/* style.css */
:root {
    /* Color Palette - Outskill AI Upskilling Theme */
    --bg: #09090E; 
    --surface: #12121D; 
    --surface-hover: #1A1A2A;
    --text: #F8FAFC;
    --text-muted: #94A3B8;
    
    /* Vibrant EdTech/AI Accents */
    --accent: #6366F1; 
    --accent-hover: #818CF8;
    --accent-glow: rgba(99, 102, 241, 0.4);
    --gradient-start: #6366F1;
    --gradient-end: #D946EF; 
    
    --border: #2A2A40;
    --border-light: rgba(255, 255, 255, 0.08);
    
    /* System Status */
    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;

    /* Typography */
    --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    
    --step--1: clamp(0.88rem, calc(0.84rem + 0.18vw), 0.95rem);
    --step-0: clamp(1.00rem, calc(0.96rem + 0.22vw), 1.13rem);
    --step-1: clamp(1.13rem, calc(1.08rem + 0.26vw), 1.27rem);
    --step-2: clamp(1.27rem, calc(1.20rem + 0.36vw), 1.42rem);
    --step-3: clamp(1.42rem, calc(1.33rem + 0.46vw), 1.60rem);
    --step-4: clamp(1.60rem, calc(1.47rem + 0.65vw), 1.95rem);
    --step-5: clamp(2.49rem, calc(2.03rem + 2.31vw), 3.82rem);

    /* Spacing & Layout */
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 4rem;
    --radius: 12px; 
    --transition: 0.3s ease;
    --max-width: 1200px;
}


/* Reset & Base */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
    background-color: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    font-size: var(--step-0);
    line-height: 1.6;
    overflow-x: hidden;
    letter-spacing: -0.01em;
}
img, svg { display: block; max-width: 100%; height: auto; }
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-hover); }
ul { list-style: none; }

/* Accessibility */
.skip-link {
    position: absolute; top: -40px; left: 0;
    background: var(--accent); color: #fff;
    padding: 8px; z-index: 9999;
    border-radius: 0 0 8px 0;
}
.skip-link:focus { top: 0; }
:focus-visible { outline: 2px dashed var(--accent); outline-offset: 4px; }
@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* Typography Enhancements */
.text-gradient {
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Layout */
.container { width: 90%; max-width: var(--max-width); margin: 0 auto; }
.section { padding: var(--space-xl) 0; }
.section-header { margin-bottom: var(--space-lg); text-align: center; }
.section-header h2 { font-size: var(--step-4); margin-bottom: var(--space-sm); font-weight: 700; letter-spacing: -0.02em; }
.grid { display: grid; gap: var(--space-lg); }

/* Buttons */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 0.75rem 1.75rem; font-weight: 600; border-radius: 50px;
    cursor: pointer; border: 2px solid transparent; transition: all var(--transition);
}
.btn-primary { 
    background: linear-gradient(135deg, var(--gradient-start), var(--accent-hover)); 
    color: #fff; 
    box-shadow: 0 4px 14px var(--accent-glow);
}
.btn-primary:hover { 
    transform: translateY(-2px); 
    box-shadow: 0 6px 20px var(--accent-glow); 
    color: #fff;
}
.btn-outline { 
    border-color: var(--border); 
    background: transparent; 
    color: var(--text); 
}
.btn-outline:hover { 
    border-color: var(--accent); 
    background: rgba(99, 102, 241, 0.05); 
    transform: translateY(-2px); 
}

/* Header & Nav */
.site-header {
    position: fixed; top: 0; width: 100%; z-index: 1000;
    background: rgba(9, 9, 14, 0.75);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: all var(--transition);
}
@media (prefers-color-scheme: light) {
    .site-header { background: rgba(248, 250, 252, 0.85); }
}
.site-header.scrolled {
    border-bottom-color: var(--border-light);
    padding: 0.5rem 0;
}
.header-inner { display: flex; justify-content: space-between; align-items: center; height: 75px; }
.logo { font-size: var(--step-1); font-weight: 800; font-family: var(--font-sans); color: var(--text); letter-spacing: -0.03em; }
.logo-accent { color: var(--accent); }

.primary-nav { display: flex; align-items: center; gap: var(--space-lg); }
.nav-links { display: flex; gap: var(--space-md); }
.nav-link { font-weight: 500; color: var(--text-muted); font-size: 0.95rem; }
.nav-link:hover { color: var(--text); }

.mobile-menu-toggle {
    display: none; background: transparent; border: none;
    color: var(--text); cursor: pointer; padding: 0.5rem;
}

