/* ===================================
   IELTS & iMentor Landing Page Styles
   ================================== */

/* CSS Variables - Color Scheme */
:root {
  /* Primary Colors */
  --primary-yellow: #FDC70F;
  --primary-green: #00B03F;
  --primary-orange: #F89725;
  
  /* Neutral Colors */
  --white: #ffffff;
  --black: #000000;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  
  /* Semantic Colors */
  --success: #10b981;
  --error: #ef4444;
  --warning: #f59e0b;
  --info: #3b82f6;
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Typography */
  --font-heading: 'Be Vietnam Pro', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  
  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  
  /* Transitions */
  --transition-fast: 150ms ease-in-out;
  --transition-base: 300ms ease-in-out;
  --transition-slow: 500ms ease-in-out;
}

/* 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(--gray-800);
  line-height: 1.6;
  background-color: var(--white);
  overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--gray-900);
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: 2.5rem;
  line-height: 1.1;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.5rem;
}

h4 {
  font-size: 1.25rem;
}

p {
  margin-bottom: var(--spacing-sm);
  color: var(--gray-600);
}

a {
  color: var(--primary-green);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--primary-orange);
}

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

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.container-wide {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Section */
.section {
  padding: var(--spacing-2xl) 0;
}

.section-title {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.section-title h2 {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-sm);
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.section-title p {
  font-size: 1.125rem;
  color: var(--gray-600);
  max-width: 600px;
  margin: 0 auto;
}

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--white);
  box-shadow: var(--shadow-md);
  z-index: 1000;
  transition: all var(--transition-base);
}

.header.scrolled {
  box-shadow: var(--shadow-lg);
}

.header-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-sm) 0;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-green);
  font-family: var(--font-heading);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo span {
  color: var(--primary-yellow);
}

.nav {
  display: flex;
  gap: var(--spacing-lg);
  align-items: center;
}

.nav a {
  color: var(--gray-700);
  font-weight: 500;
  padding: 0.5rem 0;
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
}

.nav a.btn-primary {
  padding: 0.75rem 1.5rem;
  border-bottom: none;
  color: var(--white);
}

.nav a:hover,
.nav a.active {
  color: var(--primary-green);
  border-bottom-color: var(--primary-green);
}

.nav a.btn-primary:hover {
  border-bottom: none;
  color: var(--white);
}

/* Mobile Menu Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 0.25rem;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.menu-toggle span {
  width: 25px;
  height: 3px;
  background: var(--gray-700);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, rgba(0, 176, 63, 0.05) 0%, rgba(253, 199, 15, 0.05) 100%);
  padding: calc(80px + var(--spacing-2xl)) 0 var(--spacing-2xl);
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

#particles-js {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  z-index: 1;
}

.hero .container {
  position: relative;
  z-index: 2;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xl);
  align-items: center;
}

.hero-text h1 {
  font-size: 3rem;
  line-height: 1.1;
  margin-bottom: var(--spacing-md);
}

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

.hero-text p {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-lg);
  color: var(--gray-600);
}

.hero-stats {
  display: flex;
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
  flex-wrap: wrap;
}

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

.hero-stat-number {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-green);
  display: block;
}

.hero-stat-label {
  font-size: 0.875rem;
  color: var(--gray-600);
}

.hero-image {
  position: relative;
}

.hero-image img {
  width: 100%;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  font-family: var(--font-body);
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  color: var(--white);
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--white);
  color: var(--primary-green);
  border: 2px solid var(--primary-green);
}

.btn-secondary:hover {
  background: var(--primary-green);
  color: var(--white);
}

.btn-large {
  padding: 1rem 2.5rem;
  font-size: 1.125rem;
}

.cta-buttons {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

/* Features Section */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.feature-card {
  background: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
  border: 2px solid transparent;
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-yellow);
}

.feature-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin-bottom: var(--spacing-md);
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
}

.feature-card h3 {
  color: var(--gray-900);
  margin-bottom: var(--spacing-sm);
}

.feature-card p {
  color: var(--gray-600);
  margin-bottom: 0;
}

/* Courses Section */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.course-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-base);
}

.course-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

.course-image {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
}

.course-content {
  padding: var(--spacing-lg);
}

.course-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  background: var(--primary-yellow);
  color: var(--gray-900);
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.course-card h3 {
  margin-bottom: var(--spacing-sm);
}

.course-meta {
  display: flex;
  gap: var(--spacing-md);
  margin: var(--spacing-sm) 0;
  color: var(--gray-500);
  font-size: 0.875rem;
}

.course-meta span {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

/* Testimonials Section */
.testimonials {
  background: var(--gray-50);
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
}

.testimonial-card {
  background: var(--white);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  position: relative;
}

.testimonial-quote {
  font-size: 3rem;
  color: var(--primary-yellow);
  line-height: 1;
  margin-bottom: var(--spacing-sm);
}

.testimonial-text {
  font-style: italic;
  color: var(--gray-600);
  margin-bottom: var(--spacing-md);
}

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

.testimonial-avatar {
  width: 50px;
  height: 50px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 700;
  font-size: 1.25rem;
}

.testimonial-info h4 {
  margin: 0;
  font-size: 1rem;
}

.testimonial-info p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--gray-500);
}

.testimonial-rating {
  color: var(--primary-yellow);
  margin-top: 0.25rem;
}

/* Contact Form Section */
.contact-form-section {
  background: linear-gradient(135deg, rgba(0, 176, 63, 0.05) 0%, rgba(253, 199, 15, 0.05) 100%);
}

.contact-form-wrapper {
  max-width: 600px;
  margin: 0 auto;
  background: var(--white);
  padding: var(--spacing-xl);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
}

.form-group {
  margin-bottom: var(--spacing-md);
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 600;
  color: var(--gray-700);
}

