:root {
    --bg-main: #111326;
    --bg-card: #1a1e3b;
    --header-bg: #1095a4;
    --accent-cyan: #00e5ff;
    --text-main: #ffffff;
    --text-muted: #8c93b6;
    --border-line: #2d3359;
    --green-beta: #14f65b;
}

/* =========================
   ESTILOS GENERALES
========================= */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    -webkit-tap-highlight-color: transparent;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
}

/* =========================
   ONDAS DE FONDO
========================= */

body::before,
body::after {
    content: "";
    position: fixed;
    width: 900px;
    height: 900px;
    border-radius: 45%;
    background: rgba(0, 229, 255, 0.025);
    z-index: -1;
    pointer-events: none;
}

body::before {
    top: -700px;
    left: -350px;
    animation: rotateWave 25s linear infinite;
}

body::after {
    bottom: -700px;
    right: -350px;
    animation: rotateWave 35s linear infinite reverse;
}

@keyframes rotateWave {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

/* =========================
   ENCABEZADO
========================= */

header {
    width: 100%;
    min-height: 70px;

    background: var(--header-bg);

    display: flex;
    align-items: center;
    justify-content: center;

    padding: 15px 55px;

    position: sticky;
    top: 0;
    z-index: 100;

    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
}

header h1 {
    color: white;
    font-size: 21px;
    font-weight: 700;
    text-align: center;

    display: flex;
    align-items: center;
    justify-content: center;
    gap: 7px;

    line-height: 1.2;
}

/* BETA */

header h1 h3 {
    font-size: 12px;
    font-weight: 700;
}

/* =========================
   BOTÓN VOLVER
========================= */

.volver {
    position: absolute;

    left: 15px;
    top: 50%;

    transform: translateY(-50%);

    width: 40px;
    height: 40px;

    border-radius: 50%;

    background: rgba(0, 0, 0, 0.15);

    color: white;

    display: flex;
    align-items: center;
    justify-content: center;

    text-decoration: none;

    transition:
        background 0.3s ease,
        transform 0.2s ease;
}

.volver:hover {
    background: rgba(0, 0, 0, 0.3);
}

.volver:active {
    transform: translateY(-50%) scale(0.92);
}

.volver .material-symbols-rounded {
    font-size: 24px;
}

/* =========================
   CONTENEDOR PRINCIPAL
========================= */

main {
    width: 100%;
    max-width: 600px;

    margin: 0 auto;

    padding: 20px 0 40px;
}

/* =========================
   BIENVENIDA
========================= */

.bienvenida {
    width: 92%;

    margin: 0 auto 25px;

    padding: 30px 20px;

    background: var(--bg-card);

    border: 1px solid var(--accent-cyan);

    border-radius: 16px;

    text-align: center;

    box-shadow:
        0 4px 15px rgba(0, 229, 255, 0.1);

    animation: aparecer 0.6s ease;
}

/* Icono */

.icono {
    width: 90px;
    height: 90px;

    margin: 0 auto 18px;

    border-radius: 50%;

    background:
        linear-gradient(
            135deg,
            var(--header-bg),
            var(--accent-cyan)
        );

    border: 3px solid var(--accent-cyan);

    display: flex;
    align-items: center;
    justify-content: center;

    font-size: 45px;

    box-shadow:
        0 0 15px rgba(0, 208, 255, 0.55);
}

/* Título */

.bienvenida h2 {
    color: var(--text-main);

    font-size: 25px;

    font-weight: 600;

    margin-bottom: 10px;
}

/* Texto */

.bienvenida p {
    color: var(--text-muted);

    font-size: 14px;

    line-height: 1.7;

    margin-bottom: 22px;
}

/* =========================
   BOTÓN VER TEMAS
========================= */

#btnTemas {
    border: 1px solid var(--accent-cyan);

    background: rgba(0, 229, 255, 0.08);

    color: var(--accent-cyan);

    padding: 12px 22px;

    border-radius: 12px;

    font-size: 15px;

    font-weight: 600;

    cursor: pointer;

    display: inline-flex;

    align-items: center;

    justify-content: center;

    gap: 8px;

    transition:
        background 0.3s ease,
        transform 0.2s ease,
        box-shadow 0.3s ease;
}

#btnTemas:hover {
    background: rgba(0, 229, 255, 0.16);

    box-shadow:
        0 0 12px rgba(0, 229, 255, 0.2);

    transform: translateY(-2px);
}

#btnTemas:active {
    transform: scale(0.96);
}

#btnTemas .material-symbols-rounded {
    font-size: 21px;
}

/* =========================
   SECCIÓN TEMAS
========================= */

#temas {
    width: 100%;

    display: flex;
    flex-direction: column;

    gap: 18px;
}

/* Título */

.titulo {
    width: 92%;

    margin: 5px auto 2px;

    text-align: center;

    color: var(--accent-cyan);

    font-size: 19px;

    font-weight: bold;

    text-transform: uppercase;

    letter-spacing: 1px;
}

/* Línea debajo del título */

.titulo::after {
    content: "";

    display: block;

    width: 60px;
    height: 3px;

    background: var(--accent-cyan);

    margin: 10px auto 4px;

    border-radius: 10px;

    box-shadow:
        0 0 8px rgba(0, 229, 255, 0.4);
}

/* =========================
   TARJETAS DE TEMAS
========================= */

.tema {
    width: 92%;

    margin: 0 auto;

    background: var(--bg-card);

    border: 1px solid var(--accent-cyan);

    border-radius: 16px;

    padding: 22px 20px;

    display: grid;

    grid-template-columns: 65px 1fr;

    column-gap: 16px;

    row-gap: 16px;

    box-shadow:
        0 4px 15px rgba(0, 229, 255, 0.08);

    transition:
        transform 0.25s ease,
        box-shadow 0.25s ease,
        background 0.25s ease;
}

