:root {
  --primary-color: #A8D5BA;
  --background-color: #F4E3B2;
  --accent-color-blue: #B0C4DE;
  --accent-color-orange: #FFB347;
  --text-color: #333333;
  --shadow-color: rgba(0, 0, 0, 0.1);
}

@font-face {
  font-family: 'Nunito';
  src: url('fonts/Nunito-Regular.ttf') format('truetype');
}

@font-face {
  font-family: 'Open Sans';
  src: url('fonts/OpenSans-Regular.ttf') format('truetype');
}

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

body {
  font-family: 'Open Sans', sans-serif;
  color: var(--text-color);
  background: linear-gradient(135deg, var(--background-color), #ffffff);
  line-height: 1.6;
  font-size: 16px;
  overflow-x: hidden;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.header {
  background: linear-gradient(90deg, var(--primary-color), rgba(168, 213, 186, 0.9));
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
  box-shadow: 0 4px 12px var(--shadow-color);
  padding: 15px 0;
}

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

.nav-logo {
  font-family: 'Nunito', sans-serif;
  font-size: 24px;
  color: white;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-logo img {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
}

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

.nav-link {
  color: white;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s ease;
  position: relative;
}

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

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

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

.main {
  padding-top: 80px;
}

.hero {
  height: 500px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
  border-radius: 15px;
  margin-bottom: 50px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(45deg, rgba(168, 213, 186, 0.7), rgba(244, 227, 178, 0.5));
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  color: white;
  padding: 0 20px;
  max-width: 800px;
}

.hero-title {
  font-family: 'Nunito', sans-serif;
  font-size: 48px;
  margin-bottom: 20px;
  text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
  font-size: 20px;
  margin-bottom: 30px;
}

.notice {
  background-color: rgba(255, 255, 255, 0.9);
  color: var(--text-color);
  padding: 15px 20px;
  border-radius: 8px;
  margin: 30px auto;
  max-width: 800px;
  text-align: center;
  box-shadow: 0 4px 12px var(--shadow-color);
  font-weight: 600;
}

.article-container {
  background-color: white;
  border-radius: 15px;
  padding: 40px;
  box-shadow: 0 8px 24px var(--shadow-color);
  margin-bottom: 50px;
}

article h2 {
  font-family: 'Nunito', sans-serif;
  color: var(--primary-color);
  font-size: 32px;
  margin-bottom: 25px;
  position: relative;
  padding-bottom: 10px;
}

article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 80px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color-orange));
}

article h3 {
  font-family: 'Nunito', sans-serif;
  color: var(--primary-color);
  font-size: 24px;
  margin: 30px 0 15px;
}

article p {
  margin-bottom: 20px;
  font-size: 16px;
}

pre {
  background: linear-gradient(135deg, #f5f7fa, #e4e8eb);
  border-radius: 8px;
  padding: 20px;
  margin: 20px 0;
  overflow: auto;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.1);
  border-left: 4px solid var(--accent-color-orange);
}

code {
  font-family: 'Courier New', monospace;
  color: #333;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 25px 0;
  box-shadow: 0 4px 12px var(--shadow-color);
  border-radius: 8px;
  overflow: hidden;
}

th, td {
  padding: 12px 15px;
  text-align: left;
  border-bottom: 1px solid #ddd;
}

th {
  background-color: var(--primary-color);
  color: white;
  font-weight: 600;
}

tr:nth-child(even) {
  background-color: #f9f9f9;
}

tr:hover {
  background-color: #f1f1f1;
}

.image-gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.gallery-item {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 16px var(--shadow-color);
  transition: transform 0.3s ease;
  height: 300px;
}

.gallery-item:hover {
  transform: translateY(-10px);
}

.gallery-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.gallery-item:hover img {
  transform: scale(1.05);
}

.footer {
  background: linear-gradient(90deg, var(--primary-color), rgba(168, 213, 186, 0.9));
  color: white;
  padding: 40px 0;
  text-align: center;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.footer-column h3 {
  font-family: 'Nunito', sans-serif;
  margin-bottom: 20px;
  position: relative;
  display: inline-block;
}

.footer-column h3::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 50%;
  height: 2px;
  background: var(--accent-color-orange);
}

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

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

.footer-links a {
  color: white;
  text-decoration: none;
  transition: color 0.3s ease;
}

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

.copyright {
  margin-top: 30px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

@media (max-width: 768px) {
  .nav-menu {
    gap: 15px;
  }
  
  .hero-title {
    font-size: 36px;
  }
  
  .hero-subtitle {
    font-size: 18px;
  }
  
  .article-container {
    padding: 25px;
  }
  
  article h2 {
    font-size: 28px;
  }
  
  article h3 {
    font-size: 22px;
  }
}

@media (max-width: 576px) {
  .nav {
    flex-direction: column;
    gap: 15px;
  }
  
  .hero {
    height: 400px;
  }
  
  .hero-title {
    font-size: 28px;
  }
  
  .hero-subtitle {
    font-size: 16px;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn 1s ease forwards;
}

