/* ==========================================================================
   markgo Main Stylesheet
   Modern, responsive design for the Go blog engine
   ========================================================================== */

/* CSS Variables (Custom Properties)
   Colors and typography reference --theme-* variables (set by theme CSS files)
   with hardcoded fallbacks for when no theme is loaded. */
:root {
    /* Colors — theme-aware with fallbacks */
    --color-primary: var(--theme-primary, #2563eb);
    --color-primary-dark: var(--theme-primary-dark, #1d4ed8);
    --color-secondary: var(--theme-secondary, #64748b);
    --color-accent: var(--theme-accent, #60a5fa);
    --color-success: var(--theme-success, #10b981);
    --color-warning: var(--theme-warning, #f59e0b);
    --color-error: var(--theme-error, #ef4444);

    /* Text Colors */
    --color-text-primary: var(--theme-text-primary, #0f172a);
    --color-text-secondary: var(--theme-text-secondary, #475569);
    --color-text-muted: var(--theme-text-muted, #64748b);
    --color-text-inverse: var(--theme-text-inverse, #ffffff);

    /* Background Colors */
    --color-bg-primary: var(--theme-bg-primary, #ffffff);
    --color-bg-secondary: var(--theme-bg-secondary, #f9fafb);
    --color-bg-tertiary: var(--theme-bg-tertiary, #f3f4f6);
    --color-bg-dark: var(--theme-bg-dark, #111827);

    /* Border Colors */
    --color-border: var(--theme-border, #e5e7eb);
    --color-border-light: var(--theme-border-light, #f3f4f6);
    --color-border-dark: var(--theme-border-dark, #d1d5db);

    /* Typography — theme-aware with fallbacks */
    --font-family-sans: var(--theme-font-sans,
        "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        "Helvetica Neue", Arial, sans-serif);
    --font-family-mono: var(--theme-font-mono,
        "Fira Code", "SF Mono", Monaco, Inconsolata, "Roboto Mono",
        "Source Code Pro", monospace);

    /* Font Sizes */
    --font-size-xs: 0.75rem; /* 12px */
    --font-size-sm: 0.875rem; /* 14px */
    --font-size-base: 1rem; /* 16px */
    --font-size-lg: 1.125rem; /* 18px */
    --font-size-xl: 1.25rem; /* 20px */
    --font-size-2xl: 1.5rem; /* 24px */
    --font-size-3xl: 1.875rem; /* 30px */
    --font-size-4xl: 2.25rem; /* 36px */
    --font-size-5xl: 3rem; /* 48px */

    /* Spacing */
    --spacing-1: 0.25rem; /* 4px */
    --spacing-2: 0.5rem; /* 8px */
    --spacing-3: 0.75rem; /* 12px */
    --spacing-4: 1rem; /* 16px */
    --spacing-5: 1.25rem; /* 20px */
    --spacing-6: 1.5rem; /* 24px */
    --spacing-8: 2rem; /* 32px */
    --spacing-10: 2.5rem; /* 40px */
    --spacing-12: 3rem; /* 48px */
    --spacing-16: 4rem; /* 64px */
    --spacing-20: 5rem; /* 80px */

    /* Border Radius */
    --radius-sm: 0.125rem;
    --radius-base: 0.25rem;
    --radius-md: 0.375rem;
    --radius-lg: 0.5rem;
    --radius-xl: 0.75rem;
    --radius-2xl: 1rem;
    --radius-full: 9999px;

    /* Feedback colors */
    --color-success-bg: var(--theme-success-bg, #d4edda);
    --color-success-text: var(--theme-success-text, #155724);
    --color-success-border: var(--theme-success-border, #c3e6cb);
    --color-error-bg: var(--theme-error-bg, #f8d7da);
    --color-error-text: var(--theme-error-text, #721c24);
    --color-error-border: var(--theme-error-border, #f5c6cb);

    /* Focus ring */
    --color-focus-ring: var(--theme-focus-ring, rgba(37, 99, 235, 0.1));

    /* Scrolled header shadow */
    --shadow-scrolled: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-base:
        0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md:
        0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg:
        0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl:
        0 20px 25px -5px rgba(0, 0, 0, 0.1),
        0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;

    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal: 1040;
    --z-popover: 1050;
    --z-toast: 1055;
    --z-tooltip: 1060;

    /* Container */
    --container-max-width: 1200px;
    --container-padding: var(--spacing-4);
    --max-content-width: 42rem;
}

