/* ==========================================================================
   INDEX PAGE STYLES - TRANG CHỦ
   ========================================================================== */

/* Hero Section */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  background: var(--gradient-hero);
  overflow: hidden;
  padding: var(--spacing-xxl) 0;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: 
    radial-gradient(circle at 20% 50%, rgba(0, 85, 204, 0.05) 0%, transparent 50%),
    radial-gradient(circle at 80% 80%, rgba(220, 53, 69, 0.05) 0%, transparent 50%);
  pointer-events: none;
}

.hero-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.8) 0%, rgba(255, 255, 255, 0.95) 100%);
  pointer-events: none;
}

.hero .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--spacing-xxl);
  align-items: center;
}

.hero-content {
  animation: slideInLeft 0.8s ease-out;
}

.hero-title {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
  line-height: 1.2;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.05);
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-light);
  margin-bottom: var(--spacing-xl);
  line-height: 1.8;
}

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

.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
  animation: slideInRight 0.8s ease-out;
}

.hero-image img {
  width: 100%;
  max-width: 500px;
  height: auto;
  filter: drop-shadow(0 10px 30px rgba(0, 85, 204, 0.15));
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-20px);
  }
}

/* Features Section */
.features {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-white);
}

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

.section-title {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  max-width: 600px;
  margin: var(--spacing-lg) auto 0;
}

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

.feature-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  border: 2px solid transparent;
}

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

.feature-icon {
  font-size: 4rem;
  margin-bottom: var(--spacing-md);
  display: inline-block;
  animation: bounce 2s ease-in-out infinite;
}

.feature-card:hover .feature-icon {
  animation: bounce 0.5s ease-in-out;
}

@keyframes bounce {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.feature-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.feature-description {
  color: var(--color-text-light);
  line-height: 1.8;
}

/* About Section */
.about {
  padding: var(--spacing-xxl) 0;
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
}

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

.about-image img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition-slow);
}

.about-image img:hover {
  transform: scale(1.03);
}

.about-text .section-title {
  text-align: left;
  margin-bottom: var(--spacing-lg);
}

.about-text .section-title::after {
  left: 0;
  transform: translateX(0);
}

.about-description {
  color: var(--color-text);
  line-height: 1.9;
  margin-bottom: var(--spacing-xl);
}

.about-description p {
  margin-bottom: var(--spacing-md);
  text-align: justify;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
}

.stat-item {
  text-align: center;
  padding: var(--spacing-md);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.stat-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-xs);
}

.stat-label {
  font-size: var(--font-size-base);
  color: var(--color-text-light);
}

/* Highlight Features in About section */
.highlight-features {
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
  margin-top: var(--spacing-xl);
  display: grid;
}

.feature-item {
  text-align: center;
  padding: var(--spacing-lg);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  border-top: 4px solid var(--color-primary-light);
}

.feature-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-top-color: var(--color-primary);
}

.feature-item-icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-md);
  color: var(--color-primary);
}

.feature-item-title {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.feature-item-description {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  line-height: 1.7;
}

/* How It Works Section */
.how-it-works {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-white);
}

.steps {
  max-width: 900px;
  margin: 0 auto var(--spacing-xxl);
}

.step {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
  padding: var(--spacing-lg);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  position: relative;
}

.step:hover {
  transform: translateX(10px);
  box-shadow: var(--shadow-lg);
}

.step::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 5px;
  background: var(--gradient-primary);
  border-radius: var(--radius-lg) 0 0 var(--radius-lg);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.step:hover::before {
  opacity: 1;
}

.step-number {
  flex-shrink: 0;
  width: 60px;
  height: 60px;
  background: var(--gradient-primary);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-2xl);
  font-weight: 700;
  box-shadow: var(--shadow-md);
}

.step-content {
  flex: 1;
}

.step-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-sm);
}

.step-description {
  color: var(--color-text-light);
  line-height: 1.8;
}

.cta-section {
  text-align: center;
  padding: var(--spacing-xl);
  background: var(--gradient-hero);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
}

.cta-section h3 {
  font-size: var(--font-size-2xl);
  color: var(--color-primary);
  margin-bottom: var(--spacing-lg);
  font-weight: 700;
}

