/* ============================================
   GETSKILLED - MODERN EDUCATION PLATFORM
   Premium Design System
   ============================================ */

/* ============================================
   CSS VARIABLES & DESIGN TOKENS
   ============================================ */
:root {
  /* Color Palette - Based on Getskilled Logo */
  --color-primary-dark: #1F2937;
  --color-secondary-dark: #2C3E50;
  --color-accent-green: #10B981;
  --color-accent-green-light: #34D399;
  --color-accent-green-dark: #059669;
  --color-white: #F9FAFB;
  --color-gray-light: #E5E7EB;
  --color-gray: #9CA3AF;
  --color-gray-dark: #4B5563;

  /* Typography Scale */
  --font-heading: 'Poppins', sans-serif;
  --font-body: 'Inter', sans-serif;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  /* Spacing System */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Effects */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.2);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.3);
  --shadow-green: 0 0 20px rgba(16, 185, 129, 0.3);

  --border-radius-sm: 0.375rem;
  --border-radius-md: 0.5rem;
  --border-radius-lg: 0.75rem;
  --border-radius-xl: 1rem;
  --border-radius-full: 9999px;
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  color: var(--color-white);
  background-color: var(--color-primary-dark);
  line-height: 1.6;
  overflow-x: hidden;
}

img {
  max-width: 100%;
  display: block;
}

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

ul {
  list-style: none;
}

/* ============================================
   TYPOGRAPHY
   ============================================ */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-4);
}

h1 {
  font-size: var(--text-5xl);
  background: linear-gradient(135deg, var(--color-white) 0%, var(--color-accent-green-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

h2 {
  font-size: var(--text-4xl);
  color: var(--color-white);
}

h3 {
  font-size: var(--text-2xl);
  color: var(--color-white);
}

p {
  margin-bottom: var(--space-4);
  color: var(--color-gray-light);
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section {
  padding: var(--space-20) 0;
}

.text-center {
  text-align: center;
}

.text-green {
  color: var(--color-accent-green);
}

.gradient-text {
  background: linear-gradient(135deg, var(--color-accent-green) 0%, var(--color-accent-green-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-block;
  padding: var(--space-4) var(--space-8);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--text-base);
  border-radius: var(--border-radius-lg);
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition-base);
  text-align: center;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-accent-green) 0%, var(--color-accent-green-light) 100%);
  color: var(--color-white);
  box-shadow: var(--shadow-green);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px rgba(16, 185, 129, 0.5);
}

.btn-outline {
  background: transparent;
  border-color: var(--color-accent-green);
  color: var(--color-accent-green);
}

.btn-outline:hover {
  background: var(--color-accent-green);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn-outline:focus {
  background: transparent;
  color: var(--color-accent-green);
  outline: 2px solid var(--color-accent-green-light);
  outline-offset: 2px;
}

.btn-outline:focus:hover {
  background: var(--color-accent-green);
  color: var(--color-white);
}

/* ============================================
   NAVIGATION
   ============================================ */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(31, 41, 55, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  padding: var(--space-4) 0;
  box-shadow: var(--shadow-md);
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-white);
}

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

.nav-menu {
  display: flex;
  gap: var(--space-8);
  align-items: center;
}

.nav-link {
  position: relative;
  font-weight: 500;
  color: var(--color-gray-light);
  transition: color var(--transition-base);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent-green);
  transition: width var(--transition-base);
}

.nav-link:hover {
  color: var(--color-accent-green);
}

.nav-link:hover::after {
  width: 100%;
}

.nav-link.active {
  color: var(--color-accent-green);
}

/* Dropdown Menu */
.dropdown {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
}

.dropdown-content {
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  background: rgba(31, 41, 55, 0.98);
  backdrop-filter: blur(10px);
  min-width: 220px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
  border-radius: var(--border-radius-md);
  padding: var(--space-2) 0;
  z-index: 1001;
  border: 1px solid rgba(16, 185, 129, 0.1);
  animation: fadeInUp 0.2s ease-out;
}

