/* ==========================================================================
   fail-but-pretty - Main Stylesheet
   Beautiful, interactive error pages with 10 unique designs
   ========================================================================== */

/* CSS Custom Properties - Design Tokens */
:root {
    /* Colors - Dark Theme Base */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a24;
    --fg-primary: #f0f0f5;
    --fg-secondary: #a0a0b0;
    --fg-muted: #606070;
    --accent-primary: #00d4aa;
    --accent-secondary: #6366f1;
    --accent-tertiary: #f43f5e;
    --accent-warm: #fbbf24;
    --border-color: #2a2a3a;
    --glow-primary: rgba(0, 212, 170, 0.4);
    --glow-secondary: rgba(99, 102, 241, 0.4);
    --glow-tertiary: rgba(244, 63, 94, 0.4);

    /* Typography */
    --font-mono: 'JetBrains Mono', monospace;
    --font-display: 'Space Grotesk', sans-serif;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 30px var(--glow-primary);

    /* Z-Indices */
    --z-bg: 0;
    --z-content: 10;
    --z-badge: 20;
    --z-go-back: 30;
    --z-modal: 100;
}

/* Light theme (optional, for preference) */
@media (prefers-color-scheme: light) {
    :root {
        --bg-primary: #f8fafc;
        --bg-secondary: #f1f5f9;
        --bg-tertiary: #e2e8f0;
        --fg-primary: #0f172a;
        --fg-secondary: #475569;
        --fg-muted: #94a3b8;
        --border-color: #cbd5e1;
    }
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-display);
    background-color: var(--bg-primary);
    color: var(--fg-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Focus visible for accessibility */
:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

/* Selection */
::selection {
    background: var(--accent-primary);
    color: var(--bg-primary);
}

/* ==========================================================================
   Go Back Button
   ========================================================================== */

.go-back-btn {
    position: fixed;
    bottom: var(--space-xl);
    right: var(--space-xl);
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-lg);
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-secondary));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-full);
    color: var(--fg-primary);
    font-family: var(--font-display);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    z-index: var(--z-go-back);
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-base);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.go-back-btn:hover {
    transform: translateY(-2px);
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-lg), var(--shadow-glow);
    color: var(--accent-primary);
}

.go-back-btn:active {
    transform: translateY(0);
}

.go-back-btn svg {
    flex-shrink: 0;
    transition: transform var(--transition-fast);
}

.go-back-btn:hover svg {
    transform: translateX(-2px);
}

.go-back-btn:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 3px;
}

/* ==========================================================================
   Error Badge
   ========================================================================== */

.error-badge {
    position: fixed;
    top: var(--space-xl);
    left: var(--space-xl);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
    padding: var(--space-md) var(--space-lg);
    background: linear-gradient(135deg, var(--bg-tertiary), var(--bg-secondary));
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    z-index: var(--z-badge);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.error-code {
    font-family: var(--font-mono);
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.error-name {
    font-family: var(--font-display);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--fg-secondary);
}

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

.error-container {
    position: relative;
    z-index: var(--z-content);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: var(--space-3xl) var(--space-lg);
    text-align: center;
}

.error-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 8vw, 4rem);
    font-weight: 700;
    line-height: 1.1;
    margin-bottom: var(--space-md);
    background: linear-gradient(135deg, var(--fg-primary), var(--fg-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.error-message {
    font-family: var(--font-mono);
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    color: var(--fg-secondary);
    max-width: 600px;
    margin-bottom: var(--space-2xl);
    line-height: 1.7;
}

.error-detail {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--fg-muted);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--space-md) var(--space-lg);
    max-width: 600px;
    margin-bottom: var(--space-xl);
    overflow-x: auto;
}

/* ==========================================================================
   Button Styles
   ========================================================================== */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-family: var(--font-display);
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: var(--bg-primary);
    box-shadow: 0 4px 20px var(--glow-primary);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px var(--glow-primary);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--fg-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-secondary);
    border-color: var(--accent-primary);
    color: var(--accent-primary);
}

.btn-ghost {
    background: transparent;
    color: var(--fg-secondary);
    border: 1px solid transparent;
}

.btn-ghost:hover {
    color: var(--fg-primary);
    background: var(--bg-tertiary);
}

/* ==========================================================================
   Animations
   ========================================================================== */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

.animate-fade-in { animation: fadeIn 0.6s ease forwards; }
.animate-slide-up { animation: slideUp 0.6s ease forwards; }
.animate-pulse { animation: pulse 2s ease-in-out infinite; }
.animate-float { animation: float 3s ease-in-out infinite; }
.animate-rotate { animation: rotate 20s linear infinite; }

/* Staggered animations */
.delay-1 { animation-delay: 100ms; }
.delay-2 { animation-delay: 200ms; }
.delay-3 { animation-delay: 300ms; }
.delay-4 { animation-delay: 400ms; }
.delay-5 { animation-delay: 500ms; }

/* ==========================================================================
   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;
    }
}

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 768px) {
    .go-back-btn {
        bottom: var(--space-md);
        right: var(--space-md);
        left: var(--space-md);
        justify-content: center;
        padding: var(--space-md);
    }

    .error-badge {
        top: var(--space-md);
        left: var(--space-md);
        right: var(--space-md);
        flex-direction: row;
        justify-content: center;
        align-items: center;
        padding: var(--space-sm) var(--space-md);
    }

    .error-code {
        font-size: 1.5rem;
    }

    .error-name {
        font-size: 0.625rem;
    }

    .error-container {
        padding: var(--space-2xl) var(--space-md);
    }
}

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

.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-gradient {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.glass {
    background: rgba(18, 18, 26, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--border-color);
}

.glow-primary { box-shadow: 0 0 30px var(--glow-primary); }
.glow-secondary { box-shadow: 0 0 30px var(--glow-secondary); }
.glow-tertiary { box-shadow: 0 0 30px var(--glow-tertiary); }