@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

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

:root {
    --primary-gradient: linear-gradient(135deg, #6cb495 0%, #4b85a2 100%);
    --glass-bg: rgba(255, 255, 255, 0.1);
    --glass-border: rgba(255, 255, 255, 0.2);
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.8);
    --shadow-light: 0 8px 32px rgba(0, 0, 0, 0.1);
    --shadow-heavy: 0 20px 60px rgba(0, 0, 0, 0.2);
    --border-radius: 20px;
    --animation-speed: 0.3s;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--primary-gradient);
    background-attachment: fixed;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    overflow-x: hidden;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 50%, rgba(120, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 119, 198, 0.3) 0%, transparent 50%),
        radial-gradient(circle at 40% 80%, rgba(120, 219, 255, 0.3) 0%, transparent 50%);
    z-index: -1;
    animation: backgroundShift 20s ease-in-out infinite;
}

@keyframes backgroundShift {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

.stopwatch-container {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    padding: 40px;
    box-shadow: var(--shadow-heavy);
    text-align: center;
    max-width: 500px;
    width: 100%;
    animation: slideInUp 0.8s cubic-bezier(0.16, 1, 0.3, 1);
    position: relative;
    overflow: hidden;
}

.stopwatch-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: shimmer 3s infinite;
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(60px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

@keyframes shimmer {
    0% { left: -100%; }
    100% { left: 100%; }
}

.display {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 30px;
    font-family: 'Inter', monospace;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    padding: 25px;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: inset 0 2px 4px rgba(255, 255, 255, 0.1);
    letter-spacing: 0.05em;
    transition: all var(--animation-speed) ease;
    position: relative;
    overflow: hidden;
}

.display.running {
    animation: pulse 2s ease-in-out infinite;
    box-shadow: 
        inset 0 2px 4px rgba(255, 255, 255, 0.1),
        0 0 30px rgba(255, 255, 255, 0.2);
}

@keyframes pulse {
    0%, 100% { 
        box-shadow: 
            inset 0 2px 4px rgba(255, 255, 255, 0.1),
            0 0 30px rgba(255, 255, 255, 0.2);
    }
    50% { 
        box-shadow: 
            inset 0 2px 4px rgba(255, 255, 255, 0.2),
            0 0 40px rgba(255, 255, 255, 0.3);
    }
}

.controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 12px;
    margin-bottom: 30px;
    padding: 0 10px;
}

button {
    padding: 16px 24px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: all var(--animation-speed) cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: white;
    font-family: 'Inter', sans-serif;
    min-height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
}

button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s;
}

button:hover::before {
    left: 100%;
}

.start-btn {
    background: linear-gradient(135deg, #00f260, #0575e6);
    box-shadow: 0 4px 15px rgba(5, 117, 230, 0.3);
}

.start-btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(5, 117, 230, 0.4);
}

.start-btn:active {
    transform: translateY(-1px) scale(0.98);
}

.pause-btn {
    background: linear-gradient(135deg, #f093fb, #f5576c);
    box-shadow: 0 4px 15px rgba(245, 87, 108, 0.3);
}

.pause-btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(245, 87, 108, 0.4);
}

.reset-btn {
    background: linear-gradient(135deg, #4facfe, #00f2fe);
    box-shadow: 0 4px 15px rgba(79, 172, 254, 0.3);
}

.reset-btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(79, 172, 254, 0.4);
}

.lap-btn {
    background: linear-gradient(135deg, #a8edea, #fed6e3);
    color: #333;
    box-shadow: 0 4px 15px rgba(168, 237, 234, 0.3);
}

.lap-btn:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(168, 237, 234, 0.4);
}

button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
    transform: none !important;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1) !important;
}

button:disabled::before {
    display: none;
}

.lap-times {
    max-height: 350px;
    overflow-y: auto;
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(10px);
    border-radius: 16px;
    padding: 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    animation: fadeInUp 0.6s ease 0.3s both;
}

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

.lap-times h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 1.2rem;
    font-weight: 600;
}

.lap-times::-webkit-scrollbar {
    width: 6px;
}

.lap-times::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.1);
    border-radius: 3px;
}

.lap-times::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
}

.lap-times::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.5);
}

.lap-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    margin: 8px 0;
    background: rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--animation-speed) ease;
    animation: slideInLeft 0.4s ease;
}

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

.lap-item:hover {
    background: rgba(255, 255, 255, 0.12);
    transform: translateX(5px);
}

.lap-number {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.lap-time {
    font-family: 'Inter', monospace;
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 1rem;
}

.no-laps {
    color: var(--text-secondary);
    font-style: italic;
    padding: 20px;
    text-align: center;
}

/* Responsive Design */
@media (max-width: 768px) {
    .stopwatch-container {
        padding: 30px 20px;
        margin: 10px;
    }
    
    .display {
        padding: 20px 15px;
        margin-bottom: 25px;
    }
    
    .controls {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }
    
    button {
        padding: 14px 18px;
        font-size: 0.9rem;
        min-height: 50px;
    }
}

@media (max-width: 480px) {
    body {
        padding: 10px;
    }
    
    .stopwatch-container {
        padding: 25px 15px;
    }
    
    .controls {
        grid-template-columns: 1fr;
        gap: 8px;
    }
    
    .lap-times {
        max-height: 250px;
        padding: 15px;
    }
    
    .lap-item {
        padding: 12px 15px;
        flex-direction: column;
        gap: 5px;
        text-align: center;
    }
}

@media (max-width: 320px) {
    .display {
        padding: 15px 10px;
    }
    
    button {
        padding: 12px 15px;
        font-size: 0.85rem;
        min-height: 45px;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .display.running {
        animation: none;
    }
    
    body::before {
        animation: none;
    }
}

/* Focus states for accessibility */
button:focus-visible {
    outline: 2px solid rgba(255, 255, 255, 0.8);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --glass-bg: rgba(0, 0, 0, 0.8);
        --glass-border: rgba(255, 255, 255, 0.8);
        --text-primary: #ffffff;
        --text-secondary: #ffffff;
    }
}