/* Modern Blog Design System */
:root {
    /* Color Palette - Light Mode */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f1f3f5;
    --bg-card: #ffffff;
    --bg-glass: rgba(255, 255, 255, 0.8);

    --text-primary: #212529;
    --text-secondary: #495057;
    --text-tertiary: #868e96;

    --accent-primary: #0085a1;
    --accent-secondary: #00bfd8;
    --accent-hover: #00657b;

    --border-color: #e9ecef;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, 'Andale Mono', monospace;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 3rem;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
}

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --bg-tertiary: #2d2d2d;
    --bg-card: #1e1e1e;
    --bg-glass: rgba(30, 30, 30, 0.8);

    --text-primary: #e9ecef;
    --text-secondary: #adb5bd;
    --text-tertiary: #6c757d;

    --accent-primary: #4dd0e1;
    --accent-secondary: #26c6da;
    --accent-hover: #80deea;

    --border-color: #343a40;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.5);
}

/* Base Styles */
html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* Typography Enhancements */
h1,
h2,
h3,
h4,
h5,
h6 {
    color: var(--text-primary);
    margin-top: 0;
    line-height: 1.3;
}

a {
    transition: color var(--transition-fast);
    text-decoration: none;
}

a:hover {
    color: var(--accent-hover);
    text-decoration: none;
}

/* Modern Card */
.modern-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.modern-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

/* Dark Mode Toggle */
.theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    color: var(--text-secondary);
    transition: color var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    color: var(--accent-primary);
}

/* Search Overlay */
.search-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-fast);
    display: flex;
    justify-content: center;
    padding-top: 100px;
}

.search-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.search-container {
    width: 90%;
    max-width: 600px;
    background: var(--bg-card);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    transform: translateY(-20px);
    transition: transform var(--transition-normal);
}

.search-overlay.active .search-container {
    transform: translateY(0);
}

/* Reading Progress Bar */
.reading-progress-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    z-index: 9999;
    background: transparent;
}

.reading-progress-bar {
    height: 100%;
    background: var(--accent-primary);
    width: 0%;
    transition: width 0.1s;
}

/* Scroll to Top */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 45px;
    height: 45px;
    background: var(--accent-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal), transform var(--transition-normal);
    box-shadow: var(--shadow-md);
    z-index: 99;
}

.scroll-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}

.scroll-to-top:hover {
    transform: translateY(-3px);
    background: var(--accent-hover);
}

/* Table of Contents */
.toc-container {
    position: sticky;
    top: 100px;
    max-height: calc(100vh - 120px);
    overflow-y: auto;
    padding-left: var(--spacing-md);
    border-left: 2px solid var(--border-color);
}

.toc-link {
    display: block;
    color: var(--text-secondary);
    font-size: 1.1rem;
    padding: 8px 0;
    line-height: 1.6;
    transition: color var(--transition-fast);
}

.toc-link:hover,
.toc-link.active {
    color: var(--accent-primary);
}

.toc-link.active {
    font-weight: 600;
}

/* Code Blocks */
pre {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    position: relative;
}

code {
    font-family: var(--font-mono);
}

.copy-button {
    position: absolute;
    top: 8px;
    right: 8px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 4px 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
    cursor: pointer;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

pre:hover .copy-button {
    opacity: 1;
}

/* Tag Styles */
.tag-chip {
    display: inline-block;
    padding: 4px 12px;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: 50px;
    font-size: 0.85rem;
    margin: 0 8px 8px 0;
    transition: all var(--transition-fast);
    border: 1px solid transparent;
}

.tag-chip:hover {
    background: var(--bg-secondary);
    color: var(--accent-primary);
    border-color: var(--accent-primary);
    transform: translateY(-1px);
}

/* Glassmorphism Header */
.intro-header {
    margin-bottom: 0;
    /* Removing default margin to handle it better */
}

.post-heading-wrapper {
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(2px);
    padding: 40px;
    border-radius: var(--radius-lg);
    color: white;
    /* Always white on background images */
}