/* ---
   Hoja de Estilos para "Sucesiones y Progresiones"
   Autor: Gemini para Juank (ElGuruJk)
   Descripción: Estilos modernos con añadidos para el generador de sucesiones.
--- */

/* ======== VARIABLES Y CONFIGURACIÓN GENERAL ======== */
:root {
    --color-bg: #121212;
    --color-surface: #1e1e1e;
    --color-primary: #BB86FC;
    --color-secondary: #03DAC6;
    --color-text: #e0e0e0;
    --color-text-secondary: #a0a0a0;
    --color-border: #333;
}

body.light-mode {
    --color-bg: #f4f4f9;
    --color-surface: #ffffff;
    --color-primary: #6200EE;
    --color-secondary: #018786;
    --color-text: #212121;
    --color-text-secondary: #5f5f5f;
    --color-border: #ddd;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.7;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

h1, h2, h3, h4 {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--color-text);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.2rem; border-bottom: 3px solid var(--color-primary); padding-bottom: 0.5rem; display: inline-block; }
h3 { font-size: 1.5rem; color: var(--color-primary); }
h4 { font-size: 1.2rem; color: var(--color-text-secondary); border-bottom: 1px solid var(--color-border); padding-bottom: 0.5rem; margin-top: 1rem;}


.section-intro {
    max-width: 800px;
    margin: 1rem auto 3rem auto;
    text-align: center;
    font-size: 1.1rem;
    color: var(--color-text-secondary);
}

i.fas {
    margin-right: 0.75rem;
    color: var(--color-secondary);
}

/* ======== HEADER Y PORTADA (HERO) ======== */
.hero {
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('https://images.unsplash.com/photo-1517245386807-bb43f82c33c4?q=80&w=2070&auto=format&fit=crop');
    background-size: cover;
    background-position: center;
    height: 100vh;
    display: flex;
    flex-direction: column;
    text-align: center;
    color: #fff;
}

nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: var(--color-bg); /* o #121212 si preferís hardcodear */
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--color-border);
}


.logo { font-size: 1.5rem; font-weight: 700; }
.theme-switcher { display: flex; align-items: center; gap: 0.5rem; }
.switch { position: relative; display: inline-block; width: 60px; height: 34px; }
.switch input { opacity: 0; width: 0; height: 0; }
.slider { position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0; background-color: #ccc; transition: .4s; }
.slider:before { position: absolute; content: ""; height: 26px; width: 26px; left: 4px; bottom: 4px; background-color: white; transition: .4s; }
input:checked + .slider { background-color: var(--color-primary); }
input:checked + .slider:before { transform: translateX(26px); }
.slider.round { border-radius: 34px; }
.slider.round:before { border-radius: 50%; }

.hero-content { flex-grow: 1; display: flex; flex-direction: column; justify-content: center; align-items: center; }
.hero .subtitle { font-size: 1.5rem; font-weight: 300; margin-bottom: 2rem; }
.cta-button, .cta-button-secondary { display: inline-block; padding: 1rem 2.5rem; border-radius: 50px; text-decoration: none; font-weight: 600; transition: transform 0.3s, background-color 0.3s; cursor: pointer; border: 2px solid var(--color-primary); }
.cta-button { background-color: var(--color-primary); color: #fff; }
.cta-button-secondary { background-color: transparent; color: var(--color-primary); margin-top: 1rem; }
.cta-button:hover, .cta-button-secondary:hover { transform: translateY(-5px); background-color: var(--color-primary); color: var(--color-surface); }

/* ======== SECCIÓN DE CAPAS TEÓRICAS ======== */
.layers-container { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 2rem; }
.layer-card { background-color: var(--color-surface); border: 1px solid var(--color-border); border-radius: 10px; overflow: hidden; transition: transform 0.3s, box-shadow 0.3s; display: flex; flex-direction: column; }
.layer-card:hover { transform: translateY(-10px); box-shadow: 0 10px 20px rgba(0,0,0,0.2); }
.layer-header { background-color: rgba(0,0,0,0.2); padding: 1.5rem; display: flex; align-items: center; }
.layer-header .icon { font-size: 2rem; }
.layer-body { padding: 1.5rem; flex-grow: 1; }

