/* ===== TechHub Design System ===== */
/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Poppins:wght@400;500;600;700;800&display=swap');

/* --- Design Tokens --- */
:root {
  --navy: #0F172A;
  --navy-light: #1E293B;
  --sky: #0EA5E9;
  --sky-dark: #0284C7;
  --teal: #14B8A6;
  --teal-dark: #0D9488;
  --slate: #334155;
  --slate-light: #64748B;
  --gray: #E2E8F0;
  --gray-light: #F1F5F9;
  --off-white: #F8FAFC;
  --white: #FFFFFF;
  --text-dark: #111827;
  --text-body: #374151;
  --text-muted: #6B7280;
  --danger: #EF4444;
  --success: #22C55E;
  --font-heading: 'Poppins', Arial, sans-serif;
  --font-body: 'Inter', Arial, sans-serif;
  --shadow-sm: 0 1px 3px rgba(15,23,42,.08);
  --shadow-md: 0 4px 12px rgba(15,23,42,.1);
  --shadow-lg: 0 10px 30px rgba(15,23,42,.12);
  --shadow-xl: 0 20px 50px rgba(15,23,42,.15);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --transition: .3s ease;
  --max-width: 1200px;
}

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font-body);
  color: var(--text-body);
  background: var(--off-white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; transition: color var(--transition); }
ul, ol { list-style: none; }
button { cursor: pointer; border: none; font-family: inherit; }
input, textarea, select { font-family: inherit; font-size: 1rem; }

/* --- Skip Link --- */
.skip-link {
  position: absolute; top: -100%; left: 16px; z-index: 9999;
  background: var(--sky); color: var(--white); padding: 10px 20px;
  border-radius: var(--radius-sm); font-weight: 600;
}
.skip-link:focus { top: 16px; }

/* --- Container --- */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 { font-family: var(--font-heading); color: var(--text-dark); line-height: 1.3; }
h1 { font-size: clamp(2rem, 4vw, 3rem); font-weight: 800; }
h2 { font-size: clamp(1.6rem, 3vw, 2.25rem); font-weight: 700; }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); font-weight: 600; }
h4 { font-size: 1.125rem; font-weight: 600; }
p { margin-bottom: 1rem; }
.text-sky { color: var(--sky); }
.text-teal { color: var(--teal); }
.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.section-subtitle {
  display: inline-block; font-size: .875rem; font-weight: 600; color: var(--sky);
  text-transform: uppercase; letter-spacing: 2px; margin-bottom: 8px;
}
.section-title { margin-bottom: 16px; }
.section-desc { max-width: 640px; margin: 0 auto 48px; color: var(--text-muted); font-size: 1.05rem; }

/* --- Buttons --- */
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 14px 32px;
  border-radius: var(--radius-sm); font-weight: 600; font-size: .95rem;
  transition: all var(--transition); border: 2px solid transparent;
}
.btn-primary { background: var(--sky); color: var(--white); }
.btn-primary:hover { background: var(--sky-dark); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.btn-secondary { background: transparent; color: var(--white); border-color: var(--white); }
.btn-secondary:hover { background: var(--white); color: var(--navy); }
.btn-outline { background: transparent; color: var(--sky); border-color: var(--sky); }
.btn-outline:hover { background: var(--sky); color: var(--white); }
.btn-dark { background: var(--navy); color: var(--white); }
.btn-dark:hover { background: var(--navy-light); transform: translateY(-2px); box-shadow: var(--shadow-md); }

/* ===== HEADER / NAV ===== */
.site-header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(15,23,42,.95); backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,.06);
  transition: all var(--transition);
}
.site-header.scrolled { background: rgba(15,23,42,.98); box-shadow: var(--shadow-lg); }
.nav-wrapper { display: flex; align-items: center; justify-content: space-between; height: 72px; }
.nav-logo { display: flex; align-items: center; gap: 10px; font-family: var(--font-heading); font-weight: 800; font-size: 1.5rem; color: var(--white); }
.nav-logo .logo-icon {
  width: 36px; height: 36px; background: linear-gradient(135deg, var(--sky), var(--teal));
  border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center;
  font-size: 1.1rem; color: var(--white); font-weight: 800;
}
.nav-menu { display: flex; align-items: center; gap: 4px; }
.nav-menu a {
  padding: 8px 16px; color: rgba(255,255,255,.75); font-size: .9rem; font-weight: 500;
  border-radius: var(--radius-sm); transition: all var(--transition);
}
.nav-menu a:hover, .nav-menu a.active { color: var(--white); background: rgba(255,255,255,.08); }
.nav-menu a.active { color: var(--sky); }
.nav-cta { padding: 10px 24px !important; background: var(--sky) !important; color: var(--white) !important; border-radius: var(--radius-sm) !important; }
.nav-cta:hover { background: var(--sky-dark) !important; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--white); border-radius: 2px; transition: all var(--transition); }