/* Dark mode variables — system preference (auto)
   Theme files set --theme-* dark overrides; main.css provides fallbacks */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --color-text-primary: var(--theme-text-primary, #f9fafb);
        --color-text-secondary: var(--theme-text-secondary, #d1d5db);
        --color-text-muted: var(--theme-text-muted, #a1a1aa);
        --color-bg-primary: var(--theme-bg-primary, #0f172a);
        --color-bg-secondary: var(--theme-bg-secondary, #1e293b);
        --color-bg-tertiary: var(--theme-bg-tertiary, #334155);
        --color-border: var(--theme-border, #334155);
        --color-border-light: var(--theme-border-light, #475569);
        --color-border-dark: var(--theme-border-dark, #64748b);
        --color-success-bg: var(--theme-success-bg, #1a3a2a);
        --color-success-text: var(--theme-success-text, #86efac);
        --color-success-border: var(--theme-success-border, #2d5a3e);
        --color-error-bg: var(--theme-error-bg, #3b1c22);
        --color-error-text: var(--theme-error-text, #fca5a5);
        --color-error-border: var(--theme-error-border, #5a2d35);
        --color-focus-ring: var(--theme-focus-ring, rgba(37, 99, 235, 0.25));
        --shadow-scrolled: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
    }
}

/* Dark mode variables — manual toggle override */
[data-theme="dark"] {
    --color-text-primary: var(--theme-text-primary, #f9fafb);
    --color-text-secondary: var(--theme-text-secondary, #d1d5db);
    --color-text-muted: var(--theme-text-muted, #a1a1aa);
    --color-bg-primary: var(--theme-bg-primary, #0f172a);
    --color-bg-secondary: var(--theme-bg-secondary, #1e293b);
    --color-bg-tertiary: var(--theme-bg-tertiary, #334155);
    --color-border: var(--theme-border, #334155);
    --color-border-light: var(--theme-border-light, #475569);
    --color-border-dark: var(--theme-border-dark, #64748b);
    --color-success-bg: var(--theme-success-bg, #1a3a2a);
    --color-success-text: var(--theme-success-text, #86efac);
    --color-success-border: var(--theme-success-border, #2d5a3e);
    --color-error-bg: var(--theme-error-bg, #3b1c22);
    --color-error-text: var(--theme-error-text, #fca5a5);
    --color-error-border: var(--theme-error-border, #5a2d35);
    --color-focus-ring: var(--theme-focus-ring, rgba(37, 99, 235, 0.25));
    --shadow-scrolled: 0 1px 3px 0 rgba(0, 0, 0, 0.3), 0 1px 2px 0 rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   Base Styles
   ========================================================================== */

*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    font-size: 100%;
    line-height: 1.6;
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-family-sans);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ==========================================================================
   Typography
   ========================================================================== */

h1,
h2,
h3,
h4,
h5,
h6 {
    margin: 0 0 var(--spacing-4) 0;
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-text-primary);
}

h1 {
    font-size: var(--font-size-4xl);
}
h2 {
    font-size: var(--font-size-3xl);
}
h3 {
    font-size: var(--font-size-2xl);
}
h4 {
    font-size: var(--font-size-xl);
}
h5 {
    font-size: var(--font-size-lg);
}
h6 {
    font-size: var(--font-size-base);
}

p {
    margin: 0 0 var(--spacing-4) 0;
    color: var(--color-text-primary);
}

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

a:hover {
    color: var(--color-primary-dark);
    text-decoration: underline;
}

a:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

strong,
b {
    font-weight: 600;
}

em,
i {
    font-style: italic;
}

code {
    font-family: var(--font-family-mono);
    font-size: 0.875em;
    padding: var(--spacing-1) var(--spacing-2);
    background-color: var(--color-bg-tertiary);
    border-radius: var(--radius-base);
}

pre {
    font-family: var(--font-family-mono);
    font-size: var(--font-size-sm);
    line-height: 1.5;
    padding: var(--spacing-4);
    background-color: var(--color-bg-dark);
    color: var(--color-text-inverse);
    border-radius: var(--radius-lg);
    overflow-x: auto;
    margin: var(--spacing-6) 0;
}

pre code {
    background: none;
    padding: 0;
    font-size: inherit;
}

/* Copy code button styles */
.copy-code-btn {
    position: absolute;
    top: var(--spacing-2);
    right: var(--spacing-2);
    padding: var(--spacing-1) var(--spacing-2);
    background: var(--color-bg-secondary);
    color: var(--color-text-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-base);
    font-size: var(--font-size-xs);
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-1);
    transition: all 0.2s ease;
    z-index: 1;
}

