:root {
  --primary-color: #f27023; /* Cam thương hiệu */
  --secondary-color: #002147; /* Xanh Navy */
  --accent-color: #0056b3;
  --bg-light: #f8f9fa;
  --text-dark: #2c3e50;
  --text-muted: #6c757d;
  --white: #ffffff;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--text-dark);
  background-color: var(--bg-light);
  line-height: 1.6;
}

/* Header & Nav */
.topbar {
  background-color: var(--secondary-color);
  color: #d1e1f0;
  padding: 8px 5%;
  font-size: 13px;
  display: flex;
  justify-content: space-between;
}

.main-nav {
  background: var(--white);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  padding: 12px 5%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative; 
  z-index: 9999;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand-icon {
  background: var(--primary-color);
  color: white;
  width: 42px;
  height: 42px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 18px;
}

.brand-text h1 {
  font-size: 18px;
  color: var(--secondary-color);
  font-weight: 800;
}

.brand-text p {
  font-size: 11px;
  color: var(--text-muted);
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 20px;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-dark);
  font-weight: 600;
  font-size: 14px;
  transition: color 0.2s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary-color);
}

/* Nút Hamburger Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 22px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 10001;
}

.menu-toggle span {
  width: 100%;
  height: 3px;
  background-color: var(--secondary-color);
  border-radius: 3px;
  transition: all 0.3s ease-in-out;
}

/* Hiệu ứng biến đổi Hamburger thành dấu X */
.menu-toggle.open span:nth-child(1) {
  transform: translateY(9.5px) rotate(45deg);
}
.menu-toggle.open span:nth-child(2) {
  opacity: 0;
}
.menu-toggle.open span:nth-child(3) {
  transform: translateY(-9.5px) rotate(-45deg);
}

/* --- RESPONSIVE MOBILE & TABLET MENU --- */
@media (max-width: 768px) {
  .topbar {
    flex-direction: column;
    text-align: center;
    gap: 4px;
    padding: 6px 15px;
  }

  .menu-toggle {
    display: flex !important;
  }

  .nav-links {
    display: none; /* Mặc định ẩn trên mobile */
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background-color: #ffffff;
    flex-direction: column;
    gap: 0;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    border-top: 3px solid var(--primary-color);
    z-index: 10000;
  }

  /* Kích hoạt hiển thị khi dùng class .active */
  .nav-links.active {
    display: flex !important;
  }

  .nav-links li {
    width: 100%;
    border-bottom: 1px solid #eeeeee;
  }

  .nav-links a {
    display: block;
    padding: 15px 20px;
    font-size: 15px;
    font-weight: 600;
    color: var(--secondary-color);
    text-decoration: none;
    width: 100%;
    box-sizing: border-box;
  }

  .nav-links a:hover,
  .nav-links a.active {
    background-color: #fff5ee;
    color: var(--primary-color);
  }
}

/* Hero Slider */
.hero-slider {
  position: relative;
  width: 100%;
  height: 420px;
  overflow: hidden;
  background: #111;
  z-index: 1;
}

.slide-item {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: opacity 0.8s ease-in-out;
}

.slide-item.active {
  opacity: 1;
}

.slide-item .slide-link {
  display: block;
  width: 100%;
  height: 100%;
  text-decoration: none;
  color: inherit;
  position: relative;
  cursor: pointer;
}

.slide-item .slide-link img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.slide-caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(transparent, rgba(0, 33, 71, 0.85));
  color: white;
  padding: 40px 5% 20px;
}

.slide-caption h2 {
  font-size: 24px;
}

.slider-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(0, 0, 0, 0.4);
  color: white;
  border: none;
  font-size: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  cursor: pointer;
  z-index: 10;
}

.slider-btn.prev { left: 15px; }
.slider-btn.next { right: 15px; }
.slider-btn:hover { background: var(--primary-color); }

/* Features & Stats */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  padding: 40px 5%;
  background: var(--white);
}

.stat-card {
  text-align: center;
  padding: 20px;
  border-bottom: 3px solid var(--primary-color);
  background: #fdfdfd;
  border-radius: 6px;
}

.stat-number {
  font-size: 32px;
  font-weight: 800;
  color: var(--secondary-color);
}

.stat-label {
  font-size: 13px;
  color: var(--text-muted);
}

/* Sections */
.section {
  padding: 50px 5%;
}

.section-title {
  text-align: center;
  margin-bottom: 35px;
}

.section-title h2 {
  font-size: 24px;
  color: var(--secondary-color);
  position: relative;
  display: inline-block;
  padding-bottom: 8px;
}

.section-title h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--primary-color);
}

/* News Cards */
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 25px;
}

.news-card {
  background: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  transition: transform 0.2s;
}