@media (max-width: 768px) {
    .mobile-menu-toggle { display: block; }
    .primary-nav {
        position: fixed; top: 75px; left: 0; width: 100%; height: calc(100vh - 75px);
        background: var(--bg); flex-direction: column; padding: var(--space-lg);
        transform: translateX(-100%); transition: transform var(--transition);
        overflow-y: auto; visibility: hidden;
    }
    .primary-nav.is-open { 
        transform: translateX(0); 
        visibility: visible;
    }
    .nav-links { flex-direction: column; width: 100%; text-align: center; font-size: var(--step-1); gap: var(--space-lg); }
    .nav-cta { width: 100%; margin-top: auto; }
}

/* Hero */
.hero {
    min-height: 100vh; display: flex; flex-direction: column; justify-content: center;
    position: relative; padding-top: 80px;
    background: radial-gradient(circle at 50% -20%, rgba(99, 102, 241, 0.15), var(--bg) 60%);
}
.hero-content { max-width: 850px; text-align: center; }
.hero-title { font-size: var(--step-5); line-height: 1.1; margin-bottom: var(--space-md); font-weight: 800; letter-spacing: -0.03em; }
.hero-subtitle { font-size: var(--step-1); color: var(--text-muted); margin-bottom: var(--space-lg); max-width: 700px; margin-left: auto; margin-right: auto; }
.hero-ctas { display: flex; gap: var(--space-md); justify-content: center; flex-wrap: wrap; }
.scroll-cue {
    position: absolute; bottom: 2rem; left: 50%; transform: translateX(-50%);
    color: var(--text-muted); animation: bounce 2s infinite; opacity: 0.5;
}
@keyframes bounce { 0%, 20%, 50%, 80%, 100% { transform: translate(-50%, 0); } 40% { transform: translate(-50%, -10px); } 60% { transform: translate(-50%, -5px); } }

/* Cards Generic (Glassmorphic) */
.card {
    background: linear-gradient(180deg, var(--surface) 0%, rgba(18, 18, 29, 0.4) 100%);
    border: 1px solid var(--border-light);
    border-radius: var(--radius); padding: var(--space-lg);
    transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
    backdrop-filter: blur(10px);
}
.card:hover { 
    transform: translateY(-4px); 
    border-color: rgba(99, 102, 241, 0.5);
    box-shadow: 0 10px 30px rgba(0,0,0,0.2), 0 0 15px rgba(99, 102, 241, 0.1); 
}

/* Services */
.services-grid { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.service-card h3 { font-size: var(--step-1); margin-bottom: var(--space-sm); font-weight: 600; }
.service-card p { color: var(--text-muted); font-size: var(--step--1); }
.icon-wrapper { 
    margin-bottom: var(--space-md); 
    color: var(--accent);
    background: rgba(99, 102, 241, 0.1);
    width: 56px; height: 56px;
    display: flex; align-items: center; justify-content: center;
    border-radius: 12px;
}

/* Use Cases Section (Tabs & Timeline) */
.use-cases-section { background: var(--surface); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.use-cases-container { max-width: 900px; margin: 0 auto; }

.tab-buttons { 
    display: flex; gap: var(--space-sm); justify-content: center; flex-wrap: wrap; 
    margin-bottom: var(--space-md); 
}
.tab-btn {
    background: transparent; color: var(--text-muted); border: 1px solid var(--border);
    padding: 0.5rem 1.25rem; border-radius: 50px; font-weight: 500; cursor: pointer;
    transition: all var(--transition); font-size: var(--step--1);
}
.tab-btn:hover { background: rgba(255, 255, 255, 0.05); color: var(--text); }
.tab-btn.active {
    background: var(--accent); color: #fff; border-color: var(--accent);
    box-shadow: 0 4px 10px var(--accent-glow);
}

.tab-content-wrapper { margin-bottom: var(--space-lg); }
.tab-panel { display: none; animation: fadeIn 0.4s ease; }
.tab-panel.active { display: block; }

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

.tab-panel h3 { font-size: var(--step-2); margin-bottom: 0.5rem; color: var(--accent); }
.tab-intro { font-size: var(--step-0); color: var(--text-muted); margin-bottom: var(--space-lg); }

.timeline { border-left: 2px solid var(--border); margin-left: 20px; padding: 1rem 0; }
.timeline-item { position: relative; padding-left: 2rem; margin-bottom: 1.5rem; }
.timeline-item:last-child { margin-bottom: 0; }
.timeline-icon {
    position: absolute; left: -18px; top: 0;
    width: 34px; height: 34px; border-radius: 50%;
    background: var(--surface); border: 2px solid var(--accent);
    display: flex; align-items: center; justify-content: center;
    font-size: 14px; box-shadow: 0 0 10px var(--accent-glow);
}
.timeline-content h4 { font-size: var(--step-0); margin-bottom: 0.25rem; font-weight: 600; }
.timeline-content p { color: var(--text-muted); font-size: var(--step--1); line-height: 1.5; }

.roi-footer { 
    display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); 
    gap: var(--space-md); background: rgba(99, 102, 241, 0.05); 
    padding: var(--space-lg); border-radius: var(--radius); border: 1px solid var(--border-light);
}
.roi-item h4 { font-size: var(--step-0); color: var(--accent); margin-bottom: 0.5rem; }
.roi-item p { font-size: var(--step--1); color: var(--text-muted); }

