/* ============================================
   Liquid Glass UI - URL Shortener
   Modern Glassmorphism Design System
   ============================================ */

/* CSS Variables */
:root {
    /* Color Palette */
    --accent-blue: #3b82f6;
    --accent-blue-light: #60a5fa;
    --accent-blue-dark: #2563eb;
    --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    
    --cream-white: #fefef8;
    --cream-light: #fffef5;
    --cream-muted: #f5f3e8;
    
    --dark-blue: #0f172a;
    --dark-blue-soft: #1e293b;
    --dark-blue-muted: #334155;
    
    --black: #000000;
    --black-soft: #0a0a0a;
    
    /* Glass Effects */
    --glass-bg: rgba(255, 255, 252, 0.72);
    --glass-bg-hover: rgba(255, 255, 252, 0.85);
    --glass-border: rgba(255, 255, 255, 0.5);
    --glass-shadow: 0 8px 32px rgba(15, 23, 42, 0.12);
    --glass-shadow-hover: 0 16px 48px rgba(15, 23, 42, 0.18);
    --glass-glow: 0 0 40px rgba(59, 130, 246, 0.15);
    
    /* Blur */
    --blur-strength: 16px;
    --blur-heavy: 24px;
    
    /* Spacing */
    --radius-sm: 12px;
    --radius-md: 20px;
    --radius-lg: 24px;
    --radius-pill: 50px;
    
    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'JetBrains Mono', monospace;
    
    /* Transitions */
    --transition-fast: 0.15s ease-out;
    --transition-normal: 0.25s ease-out;
    --transition-slow: 0.4s ease-out;
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    line-height: 1.6;
    color: var(--dark-blue);
    min-height: 100vh;
    
    /* Liquid gradient background */
    background: 
        radial-gradient(ellipse at 20% 20%, rgba(59, 130, 246, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(59, 130, 246, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(30, 64, 175, 0.04) 0%, transparent 70%),
        linear-gradient(180deg, var(--cream-light) 0%, var(--cream-muted) 100%);
    background-attachment: fixed;
}

/* Container */
.container {
    max-width: 640px;
    margin: 0 auto;
    padding: 48px 24px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ============================================
   Header
   ============================================ */
header {
    text-align: center;
    margin-bottom: 40px;
    animation: fadeSlideDown 0.6s ease-out;
}

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

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark-blue);
    letter-spacing: -0.03em;
    margin-bottom: 8px;
}

header h1 .icon {
    display: inline-block;
    margin-right: 8px;
    filter: drop-shadow(0 2px 4px rgba(59, 130, 246, 0.3));
}

.subtitle {
    font-size: 1.1rem;
    color: var(--dark-blue-muted);
    font-weight: 400;
}

/* ============================================
   Main Content
   ============================================ */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* ============================================
   Glass Card Base
   ============================================ */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-strength));
    -webkit-backdrop-filter: blur(var(--blur-strength));
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: 
        var(--glass-shadow),
        inset 0 1px 0 rgba(255, 255, 255, 0.8),
        inset 0 -1px 0 rgba(0, 0, 0, 0.02);
    padding: 32px;
    transition: 
        transform var(--transition-normal),
        box-shadow var(--transition-normal),
        background var(--transition-normal);
    animation: fadeSlideUp 0.5s ease-out;
}

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(24px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.glass-card:hover {
    background: var(--glass-bg-hover);
    box-shadow: 
        var(--glass-shadow-hover),
        var(--glass-glow),
        inset 0 1px 0 rgba(255, 255, 255, 0.9),
        inset 0 -1px 0 rgba(0, 0, 0, 0.02);
}

/* ============================================
   URL Form
   ============================================ */
.url-form {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-strength));
    -webkit-backdrop-filter: blur(var(--blur-strength));
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: 
        var(--glass-shadow),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    padding: 32px;
    animation: fadeSlideUp 0.5s ease-out;
}

.input-group {
    display: flex;
    gap: 12px;
    align-items: stretch;
}

/* URL Input - Pill Shape */
.input-group input[type="text"] {
    flex: 1;
    padding: 16px 24px;
    font-size: 1rem;
    font-family: var(--font-sans);
    color: var(--dark-blue);
    background: rgba(255, 255, 255, 0.6);
    border: 1px solid rgba(255, 255, 255, 0.7);
    border-radius: var(--radius-pill);
    outline: none;
    box-shadow: 
        inset 0 2px 4px rgba(15, 23, 42, 0.04),
        inset 0 0 0 1px rgba(0, 0, 0, 0.02);
    transition: 
        border-color var(--transition-fast),
        box-shadow var(--transition-fast),
        background var(--transition-fast);
}

.input-group input[type="text"]::placeholder {
    color: var(--dark-blue-muted);
    opacity: 0.6;
}

.input-group input[type="text"]:hover {
    background: rgba(255, 255, 255, 0.75);
    border-color: rgba(59, 130, 246, 0.3);
}