.form-group label .required {
  color: var(--error);
}

.form-control {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--gray-200);
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-family: var(--font-body);
  transition: all var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary-green);
  box-shadow: 0 0 0 3px rgba(0, 176, 63, 0.1);
}

.form-control.error {
  border-color: var(--error);
}

.error-message {
  color: var(--error);
  font-size: 0.875rem;
  margin-top: 0.25rem;
  display: none;
}

.error-message.show {
  display: block;
}

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

select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23374151' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

.form-checkbox {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin: var(--spacing-md) 0;
}

.form-checkbox input[type="checkbox"] {
  width: 20px;
  height: 20px;
  margin-top: 0.125rem;
  cursor: pointer;
}

.form-checkbox label {
  font-weight: 400;
  font-size: 0.875rem;
  color: var(--gray-600);
  cursor: pointer;
}

.btn-submit {
  width: 100%;
  padding: 1rem;
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  color: var(--white);
  border: none;
  border-radius: var(--radius-full);
  font-size: 1.125rem;
  font-weight: 700;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-submit:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.btn-submit.loading {
  position: relative;
  color: transparent;
}

.btn-submit.loading::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  top: 50%;
  left: 50%;
  margin-left: -10px;
  margin-top: -10px;
  border: 3px solid var(--white);
  border-radius: 50%;
  border-top-color: transparent;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* FAQ Section */
.faq-section {
  background: var(--white);
}

.faq-list {
  max-width: 800px;
  margin: var(--spacing-xl) auto 0;
}

.faq-item {
  background: var(--gray-50);
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-sm);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  padding: var(--spacing-md);
  background: none;
  border: none;
  text-align: left;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-900);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: all var(--transition-fast);
}

.faq-question:hover {
  color: var(--primary-green);
}

.faq-icon {
  font-size: 1.5rem;
  transition: transform var(--transition-fast);
  color: var(--primary-yellow);
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer-content {
  padding: 0 var(--spacing-md) var(--spacing-md);
  color: var(--gray-600);
}

/* Pricing Section */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.pricing-card {
  background: var(--white);
  padding: var(--spacing-xl);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  text-align: center;
  border: 3px solid transparent;
  transition: all var(--transition-base);
  position: relative;
}

.pricing-card.featured {
  border-color: var(--primary-yellow);
  transform: scale(1.05);
}

.pricing-badge {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  color: var(--white);
  padding: 0.5rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.875rem;
}

.pricing-card:hover {
  transform: translateY(-5px) scale(1.02);
  box-shadow: var(--shadow-xl);
}

.pricing-card.featured:hover {
  transform: translateY(-5px) scale(1.07);
}

.pricing-title {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
}

.pricing-price {
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary-green);
  margin: var(--spacing-md) 0;
}

.pricing-price-old {
  text-decoration: line-through;
  color: var(--gray-400);
  font-size: 1.5rem;
  display: block;
  margin-bottom: 0.5rem;
}

.pricing-features {
  list-style: none;
  margin: var(--spacing-lg) 0;
  text-align: left;
}

.pricing-features li {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--gray-100);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.pricing-features li:last-child {
  border-bottom: none;
}

.pricing-features li::before {
  content: "✓";
  color: var(--primary-green);
  font-weight: 700;
  font-size: 1.25rem;
}

/* Footer */
.footer {
  background: var(--gray-900);
  color: var(--gray-300);
  padding: var(--spacing-2xl) 0 var(--spacing-md);
}

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

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

.footer-section p {
  color: var(--gray-400);
  margin-bottom: var(--spacing-sm);
}

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

.footer-links li {
  margin-bottom: var(--spacing-sm);
}

.footer-links a {
  color: var(--gray-300);
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary-yellow);
}

.social-links {
  display: flex;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-md);
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-full);
  background: var(--gray-800);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-size: 1.25rem;
  transition: all var(--transition-fast);
}

.social-link:hover {
  background: linear-gradient(135deg, var(--primary-green), var(--primary-yellow));
  transform: translateY(-3px);
}

.footer-bottom {
  border-top: 1px solid var(--gray-800);
  padding-top: var(--spacing-md);
  text-align: center;
  color: var(--gray-400);
}

/* Utilities */
.text-center {
  text-align: center;
}

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

/* Animations */
.fade-in {
  animation: fadeIn 0.6s ease-in;
}

.slide-up {
  animation: slideUp 0.6s ease-out;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Scroll Reveal */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s ease-out;
}

.reveal.active {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive Design */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-text {
    order: 2;
  }
  
  .hero-image {
    order: 1;
  }
  
  .hero-stats {
    justify-content: center;
  }
  
  .cta-buttons {
    justify-content: center;
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }
  
  .nav {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--white);
    flex-direction: column;
    padding: var(--spacing-md);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-base);
  }
  
  .nav.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  
  .hero {
    padding-top: calc(72px + var(--spacing-lg));
    min-height: auto;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.75rem;
  }
  
  .section-title h2 {
    font-size: 2rem;
  }
  
  .hero-text h1 {
    font-size: 2.25rem;
  }
  
  .hero-text p {
    font-size: 1.125rem;
  }
  
  .pricing-card.featured {
    transform: scale(1);
  }
  
  .pricing-card.featured:hover {
    transform: translateY(-5px) scale(1.02);
  }
}

@media (max-width: 480px) {
  :root {
    font-size: 14px;
  }
  
  .cta-buttons {
    flex-direction: column;
    width: 100%;
  }
  
  .btn {
    width: 100%;
  }
  
  .hero-stats {
    flex-direction: column;
    gap: var(--spacing-md);
  }
  
  .contact-form-wrapper {
    padding: var(--spacing-md);
  }
}