@media (max-width: 768px) {
  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed; top: 72px; left: 0; right: 0; background: var(--navy);
    flex-direction: column; padding: 24px; gap: 8px;
    transform: translateY(-120%); transition: transform var(--transition);
    border-bottom: 1px solid rgba(255,255,255,.06);
  }
  .nav-menu.open { transform: translateY(0); }
  .nav-menu a { width: 100%; padding: 12px 16px; }
}

/* ===== HERO SLIDER ===== */
.hero {
  position: relative; min-height: 92vh; display: flex; align-items: center;
  background: var(--navy); overflow: hidden; padding-top: 72px;
}
.hero::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 30% 50%, rgba(14,165,233,.15), transparent 60%),
              radial-gradient(ellipse at 70% 80%, rgba(20,184,166,.1), transparent 50%);
}
.hero-slides { position: relative; width: 100%; }
.hero-slide {
  display: none; animation: fadeSlide .6s ease;
}
.hero-slide.active { display: block; }
@keyframes fadeSlide { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
.hero-content { position: relative; z-index: 2; max-width: 700px; }
.hero-content h1 { color: var(--white); font-size: clamp(2.2rem, 5vw, 3.5rem); margin-bottom: 20px; }
.hero-content h1 span { color: var(--sky); }
.hero-content p { color: rgba(255,255,255,.7); font-size: 1.15rem; margin-bottom: 32px; max-width: 540px; }
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }

/* ===== MODERN HERO CONTROLS ===== */
.hero-nav-arrows {
  position: absolute; top: 50%; left: 0; right: 0; transform: translateY(-50%);
  display: flex; justify-content: space-between; padding: 0 40px; z-index: 5;
  pointer-events: none;
}
.hero-prev, .hero-next {
  width: 52px; height: 52px; border-radius: 50%; 
  background: transparent; color: rgba(255, 255, 255, 0.6); 
  display: flex; align-items: center; justify-content: center;
  transition: all 0.3s ease; border: 1px solid rgba(255, 255, 255, 0.2);
  cursor: pointer; pointer-events: auto;
}
.hero-prev svg, .hero-next svg {
  width: 24px; height: 24px; transition: transform 0.3s ease;
}
.hero-prev:hover, .hero-next:hover { 
  background: rgba(255, 255, 255, 0.1); color: var(--white); border-color: rgba(255, 255, 255, 0.4); 
}
.hero-prev:hover svg { transform: translateX(-3px); }
.hero-next:hover svg { transform: translateX(3px); }

.hero-controls {
  position: absolute; bottom: 40px; left: 50%; transform: translateX(-50%);
  display: flex; align-items: center; gap: 8px; z-index: 5;
}
.hero-dot {
  width: 40px; height: 3px; border-radius: 2px; 
  background: rgba(255,255,255,0.3); transition: all 0.3s ease; cursor: pointer; border: none; padding: 0;
}
.hero-dot.active { background: var(--white); }
.hero-dot:hover:not(.active) { background: rgba(255, 255, 255, 0.6); }


/* ===== PAGE BANNER ===== */
.page-banner {
  padding: 140px 0 60px; background: var(--navy); position: relative; overflow: hidden;
}
.page-banner::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse at 50% 80%, rgba(14,165,233,.12), transparent 60%);
}
.page-banner .container { position: relative; z-index: 2; }
.page-banner h1 { color: var(--white); margin-bottom: 12px; }
.page-banner p { color: rgba(255,255,255,.65); font-size: 1.1rem; max-width: 600px; }
.breadcrumb { display: flex; gap: 8px; margin-bottom: 16px; font-size: .875rem; }
.breadcrumb a { color: rgba(255,255,255,.5); }
.breadcrumb a:hover { color: var(--sky); }
.breadcrumb span { color: var(--sky); }