.copy-code-btn:hover {
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    border-color: var(--color-border-dark);
}

.copy-code-btn:active {
    transform: scale(0.95);
}

.copy-code-btn svg {
    width: 14px;
    height: 14px;
}

.copy-code-btn.success {
    background: var(--color-success, #10b981);
    color: var(--color-text-inverse, #ffffff);
    border-color: var(--color-success, #10b981);
}

.copy-code-btn.success:hover {
    background: var(--color-success, #10b981);
    color: var(--color-text-inverse, #ffffff);
    border-color: var(--color-success, #10b981);
}

/* Dark mode copy button styles — system preference */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .copy-code-btn {
        background: var(--color-bg-tertiary, #334155);
        color: var(--color-text-primary, #f9fafb);
        border-color: var(--color-border, #334155);
    }

    :root:not([data-theme="light"]) .copy-code-btn:hover {
        background: var(--color-primary, #2563eb);
        color: var(--color-text-inverse, #ffffff);
        border-color: var(--color-primary, #2563eb);
    }

    :root:not([data-theme="light"]) .copy-code-btn.success,
    :root:not([data-theme="light"]) .copy-code-btn.success:hover {
        background: var(--color-success, #10b981);
        color: var(--color-text-inverse, #ffffff);
        border-color: var(--color-success, #10b981);
    }

    :root:not([data-theme="light"]) blockquote {
        background-color: var(--color-bg-tertiary);
        border-left-color: var(--color-accent);
    }

    :root:not([data-theme="light"]) code {
        background-color: var(--color-bg-tertiary);
        color: var(--color-text-primary);
    }
}

/* Dark mode copy button styles — manual toggle */
[data-theme="dark"] .copy-code-btn {
    background: var(--color-bg-tertiary, #334155);
    color: var(--color-text-primary, #f9fafb);
    border-color: var(--color-border, #334155);
}

[data-theme="dark"] .copy-code-btn:hover {
    background: var(--color-primary, #2563eb);
    color: var(--color-text-inverse, #ffffff);
    border-color: var(--color-primary, #2563eb);
}

[data-theme="dark"] .copy-code-btn.success,
[data-theme="dark"] .copy-code-btn.success:hover {
    background: var(--color-success, #10b981);
    color: var(--color-text-inverse, #ffffff);
    border-color: var(--color-success, #10b981);
}

[data-theme="dark"] blockquote {
    background-color: var(--color-bg-tertiary);
    border-left-color: var(--color-accent);
}

[data-theme="dark"] code {
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-primary);
}

/* Make pre elements relative positioned for absolute button positioning */
pre {
    position: relative;
}

blockquote {
    margin: var(--spacing-6) 0;
    padding: var(--spacing-4) var(--spacing-6);
    border-left: 4px solid var(--color-primary);
    background-color: var(--color-bg-secondary);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    color: var(--color-text-primary);
}

blockquote p {
    margin-bottom: 0;
    font-style: italic;
    color: var(--color-text-primary);
}

ul,
ol {
    margin: 0 0 var(--spacing-4) 0;
    padding-left: var(--spacing-6);
}

li {
    margin-bottom: var(--spacing-2);
    color: var(--color-text-primary);
}

hr {
    margin: var(--spacing-8) 0;
    border: none;
    height: 1px;
    background-color: var(--color-border);
}

/* ==========================================================================
   Layout Components
   ========================================================================== */

.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.site-header {
    background-color: var(--color-bg-primary);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

/* Simple scroll shadow effect */
.navbar.scrolled {
    box-shadow: var(--shadow-scrolled);
}

/* Navbar base styles */
.navbar {
    padding: var(--spacing-6) 0;
}

/* Smooth scroll effect for entire page */
html {
    scroll-behavior: smooth;
}

/* Enhanced focus states for better accessibility */
.nav-link:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Back to top button styles */
.back-to-top {
    position: fixed;
    bottom: var(--spacing-6);
    right: var(--spacing-6);
    width: 48px;
    height: 48px;
    background-color: var(--color-primary);
    color: var(--color-text-inverse);
    border: none;
    border-radius: 50%;
    font-size: var(--font-size-lg);
    font-weight: 700;
    cursor: pointer;
    z-index: var(--z-fixed);
    box-shadow: var(--shadow-md);
    transition: background-color var(--transition-fast);
}

.back-to-top:hover {
    background-color: var(--color-primary-dark);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

