/* ================================================
   CANALES — Hoja de estilos principal
   ================================================ */

/* --- Variables de diseño --- */
:root {
    --azul-oscuro: #0b1d33;
    --azul-medio: #1a4a6e;
    --azul-claro: #2980b9;
    --verde-azulado: #1a6b52;
    --verde: #27ae60;
    --blanco: #ffffff;
    --gris-claro: #f0f2f5;
    --gris-medio: #dde1e6;
    --gris-oscuro: #5a6572;
    --texto-oscuro: #1e2a35;
    --texto-medio: #4a5568;
    --resultado-fondo: #eef5ec;
    --error: #c0392b;
    --borde: #c8ced5;
    --sombra: 0 2px 8px rgba(0,0,0,0.10);
    --radio: 4px;
    --fuente: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

/* --- Reset --- */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 15px;
}

body {
    font-family: var(--fuente);
    color: var(--texto-oscuro);
    background: var(--gris-claro);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a { text-decoration: none; color: inherit; }
ul { list-style: none; }


/* ================================================
   CABECERA Y NAVEGACIÓN
   ================================================ */
.cabecera {
    background: var(--azul-oscuro);
    box-shadow: 0 2px 6px rgba(0,0,0,0.3);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.cabecera-contenido {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    padding: 0 1rem;
    height: 52px;
    position: relative;
}

.logo {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--blanco);
    letter-spacing: 2px;
    margin-right: 2rem;
    white-space: nowrap;
}

/* Botón hamburguesa (oculto en PC) */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    margin-left: auto;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 3px;
    background: var(--blanco);
    border-radius: 2px;
    transition: all 0.3s;
}

.menu-toggle.abierto span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 6px);
}
.menu-toggle.abierto span:nth-child(2) {
    opacity: 0;
}
.menu-toggle.abierto span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -6px);
}

/* Menú nivel 1 */
.nav-principal {
    flex: 1;
}

.menu-nivel1 {
    display: flex;
    gap: 0;
}

.menu-nivel1 > li {
    position: relative;
}

.menu-nivel1 > li > a {
    display: block;
    padding: 0.9rem 1rem;
    color: rgba(255,255,255,0.85);
    font-size: 0.88rem;
    font-weight: 500;
    transition: background 0.2s, color 0.2s;
    white-space: nowrap;
}

.menu-nivel1 > li > a:hover,
.menu-nivel1 > li.activo > a {
    background: rgba(255,255,255,0.1);
    color: var(--blanco);
}

/* Submenú nivel 2 */
.menu-nivel2 {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: var(--azul-oscuro);
    border-top: 2px solid var(--azul-claro);
    min-width: 290px;
    box-shadow: var(--sombra);
    z-index: 1001;
}

.menu-nivel1 > li.tiene-submenu:hover > .menu-nivel2 {
    display: block;
}

.menu-nivel2 li a {
    display: block;
    padding: 0.6rem 1.2rem;
    color: rgba(255,255,255,0.8);
    font-size: 0.84rem;
    transition: background 0.15s, color 0.15s;
    border-left: 3px solid transparent;
}

.menu-nivel2 li a:hover {
    background: rgba(255,255,255,0.08);
    color: var(--blanco);
    border-left-color: var(--azul-claro);
}


/* ================================================
   CONTENEDOR PRINCIPAL
   ================================================ */
.contenedor-principal {
    flex: 1;
    max-width: 1400px;
    width: 100%;
    margin: 0 auto;
    padding: 1rem;
}


/* ================================================
   PANTALLA MENÚ PRINCIPAL
   ================================================ */
.menu-pantalla {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: calc(100vh - 52px - 50px);
    background: linear-gradient(135deg, #0d2137 0%, #1a4a6e 35%, #1a6b52 70%, #27ae60 100%);
    border-radius: var(--radio);
    overflow: hidden;
    position: relative;
    margin: -1rem;
    padding: 3rem 2rem;
}

.menu-pantalla::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at 20% 80%, rgba(39,174,96,0.3) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(41,128,185,0.25) 0%, transparent 50%);
    pointer-events: none;
}

.menu-pantalla-contenido {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 680px;
}