/* ===== SECTIONS ===== */
.section { padding: 80px 0; }
.section-alt { background: var(--white); }
.section-dark { background: var(--navy); color: var(--white); }
.section-dark h2, .section-dark h3 { color: var(--white); }
.section-dark p { color: rgba(255,255,255,.7); }

/* ===== PREMIUM CARDS ===== */
.card-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 32px; }
.card {
  background: var(--white); border-radius: 20px; padding: 40px 32px;
  border: 1px solid rgba(226, 232, 240, 0.6); 
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.03);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  text-align: left !important;
  position: relative; overflow: hidden;
  display: flex; flex-direction: column;
}
.card::before {
  content: ''; position: absolute; top: 0; left: 0; width: 100%; height: 4px;
  background: linear-gradient(90deg, var(--sky), var(--teal));
  opacity: 0; transition: opacity 0.4s ease;
}
.card:hover { 
  transform: translateY(-8px); 
  box-shadow: 0 20px 40px -10px rgba(15, 23, 42, 0.1); 
  border-color: rgba(14, 165, 233, 0.2); 
}
.card:hover::before { opacity: 1; }

.card-icon {
  width: 52px; height: 52px; border-radius: 14px;
  background: var(--gray-light);
  display: inline-flex; align-items: center; justify-content: center;
  margin-bottom: 24px; color: var(--navy);
  transition: all 0.4s ease;
}
.card:hover .card-icon {
  background: var(--sky); color: var(--white); transform: scale(1.05);
}
.card h3 { margin-bottom: 14px; font-size: 1.3rem; }
.card p { color: var(--text-muted); font-size: 1rem; margin-bottom: 24px; line-height: 1.6; flex-grow: 1; }
.card-link { 
  color: var(--sky); font-weight: 600; font-size: .95rem; 
  display: inline-flex; align-items: center; gap: 8px; 
  transition: all 0.3s ease; align-self: flex-start;
}
.card-link svg { transition: transform 0.3s ease; }
.card-link:hover { color: var(--sky-dark); }
.card-link:hover svg { transform: translateX(4px); }

/* ===== STATS ===== */
.stats-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 32px; text-align: center; }
.stat-item h3 { font-size: 2.5rem; color: var(--sky); margin-bottom: 4px; }
.stat-item p { color: rgba(255,255,255,.6); font-size: .95rem; }

/* ===== PROCESS ===== */
.process-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 32px; counter-reset: step; }
.process-step { text-align: center; position: relative; counter-increment: step; }
.process-step::before {
  content: counter(step); display: flex; align-items: center; justify-content: center;
  width: 48px; height: 48px; border-radius: 50%; background: var(--sky);
  color: var(--white); font-family: var(--font-heading); font-weight: 700;
  font-size: 1.1rem; margin: 0 auto 16px;
}
.process-step h4 { margin-bottom: 8px; }
.process-step p { font-size: .9rem; color: var(--text-muted); }

/* ===== TESTIMONIAL ===== */
.testimonial-card {
  background: var(--white); border-radius: var(--radius-lg); padding: 40px;
  border: 1px solid var(--gray); max-width: 700px; margin: 0 auto;
  text-align: center; position: relative;
}
.testimonial-card::before { content: '\201C'; font-size: 4rem; color: var(--sky); font-family: serif; line-height: 1; display: block; margin-bottom: -10px; }
.testimonial-card blockquote { font-size: 1.1rem; font-style: italic; color: var(--text-body); margin-bottom: 20px; line-height: 1.8; }
.testimonial-card cite { font-style: normal; font-weight: 600; color: var(--text-dark); }
.testimonial-card cite span { display: block; font-weight: 400; font-size: .875rem; color: var(--text-muted); }

/* ===== FAQ ACCORDION ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border: 1px solid var(--gray); border-radius: var(--radius-md); margin-bottom: 12px; overflow: hidden; background: var(--white); }
.faq-question {
  width: 100%; padding: 20px 24px; background: none; text-align: left;
  display: flex; justify-content: space-between; align-items: center;
  font-size: 1rem; font-weight: 600; color: var(--text-dark);
  transition: all var(--transition);
}
.faq-question:hover { color: var(--sky); }
.faq-question .faq-icon { font-size: 1.2rem; transition: transform var(--transition); color: var(--sky); }
.faq-item.open .faq-question { color: var(--sky); }
.faq-item.open .faq-icon { transform: rotate(45deg); }
.faq-answer { padding: 0 24px; max-height: 0; overflow: hidden; transition: all .4s ease; }
.faq-item.open .faq-answer { max-height: 400px; padding: 0 24px 20px; }
.faq-answer p { color: var(--text-muted); font-size: .95rem; line-height: 1.8; }

