:root {
    --primary: #4361ee;
    --secondary: #3f37c9;
    --success: #4cc9f0;
    --danger: #f72585;
    --warning: #f8961e;
    --dark: #2b2d42;
    --light: #f8f9fa;
    --bg-color: #f4f6f9;
    --card-bg: #ffffff;
    --text-color: #333333;
    --text-muted: #6c757d;
    --border-color: #e9ecef;
    --wa-color: #25D366;
    --ig-color: #E1306C;
    --fb-color: #1877F2;
    --tk-color: #000000;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    min-height: 100vh;
}

h1, h2, h3, h4 {
    font-family: 'Poppins', sans-serif;
    color: var(--dark);
}

/* Sidebar */
.sidebar {
    width: 280px;
    background-color: var(--card-bg);
    border-right: 1px solid var(--border-color);
    padding: 2rem 1.5rem;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 3rem;
}

.logo img {
    width: 50px;
}

.logo h2 {
    font-size: 1.2rem;
    line-height: 1.2;
    color: var(--primary);
}

.nav-links {
    list-style: none;
}

.nav-links li {
    margin-bottom: 0.5rem;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 15px;
    text-decoration: none;
    color: var(--text-muted);
    border-radius: 10px;
    transition: all 0.3s ease;
    font-weight: 500;
}

.nav-links a:hover, .nav-links a.active {
    background-color: rgba(67, 97, 238, 0.1);
    color: var(--primary);
}

.nav-links a i {
    font-size: 1.2rem;
    width: 24px;
    text-align: center;
}

.nav-links a.wa.active { background-color: rgba(37, 211, 102, 0.1); color: var(--wa-color); }
.nav-links a.ig.active { background-color: rgba(225, 48, 108, 0.1); color: var(--ig-color); }
.nav-links a.fb.active { background-color: rgba(24, 119, 242, 0.1); color: var(--fb-color); }
.nav-links a.tk.active { background-color: rgba(0, 0, 0, 0.1); color: var(--tk-color); }

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 280px;
    padding: 3rem 4rem;
    max-width: 1400px;
}

.section {
    display: none;
    animation: fadeIn 0.5s ease;
}

.section.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.page-header {
    margin-bottom: 3rem;
}

.page-header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.page-header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Introduction Card */
.intro-card {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 20px;
    padding: 3rem;
    color: white;
    margin-bottom: 3rem;
    box-shadow: 0 15px 30px rgba(67, 97, 238, 0.2);
    position: relative;
    overflow: hidden;
}

.intro-card::after {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
}

.intro-card h1 {
    color: white;
    font-size: 2.8rem;
    margin-bottom: 1rem;
}

.student-form {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 2rem;
    margin-top: 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
    opacity: 0.8;
}

.form-group input {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 2px solid rgba(255, 255, 255, 0.5);
    color: white;
    padding: 0.5rem 0;
    font-size: 1.1rem;
    font-family: 'Inter', sans-serif;
    outline: none;
}

.form-group input::placeholder {
    color: rgba(255, 255, 255, 0.3);
}

.form-group input:focus {
    border-color: white;
}

/* Grid & Cards */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--card-bg);
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 15px rgba(0,0,0,0.03);
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
}

.card-icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
}

.card-icon.facebook { background: rgba(24, 119, 242, 0.1); color: var(--fb-color); }
.card-icon.instagram { background: rgba(225, 48, 108, 0.1); color: var(--ig-color); }
.card-icon.tiktok { background: rgba(0, 0, 0, 0.1); color: var(--tk-color); }
.card-icon.whatsapp { background: rgba(37, 211, 102, 0.1); color: var(--wa-color); }

.list-group {
    list-style: none;
    margin-top: 1rem;
}

.list-group li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 10px;
}

.list-group li:last-child {
    border-bottom: none;
}

.list-group li i {
    color: var(--primary);
    font-size: 0.8rem;
}

/* Exercise Styles */
.exercise-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 3rem;
    margin-bottom: 4rem;
    background: var(--card-bg);
    border-radius: 20px;
    padding: 3rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.03);
}

.exercise-content h2 {
    color: var(--primary);
    font-size: 1.2rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 0.5rem;
}

