/* Thiết lập cơ bản */
@import url('https://fonts.googleapis.com/css2?family=Be+Vietnam+Pro:wght@300;400;500;600;700&display=swap');

:root {
  --primary-color: #00796b;
  --secondary-color: #4db6ac;
  --accent-color: #009688;
  --background-light: #e0f2f1;
  --text-dark: #263238;
  --text-light: #eceff1;
  --gradient: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Be Vietnam Pro', sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background-color: #f5f5f5;
  overflow-x: hidden;
}

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

a {
  text-decoration: none;
  color: var(--accent-color);
  transition: color 0.3s;
}

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

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

/* Kiểu nút */
.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 50px;
  font-weight: 600;
  text-align: center;
  transition: all 0.3s ease;
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background: var(--gradient);
  color: white;
  box-shadow: 0 4px 15px rgba(0, 121, 107, 0.3);
}

.btn-primary:hover {
  box-shadow: 0 7px 20px rgba(0, 121, 107, 0.5);
  transform: translateY(-2px);
  color: white;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--primary-color);
  color: var(--primary-color);
}

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

/* Header */
.header {
  background-color: white;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
  height: 80px;
  display: flex;
  align-items: center;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

.logo svg {
  width: 40px;
  height: 40px;
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 25px;
}

.nav-link {
  font-weight: 500;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -5px;
  left: 0;
  background-color: var(--accent-color);
  transition: width 0.3s;
}

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

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  margin: 5px auto;
  background-color: var(--primary-color);
  transition: all 0.3s ease-in-out;
}

/* Hero Section */
.hero {
  background: var(--gradient);
  padding: 160px 0 100px;
  color: white;
  clip-path: polygon(0 0, 100% 0, 100% 85%, 0 100%);
}

.hero-content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 20px;
  line-height: 1.2;
}

.hero p {
  font-size: 1.2rem;
  margin-bottom: 30px;
  opacity: 0.9;
}

/* Tính năng Section */
.features {
  padding: 80px 0;
  background-color: white;
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 20px;
  color: var(--primary-color);
}

.section-subtitle {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 50px;
  color: #607d8b;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.feature-card {
  background: white;
  border-radius: 15px;
  padding: 30px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s;
  border-bottom: 4px solid transparent;
}

.feature-card:hover {
  transform: translateY(-10px);
  border-bottom: 4px solid var(--accent-color);
}

.feature-icon {
  margin-bottom: 20px;
  width: 70px;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--background-light);
  border-radius: 50%;
}

.feature-icon svg {
  width: 35px;
  height: 35px;
  fill: var(--primary-color);
}

.feature-card h3 {
  margin-bottom: 15px;
  font-size: 1.4rem;
  color: var(--primary-color);
}

/* Cách thức hoạt động */
.how-it-works {
  padding: 80px 0;
  background-color: var(--background-light);
}

.steps {
  max-width: 900px;
  margin: 0 auto;
}

.step {
  display: flex;
  align-items: flex-start;
  margin-bottom: 50px;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn 0.5s forwards;
  animation-delay: calc(var(--i) * 0.2s);
}

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

.step-number {
  background: var(--gradient);
  color: white;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 1.2rem;
  margin-right: 30px;
  flex-shrink: 0;
}

.step-content {
  background: white;
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
  flex: 1;
}

.step-content h3 {
  margin-bottom: 10px;
  color: var(--primary-color);
  font-size: 1.4rem;
}

/* FAQ Section */
.faq {
  padding: 80px 0;
  background-color: white;
}

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

.faq-item {
  margin-bottom: 20px;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.faq-question {
  padding: 20px;
  background: white;
  cursor: pointer;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: var(--primary-color);
  transition: all 0.3s;
}

.faq-question svg {
  transition: all 0.3s;
}

.faq-item.active .faq-question {
  background: var(--gradient);
  color: white;
}

.faq-item.active .faq-question svg {
  transform: rotate(180deg);
  stroke: white;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  background-color: white;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 20px;
}

/* Call to Action */
.cta {
  padding: 80px 0;
  background: var(--gradient);
  color: white;
  text-align: center;
}

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

.cta h2 {
  font-size: 2.5rem;
  margin-bottom: 20px;
}

.cta p {
  margin-bottom: 30px;
  opacity: 0.9;
}

.cta .btn {
  background: white;
  color: var(--primary-color);
}

.cta .btn:hover {
  box-shadow: 0 7px 20px rgba(255, 255, 255, 0.3);
}

/* Footer */
footer {
  background: #263238;
  color: white;
  padding: 60px 0 20px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-about {
  grid-column: span 2;
}

.footer-logo {
  display: flex;
  align-items: center;
  margin-bottom: 20px;
  gap: 10px;
}

.footer-logo-text {
  font-size: 1.5rem;
  font-weight: 700;
  color: white;
}

.footer-about p {
  opacity: 0.7;
  max-width: 300px;
}

.footer-heading {
  margin-bottom: 20px;
  font-size: 1.2rem;
  position: relative;
  padding-bottom: 10px;
}

.footer-heading::after {
  content: '';
  position: absolute;
  width: 40px;
  height: 3px;
  background-color: var(--accent-color);
  bottom: 0;
  left: 0;
}

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

.footer-links li {
  margin-bottom: 15px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
}

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

.copyright {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: 0.9rem;
  opacity: 0.7;
}

/* Hiệu ứng */
@keyframes fadeIn {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Media Queries */
@media (max-width: 991px) {
  .hero h1 {
    font-size: 2.5rem;
  }
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }
  
  .nav-menu {
    position: fixed;
    top: 80px;
    left: 0;
    right: 0;
    flex-direction: column;
    background-color: white;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    padding: 20px 0;
    clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
    transition: clip-path 0.4s ease-in-out;
    height: auto;
    align-items: start;
    padding-left: 5%;
  }
  
  .nav-menu.active {
    clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
  }
  
  .menu-toggle.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }
  
  .menu-toggle.active span:nth-child(2) {
    opacity: 0;
  }
  
  .menu-toggle.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }
  
  .hero {
    padding: 140px 0 80px;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .features-grid {
    grid-template-columns: 1fr;
  }
  
  .step {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .step-number {
    margin-right: 0;
    margin-bottom: 20px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-about {
    grid-column: 1;
  }
}

@media (max-width: 480px) {
  .container {
    width: 95%;
  }
  
  .hero h1 {
    font-size: 1.8rem;
  }
  
  .btn {
    padding: 10px 25px;
  }
  
  .section-title {
    font-size: 2rem;
  }
}