/* ===== CONTACT FORM ===== */
.contact-grid { display: grid; grid-template-columns: 1.2fr .8fr; gap: 48px; align-items: start; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-weight: 600; font-size: .9rem; margin-bottom: 6px; color: var(--text-dark); }
.form-group input, .form-group textarea, .form-group select {
  width: 100%; padding: 14px 16px; border: 1px solid var(--gray);
  border-radius: var(--radius-sm); background: var(--white);
  transition: all var(--transition); color: var(--text-dark);
}
.form-group input:focus, .form-group textarea:focus, .form-group select:focus {
  outline: none; border-color: var(--sky); box-shadow: 0 0 0 3px rgba(14,165,233,.15);
}
.form-group textarea { resize: vertical; min-height: 140px; }
.form-group .error-msg { color: var(--danger); font-size: .8rem; margin-top: 4px; display: none; }
.form-group.invalid input, .form-group.invalid textarea { border-color: var(--danger); }
.form-group.invalid .error-msg { display: block; }
.form-check { display: flex; align-items: flex-start; gap: 10px; margin-bottom: 20px; }
.form-check input[type="checkbox"] { width: 18px; height: 18px; margin-top: 3px; accent-color: var(--sky); }
.form-check label { font-size: .9rem; color: var(--text-muted); }
.form-success { display: none; text-align: center; padding: 40px; }
.form-success.show { display: block; }
.form-success h3 { color: var(--success); margin-bottom: 8px; }

.contact-info-card {
  background: var(--navy); border-radius: var(--radius-lg); padding: 36px;
  color: var(--white);
}
.contact-info-item { display: flex; gap: 16px; margin-bottom: 28px; }
.contact-info-item .info-icon {
  width: 44px; height: 44px; border-radius: var(--radius-sm); flex-shrink: 0;
  background: rgba(14,165,233,.15); display: flex; align-items: center;
  justify-content: center; color: var(--sky); font-size: 1.1rem;
}
.contact-info-item h4 { font-size: .95rem; color: var(--white); margin-bottom: 4px; }
.contact-info-item p { color: rgba(255,255,255,.6); font-size: .9rem; margin: 0; }
.contact-socials { display: flex; gap: 12px; margin-top: 24px; }
.contact-socials a {
  width: 40px; height: 40px; border-radius: 50%; background: rgba(255,255,255,.08);
  display: flex; align-items: center; justify-content: center;
  color: rgba(255,255,255,.6); transition: all var(--transition);
}
.contact-socials a:hover { background: var(--sky); color: var(--white); }

@media (max-width: 768px) { .contact-grid { grid-template-columns: 1fr; } }

/* ===== BLOG CARDS ===== */
.blog-card { overflow: hidden; padding: 0; }
.blog-card-img { height: 200px; background: linear-gradient(135deg, var(--navy-light), var(--slate)); position: relative; overflow: hidden; }
.blog-card-img .blog-tag {
  position: absolute; top: 16px; left: 16px; background: var(--sky); color: var(--white);
  padding: 4px 12px; border-radius: var(--radius-sm); font-size: .75rem; font-weight: 600;
}
.blog-card-body { padding: 24px; }
.blog-card-meta { font-size: .8rem; color: var(--text-muted); margin-bottom: 10px; }
.blog-card-body h3 { font-size: 1.1rem; margin-bottom: 10px; }

/* ===== TEAM ===== */
.team-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 32px; }
.team-card { text-align: center; }
.team-avatar {
  width: 120px; height: 120px; border-radius: 50%; margin: 0 auto 16px;
  background: linear-gradient(135deg, var(--sky), var(--teal)); display: flex;
  align-items: center; justify-content: center; font-size: 2.5rem;
  color: var(--white); font-family: var(--font-heading); font-weight: 700;
}
.team-card h4 { margin-bottom: 4px; }
.team-card p { color: var(--text-muted); font-size: .9rem; }

/* ===== VALUES ===== */
.values-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 28px; }