.exercise-content h3 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
}

.objective {
    background: rgba(67, 97, 238, 0.05);
    padding: 1rem 1.5rem;
    border-left: 4px solid var(--primary);
    border-radius: 0 10px 10px 0;
    margin-bottom: 1.5rem;
    font-weight: 500;
}

.task-list {
    list-style: none;
    margin-bottom: 2rem;
}

.task-list li {
    margin-bottom: 1rem;
    position: relative;
    padding-left: 1.5rem;
}

.task-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
    font-size: 1.2rem;
}

/* Mockups - Universal */
.mockup-container {
    display: flex;
    justify-content: center;
    align-items: center;
    background: var(--bg-color);
    border-radius: 15px;
    padding: 2rem;
}

/* Phone Mockup */
.phone-mockup {
    width: 320px;
    height: 650px;
    background: #000;
    border-radius: 40px;
    padding: 12px;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5);
    position: relative;
}

.phone-screen {
    background: #fff;
    width: 100%;
    height: 100%;
    border-radius: 30px;
    overflow: hidden;
    position: relative;
}

.phone-notch {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 120px;
    height: 25px;
    background: #000;
    border-bottom-left-radius: 15px;
    border-bottom-right-radius: 15px;
    z-index: 20;
}

/* WhatsApp UI */
.wa-ui {
    background: #efeae2;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.wa-header {
    background: #008069;
    color: white;
    padding: 35px 15px 15px;
    display: flex;
    align-items: center;
    gap: 10px;
    z-index: 10;
}

.wa-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: #ccc;
    object-fit: cover;
}

.wa-header-info h4 {
    color: white;
    font-family: 'Inter', sans-serif;
    font-size: 16px;
    margin: 0;
}

.wa-header-info p {
    font-size: 12px;
    opacity: 0.8;
}

.wa-chat-container {
    padding: 15px;
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.wa-bubble {
    max-width: 85%;
    padding: 8px 12px;
    border-radius: 10px;
    font-size: 14px;
    position: relative;
    box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.wa-bubble.in {
    background: #fff;
    align-self: flex-start;
    border-top-left-radius: 0;
}

.wa-bubble.out {
    background: #d9fdd3;
    align-self: flex-end;
    border-top-right-radius: 0;
}

.wa-time {
    display: block;
    font-size: 10px;
    color: #888;
    text-align: right;
    margin-top: 5px;
}

.wa-business-profile {
    background: #fff;
    height: 100%;
    overflow-y: auto;
}

.wa-profile-header {
    height: 150px;
    background: url('https://images.unsplash.com/photo-1497215728101-856f4ea42174?auto=format&fit=crop&q=80&w=400') center/cover;
    position: relative;
}

.wa-profile-info {
    padding: 20px;
    text-align: center;
    margin-top: -50px;
}

.wa-profile-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    border: 4px solid #fff;
    margin: 0 auto 10px;
    background: #fff;
    object-fit: contain;
    padding: 5px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.wa-section {
    padding: 15px 20px;
    border-top: 10px solid #f2f2f2;
}
.wa-section h5 { color: #667781; margin-bottom: 10px; font-weight: 500;}
.wa-section p { font-size: 14px; display: flex; align-items: flex-start; gap: 10px; margin-bottom: 10px; color: #111b21; }
.wa-section i { color: #8696a0; margin-top: 2px;}

.wa-catalog-item {
    display: flex;
    gap: 15px;
    margin-bottom: 15px;
}
.wa-catalog-item img {
    width: 80px;
    height: 80px;
    border-radius: 10px;
    object-fit: cover;
}
.wa-catalog-details h6 { font-size: 15px; margin-bottom: 5px; }
.wa-catalog-details .price { color: #008069; font-weight: bold; }

