CSS Animation Floating Label Example

<!doctype html>
<title>Example</title>
<style>
body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: sans-serif;
    background-color: #f0f0f0;
}

.input-container {
    position: relative;
    margin-top: 20px;
    width: 250px;
}

.floating-input {
    width: 100%;
    padding: 10px 0;
    font-size: 1rem;
    color: #333;
    border: none;
    border-bottom: 2px solid #aaa;
    outline: none;
    background-color: transparent;
    transition: border-color 0.2s;
}

.floating-label {
    position: absolute;
    top: 10px;
    left: 0;
    font-size: 1rem;
    color: #aaa;
    pointer-events: none;
    transition: all 0.2s ease;
}

.floating-input:focus,
.floating-input:not(:placeholder-shown) {
    border-bottom-color: #007bff;
}

.floating-input:focus ~ .floating-label,
.floating-input:not(:placeholder-shown) ~ .floating-label {
    top: -20px;
    font-size: 0.8rem;
    color: #007bff;
}

@media (prefers-reduced-motion: reduce) {
    .floating-input, .floating-label {
        transition: none;
    }
}
</style>