/* =======================
   ESTILOS GENERALES
======================= */
body {
    background: #f4f4f9 url('fondo.jpg') no-repeat center center / cover; /* fondo unificado */
    font-family: 'Arial', sans-serif;
    color: #333;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-attachment: fixed; /* mejora visual */
}

.container {
    max-width: 900px; 
    margin: 0 auto;   
    padding: 20px; 
}

/* Clearfix para imágenes flotadas */
.container::after {
    content: "";
    display: table;
    clear: both;
}

/* =======================
   ENCABEZADOS
======================= */
h1 {
    font-size: 200%;
    text-align: center;
    text-decoration: underline;
    text-transform: uppercase;
    margin: 20px 0;
    letter-spacing: 2px; /* requerido */
}

h2 {
    background-color: #d1e7dd;
    font-size: 180%;
    padding: 10px;
    letter-spacing: 1px; /* opcional pero útil */
}

h3 {
    background-color: #f8d7da;
    color: #721c24;
    font-size: 160%;
    padding: 5px;
    letter-spacing: 1px; /* agregado para consistencia */
}

/* =======================
   PÁRRAFOS Y TEXTO
======================= */
p {
    text-align: justify;
    font-size: 100%;
    margin: 10px 0;
    text-indent: 20px; /* requerido */
}

p::first-letter {
    font-size: 200%;
    font-weight: bold;
    color: #007bff;
    font-family: 'Georgia', serif; /* se pidió font-family */
}

blockquote {
    font-style: italic;
    background-color: #e9ecef;
    border-left: 5px solid #007bff;
    padding: 10px 20px;
    margin: 20px 0;
}

pre {
    background-color: #212529;
    color: #f8f9fa;
    font-size: 90%;
    font-weight: bold;
    padding: 15px;
    border: 2px solid #6c757d;
    overflow-x: auto;
}

/* =======================
   DIRECCIONES
======================= */
address {
    font-family: 'Georgia', serif;
    font-style: italic;
    text-align: center;
    margin: 20px 0;
}

/* =======================
   LISTAS
======================= */
ul, ol {
    margin: 10px 0 10px 40px;
    padding: 0;
    list-style-position: inside; /* mejora consistencia */
}

/* =======================
   TABLAS
======================= */
table {
    width: 100%;
    border: 2px solid #333;
    border-collapse: collapse;
    table-layout: fixed; /* requerido */
    background-color: #ffffff; /* nuevo */
    margin: 20px 0;
}

table caption {
    font-weight: bold;
    caption-side: top; /* requerido */
    margin-bottom: 10px;
    color: #333;
}

table th, table td {
    border: 1px solid #333;
    padding: 10px; /* requerido */
    text-align: center; /* requerido */
    min-height: 40px; /* mejora visual */
}

table th {
    background-color: #d1e7dd;
    color: #000;
    border-bottom: 3px solid #333; /* requerido */
}

table tr:nth-child(even) {
    background-color: #f2f2f2; /* requerido */
}

table tr:nth-child(odd) {
    background-color: #ffffff; /* requerido */
}

table tr:hover {
    background-color: #cfe2ff; /* hover */
    cursor: pointer;
}

/* =======================
   ENLACES
======================= */
a {
    color: #007bff;
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* =======================
   IMÁGENES
======================= */
img {
    max-width: 100%;
    height: auto;
    float: left; /* requerido */
    margin: 10px;
}

/* =======================
   FORMULARIOS
======================= */
input, select, textarea, button {
    font-family: inherit;
    font-size: 100%;
    padding: 5px;
    margin: 5px 0;
}

fieldset {
    padding: 15px;
    margin: 20px 0;
    border: 2px solid #007bff;
}

legend {
    font-weight: bold;
}

/* =======================
   MISC
======================= */
mark {
    background-color: #fff3cd;
    padding: 0 3px;
}

del {
    color: #dc3545;
}

ins {
    background-color: #d4edda;
    text-decoration: none;
}

small {
    font-size: 80%;
}

dfn {
    font-style: italic;
}

var {
    font-family: 'Courier New', monospace;
}

/* =======================
   AUDIO Y VIDEO
======================= */
audio, iframe {
    display: block;
    margin: 10px auto;
}

