/* ===== Reset & Base ===== */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e3a5f;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #38bdf8;
  --accent-purple: #a78bfa;
  --accent-green: #34d399;
  --accent-orange: #f97316;
  --accent-violet: #7c3aed;
  --border-color: rgba(56, 189, 248, 0.15);
  --font-main: 'Inter', system-ui, -apple-system, sans-serif;
  --max-width: 1200px;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-main);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition);
}

img, svg {
  max-width: 100%;
  height: auto;
}

ul {
  list-style: none;
}

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

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(15, 23, 42, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background var(--transition);
}

.nav-content {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.4rem;
  font-weight: 700;
}

.nav-logo img {
  height: 36px;
  width: auto;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent-blue);
  transition: width var(--transition);
}

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

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== Hero Section ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding-top: 72px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 800px;
  padding: 60px 24px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid rgba(56, 189, 248, 0.2);
  border-radius: 50px;
  color: var(--accent-blue);
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.hero h1 .highlight {
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 36px;
  line-height: 1.7;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: all var(--transition);
}

.btn-primary {
  background: var(--accent-blue);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background: #7dd3fc;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(56, 189, 248, 0.3);
}

.btn-secondary {
  background: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: rgba(56, 189, 248, 0.1);
  border-color: var(--accent-blue);
  transform: translateY(-2px);
}

/* ===== Section Styles ===== */
.section {
  padding: 100px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-label {
  display: inline-block;
  color: var(--accent-blue);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-bottom: 12px;
}

.section-header h2 {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.section-header p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ===== Course Cards ===== */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

/* ===== Roadmap Layout ===== */
.roadmap-highlight {
  max-width: 700px;
  margin: 0 auto 40px;
}

.roadmap-highlight .course-card {
  position: relative;
  border: 2px solid transparent;
  background: linear-gradient(var(--bg-secondary), var(--bg-secondary)) padding-box,
              linear-gradient(135deg, var(--accent-blue), var(--accent-purple), var(--accent-green)) border-box;
}

.roadmap-highlight .course-card:hover {
  box-shadow: 0 16px 48px rgba(56, 189, 248, 0.15), 0 16px 48px rgba(167, 139, 250, 0.1);
}

.highlight-badge {
  display: inline-block;
  padding: 4px 14px;
  background: linear-gradient(135deg, var(--accent-blue), var(--accent-purple));
  color: var(--bg-primary);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  border-radius: 6px;
  margin-bottom: 16px;
}

.card-gradient::before {
  display: none;
}

.roadmap-divider {
  text-align: center;
  margin: 40px 0;
  position: relative;
}

.roadmap-divider::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--border-color);
}

.roadmap-divider span {
  position: relative;
  background: var(--bg-primary);
  padding: 0 24px;
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
}

.roadmap {
  position: relative;
  max-width: 700px;
  margin: 0 auto;
}

.roadmap-line {
  position: absolute;
  left: 24px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-blue), var(--accent-purple), var(--accent-green));
  opacity: 0.3;
}

.roadmap-step {
  position: relative;
  padding-left: 68px;
  margin-bottom: 32px;
}

.roadmap-step:last-child {
  margin-bottom: 0;
}

.roadmap-number {
  position: absolute;
  left: 8px;
  top: 32px;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--bg-secondary);
  border: 2px solid var(--accent-blue);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 0.85rem;
  color: var(--accent-blue);
  z-index: 1;
}

.roadmap-step:nth-child(3) .roadmap-number { border-color: var(--accent-purple); color: var(--accent-purple); }
.roadmap-step:nth-child(4) .roadmap-number { border-color: var(--accent-blue); color: var(--accent-blue); }
.roadmap-step:nth-child(5) .roadmap-number { border-color: var(--accent-green); color: var(--accent-green); }
.roadmap-step:nth-child(6) .roadmap-number { border-color: var(--accent-violet); color: var(--accent-violet); }
.roadmap-step:nth-child(7) .roadmap-number { border-color: var(--accent-blue); color: var(--accent-blue); }

