label {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    transition: all 0.3s ease;
    pointer-events: none;
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
}

input:focus + label,
input:not(:placeholder-shown) + label {
    opacity: 0;
    visibility: hidden;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
    background-size: 400% 400%;
    animation: gradient 15s ease infinite;
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

@keyframes gradient {
    0% {
        background-position: 0 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0 50%;
    }
}

.container {
    background: rgba(255, 255, 255, 0.1);
    padding: 40px;
    border-radius: 20px;
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
    border: 1px solid rgba(255, 255, 255, 0.18);
    transform: translateY(0);
    transition: all 0.3s ease;
    max-width: 400px;
    width: 90%;
}

.container:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px 0 rgba(31, 38, 135, 0.45);
}

h1 {
    margin-bottom: 30px;
    font-size: 2.5em;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
    letter-spacing: 1px;
}

form {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.input-group {
    position: relative;
    width: 100%;
}

input {
    width: 100%;
    padding: 15px;
    border: 2px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    font-size: 1rem;
    transition: all 0.3s ease;
}

input:focus {
    outline: none;
    border-color: rgba(255, 255, 255, 0.5);
    background: rgba(255, 255, 255, 0.15);
}

button {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1.1em;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 1px;
    width: 100%;
    position: relative;
    overflow: hidden;
}

button:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

button:active {
    transform: translateY(1px);
}

.error {
    color: #fff;
    background: rgba(255, 77, 77, 0.9);
    padding: 10px;
    border-radius: 5px;
    margin-top: 10px;
    font-size: 0.9em;
    text-align: center;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.error.visible {
    opacity: 1;
    transform: translateY(0);
    animation: fadeOut 3s ease-in-out 3s forwards;
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: translateY(-10px);
    }
}

@media (max-width: 480px) {
    .container {
        padding: 20px;
    }

    h1 {
        font-size: 2em;
    }

    input {
        padding: 12px;
    }
}