.delay-1 {
  animation-delay: 0.2s;
}

.delay-2 {
  animation-delay: 0.4s;
}

.delay-3 {
  animation-delay: 0.6s;
}

/* Leaf animation */
.leaf {
  position: absolute;
  width: 30px;
  height: 30px;
  background: url('https://images.gptkong.com/demo/sample2.png') center/contain no-repeat;
  opacity: 0.8;
  z-index: 10;
  animation: leafFall 10s linear infinite;
}

@keyframes leafFall {
  0% {
    transform: translateY(-100px) rotate(0deg);
    opacity: 0;
  }
  10% {
    opacity: 0.8;
  }
  90% {
    opacity: 0.8;
  }
  100% {
    transform: translateY(calc(100vh + 100px)) rotate(360deg);
    opacity: 0;
  }
}

/* Floating elements */
.floating {
  animation: floating 3s ease-in-out infinite alternate;
}

@keyframes floating {
  from {
    transform: translateY(0);
  }
  to {
    transform: translateY(-15px);
  }
}

/* Button styles */
.btn {
  display: inline-block;
  padding: 12px 24px;
  background: linear-gradient(45deg, var(--accent-color-orange), #ff8c00);
  color: white;
  border: none;
  border-radius: 50px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(255, 179, 71, 0.3);
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 16px rgba(255, 179, 71, 0.4);
}

.btn-outline {
  background: transparent;
  border: 2px solid white;
  color: white;
}

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

/* Tooltip */
.tooltip {
  position: relative;
  display: inline-block;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: var(--text-color);
  color: white;
  text-align: center;
  border-radius: 6px;
  padding: 10px;
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  transition: opacity 0.3s;
}

.tooltip:hover .tooltiptext {
  visibility: visible;
  opacity: 1;
}

/* Accordion */
.accordion {
  background-color: #f9f9f9;
  color: var(--text-color);
  cursor: pointer;
  padding: 18px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 16px;
  transition: 0.4s;
  border-radius: 8px;
  margin-bottom: 10px;
  font-weight: 600;
}

.active, .accordion:hover {
  background-color: var(--primary-color);
  color: white;
}

.panel {
  padding: 0 18px;
  background-color: white;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.2s ease-out;
  border-radius: 0 0 8px 8px;
  margin-bottom: 20px;
}

/* Tabs */
.tab {
  overflow: hidden;
  border: 1px solid #ccc;
  background-color: #f1f1f1;
  border-radius: 8px 8px 0 0;
}

.tab button {
  background-color: inherit;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  transition: 0.3s;
  font-weight: 600;
}

.tab button:hover {
  background-color: #ddd;
}

.tab button.active {
  background-color: var(--primary-color);
  color: white;
}

.tabcontent {
  display: none;
  padding: 20px;
  border: 1px solid #ccc;
  border-top: none;
  border-radius: 0 0 8px 8px;
  animation: fadeEffect 1s;
}

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

/* Progress bar */
.progress-container {
  width: 100%;
  background-color: #f1f1f1;
  border-radius: 8px;
  margin: 20px 0;
}

.progress-bar {
  height: 20px;
  background: linear-gradient(90deg, var(--primary-color), var(--accent-color-orange));
  border-radius: 8px;
  width: 0;
  transition: width 1s ease;
  text-align: center;
  color: white;
  font-weight: 600;
  line-height: 20px;
}

/* Card styles */
.card {
  background: white;
  border-radius: 12px;
  box-shadow: 0 8px 16px var(--shadow-color);
  overflow: hidden;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  margin-bottom: 30px;
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.15);
}

.card-img {
  height: 200px;
  overflow: hidden;
}

.card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.card:hover .card-img img {
  transform: scale(1.1);
}

.card-body {
  padding: 20px;
}

.card-title {
  font-family: 'Nunito', sans-serif;
  color: var(--primary-color);
  margin-bottom: 10px;
  font-size: 20px;
}

.card-text {
  margin-bottom: 15px;
}

/* Timeline */
.timeline {
  position: relative;
  max-width: 1200px;
  margin: 40px auto;
}

.timeline::after {
  content: '';
  position: absolute;
  width: 6px;
  background-color: var(--primary-color);
  top: 0;
  bottom: 0;
  left: 50%;
  margin-left: -3px;
  border-radius: 3px;
}

.timeline-item {
  padding: 10px 40px;
  position: relative;
  width: 50%;
  box-sizing: border-box;
}

.timeline-item::after {
  content: '';
  position: absolute;
  width: 25px;
  height: 25px;
  right: -12px;
  background-color: white;
  border: 4px solid var(--accent-color-orange);
  top: 15px;
  border-radius: 50%;
  z-index: 1;
}

.left {
  left: 0;
}

.right {
  left: 50%;
}

.right::after {
  left: -12px;
}

.timeline-content {
  padding: 20px;
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 4px 8px var(--shadow-color);
}

@media screen and (max-width: 768px) {
  .timeline::after {
    left: 31px;
  }
  
  .timeline-item {
    width: 100%;
    padding-left: 70px;
    padding-right: 25px;
  }
  
  .timeline-item::after {
    left: 18px;
  }
  
  .left::after, .right::after {
    left: 18px;
  }
  
  .right {
    left: 0%;
  }
}