.navbar-brand {
    min-width: 0;
    overflow: hidden;
}

.brand-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
    text-decoration: none;
    color: inherit;
}

.brand-link:hover {
    text-decoration: none;
}

.brand-logo {
    flex-shrink: 0;
}

.brand-text {
    min-width: 0;
}

.brand-title {
    font-size: var(--font-size-lg);
    font-weight: 700;
    margin: 0;
    color: var(--color-text-primary);
}

.brand-subtitle {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
    margin: 0;
    margin-top: var(--spacing-1);
}

.navbar-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-bg-primary);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-4);
    box-shadow: var(--shadow-lg);
}

.navbar-menu.active {
    display: block;
}

.navbar-nav {
    display: flex;
    flex-direction: column;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: var(--spacing-2);
}

.nav-item {
    margin: 0;
}

.nav-link {
    color: var(--color-text-primary);
    font-weight: 500;
    padding: var(--spacing-3);
    border-radius: var(--radius-lg);
    transition: all var(--transition-fast);
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

.nav-link:hover {
    color: var(--color-primary);
    background-color: var(--color-bg-secondary);
    text-decoration: none;
}

.nav-link.active {
    color: var(--color-primary);
    font-weight: 600;
}

.navbar-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

.nav-action-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    cursor: pointer;
    color: var(--color-text-primary);
    transition: all var(--transition-fast);
    text-decoration: none;
}

.nav-action-btn:hover {
    background-color: var(--color-bg-secondary);
    color: var(--color-primary);
    border-color: var(--color-border-dark);
    text-decoration: none;
}

.nav-action-btn:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}


/* ==========================================================================
   Main Content
   ========================================================================== */

.main-content {
    min-height: calc(100vh - 120px);
    padding: 0;
}

/* Page Header - Content-first, minimal */
.page-header {
    padding: var(--spacing-6) 0 var(--spacing-4);
    max-width: var(--max-content-width);
    margin: 0 auto;
}

.page-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin: 0 0 var(--spacing-2);
    color: var(--color-text-primary);
}

.page-subtitle {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin: 0;
}

/* Back link - consistent across pages */
.page-back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-1);
    color: var(--color-text-muted);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: color var(--transition-fast);
}

.page-back-link:hover {
    color: var(--color-primary);
    text-decoration: none;
}

.page-back-link-container {
    padding-top: var(--spacing-6);
}

/* Content separator */
.content-separator {
    border: none;
    border-top: 1px solid var(--color-border-light);
    margin: var(--spacing-6) 0;
}


/* Simple pagination - Newer/Older pattern */
.simple-pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-4);
    padding: var(--spacing-6) 0;
    max-width: var(--max-content-width);
    margin: 0 auto;
}

.simple-pagination a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-2) var(--spacing-4);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: background-color var(--transition-fast);
}

.simple-pagination a:hover {
    background-color: var(--color-bg-tertiary);
    text-decoration: none;
}

.simple-pagination .pagination-info {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}


/* ==========================================================================
   Shared Layout Components
   ========================================================================== */

.stat-item {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text-primary);
}

/* ==========================================================================
   Card Styles (used by admin templates)
   ========================================================================== */

.card-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    margin-bottom: var(--spacing-3);
}

.card-title a {
    color: var(--color-text-primary);
    text-decoration: none;
}

.card-title a:hover {
    color: var(--color-primary);
}

/* ==========================================================================
   Tags & Categories (used by admin/preview templates)
   ========================================================================== */

.tag,
.category {
    display: inline-block;
    padding: var(--spacing-1) var(--spacing-3);
    background-color: var(--color-bg-tertiary);
    color: var(--color-text-primary);
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition-fast);
    border: 1px solid var(--color-border-light);
}

.tag:hover,
.category:hover {
    background-color: var(--color-primary);
    color: var(--color-text-inverse);
    text-decoration: none;
    transform: translateY(-1px);
}

.tag-count {
    font-size: var(--font-size-xs);
    opacity: 0.8;
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-3) var(--spacing-6);
    border-radius: var(--radius-lg);
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition-fast);
    border: 2px solid transparent;
    cursor: pointer;
    font-size: var(--font-size-base);
    line-height: 1;
    gap: var(--spacing-2);
}

.btn-primary {
    background-color: var(--color-text-inverse);
    color: var(--color-primary);
    border-color: var(--color-text-inverse);
}

.btn-primary:hover {
    background-color: transparent;
    color: var(--color-text-inverse);
    border-color: var(--color-text-inverse);
    text-decoration: none;
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-text-inverse);
    border-color: var(--color-text-inverse);
}