.dropdown-content a {
  color: var(--color-gray-light);
  padding: var(--space-3) var(--space-6);
  text-decoration: none;
  display: block;
  transition: all var(--transition-fast);
  font-size: var(--text-sm);
  border-left: 3px solid transparent;
}

.dropdown-content a:hover {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-accent-green);
  border-left-color: var(--color-accent-green);
  padding-left: var(--space-8);
}

.dropdown:hover .dropdown-content {
  display: block;
}

/* Nested Dropdown Menu */
.nested-dropdown {
  position: relative;
}

.nested-dropdown-content {
  display: none;
  position: absolute;
  top: 0;
  left: 100%;
  background: rgba(31, 41, 55, 0.98);
  backdrop-filter: blur(10px);
  min-width: 220px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
  border-radius: var(--border-radius-md);
  padding: var(--space-2) 0;
  z-index: 1002;
  border: 1px solid rgba(16, 185, 129, 0.1);
  animation: fadeInUp 0.2s ease-out;
}

.nested-dropdown:hover .nested-dropdown-content {
  display: block;
}

.nested-dropdown-content a {
  color: var(--color-gray-light);
  padding: var(--space-3) var(--space-6);
  text-decoration: none;
  display: block;
  transition: all var(--transition-fast);
  font-size: var(--text-sm);
  border-left: 3px solid transparent;
}

.nested-dropdown-content a:hover {
  background: rgba(16, 185, 129, 0.1);
  color: var(--color-accent-green);
  border-left-color: var(--color-accent-green);
  padding-left: var(--space-8);
}

.nested-nav-link {
  display: flex !important;
  justify-content: space-between !important;
  align-items: center !important;
}

.nav-arrow {
  margin-left: var(--space-2);
  font-size: 0.8em;
  color: var(--color-gray);
  transition: transform var(--transition-fast);
}

.nested-dropdown:hover .nav-arrow {
  color: var(--color-accent-green);
}

.mobile-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  cursor: pointer;
}

.mobile-toggle span {
  width: 25px;
  height: 3px;
  background: var(--color-white);
  border-radius: var(--border-radius-full);
  transition: all var(--transition-base);
}

/* ============================================
   HERO SECTION
   ============================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-secondary-dark) 100%);
  background-attachment: fixed;
  overflow: hidden;
  padding-top: var(--space-20);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 20% 50%, rgba(16, 185, 129, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(16, 185, 129, 0.08) 0%, transparent 50%);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
}

.hero h1 {
  font-size: var(--text-6xl);
  margin-bottom: var(--space-6);
  animation: fadeInUp 0.8s ease-out;
}

.hero p {
  font-size: var(--text-xl);
  color: var(--color-gray-light);
  margin-bottom: var(--space-8);
  animation: fadeInUp 0.8s ease-out 0.2s backwards;
}

.hero-buttons {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 0.4s backwards;
}

.hero-decoration {
  position: absolute;
  right: 10%;
  top: 50%;
  transform: translateY(-50%);
  opacity: 0.1;
  pointer-events: none;
}

.hero-circle {
  width: 400px;
  height: 400px;
  border-radius: 50%;
  border: 3px solid var(--color-accent-green);
  animation: pulse 3s ease-in-out infinite;
}

/* ============================================
   FEATURES SECTION
   ============================================ */
.features {
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-secondary-dark) 100%);
  background-attachment: fixed;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-8);
  margin-top: var(--space-12);
}

.feature-card {
  background: rgba(44, 62, 80, 0.5);
  backdrop-filter: blur(10px);
  padding: var(--space-8);
  border-radius: var(--border-radius-xl);
  border: 1px solid rgba(16, 185, 129, 0.2);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, transparent 100%);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-green);
  border-color: var(--color-accent-green);
}

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

.feature-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--color-accent-green) 0%, var(--color-accent-green-light) 100%);
  border-radius: var(--border-radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-3xl);
  margin-bottom: var(--space-4);
}

