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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}

.container {
    background: rgba(255, 255, 255, 0.95);
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    backdrop-filter: blur(10px);
}

.timer {
    text-align: center;
}

.time-display {
    font-size: 4rem;
    font-weight: 300;
    color: #333;
    margin-bottom: 2rem;
    font-variant-numeric: tabular-nums;
}

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

.btn {
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    border: none;
    border-radius: 10px;
    background: #007AFF;
    color: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn:hover {
    background: #0056b3;
    transform: translateY(-2px);
}

.btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

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