/* Reset & base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 300px; /* Account for sticky header height */
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Helvetica Neue", Arial, sans-serif;
  line-height: 1.7;
  background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
  color: #2d3748;
  min-height: 100vh;
}

:root {
  --primary: #3182ce;
  --primary-dark: #2c5282;
  --secondary: #2d3748;
  --accent: #48bb78;
  --bg: #ffffff;
  --text: #2d3748;
  --text-light: #718096;
  --card-bg: #ffffff;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.12);
}

/* Layout Container */
body > * {
  animation: fadeIn 0.6s ease-in;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* Header */
header {
  background: #1e3a8a;
  box-shadow: var(--shadow-md);
  padding: 2rem 2rem 1.5rem;
  text-align: center;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(10px);
}

header img {
  margin-bottom: 1.5rem;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.1));
  transition: transform 0.3s ease;
}

header img:hover {
  transform: scale(1.05);
}

nav {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
}

nav a {
  text-decoration: none;
  color: #ffffff;
  font-weight: 600;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  transition: all 0.3s ease;
  font-size: 0.95rem;
  letter-spacing: 0.3px;
  position: relative;
}

nav a:not([href*="index-"]):hover {
  background: #3b82f6;
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

nav a[href*="index-"] {
  margin-left: auto;
  border: 2px solid #3b82f6;
  color: #3b82f6;
  font-weight: 700;
}

nav a[href*="index-"]:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* Language Selector */
.language-dropdown {
  position: relative;
  margin-left: auto;
}

.language-btn {
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  border: none;
  background: #E3F2FD;
  color: var(--text);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Helvetica Neue", Arial, sans-serif;
  letter-spacing: 0.3px;
}

.language-btn:hover {
  background: var(--primary);
  color: #fff;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.language-menu {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  background: #E3F2FD;
  border: none;
  border-radius: 8px;
  box-shadow: var(--shadow-lg);
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.3s ease;
  z-index: 1000;
}

.language-menu.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.language-menu a {
  display: block;
  padding: 0.75rem 1.25rem;
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: all 0.2s ease;
  border-bottom: none;
}

.language-menu a:last-child {
  border-bottom: none;
}

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

.language-menu a:first-child:hover {
  border-radius: 6px 6px 0 0;
}

.language-menu a:last-child:hover {
  border-radius: 0 0 6px 6px;
}

/* Main Content */
section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem;
}

hr {
  border: none;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--primary), transparent);
  margin: 3rem auto;
  max-width: 200px;
}

/* Sections */
.section {
  background: var(--card-bg);
  padding: 3rem;
  margin: 2rem auto;
  border-radius: 16px;
  box-shadow: var(--shadow-lg);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  border: 1px solid rgba(0, 0, 0, 0.05);
}

.section:hover {
  transform: translateY(-4px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.section h2 {
  margin-bottom: 1.5rem;
  font-size: 2rem;
  color: var(--primary);
  font-weight: 700;
  position: relative;
  padding-bottom: 0.75rem;
}

.section h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
}

.section h3 {
  margin: 2rem 0 1rem;
  color: var(--secondary);
  font-size: 1.4rem;
  font-weight: 600;
}

.section p {
  color: var(--text);
  font-size: 1.05rem;
  line-height: 1.8;
  margin-bottom: 1rem;
}

.section ul {
  margin-left: 0;
  list-style: none;
  margin-top: 1rem;
}

.section ul li {
  padding: 0.75rem 0;
  padding-left: 0;
  position: relative;
  color: var(--text);
  font-size: 1.05rem;
  line-height: 1.6;
  transition: color 0.2s ease;
}

.section ul li:hover {
  color: var(--primary);
}

.section > ul > li > a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.2s ease;
}

.section > ul > li > a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

/* Contact */
#contact .section ul li {
  padding: 1rem 0;
  padding-left: 0;
  font-size: 1.1rem;
}

#contact .section ul li::before {
  display: none;
}

#contact a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 600;
  transition: color 0.2s ease;
}

#contact a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

/* Partner List */
.partner-list li {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.partner-logo {
  width: 24px;
  height: 24px;
  object-fit: contain;
  flex-shrink: 0;
  border-radius: 4px;
  background: #fff;
  padding: 2px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

/* Technology List */
.tech-list li {
  padding: 1rem 0;
  padding-left: 0;
}

.tech-list li strong {
  color: var(--primary);
  font-size: 1.1rem;
}

/* Footer */
footer {
  text-align: center;
  padding: 2.5rem;
  background: linear-gradient(135deg, var(--secondary) 0%, #1a202c 100%);
  color: #fff;
  margin-top: 4rem;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.1);
  font-size: 0.95rem;
  letter-spacing: 0.3px;
}

/* Responsive Design */
@media (max-width: 768px) {
  html {
    scroll-padding-top: 0 !important;
  }

  body {
    padding: 0;
  }

  header {
    padding: 1.5rem 1rem !important;
    position: static !important;
    top: auto !important;
    margin-bottom: 0 !important;
  }

  nav {
    display: none !important;
  }

  .language-dropdown {
    display: none !important;
  }

  header img {
    height: 120px;
    margin-bottom: 0 !important;
  }

  section {
    padding: 1rem;
  }

  .section {
    padding: 2rem 1.5rem;
    margin: 1.5rem auto;
  }

  .section h2 {
    font-size: 1.6rem;
  }

  .section h3 {
    font-size: 1.2rem;
  }

  .section p,
  .section ul li {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .section {
    padding: 1.5rem 1rem;
  }
}