.roadmap-step .course-card {
  margin: 0;
}

@media (max-width: 768px) {
  .roadmap-step {
    padding-left: 56px;
  }

  .roadmap-line {
    left: 16px;
  }

  .roadmap-number {
    left: 0;
    width: 30px;
    height: 30px;
    font-size: 0.8rem;
  }
}

.course-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 32px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--card-accent, var(--accent-blue));
  opacity: 0;
  transition: opacity var(--transition);
}

.course-card:hover {
  transform: translateY(-4px);
  border-color: var(--card-accent, var(--accent-blue));
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.3);
}

.course-card:hover::before {
  opacity: 1;
}

.course-card .card-icon {
  width: 56px;
  height: 56px;
  margin-bottom: 20px;
  border-radius: 12px;
}

.course-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.course-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 16px;
}

.course-card .card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 4px 12px;
  background: rgba(56, 189, 248, 0.1);
  border-radius: 6px;
  font-size: 0.8rem;
  color: var(--accent-blue);
  font-weight: 500;
}

.card-blue { --card-accent: var(--accent-blue); }
.card-purple { --card-accent: var(--accent-purple); }
.card-green { --card-accent: var(--accent-green); }
.card-orange { --card-accent: var(--accent-orange); }
.card-violet { --card-accent: var(--accent-violet); }

/* ===== Why Section ===== */
.why-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
}

.why-card {
  text-align: center;
  padding: 40px 24px;
}

.why-card .icon-circle {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: rgba(56, 189, 248, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  font-size: 1.5rem;
}

.why-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.why-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== Stats Section ===== */
.stats {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.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;
  font-weight: 800;
  color: var(--accent-blue);
  margin-bottom: 4px;
}

.stat-item p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== CTA Section ===== */
.cta {
  text-align: center;
  padding: 80px 0;
}

.cta-box {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.1), rgba(167, 139, 250, 0.1));
  border: 1px solid var(--border-color);
  border-radius: 24px;
  padding: 60px 40px;
}

.cta-box h2 {
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-box p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 500px;
  margin: 0 auto 32px;
}

/* ===== About Page ===== */
.page-hero {
  padding: 160px 0 80px;
  text-align: center;
  position: relative;
}

.page-hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 800;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.page-hero p {
  color: var(--text-secondary);
  font-size: 1.15rem;
  max-width: 600px;
  margin: 0 auto;
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-content .text h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 16px;
}

.about-content .text p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-image {
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.values-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 24px;
}

.value-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 32px;
  transition: all var(--transition);
}

.value-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.3);
}

.value-card .value-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.value-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.value-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== Topics Section ===== */
.topics-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
}

.topic-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  transition: all var(--transition);
}

.topic-item:hover {
  border-color: var(--accent-blue);
  background: rgba(56, 189, 248, 0.05);
}

.topic-item img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}

.topic-item span {
  font-weight: 600;
  font-size: 0.95rem;
}

/* ===== Contact Page ===== */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.contact-form {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 40px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 8px;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 10px;
  color: var(--text-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: border-color var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent-blue);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 32px;
}

.contact-info-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 28px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  transition: all var(--transition);
}

.contact-info-card:hover {
  border-color: var(--accent-blue);
}

.contact-info-card .info-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(56, 189, 248, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.contact-info-card h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.contact-info-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.social-links {
  display: flex;
  gap: 12px;
  margin-top: 8px;
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(56, 189, 248, 0.1);
  border: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
  font-size: 1.1rem;
}

.social-link:hover {
  background: var(--accent-blue);
  color: var(--bg-primary);
  transform: translateY(-2px);
}

/* ===== Footer ===== */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 60px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-top: 12px;
  max-width: 300px;
  line-height: 1.6;
}

.footer-col h4 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.footer-col a {
  display: block;
  color: var(--text-secondary);
  font-size: 0.9rem;
  padding: 4px 0;
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 32px 24px;
    gap: 24px;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition);
    border-bottom: 1px solid var(--border-color);
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .contact-grid {
    grid-template-columns: 1fr;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }

  .courses-grid {
    grid-template-columns: 1fr;
  }

  .hero-content {
    padding: 40px 16px;
  }

  .section {
    padding: 60px 0;
  }

  .cta-box {
    padding: 40px 24px;
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }
}