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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #f5f5f7;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    background: rgba(255, 255, 255, 0.9);
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
}

.timer {
    text-align: center;
}

.time-display {
    font-size: 4.5rem;
    font-weight: 300;
    color: #1d1d1f;
    font-variant-numeric: tabular-nums;
    margin-bottom: 2rem;
    font-feature-settings: "tnum";
}

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

.btn {
    border: none;
    background: #0071e3;
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 980px;
    font-size: 1rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.btn:hover {
    background: #0077ED;
    transform: translateY(-1px);
}

.btn:active {
    transform: translateY(1px);
}

.btn:disabled {
    background: #999;
    cursor: not-allowed;
}

.icon {
    width: 1.2em;
    height: 1.2em;
    fill: currentColor;
}

@media (max-width: 480px) {
    .container {
        padding: 1.5rem;
        margin: 1rem;
    }

    .time-display {
        font-size: 3.5rem;
    }

    .controls {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}