var(--border-color); color: var(--text-muted); font-size: .9rem; text-align: center; }
.site-footer a { color: var(--accent); text-decoration: none; }
@media (max-width: 576px) { .page-nav { grid-template-columns: 1fr; } .page-nav .next { grid-column: 1; } }