.news-card:hover {
  transform: translateY(-4px);
}

.news-card img {
  width: 100%;
  height: 180px;
  object-fit: cover;
}

.news-body {
  padding: 20px;
}

.news-body .badge {
  background: #eef5ff;
  color: var(--accent-color);
  font-size: 11px;
  padding: 3px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.news-body h3 {
  font-size: 16px;
  margin: 10px 0;
  color: var(--secondary-color);
}

.news-body h3 a {
  text-decoration: none;
  color: inherit;
}

.news-body p {
  font-size: 13px;
  color: var(--text-muted);
}

/* Consultation Form Section */
.consult-section {
  background: linear-gradient(135deg, var(--secondary-color), #003366);
  color: white;
  border-radius: 12px;
  padding: 40px;
  margin: 20px 5%;
}

.consult-form {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 15px;
  margin-top: 20px;
}

.consult-form input, .consult-form select, .consult-form button {
  padding: 12px 15px;
  border-radius: 6px;
  border: 1px solid #ddd;
  font-size: 14px;
  width: 100%;
}

.consult-form button {
  background: var(--primary-color);
  color: white;
  border: none;
  font-weight: 700;
  cursor: pointer;
  transition: background 0.2s;
}

.consult-form button:hover {
  background: #d95d13;
}

/* --- FOOTER CTA BANNER (MÀU CAM) --- */
.footer-cta-banner {
  background-color: var(--primary-color);
  color: #ffffff;
  padding: 35px 8%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
}

.cta-content h2 {
  font-size: 26px;
  font-weight: 800;
  margin-bottom: 6px;
  letter-spacing: -0.3px;
}

.cta-content p {
  font-size: 14px;
  opacity: 0.95;
}

.btn-cta {
  background-color: #001e3d;
  color: #ffffff;
  padding: 14px 28px;
  border-radius: 8px;
  font-weight: 700;
  text-decoration: none;
  font-size: 15px;
  white-space: nowrap;
  display: inline-block;
  transition: background-color 0.2s ease, transform 0.2s ease;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.btn-cta:hover {
  background-color: #001226;
  transform: translateY(-2px);
}

/* --- FOOTER CHÍNH (NỀN XANH NAVY TỐI) --- */
.site-footer {
  background-color: #00152b;
  color: #a3b8cc;
  padding-top: 50px;
  font-size: 13.5px;
  line-height: 1.6;
}

.footer-container {
  display: grid;
  grid-template-columns: 1.2fr 0.9fr 1.1fr 1fr;
  gap: 30px;
  max-width: 1250px;
  margin: 0 auto;
  padding: 0 5% 40px 5%;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 15px;
}

.logo-box {
  background-color: var(--primary-color);
  color: #ffffff;
  font-weight: 900;
  font-size: 16px;
  padding: 6px 10px;
  border-radius: 6px;
}

.logo-text {
  color: #ffffff;
  font-weight: 800;
  font-size: 18px;
  letter-spacing: 0.5px;
}

.school-desc {
  margin-bottom: 18px;
  font-size: 13px;
  line-height: 1.5;
}

.social-links {
  display: flex;
  gap: 10px;
}

.social-icon {
  width: 32px;
  height: 32px;
  background-color: rgba(255, 255, 255, 0.1);
  color: #ffffff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  font-size: 13px;
  transition: background 0.2s;
}

.social-icon:hover {
  background-color: var(--primary-color);
}

.footer-heading {
  color: #ffffff;
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 18px;
  position: relative;
  padding-left: 10px;
  border-left: 3px solid var(--primary-color);
}

.footer-links {
  list-style: none;
  padding: 0;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  color: #a3b8cc;
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover {
  color: #ffffff;
}

.info-list p {
  margin-bottom: 8px;
  font-size: 13px;
}

.info-list strong {
  color: #ffffff;
}

.dev-text {
  margin-bottom: 15px;
  font-size: 13px;
}

.btn-dev-code {
  background-color: #004080;
  color: #ffffff;
  border: none;
  padding: 12px 20px;
  border-radius: 6px;
  font-weight: 700;
  cursor: pointer;
  width: 100%;
  font-size: 13.5px;
  transition: background-color 0.2s;
}

.btn-dev-code:hover {
  background-color: #0052a3;
}

.footer-copyright {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
  padding: 18px 20px;
  font-size: 12.5px;
  color: #7088a0;
}

@media (max-width: 992px) {
  .footer-cta-banner {
    flex-direction: column;
    text-align: center;
  }
  
  .footer-container {
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
  }
}

@media (max-width: 576px) {
  .footer-container {
    grid-template-columns: 1fr;
  }
}