/* About */
.about-container { display: flex; gap: var(--space-xl); align-items: center; }
.about-content { flex: 1; }
.about-content h2 { font-size: var(--step-3); margin-bottom: var(--space-md); font-weight: 700; }
.about-list { margin-top: var(--space-md); }
.about-list li { margin-bottom: 0.75rem; position: relative; padding-left: 1.75rem; color: var(--text-muted); }
.about-list li strong { color: var(--text); }
.about-list li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: bold; }
.about-image { flex: 1; text-align: center; }
.avatar { border-radius: var(--radius); border: 1px solid var(--border-light); margin: 0 auto; max-width: 350px; box-shadow: 0 10px 30px rgba(0,0,0,0.3); }
@media (max-width: 768px) { .about-container { flex-direction: column; } }

/* FAQ */
.faq-section { background: var(--surface); }
.faq-accordion { max-width: 800px; margin: 0 auto; display: flex; flex-direction: column; gap: 1rem; }
.faq-item {
    background: var(--bg); border: 1px solid var(--border-light);
    border-radius: var(--radius); overflow: hidden; transition: border-color 0.2s;
}
.faq-item:hover { border-color: var(--accent); }
.faq-item summary {
    padding: var(--space-md); font-weight: 600; cursor: pointer;
    list-style: none; display: flex; justify-content: space-between; align-items: center;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: "↓"; color: var(--accent); font-size: 1.2rem; transition: transform 0.3s; }
.faq-item[open] summary::after { transform: rotate(180deg); }
.faq-content { padding: 0 var(--space-md) var(--space-md); color: var(--text-muted); font-size: var(--step--1); }

/* Contact */
.contact-container { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-xl); max-width: 1000px; }
@media (max-width: 768px) { .contact-container { grid-template-columns: 1fr; } }
.contact-info h2 { font-size: var(--step-3); margin-bottom: var(--space-md); font-weight: 700; }
.direct-contact { margin-top: var(--space-lg); display: flex; flex-direction: column; gap: 1rem; }
.contact-link { display: inline-flex; align-items: center; gap: 0.75rem; font-size: var(--step--1); color: var(--text-muted); }
.contact-link:hover { color: var(--accent); }
.contact-link svg { color: var(--accent); }
.contact-form { background: var(--surface); padding: var(--space-lg); border-radius: var(--radius); border: 1px solid var(--border-light); }
.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-muted); }
.form-group input, .form-group textarea {
    width: 100%; padding: 0.85rem; background: var(--bg); color: var(--text);
    border: 1px solid var(--border); border-radius: 8px; font-family: inherit; transition: border-color 0.2s;
}
.form-group input:focus, .form-group textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15); }
.form-status { margin-top: 1rem; font-size: var(--step--1); font-weight: 600; }
.status-success { color: var(--success); }
.status-error { color: var(--danger); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: var(--space-lg) 0; background: var(--bg); text-align: center; }
.footer-logo { font-size: var(--step-1); font-weight: 800; margin-bottom: 1.5rem; letter-spacing: -0.02em; }
.footer-nav { display: flex; justify-content: center; gap: var(--space-md); flex-wrap: wrap; margin-bottom: 1.5rem; font-size: var(--step--1); }
.footer-social { margin-bottom: 1.5rem; }
.footer-social a { color: var(--text-muted); display: inline-block; transition: transform 0.2s, color 0.2s; }
.footer-social a:hover { color: var(--accent); transform: translateY(-2px); }
.footer-copy { font-size: 0.85rem; color: var(--text-muted); }

/* FABs */
.back-to-top {
    position: fixed; bottom: 80px; right: 20px;
    width: 44px; height: 44px; border-radius: 50%;
    background: var(--surface); color: var(--text); border: 1px solid var(--border-light);
    display: flex; align-items: center; justify-content: center;
    cursor: pointer; z-index: 99; opacity: 0; pointer-events: none;
    transition: opacity var(--transition), transform var(--transition);
}
.back-to-top.visible { opacity: 1; pointer-events: auto; }
.back-to-top:hover { background: var(--accent); color: #fff; transform: translateY(-3px); border-color: var(--accent); }

.whatsapp-fab {
    position: fixed; bottom: 20px; right: 20px;
    width: 50px; height: 50px; border-radius: 50%;
    background: #25D366; color: #fff;
    display: flex; align-items: center; justify-content: center;
    box-shadow: 0 4px 14px rgba(37, 211, 102, 0.4); z-index: 99;
    transition: transform var(--transition), box-shadow var(--transition);
}
.whatsapp-fab:hover { transform: scale(1.1); box-shadow: 0 6px 20px rgba(37, 211, 102, 0.6); color: #fff; }