.feature-card h3 {
  margin-bottom: var(--space-3);
}

.feature-card p {
  color: var(--color-gray);
  margin-bottom: 0;
}

/* ============================================
   COURSES SECTION
   ============================================ */
.courses {
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-secondary-dark) 100%);
  background-attachment: fixed;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-8);
  margin-top: var(--space-12);
}

.course-card {
  background: rgba(31, 41, 55, 0.8);
  border-radius: var(--border-radius-xl);
  overflow: hidden;
  transition: all var(--transition-base);
  border: 1px solid transparent;
}

.course-card:hover {
  transform: scale(1.05);
  border-color: var(--color-accent-green);
  box-shadow: var(--shadow-green);
}

.course-image {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, var(--color-accent-green-dark) 0%, var(--color-accent-green) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-5xl);
  overflow: hidden;
}

.course-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.course-card:nth-child(3) .course-image img {
  object-position: 20% center;
  /* Shift image right to show "AI" text fully */
}


.course-content {
  padding: var(--space-6);
}

.course-category {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  background: rgba(16, 185, 129, 0.2);
  color: var(--color-accent-green);
  border-radius: var(--border-radius-full);
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: var(--space-3);
}

.course-card h3 {
  margin-bottom: var(--space-2);
}

.course-meta {
  display: flex;
  gap: var(--space-6);
  color: var(--color-gray);
  font-size: var(--text-sm);
  margin-top: var(--space-4);
}

/* ============================================
   STATS SECTION
   ============================================ */
.stats {
  background: rgba(16, 185, 129, 0.05);
  border-top: 1px solid rgba(16, 185, 129, 0.2);
  border-bottom: 1px solid rgba(16, 185, 129, 0.2);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-8);
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-family: var(--font-heading);
  font-size: var(--text-5xl);
  font-weight: 700;
  color: var(--color-accent-green);
  display: inline-block;
  margin-bottom: var(--space-2);
}


.stat-suffix {
  font-family: var(--font-heading);
  font-size: var(--text-5xl);
  font-weight: 700;
  color: var(--color-accent-green);
  display: inline-block;
  margin-bottom: var(--space-2);
}

.stat-label {
  color: var(--color-gray-light);
  font-size: var(--text-lg);
  display: block;
}

/* ============================================
   TESTIMONIALS SECTION
   ============================================ */
.testimonials {
  background: var(--color-primary-dark);
}

.testimonial-slider {
  max-width: 800px;
  margin: var(--space-12) auto 0;
  position: relative;
}

.testimonial-card {
  background: rgba(44, 62, 80, 0.5);
  backdrop-filter: blur(10px);
  padding: var(--space-10);
  border-radius: var(--border-radius-xl);
  border-left: 4px solid var(--color-accent-green);
  display: none;
}

.testimonial-card.active {
  display: block;
  animation: fadeIn 0.5s ease-out;
}

.testimonial-text {
  font-size: var(--text-lg);
  font-style: italic;
  color: var(--color-gray-light);
  margin-bottom: var(--space-6);
  line-height: 1.8;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.author-avatar {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--color-accent-green) 0%, var(--color-accent-green-light) 100%);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-2xl);
  font-weight: 700;
}

.author-info h4 {
  margin-bottom: var(--space-1);
  font-size: var(--text-lg);
}

.author-role {
  color: var(--color-gray);
  font-size: var(--text-sm);
}

.testimonial-dots {
  display: flex;
  justify-content: center;
  gap: var(--space-3);
  margin-top: var(--space-8);
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-gray-dark);
  cursor: pointer;
  transition: all var(--transition-base);
}

.dot.active {
  background: var(--color-accent-green);
  transform: scale(1.3);
}

/* ============================================
   CTA SECTION
   ============================================ */
.cta {
  background: linear-gradient(135deg, var(--color-accent-green-dark) 0%, var(--color-accent-green) 100%);
  text-align: center;
}

.cta h2 {
  font-size: var(--text-4xl);
  margin-bottom: var(--space-4);
}

.cta p {
  font-size: var(--text-xl);
  margin-bottom: var(--space-8);
  color: var(--color-white);
  opacity: 0.9;
}

