* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
    background-color: #f5f5f7;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background-color: white;
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    text-align: center;
}

.timer {
    font-size: 4rem;
    font-weight: 300;
    color: #1d1d1f;
    margin-bottom: 2rem;
    font-variant-numeric: tabular-nums;
}

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

.btn {
    background-color: #0071e3;
    color: white;
    border: none;
    padding: 0.8rem 1.5rem;
    border-radius: 980px;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn:hover {
    background-color: #0077ed;
}

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

#resetBtn {
    background-color: #ff3b30;
}

#resetBtn:hover {
    background-color: #ff453a;
}