:root {
    --bg-color: #0a0b10;
    --card-bg: rgba(25, 28, 40, 0.7);
    --accent-color: #00f0ff;
    --text-main: #ffffff;
    --text-muted: #94a3b8;
    --border-color: rgba(255, 255, 255, 0.08);
    --nav-bg: rgba(10, 11, 16, 0.85);
    --logo-core: #ffffff;
    --input-bg: rgba(15, 17, 23, 0.6);
}

[data-theme="light"] {
    --bg-color: #f8fafc;
    --card-bg: rgba(255, 255, 255, 0.85);
    --accent-color: #0284c7;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border-color: rgba(0, 0, 0, 0.08);
    --nav-bg: rgba(248, 250, 252, 0.85);
    --logo-core: #0f172a;
    --input-bg: rgba(241, 245, 249, 0.8);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    padding: 0 1.5rem;
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: absolute;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-color) 0%, rgba(0,0,0,0) 70%);
    opacity: 0.12;
    top: 5%;
    left: 50%;
    transform: translateX(-50%);
    z-index: -1;
}

/* Barra de Navegación */
nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--nav-bg);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2.5rem;
    z-index: 1000;
}

.nav-brand-group {
    display: flex;
    flex-direction: column;
}

.nav-logo {
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: 1px;
    color: var(--text-main);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-logo span {
    color: var(--accent-color);
}

.nav-logo svg .logo-inner {
    stroke: var(--logo-core);
}

.home-sublink {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-decoration: none;
    margin-top: 2px;
    transition: color 0.2s;
}

.home-sublink:hover {
    color: var(--accent-color);
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    list-style: none;
    align-items: center;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover, .nav-links a.active {
    color: var(--accent-color);
}

.nav-controls {
    display: flex;
    gap: 0.75rem;
    align-items: center;
}

.control-btn, .lang-selector {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    font-size: 0.85rem;
    cursor: pointer;
    backdrop-filter: blur(10px);
    outline: none;
}

.control-btn:hover, .lang-selector:hover {
    border-color: var(--accent-color);
}

/* Contenido Principal */
.container {
    max-width: 1100px;
    width: 100%;
    margin-top: 16vh;
    margin-bottom: 4rem;
    text-align: center;
}

.header-section {
    margin-bottom: 3.5rem;
}

h1 {
    font-size: 3.2rem;
    letter-spacing: 2px;
    margin-bottom: 0.75rem;
    font-weight: 800;
}

h1 span {
    color: var(--accent-color);
    text-shadow: 0 0 20px rgba(0, 240, 255, 0.3);
}

.tagline {
    font-size: 1.1rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 3px;
}

.hub-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    align-items: stretch;
}

.hub-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 2.5rem 2rem;
    box-shadow: 0 15px 35px rgba(0,0,0,0.2);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    text-decoration: none;
    color: inherit;
    transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
    text-align: left;
}

.hub-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-color);
    box-shadow: 0 20px 40px rgba(0, 240, 255, 0.15);
}

.card-icon {
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    display: flex;
    justify-content: center;
}

.hub-card h3 {
    font-size: 1.35rem;
    color: var(--text-main);
    margin-bottom: 0.75rem;
    font-weight: 700;
}

.hub-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 2rem;
}

.card-action {
    color: var(--accent-color);
    font-weight: 700;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
}

/* Footer */
footer {
    width: 100%;
    max-width: 1100px;
    border-top: 1px solid var(--border-color);
    padding: 1.5rem 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: var(--accent-color);
}

@media (max-width: 768px) {
    .nav-links { display: none; }
    h1 { font-size: 2.3rem; }
    footer { flex-direction: column; text-align: center; justify-content: center; }
}