body {
    background: linear-gradient(135deg, #e0e7ff, #93c5fd);
    background-attachment: fixed;
    transition: background 0.5s ease;
}
.dark body {
    background: linear-gradient(135deg, #444d5f, #3d4c61);
}
.fade-in {
    animation: fadeIn 1s ease-in-out;
}
@keyframes fadeIn {
    0% { opacity: 0; transform: translateY(20px); }
    100% { opacity: 1; transform: translateY(0); }
}
.switch {
    position: relative;
    display: inline-block;
    width: 50px;
    height: 24px;
}
.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}
.switch .slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #e2e2e2e0;
    transition: 0.4s;
    border-radius: 24px;
}
.switch .slider:before {
    position: absolute;
    content: "🌞";
    height: 20px;
    width: 20px;
    left: 2px;
    bottom: 2px;
    background-color: #fcfdff;
    transition: 0.4s;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
}
.switch input:checked + .slider {
    background-color: #00af75;
}
.switch input:checked + .slider:before {
    transform: translateX(26px);
    content: "🌙";
}
.input-transition {
    transition: all 0.3s ease;
}
.input-transition:focus {
    transform: scale(1.02);
}