* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    font-family: Calibri, Arial, sans-serif;
    background-color: #74aaf0;
}

.site-header {
    position: sticky;
    top: 0;
    width: 100%;
    background-color: #000000e0;
    color: #ffffff;
    padding: 18px 0;
    text-align: center;
    z-index: 10;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.12);
}

.site-header h1 {
    margin: 0;
    font-size: 50px;
    letter-spacing: 0.05em;
}

.contenedor {
    width: min(100%, 520px);
    padding: 20px;
    margin: 20px;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.08);
}

label {
    display: block;
    margin: 10px 0 5px;
}

input,
select {
    width: 100%;
    padding: 8px;
    margin-bottom: 10px;
    border: 1px solid #0400ff;
    border-radius: 8px;
}

button,
input[type="submit"],
input[type="reset"] {
    width: 100%;
    padding: 12px 18px;
    margin-top: 10px;
    background-color: #000000e0;
    color: #ffffff;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s ease, background-color 0.2s ease, box-shadow 0.2s ease;
    box-shadow: 0 8px 18px rgba(30, 144, 255, 0.18);
}

button:hover,
input[type="submit"]:hover,
input[type="reset"]:hover {
    background-color: #000000;
    transform: translateY(-1px);
    box-shadow: 0 12px 22px rgba(0, 119, 230, 0.22);
}

button:focus,
input[type="submit"]:focus,
input[type="reset"]:focus {
    outline: 3px solid rgb(0, 0, 0);
    outline-offset: 2px;
}

.mensaje {
    padding: 10px;
    margin-bottom: 15px;
}