.btn-secondary:hover {
    background-color: var(--color-text-inverse);
    color: var(--color-primary);
    text-decoration: none;
}

/* ==========================================================================
   Footer — Light Colophon
   ========================================================================== */

.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-8) 0;
    text-align: center;
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-2) var(--spacing-4);
    margin-bottom: var(--spacing-4);
}

.footer-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: color var(--transition-fast);
}

.footer-link:hover {
    color: var(--color-primary);
    text-decoration: none;
}

.footer-link.active {
    color: var(--color-primary);
}

.footer-subscribe {
    color: var(--color-primary);
    font-weight: 500;
}

.footer-colophon {
    color: var(--color-text-muted);
    font-size: var(--font-size-xs);
    margin: 0;
    line-height: 1.6;
}

.footer-colophon a {
    color: var(--color-text-muted);
    text-decoration: underline;
    text-decoration-color: var(--color-border);
    text-underline-offset: 2px;
}

.footer-colophon a:hover {
    color: var(--color-primary);
}

.footer-version {
    font-family: var(--font-family-mono);
}

/* ==========================================================================
   Responsive Design (Mobile-first)
   ========================================================================== */

/* Large phones and up */
@media (min-width: 481px) {
    .page-header {
        padding: var(--spacing-6) 0 var(--spacing-4);
    }

    .page-title {
        font-size: var(--font-size-2xl);
    }
}

/* Tablet and up */
@media (min-width: 769px) {
    .navbar-menu {
        display: flex;
        align-items: center;
        position: static;
        background-color: transparent;
        border-top: none;
        padding: 0;
        box-shadow: none;
    }

    .navbar-nav {
        flex-direction: row;
        gap: var(--spacing-6);
    }

    .nav-link {
        padding: var(--spacing-2) var(--spacing-3);
        border-radius: var(--radius-base);
    }

    .navbar-brand {
        overflow: visible;
    }

    .brand-link {
        gap: var(--spacing-3);
    }

    .brand-logo {
        width: 32px;
        height: 32px;
    }

    .brand-title {
        font-size: var(--font-size-2xl);
    }

    .brand-subtitle {
        font-size: var(--font-size-sm);
    }

    .page-title {
        font-size: var(--font-size-3xl);
    }

    .page-header {
        padding: var(--spacing-8) 0 var(--spacing-4);
    }

}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

/* Skip-to-content link — visible on focus for keyboard users */
.skip-link {
    position: fixed;
    top: -100%;
    left: var(--spacing-4);
    z-index: 99999;
    padding: var(--spacing-2) var(--spacing-4);
    background: var(--color-primary);
    color: var(--color-text-inverse);
    border-radius: 0 0 var(--radius-md) var(--radius-md);
    font-weight: 500;
    font-size: var(--font-size-sm);
    text-decoration: none;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 0;
    outline: 2px solid var(--color-text-inverse);
    outline-offset: -2px;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.text-center {
    text-align: center;
}
.text-left {
    text-align: left;
}
.text-right {
    text-align: right;
}

.hidden {
    display: none;
}
.block {
    display: block;
}
.inline-block {
    display: inline-block;
}
.flex {
    display: flex;
}
.grid {
    display: grid;
}

.mt-0 {
    margin-top: 0;
}
.mb-0 {
    margin-bottom: 0;
}
.ml-0 {
    margin-left: 0;
}
.mr-0 {
    margin-right: 0;
}

/* ==========================================================================
   Theme Presets
   ========================================================================== */

/* Theme: Ocean */
[data-color-theme="ocean"] {
    --color-primary: #0891b2;
    --color-primary-dark: #0e7490;
    --color-accent: #22d3ee;
    --color-success: #14b8a6;
}

/* Theme: Forest */
[data-color-theme="forest"] {
    --color-primary: #059669;
    --color-primary-dark: #047857;
    --color-accent: #34d399;
    --color-success: #34d399;
}

/* Theme: Sunset */
[data-color-theme="sunset"] {
    --color-primary: #ea580c;
    --color-primary-dark: #c2410c;
    --color-accent: #fb923c;
    --color-success: #10b981;
}

/* Theme: Berry */
[data-color-theme="berry"] {
    --color-primary: #9333ea;
    --color-primary-dark: #7e22ce;
    --color-accent: #c084fc;
    --color-success: #10b981;
}

/* ==========================================================================
   Theme Popover
   ========================================================================== */

