body {
    font-family: 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    color: #ffffff;
    min-height: 100vh;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

h1 {
    margin-bottom: 2rem;
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    letter-spacing: 1px;
    color: #00d4ff;
}

div {
    margin-bottom: 1.5rem;
    width: 100%;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

label {
    font-size: 1rem;
    font-weight: 500;
    color: #d0e6fa;
}

select,
input[type="datetime-local"] {
    width: 100%;
    background: rgba(255, 255, 255, 0.13);
    border: 1px solid rgba(255,255,255,0.18);
    border-radius: 0.5rem;
    padding: 0.75rem;
    color: #fff;
    font-size: 1rem;
    margin-top: 0.25rem;
    transition: border-color 0.2s, box-shadow 0.2s;
}

select:focus,
input[type="datetime-local"]:focus {
    outline: none;
    border-color: #00d4ff;
    box-shadow: 0 0 0 2px rgba(0, 212, 255, 0.15);
}

button {
    background: linear-gradient(135deg, #00d4ff 0%, #1a5193 100%);
    border: none;
    color: #fff;
    padding: 0.8rem 2rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 600;
    font-size: 1.1rem;
    transition: background 0.2s, box-shadow 0.2s;
}

button:hover {
    box-shadow: 0 4px 20px rgba(0,212,255,0.13);
    background: linear-gradient(135deg, #00d4ff 0%, #176ec6 100%);
}

#result {
    display: none; /* Default, shown via JS */
    background: rgba(255, 255, 255, 0.09);
    border: 1px solid rgba(255,255,255,0.13);
    border-radius: 0.75rem;
    padding: 1.25rem;
    text-align: center;
    margin-top: 1.5rem;
    max-width: 400px;
}

#resultTime {
    color: #00d4ff;
    font-size: 1.35rem;
    font-weight: 700;
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.25rem;
        margin-bottom: 1.2rem;
    }
    div, #result {
        max-width: 95vw;
        padding: 0.65rem;
    }
    button {
        font-size: 1rem;
        padding: 0.6rem 1.2rem;
    }
}