/* 
* DeepfakeVN.site Main Stylesheet
* Theme: Vibrant Orange
* Optimized for Vietnamese language and responsive design
*/

:root {
  --primary: #FF5722;
  --primary-light: #FFCCBC;
  --primary-dark: #E64A19;
  --secondary: #FFA000;
  --secondary-light: #FFECB3;
  --accent: #7C4DFF;
  --text-dark: #212121;
  --text-light: #757575;
  --text-white: #FFFFFF;
  --bg-white: #FFFFFF;
  --bg-light: #FBE9E7;
  --bg-dark: #263238;
  --bg-gradient: linear-gradient(135deg, var(--primary), var(--secondary));
  --shadow-sm: 0 2px 6px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 10px rgba(0, 0, 0, 0.15);
  --shadow-lg: 0 8px 20px rgba(0, 0, 0, 0.2);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  color: var(--text-dark);
  line-height: 1.6;
  font-size: 16px;
  background-color: #FAFAFA;
}

.container {
  width: 90%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

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

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

ul {
  list-style: none;
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1rem;
  color: var(--text-dark);
}

h1 {
  font-size: 2.8rem;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 2.2rem;
}

h3 {
  font-size: 1.5rem;
  color: var(--primary);
}

p {
  margin-bottom: 1.5rem;
}

.section-title {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
  display: inline-block;
  padding-bottom: 10px;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: var(--primary);
  border-radius: 2px;
}

.light {
  color: var(--text-white);
}

.light::after {
  background: var(--text-white);
}

.highlight {
  color: var(--primary);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 14px 32px;
  border-radius: var(--radius-md);
  font-weight: 600;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 1rem;
}

.primary-btn {
  background: var(--bg-gradient);
  color: var(--text-white);
  box-shadow: var(--shadow-md);
}

.primary-btn:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  color: var(--text-white);
}

/* Header */
.header {
  position: fixed;
  width: 100%;
  top: 0;
  left: 0;
  z-index: 1000;
  background-color: var(--bg-white);
  box-shadow: var(--shadow-sm);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 15px 0;
  height: 80px;
}

.logo {
  display: flex;
  align-items: center;
}

.logo-icon {
  width: 40px;
  height: 40px;
  margin-right: 10px;
}

.logo span {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

.nav {
  display: flex;
  align-items: center;
}

.menu {
  display: flex;
  gap: 30px;
}

.menu a {
  color: var(--text-dark);
  font-weight: 500;
  padding: 8px 0;
  position: relative;
}

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

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

.menu a:hover::after {
  width: 100%;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 32px;
  height: 24px;
  position: relative;
}

.bar {
  display: block;
  width: 100%;
  height: 3px;
  background: var(--primary);
  margin: 5px 0;
  border-radius: 3px;
  transition: var(--transition);
}

/* Hero Section */
.hero {
  min-height: 100vh;
  background: linear-gradient(135deg, #263238, #37474F);
  color: var(--text-white);
  display: flex;
  align-items: center;
  padding: 100px 0 50px;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 600px;
  position: relative;
  z-index: 2;
}

.hero-text {
  font-size: 1.2rem;
  opacity: 0.9;
  margin-bottom: 2rem;
}

.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 3rem;
}

.stat {
  text-align: center;
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 5px;
}

.stat-text {
  font-size: 1rem;
  opacity: 0.8;
}

.hero-visual {
  position: absolute;
  right: 0;
  top: 0;
  width: 50%;
  height: 100%;
  z-index: 1;
}

.visual-element {
  position: absolute;
  border-radius: 50%;
}

.element-1 {
  width: 300px;
  height: 300px;
  background: var(--primary);
  opacity: 0.1;
  top: 20%;
  right: 10%;
  animation: float 8s infinite alternate;
}

.element-2 {
  width: 200px;
  height: 200px;
  background: var(--secondary);
  opacity: 0.15;
  bottom: 15%;
  right: 25%;
  animation: float 10s infinite alternate-reverse;
}

.element-3 {
  width: 150px;
  height: 150px;
  background: var(--accent);
  opacity: 0.1;
  top: 40%;
  right: 35%;
  animation: float 7s infinite alternate;
}

@keyframes float {
  0% {
    transform: translateY(0) rotate(0);
  }
  100% {
    transform: translateY(-20px) rotate(10deg);
  }
}

/* Features Section */
.features {
  padding: 100px 0;
  background-color: var(--bg-white);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
}

.feature-card {
  background: var(--bg-white);
  padding: 30px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  text-align: center;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-lg);
}

.feature-icon-wrapper {
  width: 80px;
  height: 80px;
  margin: 0 auto 20px;
}

.feature-icon {
  width: 100%;
  height: 100%;
}

/* How It Works Section */
.how-it-works {
  padding: 100px 0;
  background: var(--primary);
  color: var(--text-white);
}

