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

/* ===== Loader Spinner ===== */
#loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.spinner {
    --size: 30px;
    --first-block-clr: #37474f;
    --second-block-clr: #6C132B;
    --clr: #111;
    width: 100px;
    height: 100px;
    position: relative;
}

.spinner::after,
.spinner::before {
    box-sizing: border-box;
    position: absolute;
    content: "";
    width: var(--size);
    height: var(--size);
    top: 50%;
    animation: up 2.4s cubic-bezier(0, 0, 0.24, 1.21) infinite;
    left: 50%;
    background: var(--first-block-clr);
}

.spinner::after {
    background: var(--second-block-clr);
    top: calc(50% - var(--size));
    left: calc(50% - var(--size));
    animation: down 2.4s cubic-bezier(0, 0, 0.24, 1.21) infinite;
}

@keyframes down {

    0%,
    100% {
        transform: none;
    }

    25% {
        transform: translateX(100%);
    }

    50% {
        transform: translateX(100%) translateY(100%);
    }

    75% {
        transform: translateY(100%);
    }
}

@keyframes up {

    0%,
    100% {
        transform: none;
    }

    25% {
        transform: translateX(-100%);
    }

    50% {
        transform: translateX(-100%) translateY(-100%);
    }

    75% {
        transform: translateY(-100%);
    }
}


footer {
    margin: 50px auto 0 auto;
    /* arriba y abajo automargin centran horizontalmente */
    padding: 20px;
    max-width: 800px;
    /* limita ancho para que no sea tan ancho */
    text-align: left;
    background-color: #f2f2f2;
    font-family: sans-serif;
    color: #333;
}

body {
    font-size: 14px;
    font-family: Arial, sans-serif;
    background-color: #e9ecf1;
}

form,
table {
    max-width: 600px;
    margin: 0 auto;
}

/* Encabezado */
header {
    background-color: #6C132B;
    color: white;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 25px;
}

.logoI img {
    height: 50px;
    width: 170px;
}

/* Navegación */
nav {
    display: flex;
    justify-content: center;
    background-color: #37474f;
}

nav a {
    color: white;
    padding: 14px 20px;
    text-decoration: none;
    text-align: center;
}

nav a:hover {
    background-color: #546e7a;
}

/* Título */
h2 {
    text-align: center;
    margin-top: 40px;
    font-size: 28px;
    color: #1a237e;
}

/* Formularios */
form {
    width: 95%;
    margin: 0 auto;
    padding: 10px;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    margin-top: 20px;
}

form label {
    display: block;
    margin-bottom: 10px;
    color: #263238;
    font-size: 16px;
}

form input[type="text"] {
    width: 100%;
    padding: 10px;
    border: 1px solid #ff0000;
    border-radius: 4px;
    font-size: 16px;
    margin-bottom: 20px;
}

/* Botón principal */
form input[type="submit"] {
    width: 100%;
    padding: 10px;
    background-color: black;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
}


form input[type="submit"]:hover {
    background-color: gray;
}

/* Select para actividades */
form select {
    width: 100%;
    padding: 10px;
    background-color: white;
    color: black;
    border-radius: 4px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
}

a.btn {
    display: inline-block;
    width: 100%;
    padding: 10px;
    background-color: black;
    color: white;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: 4px;
    font-size: 18px;
    cursor: pointer;
    transition: background-color 0.3s;
}

a.btn:hover {
    background-color: gray;
}

/* Tabla de datos */
table {
    width: 100%;
    font-size: 14px;
    margin: 30px auto;
    border-collapse: collapse;
    background-color: #ffffff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
}

table th,
table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

table th {
    background-color: #1a237e;
    color: white;
    font-size: 16px;
    text-transform: uppercase;
}

table tr:hover {
    background-color: #f1f1f1;
}

/* Mensajes */
p {
    text-align: center;
    color: #c62828;
    font-size: 18px;
}