.tema:hover {
    transform: translateY(-3px);

    background:
        linear-gradient(
            135deg,
            #1a1e3b,
            #1d2345
        );

    box-shadow:
        0 7px 22px rgba(0, 229, 255, 0.14);
}

/* =========================
   ICONO DEL TEMA
========================= */

.temaIcono {
    width: 60px;
    height: 60px;

    border-radius: 16px;

    background:
        rgba(0, 229, 255, 0.08);

    border: 1px solid rgba(0, 229, 255, 0.5);

    display: flex;

    align-items: center;

    justify-content: center;

    font-size: 30px;

    box-shadow:
        inset 0 0 10px rgba(0, 229, 255, 0.04);

    transition:
        transform 0.25s ease,
        background 0.25s ease;
}

.tema:hover .temaIcono {
    transform: scale(1.06);

    background:
        rgba(0, 229, 255, 0.14);
}

/* =========================
   CONTENIDO DEL TEMA
========================= */

.temaContenido {
    min-width: 0;
}

.temaContenido h3 {
    color: var(--text-main);

    font-size: 20px;

    font-weight: 600;

    margin-bottom: 7px;
}

.temaContenido p {
    color: var(--text-muted);

    font-size: 14px;

    line-height: 1.6;

    margin-bottom: 10px;
}

/* Lista */

.temaContenido ul {
    padding-left: 18px;

    margin: 0;
}

.temaContenido li {
    color: var(--text-muted);

    font-size: 13px;

    margin-bottom: 5px;

    line-height: 1.5;
}

.temaContenido li::marker {
    color: var(--accent-cyan);
}

/* =========================
   BOTÓN EXPLORAR
========================= */

.explorar {
    grid-column: 1 / -1;

    width: 100%;

    padding: 13px 16px;

    border-radius: 12px;

    border: 1px solid var(--accent-cyan);

    background:
        rgba(0, 229, 255, 0.08);

    color: var(--accent-cyan);

    text-decoration: none;

    font-size: 15px;

    font-weight: 600;

    display: flex;

    align-items: center;

    justify-content: center;

    gap: 8px;

    transition:
        background 0.3s ease,
        transform 0.2s ease,
        box-shadow 0.3s ease;
}

.explorar:hover {
    background:
        rgba(0, 229, 255, 0.16);

    box-shadow:
        0 0 12px rgba(0, 229, 255, 0.2);

    transform: translateY(-2px);
}

.explorar:active {
    transform: scale(0.97);
}

.explorar .material-symbols-rounded {
    font-size: 21px;

    transition:
        transform 0.2s ease;
}

.explorar:hover .material-symbols-rounded {
    transform: translateX(3px);
}

/* =========================
   CONSEJO
========================= */

.consejo {
    width: 92%;

    margin: 25px auto 0;

    padding: 25px 20px;

    background:
        linear-gradient(
            135deg,
            rgba(0, 229, 255, 0.08),
            var(--bg-card)
        );

    border: 1px solid var(--accent-cyan);

    border-radius: 16px;

    box-shadow:
        0 4px 15px rgba(0, 229, 255, 0.1);

    text-align: center;
}

.consejo h2 {
    color: var(--accent-cyan);

    font-size: 20px;

    margin-bottom: 15px;
}

.consejo p {
    color: var(--text-muted);

    font-size: 14px;

    line-height: 1.7;
}

/* =========================
   ANIMACIONES
========================= */

@keyframes aparecer {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tema {
    animation: aparecer 0.5s ease both;
}

.tema:nth-child(2) {
    animation-delay: 0.08s;
}

.tema:nth-child(3) {
    animation-delay: 0.16s;
}

.tema:nth-child(4) {
    animation-delay: 0.24s;
}

.tema:nth-child(5) {
    animation-delay: 0.32s;
}

/* =========================
   RESPONSIVE
========================= */

@media (max-width: 480px) {

    header {
        min-height: 65px;

        padding: 13px 50px;
    }

    header h1 {
        font-size: 18px;
    }

    header h1 h3 {
        font-size: 10px;
    }

    main {
        padding-top: 15px;
    }

    .bienvenida,
    .tema,
    .consejo {
        width: 92%;
    }

    .bienvenida {
        padding: 25px 17px;
    }

    .bienvenida h2 {
        font-size: 22px;
    }

    .bienvenida p {
        font-size: 13.5px;
    }

    .tema {
        grid-template-columns: 55px 1fr;

        column-gap: 13px;

        padding: 18px 16px;
    }

    .temaIcono {
        width: 52px;
        height: 52px;

        font-size: 26px;

        border-radius: 14px;
    }

    .temaContenido h3 {
        font-size: 18px;
    }

    .temaContenido p {
        font-size: 13px;
    }

    .temaContenido li {
        font-size: 12.5px;
    }

    .explorar {
        font-size: 14px;
    }

    .consejo {
        padding: 22px 17px;
    }

    .consejo p {
        font-size: 13.5px;
    }
}

/* =========================
   PANTALLAS MUY PEQUEÑAS
========================= */

@media (max-width: 360px) {

    .tema {
        grid-template-columns: 1fr;

        text-align: center;
    }

    .temaIcono {
        margin: 0 auto;
    }

    .temaContenido ul {
        text-align: left;
    }

    .temaContenido h3 {
        margin-top: 2px;
    }
}