body {
    height: 100vh;
    margin: 0;
    background: #0f2027;
    color: #00fff7;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: 'Courier New', monospace;
    user-select: none;
}

.clock {
    font-size: 30px;
    padding: 20px 40px;
    background: #1c1c1c;
    border-radius: 12px;
    letter-spacing: 4px;
    user-select: none;
}

.controls {
    margin-top: 20px;
    position: absolute;
    bottom: 40px;
    user-select: none;
}

.back-btn {
    display: inline-block;
    text-decoration: none;
    padding: 10px 18px;
    border-radius: 10px;
    background: rgba(255,255,255,0.9);
    color: #3a3a3a;
    box-shadow: 0 6px 18px rgba(0,0,0,0.15);
    font-weight: bold;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
    user-select: none;
}

.back-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 24px rgba(0,0,0,0.18);
    user-select: none;
}