/* Feedback CTA Section */
.feedback-cta {
  padding: var(--spacing-xxl) 0;
  background: var(--gradient-primary);
  color: var(--color-white);
  text-align: center;
}

.feedback-cta-content {
  max-width: 700px;
  margin: 0 auto;
}

.feedback-cta-icon {
  font-size: 5rem;
  margin-bottom: var(--spacing-md);
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
}

.feedback-cta h2 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  margin-bottom: var(--spacing-md);
}

.feedback-cta p {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-xl);
  line-height: 1.8;
  opacity: 0.95;
}

.feedback-cta .btn-secondary {
  background-color: var(--color-white);
  color: var(--color-primary);
  border: none;
}

.feedback-cta .btn-secondary:hover {
  background-color: var(--color-gray-light);
  transform: translateY(-2px) scale(1.05);
}

/* History Details Section */
.history-details {
  padding: var(--spacing-xxl) 0;
  background-color: var(--color-white);
}

.history-timeline {
  max-width: 900px;
  margin: 0 auto;
  position: relative;
  padding: var(--spacing-lg) 0;
}

.history-timeline::before {
  content: '';
  position: absolute;
  top: 0;
  left: 30px;
  height: 100%;
  width: 4px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.timeline-item {
  margin-bottom: var(--spacing-xl);
  position: relative;
  padding-left: 70px;
  display: flex;
}

.timeline-icon {
  position: absolute;
  left: 0;
  top: 0;
  width: 60px;
  height: 60px;
  background: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  border: 4px solid var(--color-primary-light);
  box-shadow: var(--shadow-md);
  color: var(--color-primary);
}

.timeline-content {
  background: var(--color-background);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  width: 100%;
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
}

.timeline-item:hover .timeline-content {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-md);
}

.timeline-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--spacing-md);
}

.timeline-content p,
.timeline-content ul {
  margin-bottom: var(--spacing-sm);
  line-height: 1.8;
  color: var(--color-text);
}

.timeline-content ul {
  list-style-type: disc;
  padding-left: var(--spacing-lg);
}

.timeline-content li {
  margin-bottom: var(--spacing-xs);
}

.timeline-content strong {
    color: var(--color-primary);
    font-weight: 600;
}

/* ==========================================================================
   RESPONSIVE DESIGN
   ========================================================================== */

@media (max-width: 1024px) {
  .hero .container {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .hero-image {
    order: -1;
  }

  .hero-image img {
    max-width: 400px;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
  }

  .about-image {
    order: -1;
  }
}

@media (max-width: 768px) {
  .hero {
    min-height: auto;
    padding: var(--spacing-xl) 0;
  }

  .hero-title {
    font-size: var(--font-size-2xl);
  }

  .hero-subtitle {
    font-size: var(--font-size-base);
  }

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

  .hero-cta .btn {
    width: 100%;
  }

  .section-title {
    font-size: var(--font-size-2xl);
  }

  .section-subtitle {
    font-size: var(--font-size-base);
  }

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

  .about-stats {
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
  }

  .step {
    flex-direction: column;
    text-align: center;
  }

  .step-number {
    margin: 0 auto;
  }

  .feedback-cta h2 {
    font-size: var(--font-size-2xl);
  }

  .feedback-cta p {
    font-size: var(--font-size-base);
  }
}

@media (max-width: 640px) {
  .hero-image img {
    max-width: 280px;
  }

  .feature-card {
    padding: var(--spacing-lg);
  }

  .feature-icon {
    font-size: 3rem;
  }

  .feature-title {
    font-size: var(--font-size-lg);
  }

  .cta-section h3 {
    font-size: var(--font-size-xl);
  }

  .feedback-cta-icon {
    font-size: 4rem;
  }
}

/* Print Styles */
@media print {
  .header,
  .footer,
  .hero-cta,
  .feedback-cta,
  .nav-toggle {
    display: none;
  }

  .hero {
    min-height: auto;
    padding: var(--spacing-md) 0;
  }

  body {
    font-size: 12pt;
  }

  .section-title {
    page-break-after: avoid;
  }

  .feature-card,
  .step {
    page-break-inside: avoid;
  }
}