/* ===== PRICING / COURSE CARDS ===== */
.course-card { padding: 0; overflow: hidden; }
.course-header { padding: 24px 28px 16px; background: linear-gradient(135deg, rgba(14,165,233,.05), rgba(20,184,166,.05)); }
.course-header h3 { font-size: 1.1rem; }
.course-header .course-tag { font-size: .75rem; font-weight: 600; color: var(--sky); text-transform: uppercase; letter-spacing: 1px; }
.course-body { padding: 0 28px 28px; }
.course-body ul { margin-bottom: 20px; }
.course-body li { padding: 8px 0; border-bottom: 1px solid var(--gray); font-size: .9rem; color: var(--text-muted); display: flex; align-items: center; gap: 8px; }
.course-body li::before { content: '✓'; color: var(--teal); font-weight: 700; }

/* ===== CTA SECTION ===== */
.cta-section {
  background: linear-gradient(135deg, var(--navy), var(--navy-light));
  padding: 80px 0; text-align: center; position: relative; overflow: hidden;
}
.cta-section::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(circle at 30% 50%, rgba(14,165,233,.2), transparent 50%),
              radial-gradient(circle at 70% 50%, rgba(20,184,166,.15), transparent 50%);
}
.cta-section .container { position: relative; z-index: 2; }
.cta-section h2 { color: var(--white); margin-bottom: 16px; }
.cta-section p { color: rgba(255,255,255,.65); max-width: 540px; margin: 0 auto 32px; font-size: 1.05rem; }

/* ===== FOOTER ===== */
.site-footer { background: var(--navy); padding: 64px 0 0; color: rgba(255,255,255,.6); }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
.footer-brand p { font-size: .9rem; line-height: 1.8; margin-top: 16px; }
.footer-col h4 { color: var(--white); font-size: .95rem; margin-bottom: 20px; position: relative; padding-bottom: 12px; }
.footer-col h4::after { content: ''; position: absolute; bottom: 0; left: 0; width: 30px; height: 2px; background: var(--sky); }
.footer-col a { display: block; padding: 6px 0; font-size: .9rem; transition: all var(--transition); }
.footer-col a:hover { color: var(--sky); padding-left: 6px; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.08); padding: 24px 0;
  display: flex; justify-content: space-between; align-items: center;
  font-size: .85rem; flex-wrap: wrap; gap: 16px;
}
@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { justify-content: center; text-align: center; }
}

/* ===== BACK TO TOP ===== */
.back-to-top {
  position: fixed; bottom: 32px; right: 32px; width: 44px; height: 44px;
  border-radius: 50%; background: var(--sky); color: var(--white);
  display: flex; align-items: center; justify-content: center; font-size: 1.2rem;
  box-shadow: var(--shadow-md); opacity: 0; visibility: hidden;
  transition: all var(--transition); z-index: 900;
}
.back-to-top.visible { opacity: 1; visibility: visible; }
.back-to-top:hover { background: var(--sky-dark); transform: translateY(-3px); }

/* ===== SERVICE DETAIL ===== */
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 28px; }
.feature-item { display: flex; gap: 16px; }
.feature-item .feat-icon {
  width: 48px; height: 48px; border-radius: var(--radius-sm); flex-shrink: 0;
  background: linear-gradient(135deg, rgba(14,165,233,.1), rgba(20,184,166,.1));
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem; color: var(--sky);
}
.feature-item h4 { margin-bottom: 6px; }
.feature-item p { font-size: .9rem; color: var(--text-muted); margin: 0; }

/* ===== UTILITIES ===== */
.mt-1 { margin-top: 8px; }  .mt-2 { margin-top: 16px; } .mt-3 { margin-top: 24px; } .mt-4 { margin-top: 32px; }
.mb-1 { margin-bottom: 8px; } .mb-2 { margin-bottom: 16px; } .mb-3 { margin-bottom: 24px; } .mb-4 { margin-bottom: 32px; }
.py-1 { padding: 8px 0; } .py-2 { padding: 16px 0; } .py-3 { padding: 24px 0; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; }
@media (max-width: 768px) { .two-col { grid-template-columns: 1fr; } }

/* ===== ANIMATIONS ===== */
.fade-up { opacity: 0; transform: translateY(30px); transition: all .6s ease; }
.fade-up.visible { opacity: 1; transform: translateY(0); }