* {
    box-sizing: border-box;
}
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    min-height: 100vh;
    margin: 0;
    padding: 1.5rem 1rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}
.container {
    background: #fff;
    padding: 2rem 1.5rem;
    border-radius: 16px;
    box-shadow: 0 8px 30px rgba(0,0,0,0.2);
    text-align: center;
    width: 100%;
    max-width: 420px;
}
h1 {
    font-size: 1.25rem;
    margin: 0 0 1.5rem;
    color: #333;
    font-weight: 600;
}
label {
    display: block;
    text-align: left;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #555;
    font-size: 0.95rem;
}
input[type="datetime-local"] {
    width: 100%;
    padding: 0.9rem 1rem;
    font-size: 1.1rem;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    background: #fafafa;
    color: #333;
    -webkit-appearance: none;
    appearance: none;
}
input[type="datetime-local"]:focus {
    outline: none;
    border-color: #667eea;
    background: #fff;
}
button {
    width: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border: none;
    padding: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    margin-top: 0.5rem;
    -webkit-tap-highlight-color: transparent;
}
button:active {
    transform: scale(0.98);
}
#result {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 0 0 1.5rem;
    min-height: 3.5rem;
    line-height: 3.5rem;
}
@media (max-width: 360px) {
    .container {
        padding: 1.5rem 1.2rem;
    }
    input[type="datetime-local"] {
        font-size: 1rem;
        padding: 0.8rem 0.9rem;
    }
    button {
        padding: 0.9rem;
        font-size: 1rem;
    }
.toggle-label {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.95rem;
    font-weight: 600;
    color: #555;
}
.switch {
    position: relative;
    display: inline-block;
    width: 52px;
    height: 28px;
    flex-shrink: 0;
}
.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}
.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: #ccc;
    border-radius: 28px;
    transition: 0.3s;
}
.slider:before {
    position: absolute;
    content: "";
    height: 22px;
    width: 22px;
    left: 3px;
    bottom: 3px;
    background: #fff;
    border-radius: 50%;
    transition: 0.3s;
}
input:checked + .slider {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}
input:checked + .slider:before {
    transform: translateX(24px);
}
#result {
        font-size: 2rem;
    }
}