.theme-popover {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: var(--spacing-2);
    background: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-lg);
    z-index: var(--z-popover);
    padding: var(--spacing-4);
}

@media (min-width: 481px) {
    .theme-popover {
        left: auto;
        width: 320px;
    }
}

.theme-popover[hidden] {
    display: none;
}

.theme-section + .theme-section {
    margin-top: var(--spacing-3);
    padding-top: var(--spacing-3);
    border-top: 1px solid var(--color-border-light);
}

.theme-section-label {
    font-size: var(--font-size-xs);
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-2);
}

/* Segmented control for Light / Dark / Auto */
.theme-mode-group {
    display: flex;
    gap: 0;
    background: var(--color-bg-tertiary);
    border-radius: var(--radius-md);
    padding: 2px;
}

.theme-mode-btn {
    flex: 1;
    padding: var(--spacing-1) var(--spacing-2);
    border: none;
    background: none;
    border-radius: var(--radius-base);
    font-size: var(--font-size-sm);
    font-weight: 500;
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-mode-btn:hover {
    color: var(--color-text-primary);
}

.theme-mode-btn:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: -2px;
}

.theme-mode-btn.active {
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    box-shadow: var(--shadow-sm);
}

/* Color swatches */
.theme-color-group {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
}

.color-swatch {
    width: 24px;
    height: 24px;
    border-radius: var(--radius-full);
    border: 2px solid var(--color-border);
    cursor: pointer;
    padding: 0;
    transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.color-swatch:hover {
    transform: scale(1.15);
}

.color-swatch:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

.color-swatch.active {
    border-color: var(--color-text-primary);
    box-shadow: 0 0 0 2px var(--color-bg-primary), 0 0 0 3px var(--color-text-primary);
}

.color-swatch[data-color="default"] { background: #2563eb; }
.color-swatch[data-color="ocean"]   { background: #0891b2; }
.color-swatch[data-color="forest"]  { background: #059669; }
.color-swatch[data-color="sunset"]  { background: #ea580c; }
.color-swatch[data-color="berry"]   { background: #9333ea; }

/* ==========================================================================
   Reduced Motion
   ========================================================================== */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */

@media print {
    .navbar,
    .site-footer {
        display: none;
    }

    .main-content {
        padding: 0;
    }

    a {
        color: inherit;
        text-decoration: underline;
    }
}

/* ==========================================================================
   SPA Router
   ========================================================================== */

/* Content transition */
.main-content {
    transition: opacity 120ms ease;
}

.main-content.swapping {
    opacity: 0;
}

/* Progress bar */
.router-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    background: var(--color-primary);
    z-index: 9999;
    width: 0;
    opacity: 0;
    pointer-events: none;
}

.router-progress.active {
    opacity: 1;
    width: 70%;
    transition: width 8s cubic-bezier(0.1, 0.5, 0.1, 1), opacity 150ms ease;
}

.router-progress.done {
    width: 100%;
    transition: width 120ms ease;
}

.router-progress.hiding {
    opacity: 0;
    transition: opacity 300ms ease;
}

@media (prefers-reduced-motion: reduce) {
    .main-content {
        transition: none;
    }

    .router-progress {
        transition: none;
    }

    .router-progress.active,
    .router-progress.done {
        transition: none;
    }

    .router-progress.hiding {
        transition: opacity 100ms ease;
    }
}

/* ==========================================================================
   Install Banner
   ========================================================================== */

.install-banner {
    position: fixed;
    bottom: var(--spacing-4);
    left: var(--spacing-4);
    right: var(--spacing-4);
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    padding: var(--spacing-3) var(--spacing-4);
    background: var(--color-bg-primary);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    z-index: var(--z-toast);
    animation: installSlideUp 250ms ease;
}

.install-banner-text {
    flex: 1;
    font-size: var(--font-size-sm);
    color: var(--color-text-primary);
}

.install-banner-btn {
    padding: var(--spacing-2) var(--spacing-4);
    background: var(--color-primary);
    color: var(--color-text-inverse);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    white-space: nowrap;
}

.install-banner-dismiss {
    padding: var(--spacing-1);
    background: none;
    border: none;
    color: var(--color-text-muted);
    font-size: 1.25rem;
    line-height: 1;
    cursor: pointer;
}

@keyframes installSlideUp {
    from { transform: translateY(100%); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@media (min-width: 481px) {
    .install-banner {
        left: auto;
        right: var(--spacing-6);
        bottom: var(--spacing-6);
        max-width: 360px;
    }
}