.menu-pantalla-contenido h1 {
    font-size: 3rem;
    font-weight: 800;
    color: var(--blanco);
    letter-spacing: 4px;
    margin-bottom: 0.4rem;
}

.menu-pantalla-contenido h2 {
    font-size: 1.15rem;
    font-weight: 400;
    color: rgba(255,255,255,0.8);
    margin-bottom: 2rem;
}

.menu-pantalla-contenido p {
    font-size: 0.95rem;
    line-height: 1.7;
    color: rgba(255,255,255,0.72);
    margin-bottom: 0.8rem;
}


/* ================================================
   LAYOUT MÓDULOS DE CÁLCULO
   ================================================ */
.modulo-calculo {
    display: flex;
    gap: 1.5rem;
    align-items: flex-start;
}

.panel-formulario {
    flex: 1;
    min-width: 0;
    background: var(--blanco);
    border-radius: var(--radio);
    box-shadow: var(--sombra);
    overflow: hidden;
}

.panel-svg {
    flex: 0 0 380px;
    background: var(--blanco);
    border-radius: var(--radio);
    box-shadow: var(--sombra);
    padding: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 420px;
}

.panel-svg svg {
    max-width: 100%;
    height: auto;
}


/* --- Título del módulo --- */
.modulo-titulo {
    background: var(--azul-medio);
    color: var(--blanco);
    padding: 0.8rem 1.2rem;
    font-size: 1rem;
    font-weight: 600;
}


/* --- Secciones --- */
.seccion {
    padding: 1rem 1.2rem;
}

.seccion-titulo {
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--gris-oscuro);
    margin-bottom: 0.8rem;
    padding-bottom: 0.4rem;
    border-bottom: 2px solid var(--gris-medio);
}

.seccion-resultados {
    background: var(--resultado-fondo);
    border-top: 1px solid var(--gris-medio);
}

.seccion-error {
    background: #fdecea;
    border-top: 1px solid #e57373;
    color: var(--error);
    font-weight: 600;
    font-size: 0.9rem;
}

.mensaje-error {
    color: var(--error);
    font-weight: 600;
    margin-bottom: 0.5rem;
}


/* --- Filas de campos --- */
.fila-campo {
    display: flex;
    align-items: center;
    margin-bottom: 0.5rem;
    gap: 0.5rem;
}

.fila-campo label {
    flex: 0 0 auto;
    font-size: 0.88rem;
    color: var(--texto-medio);
    white-space: nowrap;
}

.fila-campo input {
    flex: 1;
    max-width: 140px;
    padding: 0.45rem 0.6rem;
    border: 1px solid var(--borde);
    border-radius: var(--radio);
    font-size: 0.9rem;
    font-family: var(--fuente);
    text-align: right;
    transition: border-color 0.2s;
}

.fila-campo input:focus {
    outline: none;
    border-color: var(--azul-claro);
    box-shadow: 0 0 0 2px rgba(41,128,185,0.2);
}

.fila-campo input[readonly] {
    background: var(--resultado-fondo);
    border-color: var(--gris-medio);
    color: var(--texto-oscuro);
    font-weight: 600;
}

.fila-campo .unidad {
    flex: 0 0 auto;
    font-size: 0.82rem;
    color: var(--gris-oscuro);
    min-width: 35px;
}

.campo-descripcion {
    margin-bottom: 0.8rem;
}

.campo-descripcion label {
    display: block;
    font-size: 0.88rem;
    color: var(--texto-medio);
    margin-bottom: 0.3rem;
}

.campo-descripcion input {
    width: 100%;
    padding: 0.45rem 0.6rem;
    border: 1px solid var(--borde);
    border-radius: var(--radio);
    font-size: 0.9rem;
    font-family: var(--fuente);
    transition: border-color 0.2s;
}

.campo-descripcion input:focus {
    outline: none;
    border-color: var(--azul-claro);
    box-shadow: 0 0 0 2px rgba(41,128,185,0.2);
}


/* --- Botones --- */
.botones {
    display: flex;
    gap: 0.8rem;
    padding: 1rem 1.2rem;
    border-top: 1px solid var(--gris-medio);
}

