/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-hover: #5855eb;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --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);
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #6366f1 100%);
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
    position: relative;
    overflow-x: hidden;
}

/* Background animation */
.background-animation {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(-45deg, #667eea, #764ba2, #6366f1, #8b5cf6);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}

/* Header */
.header {
    position: relative;
    z-index: 100;
    padding: 1rem 0;
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
}

.logo i {
    font-size: 1.8rem;
    color: var(--accent-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a:hover {
    color: white;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-color);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* Main content */
.main {
    position: relative;
    z-index: 10;
}

/* Hero section */
.hero {
    text-align: center;
    padding: 4rem 2rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.hero-content {
    max-width: 700px;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    color: white;
    margin-bottom: 1.5rem;
    line-height: 1.1;
}

.highlight {
    background: linear-gradient(45deg, var(--accent-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.25rem;
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 3rem;
    line-height: 1.6;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Shortener card */
.shortener-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius);
    padding: 2.5rem;
    box-shadow: var(--shadow-xl);
    border: 1px solid rgba(255, 255, 255, 0.2);
    margin-bottom: 4rem;
    transition: var(--transition);
}

.shortener-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 2rem;
    justify-content: center;
}

.card-header i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.card-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* Form styles */
.shortener-form {
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    gap: 1rem;
    align-items: stretch;
}

.input-wrapper {
    position: relative;
    flex: 1;
    display: flex;
    align-items: center;
}

.input-wrapper.focused {
    transform: scale(1.02);
}

.input-icon {
    position: absolute;
    left: 1rem;
    color: var(--text-light);
    z-index: 2;
    transition: var(--transition);
}

.input-wrapper.focused .input-icon {
    color: var(--primary-color);
}

#url {
    width: 100%;
    padding: 1rem 1rem 1rem 3rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
    background: var(--bg-primary);
    color: var(--text-primary);
}

#url:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

#url::placeholder {
    color: var(--text-light);
}

.shorten-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    min-width: 160px;
    justify-content: center;
}

.shorten-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.shorten-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top: 2px solid white;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Result styles */
.result {
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition);
    pointer-events: none;
}

.result.show {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.result-success {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(6, 182, 212, 0.1));
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.result-error {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.1), rgba(245, 101, 101, 0.1));
    border: 1px solid rgba(239, 68, 68, 0.2);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    text-align: center;
}

.result-header {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
    justify-content: center;
}

.result-header i {
    font-size: 1.25rem;
    color: var(--success-color);
}

.result-error i {
    color: var(--error-color);
}

.result-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.url-display {
    margin-bottom: 1.5rem;
}

.url-label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.url-container {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 0.5rem;
}

.short-url-input {
    flex: 1;
    padding: 0.75rem;
    border: none;
    background: transparent;
    font-size: 1rem;
    color: var(--text-primary);
    font-family: 'JetBrains Mono', 'Fira Code', monospace;
}

.short-url-input:focus {
    outline: none;
}

.copy-btn {
    padding: 0.75rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.copy-btn:hover {
    background: var(--primary-hover);
    transform: scale(1.05);
}

.result-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.test-link,
.stats-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    font-size: 0.875rem;
}

.test-link {
    background: var(--accent-color);
    color: white;
}

.test-link:hover {
    background: #0891b2;
    transform: translateY(-2px);
}

.stats-link {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.stats-link:hover {
    background: var(--bg-secondary);
    transform: translateY(-2px);
}

/* Features section */
.features {
    padding: 4rem 0;
    text-align: center;
}

.features-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition);
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
}

.feature-icon i {
    font-size: 2rem;
    color: white;
}

.feature-card h4 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Footer */
.footer {
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    margin-top: 4rem;
}

.footer-content p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.875rem;
}

/* Notifications */
.notification {
    position: fixed;
    top: 2rem;
    right: 2rem;
    background: var(--success-color);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 500;
    z-index: 1000;
    transform: translateX(100%);
    transition: transform 0.3s ease;
}

.notification.show {
    transform: translateX(0);
}

.notification i {
    font-size: 1.25rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .nav {
        padding: 0 1rem;
    }
    
    .nav-links {
        display: none;
    }
    
    .hero {
        padding: 2rem 1rem;
    }
    
    .container {
        padding: 0 1rem;
    }
    
    .shortener-card {
        padding: 1.5rem;
    }
    
    .input-group {
        flex-direction: column;
    }
    
    .shorten-btn {
        width: 100%;
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .result-actions {
        flex-direction: column;
    }
    
    .notification {
        top: 1rem;
        left: 1rem;
        right: 1rem;
        transform: translateY(-100%);
    }
    
    .notification.show {
        transform: translateY(0);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-description {
        font-size: 1rem;
    }
    
    .shortener-card {
        padding: 1rem;
    }
    
    .feature-card {
        padding: 1.5rem;
    }
}