body {
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    /* Use dynamic viewport where supported; fallback to --vh set by JS */
    min-height: calc(var(--vh, 1vh) * 100);
    /* final fallback for modern browsers that support dvh */
    min-height: 100dvh;
    background: #f5f5f5;
    color: #333;
}

/* Keep container centered but constrained */
.container {
    width: 100%;
    max-width: 400px;
}

/* Prefer top-aligned on small screens to reduce keyboard-driven jumps */
@media (max-width: 800px) {
    body {
        align-items: flex-start;
        padding-top: 8vh; /* stable spacing from top */
        min-height: calc(var(--vh, 1vh) * 100);
    }
}

.card {
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

h2 {
    text-align: center;
    color: #333;
}

form {
    display: flex;
    flex-direction: column;
}

input {
    padding: 10px;
    margin-bottom: 12px;
    border: 1px solid #ddd;
    border-radius: 4px;
    transition: border-color 0.3s ease-in-out;
    outline: none;
    color: #333;
}

    input:focus {
        border-color: #555;
    }

button {
    padding: 10px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: background-color 0.3s ease-in-out;
}

    button:hover {
        background-color: #2980b9;
    }