.steps {
  max-width: 800px;
  margin: 0 auto;
}

.step {
  display: flex;
  align-items: flex-start;
  margin-bottom: 50px;
}

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

.step-number {
  font-size: 3rem;
  font-weight: 800;
  color: var(--primary-light);
  margin-right: 30px;
  line-height: 1;
  flex-shrink: 0;
  width: 80px;
  text-align: center;
}

.step-details h3 {
  color: var(--text-white);
  margin-bottom: 10px;
}

/* Testimonials Section */
.testimonials {
  padding: 100px 0;
  background: var(--bg-light);
}

.testimonial-slider {
  max-width: 800px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 30px;
}

.testimonial-item {
  background: var(--bg-white);
  padding: 30px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.rating {
  display: flex;
  margin-bottom: 15px;
}

.star {
  width: 20px;
  height: 20px;
  margin-right: 5px;
}

.testimonial-text {
  font-style: italic;
  margin-bottom: 15px;
  color: var(--text-dark);
}

.testimonial-author {
  font-weight: 600;
  text-align: right;
  color: var(--primary);
}

/* FAQ Section */
.faq {
  padding: 100px 0;
  background: var(--bg-white);
}

.accordion {
  max-width: 800px;
  margin: 0 auto;
}

.accordion-item {
  margin-bottom: 15px;
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.accordion-header {
  background: var(--bg-white);
  padding: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
}

.accordion-header h3 {
  margin: 0;
  font-size: 1.1rem;
}

.accordion-icon {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--primary);
}

.accordion-content {
  padding: 0 20px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.accordion-item.active .accordion-content {
  padding: 0 20px 20px;
  max-height: 200px;
}

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

/* CTA Section */
.cta {
  padding: 100px 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='100' height='100' viewBox='0 0 100 100'%3E%3Cpath d='M0 0L50 50L0 100Z' fill='%23ff5722' fill-opacity='0.05'/%3E%3Cpath d='M100 0L50 50L100 100Z' fill='%23ff5722' fill-opacity='0.05'/%3E%3C/svg%3E"), var(--bg-light);
  background-size: 30px 30px;
}

.cta-content {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
}

.cta h2 {
  color: var(--primary);
  margin-bottom: 15px;
}

.cta p {
  font-size: 1.2rem;
  margin-bottom: 30px;
}

/* Footer */
.footer {
  background: var(--bg-dark);
  color: var(--text-white);
  padding: 80px 0 30px;
}

.footer-top {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  margin-bottom: 50px;
}

.footer-logo {
  display: flex;
  align-items: center;
  margin-bottom: 30px;
}

.footer-icon {
  width: 60px;
  height: 60px;
  margin-right: 15px;
}

.footer-title {
  font-size: 1.5rem;
  font-weight: 700;
}

.footer-menus {
  display: flex;
  gap: 60px;
}

.footer-menu h4 {
  color: var(--text-white);
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--primary);
  display: inline-block;
}

.footer-menu ul li {
  margin-bottom: 10px;
}

.footer-menu ul li a {
  color: rgba(255, 255, 255, 0.7);
}

.footer-menu ul li a:hover {
  color: var(--text-white);
}

.footer-bottom {
  text-align: center;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.9rem;
  opacity: 0.7;
}

/* Responsive Design */
@media (max-width: 992px) {
  h1 {
    font-size: 2.3rem;
  }
  
  h2 {
    font-size: 1.8rem;
  }
  
  .hero-stats {
    gap: 20px;
  }
  
  .stat-number {
    font-size: 2rem;
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }
  
  .menu {
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    flex-direction: column;
    background: var(--bg-white);
    padding: 20px;
    gap: 15px;
    box-shadow: var(--shadow-md);
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    z-index: 999;
  }
  
  .menu.active {
    transform: translateY(0);
  }
  
  .hero {
    text-align: center;
  }
  
  .hero-content {
    margin: 0 auto;
  }
  
  .hero-stats {
    justify-content: center;
  }
  
  .hero-visual {
    display: none;
  }
  
  .step {
    flex-direction: column;
    text-align: center;
  }
  
  .step-number {
    margin: 0 auto 15px;
  }
  
  .footer-top {
    flex-direction: column;
  }
  
  .footer-menus {
    flex-direction: column;
    gap: 30px;
  }
}

@media (max-width: 576px) {
  h1 {
    font-size: 2rem;
  }
  
  .hero-stats {
    flex-direction: column;
    gap: 20px;
  }
  
  .testimonial-slider {
    grid-template-columns: 1fr;
  }
}