.btn {
    padding: 0.6rem 1.8rem;
    border: none;
    border-radius: var(--radio);
    font-size: 0.9rem;
    font-weight: 600;
    font-family: var(--fuente);
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

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

.btn-calcular {
    background: var(--azul-claro);
    color: var(--blanco);
}

.btn-calcular:hover {
    background: #2471a3;
}

.btn-limpiar {
    background: var(--gris-medio);
    color: var(--texto-oscuro);
}

.btn-limpiar:hover {
    background: #c0c6cc;
}


/* ================================================
   PANTALLA DE AYUDA
   ================================================ */
.ayuda-contenido {
    background: var(--blanco);
    border-radius: var(--radio);
    box-shadow: var(--sombra);
    padding: 2rem;
    line-height: 1.8;
}

.ayuda-contenido h2 {
    color: var(--azul-medio);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.ayuda-contenido h3 {
    color: var(--azul-oscuro);
    margin: 1.5rem 0 0.5rem;
    font-size: 1.05rem;
}

.ayuda-contenido p {
    margin-bottom: 0.8rem;
}

.ayuda-contenido ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
    list-style: disc;
}

.ayuda-contenido li {
    margin-bottom: 0.3rem;
}


/* ================================================
   PIE DE PÁGINA
   ================================================ */
.pie {
    text-align: center;
    padding: 0.8rem 1rem;
    font-size: 0.78rem;
    color: var(--gris-oscuro);
    background: var(--blanco);
    border-top: 1px solid var(--gris-medio);
}

.pie-legal {
    font-size: 0.7rem;
    color: #888;
    max-width: 900px;
    margin: 0 auto;
    line-height: 1.4;
}


/* ================================================
   RESPONSIVE — TABLET Y MÓVIL (≤ 1024px)
   ================================================ */

@media (max-width: 1024px) {
    .modulo-calculo {
        flex-direction: column;
    }

    .panel-svg {
        flex: none;
        width: 100%;
        min-height: 300px;
    }

    .menu-toggle {
        display: flex;
    }

    .nav-principal {
        display: none;
        position: absolute;
        top: 52px;
        left: 0;
        right: 0;
        background: var(--azul-oscuro);
        box-shadow: 0 4px 10px rgba(0,0,0,0.4);
        max-height: calc(100vh - 52px);
        overflow-y: auto;
        z-index: 1001;
        -webkit-overflow-scrolling: touch;
    }

    .nav-principal.abierto {
        display: block !important;
    }

    .menu-nivel1 {
        flex-direction: column;
    }

    .menu-nivel1 > li > a {
        padding: 1rem 1.2rem;
        border-bottom: 1px solid rgba(255,255,255,0.06);
        font-size: 1rem;
    }

    /* Submenú: oculto por defecto */
    .menu-nivel2 {
        display: none;
        position: static;
        background: rgba(0,0,0,0.2);
        border-top: none;
        min-width: auto;
        box-shadow: none;
    }

    /* Clase controlada por JavaScript para desplegar el submenú */
    .menu-nivel2.abierto {
        display: block !important;
    }

    .menu-nivel2 li a {
        padding: 0.8rem 2rem;
        border-left: none;
        font-size: 0.95rem;
    }
}


/* ================================================
   RESPONSIVE — MÓVIL PEQUEÑO (≤ 600px)
   ================================================ */
@media (max-width: 600px) {
    html {
        font-size: 14px;
    }

    .menu-pantalla {
        min-height: calc(100vh - 52px - 44px);
        padding: 2rem 1.5rem;
        margin: -1rem;
    }

    .menu-pantalla-contenido h1 {
        font-size: 2.2rem;
    }

    /* Formularios */
    .fila-campo {
        flex-wrap: wrap;
    }

    .fila-campo input {
        max-width: 100%;
    }

    .botones {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        text-align: center;
    }

    .ayuda-contenido {
        padding: 1.2rem;
    }
@media (max-width: 1024px) {
    .nav-principal.abierto {
        display: block !important;
    }

    .menu-nivel2.abierto {
        display: block !important;
    }
}
}