.input-group input[type="text"]:focus {
    background: rgba(255, 255, 255, 0.9);
    border-color: var(--accent-blue);
    box-shadow: 
        inset 0 2px 4px rgba(15, 23, 42, 0.04),
        0 0 0 3px rgba(59, 130, 246, 0.12),
        0 0 20px rgba(59, 130, 246, 0.1);
}

/* Submit Button */
.input-group button[type="submit"],
.btn-primary {
    padding: 16px 32px;
    font-size: 1rem;
    font-weight: 600;
    font-family: var(--font-sans);
    color: white;
    background: var(--accent-gradient);
    border: none;
    border-radius: var(--radius-pill);
    cursor: pointer;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
    transition: 
        transform var(--transition-fast),
        box-shadow var(--transition-normal);
    box-shadow: 
        0 4px 12px rgba(59, 130, 246, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.input-group button[type="submit"]::before,
.btn-primary::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.2) 0%, transparent 50%);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.input-group button[type="submit"]:hover,
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 
        0 8px 24px rgba(59, 130, 246, 0.4),
        0 0 40px rgba(59, 130, 246, 0.2),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.input-group button[type="submit"]:hover::before,
.btn-primary:hover::before {
    opacity: 1;
}

.input-group button[type="submit"]:active,
.btn-primary:active {
    transform: translateY(0) scale(0.98);
    box-shadow: 
        0 2px 8px rgba(59, 130, 246, 0.3),
        inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.input-group button[type="submit"]:focus-visible,
.btn-primary:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

/* ============================================
   Messages
   ============================================ */
.message {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    border-radius: var(--radius-md);
    animation: fadeSlideUp 0.4s ease-out;
}

.message.error {
    background: rgba(239, 68, 68, 0.08);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: #b91c1c;
}

.message .icon {
    font-size: 1.2rem;
    flex-shrink: 0;
}

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

/* ============================================
   Result Card
   ============================================ */
.result {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-heavy));
    -webkit-backdrop-filter: blur(var(--blur-heavy));
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: 
        var(--glass-shadow),
        var(--glass-glow),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
    padding: 32px;
    text-align: center;
    animation: resultAppear 0.5s ease-out;
}

@keyframes resultAppear {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.result h2 {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--dark-blue-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 20px;
}

.short-url-container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

/* Short URL Display */
.short-url {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--accent-blue);
    text-decoration: none;
    padding: 14px 24px;
    background: rgba(59, 130, 246, 0.06);
    border: 1px solid rgba(59, 130, 246, 0.15);
    border-radius: var(--radius-md);
    transition: 
        background var(--transition-fast),
        border-color var(--transition-fast),
        transform var(--transition-fast);
    word-break: break-all;
}

.short-url:hover {
    background: rgba(59, 130, 246, 0.1);
    border-color: rgba(59, 130, 246, 0.3);
    transform: translateY(-1px);
}

/* Copy Button */
.copy-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 14px 20px;
    font-size: 0.95rem;
    font-weight: 500;
    font-family: var(--font-sans);
    color: var(--dark-blue);
    background: rgba(255, 255, 255, 0.7);
    border: 1px solid rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: 
        background var(--transition-fast),
        border-color var(--transition-fast),
        transform var(--transition-fast),
        box-shadow var(--transition-fast);
    box-shadow: 
        0 2px 8px rgba(15, 23, 42, 0.06),
        inset 0 1px 0 rgba(255, 255, 255, 0.8);
}

.copy-btn:hover {
    background: rgba(255, 255, 255, 0.9);
    border-color: var(--accent-blue-light);
    transform: translateY(-1px);
    box-shadow: 
        0 4px 12px rgba(15, 23, 42, 0.1),
        0 0 20px rgba(59, 130, 246, 0.1),
        inset 0 1px 0 rgba(255, 255, 255, 0.9);
}

.copy-btn:active {
    transform: translateY(0) scale(0.98);
}

.copy-btn:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

/* Copy Feedback */
.copy-feedback {
    margin-top: 16px;
    font-size: 0.9rem;
    min-height: 24px;
    transition: opacity var(--transition-fast);
}

.copy-feedback.success {
    color: #059669;
}

.copy-feedback.error {
    color: #dc2626;
}

/* ============================================
   404 Error Page
   ============================================ */
.error-page {
    display: flex;
    align-items: center;
    justify-content: center;
    flex: 1;
}

.error-content {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-heavy));
    -webkit-backdrop-filter: blur(var(--blur-heavy));
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    padding: 56px 48px;
    text-align: center;
    animation: fadeSlideUp 0.5s ease-out;
}

.error-code {
    font-size: 6rem;
    font-weight: 800;
    color: var(--dark-blue);
    line-height: 1;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--dark-blue) 0%, var(--accent-blue) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.error-content h2 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--dark-blue);
    margin-bottom: 12px;
}

