:root {
  --primary: #c8102e;
  --accent: #ff6b00;
  --gold: #ffd700;
  --dark: #1e2937;
  --light: #f8f9fa;
}

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

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--light);
  color: #333;
  line-height: 1.75;
}

/* ===================== HEADER ===================== */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 999;
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0,0,0,.08);
  transition: all 0.4s ease;
}

header.scrolled {
  box-shadow: 0 10px 30px rgba(0,0,0,.1);
}

.nav {
  max-width: 1400px;
  height: 85px;
  margin: auto;
  padding: 0 40px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Logo */
.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: inherit;
}

.logo img {
  width: 58px;
  height: 58px;
  object-fit: contain;
  border-radius: 50%;
  transition: 0.4s;
}

.logo img:hover {
  transform: rotate(-10deg) scale(1.1);
}

.logo-text h2 {
  font-size: 28px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.logo-text span {
  font-size: 13px;
  color: #555;
}

.overlay.active{
    opacity:1;
    visibility:visible;
}

/* Menu */
.nav-links {
    display:flex;
    align-items:center;
    gap:32px;
}

.nav-links a{
    position:relative;
    color:#243b55;
    text-decoration:none;
    font-weight:600;
    transition:.3s;
}

.nav-links a.active{
    color:#c8102e;
}

.nav-links a.active::after{
    content:"";
    position:absolute;
    left:0;
    bottom:-10px;
    width:100%;
    height:3px;
    background:#c8102e;
}

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

.hamburger{
    display:none;
    font-size:28px;
    cursor:pointer;
    color:var(--primary);
}

/* ===================== MOBILE MENU (Dropdown dọc) ===================== */
@media (max-width: 767px) {
  .hamburger {
    display: block;
  }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: center;
    padding: 25px 0;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    gap: 18px;
    display: none;
    border-top: 1px solid #eee;
    transition: all 0.4s ease;
  }

  .nav-links.active {
    display: flex;
  }

  .nav-links a {
    font-size: 18px;
    padding: 8px 0;
    width: 100%;
    text-align: center;
  }
}
/* ===================== HERO ===================== */
.hero {
  min-height: 100vh;
  padding-top: 85px;
  display: flex;
  align-items: center;
  position: relative;
  background: linear-gradient(135deg, #f8fbff 0%, #dceeff 40%, #b8dcff 100%);
}

.hero-content {
  max-width: 1300px;
  margin: 0 auto;
  padding: 0 20px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
}

.hero-text h1 {
  font-size: clamp(2.6rem, 6.5vw, 4.5rem);
  line-height: 1.1;
  font-weight: 900;
  color: #173B6C;
  margin-bottom: 20px;
}

.hero-text h1 span {
  color: #D62828;
  position: relative;
}

.hero-text h1 span::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 6px;
  width: 100%;
  height: 16px;
  background: #FFD54F;
  opacity: 0.45;
  z-index: -1;
  border-radius: 20px;
}

.hero-text p {
  font-size: clamp(1.2rem, 3vw, 1.45rem);
  line-height: 1.7;
  color: #425466;
  margin-bottom: 35px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 16px 40px;
  background: linear-gradient(45deg, #ff6b00, #ff8c00);
  color: white;
  border: none;
  border-radius: 50px;
  font-size: 1.25rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 10px 30px rgba(255, 107, 0, 0.5);
  transition: all 0.4s;
}

.btn:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 40px rgba(255, 107, 0, 0.6);
}

.hero-image img {
  width: 100%;
  max-width: 480px;
  border-radius: 20px;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.4);
  animation: float 6s ease-in-out infinite;
}


/* ===================== CONTENT ===================== */
.content {
  padding: 140px 40px 120px;
  background: #fff;
}

.container {
  max-width: 1250px;
  margin: 0 auto;
}

.main-title {
  text-align: center;
  font-size: clamp(1.85rem, 5.5vw, 2.6rem);
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 12px;
  line-height: 1.2;
}

.highlight {
  text-align: center;
  font-size: clamp(1.95rem, 6vw, 2.7rem);
  font-weight: 900;
  color: var(--primary);
  margin: 8px 0 16px;
  line-height: 1.1;
}

.subtitle {
  text-align: center;
  font-size: clamp(1.1rem, 3.2vw, 1.35rem);
  color: #2c3e50;
  max-width: 780px;
  margin: 0 auto 60px;
  line-height: 1.5;
}

/* Features */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
  margin: 70px 0;
}

.feature-card {
  background: white;
  padding: 42px 32px;
  border-radius: 24px;
  box-shadow: 0 10px 35px rgba(0, 0, 0, 0.07);
  transition: all 0.4s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-18px);
  box-shadow: 0 25px 55px rgba(200, 16, 46, 0.18);
}

.icon-circle {
  width: 78px;
  height: 78px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.2rem;
  margin-bottom: 28px;
  box-shadow: 0 12px 30px rgba(200, 16, 46, 0.3);
}

.feature-card h3 {
  font-size: 1.65rem;
  color: var(--primary);
  margin-bottom: 22px;
}

/* Purpose & Showcase */
.purpose-section {
  background: linear-gradient(135deg, #f8fafc, #f1f5f9);
  padding: 60px;
  border-radius: 28px;
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.08);
  text-align: center;
  margin-top: 50px;
}

.section-title {
  font-size: 1.8rem;
  color: var(--primary);
  margin-bottom: 20px;
}

.showcase-image {
  text-align: center;
  margin: 70px 0;
}

.showcase-image img {
  max-width: 100%;
  border-radius: 24px;
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.2);
  transition: 0.5s;
}

.showcase-image img:hover {
  transform: scale(1.03);
}


/* Footer */
footer {
   background:linear-gradient(135deg,#f8fbff,#dceeff,#b8dcff);
    color:#222;
    text-align:center;
    padding:60px 20px 30px;
}

/* ===================== RESPONSIVE ===================== */
@media (max-width: 767px) {
  .nav {
    padding: 0 20px;
    height: 75px;
  }

  .content {
    padding: 100px 20px 80px;
  }

  .purpose-section {
    padding: 40px 25px;
  }
}
  @media (max-width: 767px) {
  .nav {
    height: 75px;
  }

  .hero {
    min-height: 80vh;
  }

  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 40px;
  }

  .hero-image img {
    max-width: 360px;
  }

  .explore {
    padding: 80px 15px;
  }

  .cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-text h1 {
    font-size: clamp(2rem, 8.5vw, 2.6rem);
  }
}