/* Instagram UI */
.ig-ui { background: #fff; height: 100%; display: flex; flex-direction: column; }
.ig-header { padding: 35px 15px 10px; border-bottom: 1px solid #dbdbdb; display: flex; justify-content: space-between; align-items: center; font-weight: bold; }
.ig-profile-top { padding: 20px 15px; display: flex; align-items: center; gap: 20px; }
.ig-avatar-ring {
    width: 86px; height: 86px; border-radius: 50%;
    background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
    display: flex; align-items: center; justify-content: center;
}
.ig-avatar-ring img { width: 78px; height: 78px; border-radius: 50%; border: 3px solid #fff; object-fit: cover; background: #fff;}
.ig-stats { flex: 1; display: flex; justify-content: space-around; text-align: center; }
.ig-stats .num { font-weight: bold; font-size: 16px; display: block; }
.ig-stats .label { font-size: 12px; color: #262626; }
.ig-bio { padding: 0 15px 15px; font-size: 14px; line-height: 1.4; }
.ig-bio .name { font-weight: bold; }
.ig-bio .category { color: #8e8e8e; margin-bottom: 4px; }
.ig-btn-group { padding: 0 15px; display: flex; gap: 8px; margin-bottom: 15px;}
.ig-btn { flex: 1; background: #efefef; color: #262626; text-align: center; padding: 6px 0; border-radius: 8px; font-weight: 600; font-size: 14px; border: none; }
.ig-btn.primary { background: #0095f6; color: white; }

.ig-post { border-bottom: 1px solid #efefef; padding-bottom: 10px;}
.ig-post-header { padding: 10px 15px; display: flex; align-items: center; gap: 10px; }
.ig-post-header img { width: 32px; height: 32px; border-radius: 50%; object-fit: cover;}
.ig-post-image { width: 100%; height: 320px; object-fit: cover; }
.ig-post-actions { padding: 10px 15px; display: flex; gap: 15px; font-size: 24px; }
.ig-post-caption { padding: 0 15px; font-size: 14px; }

/* Facebook UI (Desktop Mockup) */
.desktop-mockup {
    width: 100%;
    max-width: 800px;
    background: #f0f2f5;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    overflow: hidden;
    border: 1px solid #e4e6eb;
}
.browser-bar {
    height: 40px; background: #fff; border-bottom: 1px solid #e4e6eb;
    display: flex; align-items: center; padding: 0 15px; gap: 15px;
}
.browser-dots { display: flex; gap: 6px; }
.browser-dots span { width: 12px; height: 12px; border-radius: 50%; background: #ff5f56; }
.browser-dots span:nth-child(2) { background: #ffbd2e; }
.browser-dots span:nth-child(3) { background: #27c93f; }
.browser-url { background: #f0f2f5; border-radius: 20px; height: 24px; flex: 1; margin: 0 20px; }

.fb-cover { height: 250px; background: url('https://images.unsplash.com/photo-1516321318423-f06f85e504b3?auto=format&fit=crop&q=80&w=1000') center/cover; position: relative;}
.fb-cover-content { position: absolute; bottom: -60px; left: 40px; display: flex; align-items: flex-end; gap: 20px; width: calc(100% - 80px); }
.fb-avatar { width: 168px; height: 168px; border-radius: 50%; border: 4px solid #fff; object-fit: cover; background:#fff;}
.fb-title-area { padding-bottom: 15px; flex: 1; }
.fb-title-area h1 { font-size: 32px; margin: 0; color: #1c1e21;}
.fb-title-area p { color: #65676b; font-size: 15px; font-weight: 500;}
.fb-actions { padding-bottom: 15px; display: flex; gap: 10px; }
.fb-btn { padding: 8px 16px; border-radius: 6px; font-weight: 600; font-size: 15px; border: none; cursor: pointer; display: flex; align-items: center; gap: 8px;}
.fb-btn-blue { background: #1b74e4; color: white; }
.fb-btn-gray { background: #e4e6eb; color: #050505; }
.fb-nav { display: flex; gap: 20px; padding: 75px 40px 0; border-bottom: 1px solid #ced0d4; background: #fff;}
.fb-nav-item { padding: 15px 0; font-weight: 600; color: #65676b; position: relative; }
.fb-nav-item.active { color: #1b74e4; }
.fb-nav-item.active::after { content: ''; position: absolute; bottom: 0; left: 0; width: 100%; height: 3px; background: #1b74e4; }

