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

/* Variables CSS para temas */
:root {
    /* Tema Oscuro (por defecto) */
    --bg-gradient-dark: linear-gradient(135deg, #000000 0%, #1c1c1e 50%, #2c2c2e 100%);
    --bg-gradient-light: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 50%, #dee2e6 100%);
    --text-color-dark: #f2f2f7;
    --text-color-light: #1c1c1e;
    --container-bg-dark: rgba(28, 28, 30, 0.8);
    --container-bg-light: rgba(255, 255, 255, 0.9);
    --accent-color: #007aff;
    --accent-secondary: #5856d6;
    --highlight-color: #ff9f0a;
    --section-bg-dark: rgba(44, 44, 46, 0.6);
    --section-bg-light: rgba(248, 249, 250, 0.8);
    --border-color-dark: rgba(255, 255, 255, 0.08);
    --border-color-light: rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg-gradient-dark);
    color: var(--text-color-dark);
    line-height: 1.7;
    min-height: 100vh;
    padding: 0;
    margin: 0;
    position: relative;
    transition: all 0.3s ease;
}

/* Efecto de partículas de fondo estilo Apple */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(120, 119, 198, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 69, 58, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(48, 209, 88, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: -1;
    transition: opacity 0.3s ease;
}

/* Tema claro */
body.light {
    background: var(--bg-gradient-light);
    color: var(--text-color-light);
}

body.light::before {
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(0, 122, 255, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 69, 58, 0.05) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(48, 209, 88, 0.05) 0%, transparent 50%);
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px;
    background: var(--container-bg-dark);
    backdrop-filter: blur(20px);
    border-radius: 20px;
    margin-top: 40px;
    margin-bottom: 40px;
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.4),
        0 0 0 1px rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color-dark);
    animation: fadeInUp 0.8s ease-out;
    transition: all 0.3s ease;
}

body.light .container {
    background: var(--container-bg-light);
    box-shadow: 
        0 20px 40px rgba(0, 0, 0, 0.1),
        0 0 0 1px rgba(0, 0, 0, 0.05);
    border: 1px solid var(--border-color-light);
}

h1 {
    color: var(--accent-color);
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    text-align: center;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: 0 0 30px rgba(0, 122, 255, 0.3);
    position: relative;
}

h1::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-secondary));
    border-radius: 2px;
    box-shadow: 0 0 10px rgba(0, 122, 255, 0.5);
}

h2, h3 {
    color: var(--accent-secondary);
    font-size: 1.5rem;
    font-weight: 600;
    margin: 30px 0 15px 0;
    padding: 15px 20px;
    background: rgba(0, 122, 255, 0.08);
    border-radius: 12px;
    border-left: 4px solid var(--accent-color);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

body.light h2, body.light h3 {
    background: rgba(0, 122, 255, 0.05);
}

h2::before, h3::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 122, 255, 0.1), transparent);
    transition: left 0.5s ease;
}

h2:hover::before, h3:hover::before {
    left: 100%;
}

h2:hover, h3:hover {
    background: rgba(0, 122, 255, 0.12);
    transform: translateX(5px);
    box-shadow: 0 5px 20px rgba(0, 122, 255, 0.2);
}

body.light h2:hover, body.light h3:hover {
    background: rgba(0, 122, 255, 0.08);
}

h3 {
    font-size: 1.3rem;
    padding: 12px 15px;
}

p {
    margin-bottom: 16px;
    color: #e5e5e7;
    font-size: 1.1rem;
    text-align: justify;
    padding: 0 10px;
    line-height: 1.8;
    transition: color 0.3s ease;
}

body.light p {
    color: #374151;
}

p em {
    color: #8e8e93;
    font-style: italic;
    text-align: center;
    display: block;
    margin-bottom: 30px;
    padding: 15px;
    background: rgba(142, 142, 147, 0.1);
    border-radius: 12px;
    border: 1px solid rgba(142, 142, 147, 0.2);
    backdrop-filter: blur(10px);
}

body.light p em {
    color: #6b7280;
    background: rgba(107, 114, 128, 0.1);
    border: 1px solid rgba(107, 114, 128, 0.2);
}

strong {
    color: var(--highlight-color);
    font-weight: 600;
    text-shadow: 0 0 5px rgba(255, 159, 10, 0.3);
}

ul {
    margin: 16px 0;
    padding-left: 30px;
}

li {
    margin-bottom: 8px;
    color: #d1d5db;
    font-size: 1.05rem;
    line-height: 1.7;
    transition: color 0.3s ease;
}

body.light li {
    color: #4b5563;
}

pre {
    background: var(--section-bg-dark);
    border-radius: 16px;
    border: 1px solid var(--border-color-dark);
    padding: 25px;
    margin: 20px 0;
    white-space: pre-wrap;
    word-wrap: break-word;
    color: #e5e5e7;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.6;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
}

body.light pre {
    background: var(--section-bg-light);
    border: 1px solid var(--border-color-light);
    color: #374151;
}

pre::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(0, 122, 255, 0.5), transparent);
}

pre:hover {
    background: rgba(44, 44, 46, 0.8);
    transform: translateY(-2px);
    box-shadow: 
        0 15px 35px rgba(0, 0, 0, 0.3),
        0 0 0 1px rgba(0, 122, 255, 0.1);
}

body.light pre:hover {
    background: rgba(248, 249, 250, 0.9);
    box-shadow: 
        0 15px 35px rgba(0, 0, 0, 0.1),
        0 0 0 1px rgba(0, 122, 255, 0.1);
}

/* Controles de idioma y tema */
.controls {
    position: fixed;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 10px;
    z-index: 1000;
}

.control-btn {
    background: rgba(28, 28, 30, 0.9);
    color: var(--text-color-dark);
    border: 2px solid var(--accent-color);
    padding: 12px 18px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(0, 122, 255, 0.2);
}

body.light .control-btn {
    background: rgba(255, 255, 255, 0.9);
    color: var(--text-color-light);
}

.control-btn:hover {
    background: var(--accent-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 122, 255, 0.4);
}

/* Sistema de idiomas */
.lang-es { 
    display: none; 
}

:lang(es) .lang-es { 
    display: block; 
}

:lang(es) .lang-en { 
    display: none; 
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        margin: 20px;
        padding: 30px 20px;
        border-radius: 15px;
    }

    h1 {
        font-size: 2rem;
    }

    h2, h3 {
        font-size: 1.3rem;
        padding: 12px 15px;
    }

    p {
        font-size: 1rem;
        padding: 0 5px;
    }

    .controls {
        top: 10px;
        right: 10px;
        gap: 8px;
    }

    .control-btn {
        padding: 10px 14px;
        font-size: 12px;
    }
}

/* Animaciones */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.7;
    }
}

/* Efectos adicionales para compatibilidad con WebKit */
@supports (-webkit-backdrop-filter: blur(10px)) {
    .container {
        -webkit-backdrop-filter: blur(20px);
    }
    
    .control-btn {
        -webkit-backdrop-filter: blur(10px);
    }
    
    p em {
        -webkit-backdrop-filter: blur(10px);
    }
}