.error-content p {
    color: var(--dark-blue-muted);
    margin-bottom: 28px;
    line-height: 1.6;
}

.error-content code {
    font-family: var(--font-mono);
    font-size: 0.9rem;
    background: rgba(59, 130, 246, 0.08);
    color: var(--accent-blue);
    padding: 4px 10px;
    border-radius: 6px;
}

.btn-home {
    display: inline-block;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background: var(--accent-gradient);
    text-decoration: none;
    border-radius: var(--radius-pill);
    transition: 
        transform var(--transition-fast),
        box-shadow var(--transition-normal);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.btn-home:hover {
    transform: translateY(-2px);
    box-shadow: 
        0 8px 24px rgba(59, 130, 246, 0.4),
        0 0 40px rgba(59, 130, 246, 0.2);
}

.btn-home:active {
    transform: translateY(0) scale(0.98);
}

/* ============================================
   Analytics Table
   ============================================ */
.analytics-table-container {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-strength));
    -webkit-backdrop-filter: blur(var(--blur-strength));
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    overflow: hidden;
    animation: fadeSlideUp 0.5s ease-out;
}

.analytics-table {
    width: 100%;
    border-collapse: collapse;
}

.analytics-table th,
.analytics-table td {
    padding: 16px 20px;
    text-align: left;
}

.analytics-table th {
    background: rgba(15, 23, 42, 0.03);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--dark-blue-muted);
    border-bottom: 1px solid rgba(15, 23, 42, 0.06);
}

.analytics-table td {
    border-bottom: 1px solid rgba(15, 23, 42, 0.04);
    font-size: 0.95rem;
}

.analytics-table tbody tr {
    transition: background var(--transition-fast);
}

.analytics-table tbody tr:hover {
    background: rgba(59, 130, 246, 0.04);
}

.analytics-table tbody tr:last-child td {
    border-bottom: none;
}

.short-link {
    font-family: var(--font-mono);
    font-weight: 600;
    color: var(--accent-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
}

.short-link:hover {
    color: var(--accent-blue-dark);
    text-decoration: underline;
}

.long-url {
    color: var(--dark-blue-muted);
    font-size: 0.875rem;
    max-width: 180px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.click-count {
    font-weight: 700;
    font-family: var(--font-mono);
    color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.08);
    padding: 4px 10px;
    border-radius: 6px;
    display: inline-block;
}

.created-date {
    font-size: 0.85rem;
    color: var(--dark-blue-muted);
    font-family: var(--font-mono);
}

/* Empty State */
.empty-state {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-strength));
    -webkit-backdrop-filter: blur(var(--blur-strength));
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    padding: 56px 32px;
    text-align: center;
    animation: fadeSlideUp 0.5s ease-out;
}

.empty-state p {
    font-size: 1.1rem;
    color: var(--dark-blue-muted);
    margin-bottom: 24px;
}

/* ============================================
   Footer
   ============================================ */
footer {
    margin-top: 48px;
    text-align: center;
    animation: fadeSlideUp 0.6s ease-out 0.2s both;
}

footer nav {
    margin-bottom: 16px;
    display: flex;
    justify-content: center;
    gap: 8px;
}

footer nav a {
    color: var(--dark-blue-muted);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: 
        color var(--transition-fast),
        background var(--transition-fast);
}

footer nav a:hover {
    color: var(--accent-blue);
    background: rgba(59, 130, 246, 0.06);
}

footer nav a:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

.copyright {
    color: var(--dark-blue-muted);
    font-size: 0.85rem;
    opacity: 0.7;
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 640px) {
    .container {
        padding: 32px 16px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .url-form,
    .glass-card,
    .result {
        padding: 24px;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .input-group input[type="text"] {
        padding: 14px 20px;
    }
    
    .input-group button[type="submit"] {
        width: 100%;
        padding: 14px 24px;
    }
    
    .short-url-container {
        flex-direction: column;
        gap: 16px;
    }
    
    .short-url {
        font-size: 1rem;
        padding: 12px 20px;
        width: 100%;
        text-align: center;
    }
    
    .copy-btn {
        width: 100%;
        justify-content: center;
    }
    
    .error-content {
        padding: 40px 24px;
    }
    
    .error-code {
        font-size: 4.5rem;
    }
    
    .analytics-table-container {
        border-radius: var(--radius-md);
    }
    
    .analytics-table th,
    .analytics-table td {
        padding: 12px 14px;
        font-size: 0.85rem;
    }
    
    .long-url {
        max-width: 100px;
    }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --glass-bg: rgba(255, 255, 255, 0.95);
        --glass-border: rgba(0, 0, 0, 0.2);
    }
    
    .input-group input[type="text"] {
        border-color: var(--dark-blue);
    }
}

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

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

/* Selection styling */
::selection {
    background: rgba(59, 130, 246, 0.2);
    color: var(--dark-blue);
}