/* TikTok UI */
.tk-ui { background: #000; height: 100%; color: white; position: relative; }
.tk-video-bg { position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: url('https://images.unsplash.com/photo-1522202176988-66273c2fd55f?auto=format&fit=crop&q=80&w=400') center/cover; opacity: 0.6; }
.tk-content { position: absolute; bottom: 0; left: 0; right: 0; padding: 20px; background: linear-gradient(transparent, rgba(0,0,0,0.8)); z-index: 10; }
.tk-user { font-weight: bold; font-size: 16px; margin-bottom: 8px;}
.tk-caption { font-size: 14px; margin-bottom: 8px;}
.tk-music { font-size: 13px; display: flex; align-items: center; gap: 8px; }
.tk-actions { position: absolute; right: 15px; bottom: 80px; display: flex; flex-direction: column; gap: 20px; align-items: center; z-index: 10; }
.tk-action-item { display: flex; flex-direction: column; align-items: center; gap: 5px; font-size: 12px; font-weight: 600; }
.tk-action-item i { font-size: 28px; }
.tk-hook-overlay { position: absolute; top: 30%; left: 50%; transform: translateX(-50%); background: rgba(0,0,0,0.7); padding: 15px; border-radius: 10px; width: 80%; text-align: center; font-weight: bold; font-size: 18px; border: 2px solid var(--primary); z-index: 15; box-shadow: 0 0 20px var(--primary);}

/* Extras for mockups */
.badge { display: inline-block; padding: 3px 8px; background: #f0f2f5; border-radius: 12px; font-size: 12px; font-weight: 600; margin-right: 5px; margin-bottom: 5px;}
.tag { padding: 4px 10px; border-radius: 15px; font-size: 12px; font-weight: bold; color: white;}
.tag.nuevo { background: #25d366; }
.tag.interesado { background: #f5a623; }
.tag.pago { background: #d0021b; }

/* Responsive */
@media (max-width: 1024px) {
    .exercise-wrapper {
        grid-template-columns: 1fr;
        gap: 2rem;
        padding: 2rem;
    }
    .exercise-content, .mockup-container {
        grid-column: 1 / -1 !important;
        grid-row: auto !important;
        margin-top: 0 !important;
    }
    .mockup-container {
        padding: 1rem;
    }
}

@media (max-width: 768px) {
    body {
        display: block;
    }
    .sidebar { 
        width: 100%; 
        height: auto; 
        position: sticky; 
        top: 0; 
        padding: 1rem; 
        z-index: 1000;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        box-shadow: 0 4px 10px rgba(0,0,0,0.05);
    }
    .logo {
        margin-bottom: 1rem;
        justify-content: center;
    }
    .logo h2 {
        font-size: 1rem;
    }
    .nav-links { 
        display: flex; 
        flex-wrap: wrap; /* Permite que los botones bajen a la siguiente línea */
        justify-content: center;
        gap: 8px; 
        padding-bottom: 5px;
    }
    .nav-links li {
        margin-bottom: 0;
    }
    .nav-links a {
        padding: 6px 12px;
        font-size: 0.85rem; /* Letra un poco más ajustada */
    }
    .nav-links a i {
        font-size: 1rem;
    }
    .main-content { 
        margin-left: 0; 
        padding: 1.5rem 1rem; 
    }
    
    .grid-2 {
        grid-template-columns: 1fr;
    }
    
    .intro-card {
        padding: 2rem 1.5rem;
    }
    
    .intro-card h1 {
        font-size: 2rem;
    }
    
    .page-header h1 {
        font-size: 1.8rem;
    }
    
    .student-form {
        grid-template-columns: 1fr;
    }

    .phone-mockup {
        width: 100%;
        max-width: 320px;
    }
    
    .desktop-mockup {
        border-radius: 8px;
    }

    .fb-cover-content {
        position: relative;
        bottom: auto;
        left: auto;
        margin-top: -60px;
        flex-direction: column;
        align-items: center;
        text-align: center;
        width: 100%;
        gap: 15px;
    }

    .fb-avatar {
        width: 140px;
        height: 140px;
    }

    .fb-title-area h1 {
        font-size: 24px;
    }

    .fb-nav {
        padding: 20px 15px 0;
        overflow-x: auto;
    }

    .tk-hook-overlay {
        width: 90%;
        font-size: 16px;
        padding: 10px;
    }

    .list-group {
        display: flex !important;
        flex-direction: column;
        grid-template-columns: 1fr !important;
    }
}