.cta .btn {
  background: var(--color-white);
  color: var(--color-accent-green);
  font-size: var(--text-lg);
  padding: var(--space-5) var(--space-12);
}

.cta .btn:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  background: var(--color-secondary-dark);
  padding: var(--space-16) 0 var(--space-8);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

.footer-section h3 {
  margin-bottom: var(--space-4);
  color: var(--color-white);
}

.footer-section h3 span {
  color: var(--color-accent-green);
}

.footer-section p,
.footer-section a {
  color: var(--color-gray);
  font-size: var(--text-sm);
  line-height: 2;
}

.footer-section a:hover {
  color: var(--color-accent-green);
}

.social-links {
  display: flex;
  gap: var(--space-4);
  margin-top: var(--space-4);
}

.social-link {
  width: 40px;
  height: 40px;
  background: rgba(16, 185, 129, 0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-accent-green);
  transition: all var(--transition-base);
}

.social-links .social-link:hover {
  background: var(--color-accent-green);
  color: var(--color-white);
  transform: translateY(-4px);
}

.footer-bottom {
  text-align: center;
  padding-top: var(--space-8);
  border-top: 1px solid rgba(156, 163, 175, 0.2);
  color: var(--color-gray);
  font-size: var(--text-sm);
}

/* ============================================
   ANIMATIONS
   ============================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@keyframes pulse {

  0%,
  100% {
    transform: translateY(-50%) scale(1);
    opacity: 0.1;
  }

  50% {
    transform: translateY(-50%) scale(1.05);
    opacity: 0.15;
  }
}

.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: all var(--transition-slow);
}

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

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
  :root {
    --text-6xl: 2.5rem;
    --text-5xl: 2rem;
    --text-4xl: 1.75rem;
  }

  .navbar .container {
    position: relative;
  }

  .mobile-toggle {
    display: flex;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--color-secondary-dark);
    flex-direction: column;
    padding: var(--space-6);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-base);
    max-height: calc(100vh - 80px);
    /* Enable scrolling for landscape */
    overflow-y: auto;
  }

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

  /* Center nav items on mobile */
  .nav-menu li {
    text-align: center;
  }

  /* Mobile dropdown menu */
  .dropdown {
    width: 100%;
    flex-direction: column;
    align-items: center;
  }

  .dropdown>.nav-link {
    width: 100%;
    text-align: center;
    padding-left: 15px;
    /* Nudge to the right to balance the arrow icon */
  }

  .dropdown-content {
    position: static !important;
    width: 100%;
    margin-top: var(--space-2);
    box-shadow: none;
    border: none;
    background: rgba(44, 62, 80, 0.5);
    padding: 0;
    display: none;
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base);
  }

  .dropdown-content.active {
    display: block !important;
    max-height: 500px;
  }

  .dropdown-content a {
    padding-left: var(--space-8);
    text-align: center;
  }

  /* Mobile nested dropdown */
  .nested-dropdown {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
  }

  .nested-nav-link {
    width: 100%;
    justify-content: center !important;
    padding-left: var(--space-8) !important;
  }

  .nav-arrow {
    position: absolute;
    right: 20px;
  }

  .nested-dropdown-content {
    position: static !important;
    width: 100%;
    background: rgba(16, 185, 129, 0.05);
    padding: 0;
    display: none;
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base);
    box-shadow: inset 0 2px 5px rgba(0,0,0,0.1);
    border: none;
  }

  .nested-dropdown-content.active {
    display: block !important;
    max-height: 800px;
  }

  .nested-dropdown-content a {
    padding-left: var(--space-12) !important;
    font-size: 0.9em;
  }

  .hero {
    min-height: 60vh;
    padding-top: var(--space-24);
  }

  .hero h1 {
    font-size: var(--text-4xl);
  }

  .hero p {
    font-size: var(--text-lg);
  }

  .hero-buttons {
    flex-direction: column;
  }

  .hero-decoration {
    display: none;
  }

  .section {
    padding: var(--space-12) 0;
  }
}

@media (max-width: 768px) {

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

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-4);
  }

  .btn {
    width: 100%;
  }
}