/* Biến CSS */
:root {
  --primary-color: #1A1A2E;
  --secondary-color: #E9B824;
  --text-color: #F0F0F0;
  --accent-color: #FFD700;
  --background-dark: #0F0F1A;
}

/* Đặt lại cơ bản */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--text-color);
  background-color: var(--background-dark);
  direction: ltr;
}

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

a:hover {
  text-decoration: underline;
}

ul {
  list-style: none;
}

.btn {
  display: inline-block;
  padding: 10px 20px;
  border-radius: 5px;
  font-weight: bold;
  text-align: center;
  cursor: pointer;
  transition: background-color 0.3s ease, color 0.3s ease;
  border: none;
}

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

.btn-primary:hover {
  background-color: var(--accent-color);
  color: var(--primary-color);
  text-decoration: none;
}

.btn-secondary {
  background-color: transparent;
  color: var(--secondary-color);
  border: 1px solid var(--secondary-color);
}

.btn-secondary:hover {
  background-color: var(--secondary-color);
  color: var(--primary-color);
  text-decoration: none;
}

/* Header */
.site-header {
  background-color: var(--primary-color);
  padding: 15px 0;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.header-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 28px;
  font-weight: bold;
  color: var(--secondary-color);
  text-transform: uppercase;
  letter-spacing: 1px;
  text-decoration: none;
  transition: color 0.3s ease;
}

.logo:hover {
  color: var(--accent-color);
  text-decoration: none;
}

.main-nav .nav-list {
  display: flex;
  gap: 25px;
}

.main-nav a {
  color: var(--text-color);
  font-weight: 500;
  font-size: 16px;
  padding: 5px 0;
  position: relative;
  transition: color 0.3s ease;
}

.main-nav a:hover {
  color: var(--secondary-color);
  text-decoration: none;
}

.main-nav a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 2px;
  background-color: var(--secondary-color);
  transition: width 0.3s ease;
}

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

.header-actions {
  display: flex;
  gap: 10px;
}

.hamburger-menu {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 30px;
  height: 25px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1001;
}

.hamburger-menu .bar {
  width: 100%;
  height: 3px;
  background-color: var(--secondary-color);
  border-radius: 5px;
  transition: all 0.3s ease;
}

/* Footer */
.site-footer {
  background-color: var(--primary-color);
  padding: 40px 0 20px;
  color: var(--text-color);
  font-size: 14px;
  box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.3);
}

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

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

.footer-brand .footer-logo {
  font-size: 24px;
  margin-bottom: 15px;
  display: block;
}

.footer-brand p {
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.8;
}

.footer-nav h3,
.footer-contact h3 {
  color: var(--secondary-color);
  font-size: 18px;
  margin-bottom: 20px;
  position: relative;
}

.footer-nav h3::after,
.footer-contact h3::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -5px;
  width: 40px;
  height: 2px;
  background-color: var(--secondary-color);
}

.footer-nav ul li,
.footer-contact p {
  margin-bottom: 10px;
}

.footer-nav ul a,
.footer-contact a {
  color: rgba(255, 255, 255, 0.7);
  transition: color 0.3s ease;
}

.footer-nav ul a:hover,
.footer-contact a:hover {
  color: var(--secondary-color);
  text-decoration: none;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 20px;
  text-align: center;
  color: rgba(255, 255, 255, 0.6);
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-container {
    flex-wrap: wrap;
    padding: 0 15px;
  }

  .logo {
    flex-grow: 1;
    text-align: left;
  }

  .main-nav {
    order: 3;
    flex-basis: 100%;
    display: none;
    margin-top: 15px;
    background-color: var(--primary-color);
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.3);
  }

  .main-nav.active {
    display: block;
  }

  .main-nav .nav-list {
    flex-direction: column;
    align-items: center;
    padding: 20px 0;
  }

  .main-nav .nav-list li {
    width: 100%;
    text-align: center;
  }

  .main-nav a {
    display: block;
    padding: 12px 0;
    font-size: 18px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  }

  .main-nav a:hover::after {
    width: 0; /* Disable underline on mobile for cleaner look */
  }

  .header-actions {
    order: 2;
    margin-left: auto;
    gap: 5px;
  }

  .header-actions .btn {
    padding: 8px 12px;
    font-size: 14px;
  }

  .hamburger-menu {
    display: flex;
    order: 1;
    margin-right: 15px; /* Space between logo and hamburger */
  }

  .hamburger-menu.active .bar:nth-child(1) {
    transform: translateY(11px) rotate(45deg);
  }

  .hamburger-menu.active .bar:nth-child(2) {
    opacity: 0;
  }

  .hamburger-menu.active .bar:nth-child(3) {
    transform: translateY(-11px) rotate(-45deg);
  }

  .footer-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .footer-nav h3::after,
  .footer-contact h3::after {
    left: 50%;
    transform: translateX(-50%);
  }
}