/* ======== SECCIÓN GENERADOR DE SUCESIONES ======== */
.sequence-generator {
    display: grid;
    grid-template-columns: 350px 1fr;
    gap: 2rem;
    background: var(--color-surface);
    padding: 2rem;
    border-radius: 15px;
    border: 1px solid var(--color-border);
}
.controls-panel { display: flex; flex-direction: column; gap: 1rem; }
.input-group { display: flex; flex-direction: column; gap: 0.5rem; }
.input-group label { color: var(--color-text-secondary); font-weight: 600; }
.input-group input, .input-group select {
    width: 100%; padding: 0.8rem; background-color: var(--color-bg); border: 1px solid var(--color-border);
    border-radius: 5px; color: var(--color-text); font-family: 'Poppins', sans-serif; font-size: 1rem;
}

.results-panel { display: flex; flex-direction: column; }
.result-box {
    background-color: var(--color-bg); padding: 1rem; border-radius: 8px; margin-bottom: 1rem;
    font-family: 'Courier New', Courier, monospace; font-size: 1.1rem;
    word-wrap: break-word;
    color: var(--color-secondary);
}

.visualization {
    background-color: var(--color-bg); padding: 1rem; border-radius: 8px; margin-top: 1rem;
    height: 200px; display: flex; align-items: flex-end; gap: 5px;
}
.bar {
    flex-grow: 1;
    background-color: var(--color-primary);
    border-radius: 3px 3px 0 0;
    transition: height 0.3s ease-in-out;
    position: relative;
}
.bar:hover .bar-value { opacity: 1; }
.bar-value {
    position: absolute; bottom: 105%; left: 50%; transform: translateX(-50%);
    background: var(--color-surface); color: var(--color-text); padding: 2px 6px;
    border-radius: 4px; font-size: 0.8rem; opacity: 0; transition: opacity 0.2s;
    white-space: nowrap;
}


/* ======== SECCIÓN APLICACIONES ======== */
.apps-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 1.5rem; }
.app-card { background-color: var(--color-surface); padding: 2rem; text-align: center; border-radius: 10px; border: 1px solid var(--color-border); }
.app-card i { font-size: 3rem; margin-bottom: 1rem; }

/* ======== SECCIÓN QUIZ ======== */
.quiz-question { background: var(--color-surface); padding: 1.5rem; border-radius: 8px; margin-bottom: 1.5rem; border-left: 5px solid var(--color-secondary); }
.quiz-options label { display: block; margin: 0.5rem 0; padding: 0.8rem; background: rgba(255,255,255,0.05); border-radius: 5px; cursor: pointer; transition: background-color 0.3s; }
.quiz-options label:hover { background: rgba(255,255,255,0.1); }
.quiz-options input { margin-right: 1rem; }
.quiz-feedback { margin-top: 2rem; font-size: 1.2rem; font-weight: bold; text-align: center; }
.correct { background-color: #2e7d32 !important; color: white; }
.incorrect { background-color: #c62828 !important; color: white; }

/* ======== FOOTER ======== */
#footer { background-color: var(--color-surface); text-align: center; padding: 3rem 2rem; margin-top: 3rem; border-top: 1px solid var(--color-border); }
#footer ul { list-style: none; padding: 0; margin: 1rem 0; display: flex; justify-content: center; gap: 2rem; flex-wrap: wrap; }
#footer a { color: var(--color-secondary); text-decoration: none; font-weight: 600; }
#footer .copyright { margin-top: 2rem; color: var(--color-text-secondary); font-size: 0.9rem; }

/* ======== RESPONSIVE DESIGN ======== */
@media (max-width: 992px) {
    .sequence-generator { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 1.8rem; }
    .hero { height: auto; padding-bottom: 4rem; }
    .layers-container { grid-template-columns: 1fr; }
}