/* =======================
   FORMULARIOS
======================= */

/* Fuente general para formularios */
form {
    font-family: 'Open Sans', sans-serif;
    background-color: #ffffffcc;
    padding: 20px;
    border-radius: 10px;
    margin: 20px auto;
    border: 1px solid #ccc;
    backdrop-filter: blur(3px);
}

/* Etiquetas */
form label {
    display: block;
    font-weight: bold;
    margin-top: 10px;
    cursor: pointer;
}

/* Inputs, selects y textarea */
form input,
form select,
form textarea {
    width: 100%;
    padding: 10px;
    margin-top: 5px;
    border: 2px solid #999;
    border-radius: 5px;
    outline: none;
    background-color: #f8f9fa;
    background-image: linear-gradient(to right, #e3e3e3, #f8f8f8);
    background-position: left;
    transition: 0.3s ease;
}

/* Limitar resize solo a textarea */
form textarea {
    resize: none;
}

/* Placeholder */
form input::placeholder,
form textarea::placeholder {
    color: #777;
    font-style: italic;
}

/* Focus */
form input:focus,
form textarea:focus,
form select:focus {
    border-color: #007bff;
    background-color: #ffffff;
    box-shadow: 0 0 5px #007bff88;
}

/* Hover */
form input:hover,
form textarea:hover,
form select:hover {
    border-color: #555;
}

/* Checkbox y radio */
form input[type="checkbox"],
form input[type="radio"] {
    width: auto;
    cursor: pointer;
}

form input[type="checkbox"]:checked,
form input[type="radio"]:checked {
    box-shadow: 0 0 0 3px #007bff; 
}

/* Botón enviar */
form input[type="submit"],
form button[type="submit"] {
    background-color: #007bff;
    color: #fff;
    border: none;
    border-bottom: 4px solid #0056b3;
    cursor: pointer;
    padding: 12px 20px;
    border-radius: 8px;
    margin-top: 15px;
    font-weight: bold;
    transition: 0.3s ease-in-out;
}

/* Hover botón */
form input[type="submit"]:hover,
form button[type="submit"]:hover {
    background-color: #0056b3;
}


/* =======================
   BARRA DE INTENSIDAD
======================= */
input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 4px; 
    border-radius: 3px; 
    background: linear-gradient(to right, #00ff73, #ff0000);
    outline: none;
    margin-top: 5px;
    transition: 0.3s;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px; 
    height: 20px;
    border-radius: 50%;
    background: #0056b3;
    cursor: pointer;
    border: 2px solid #fff;
    box-shadow: 0 0 5px #007bff88;
    transition: 0.3s;
    margin-top: -7px; 
}

input[type="range"]::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #0056b3;
    cursor: pointer;
    border: 2px solid #fff;
    box-shadow: 0 0 5px #007bff88;
    transition: 0.3s;
}

/* Valor mostrado al lado */
#intensidad-value {
    display: inline-block;
    margin-left: 10px;
    font-weight: bold;
}


/* =======================
   NAV PRINCIPAL
======================= */
nav.menu-principal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(34, 34, 34, 0.95); 
    padding: 12px 0;
    z-index: 9999;
    border-bottom: 3px solid #00e0ff;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    backdrop-filter: blur(5px);
    transition: background 0.3s ease;
}

nav.menu-principal ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    list-style: none;
    margin: 0;
    padding: 0;
}

nav.menu-principal li {
    position: relative; 
}

nav.menu-principal a {
    color: #ffffff;
    text-decoration: none;
    font-weight: bold;
    font-size: 15px;
    padding: 8px 12px;
    border-radius: 5px;
    transition: all 0.3s ease;
}

nav.menu-principal a:hover,
nav.menu-principal a:focus {
    color: #00e0ff;
    background-color: rgba(255, 255, 255, 0.1);
    box-shadow: 0 2px 6px rgba(0, 224, 255, 0.5);
}


body {
    padding-top: 70px; 
}