:root {
  --primary: #0066cc; /* Xanh dương chủ đạo */
  --secondary: #e02f2f; /* Đỏ nhấn */
  --accent: #f1c40f; /* Vàng nổi bật */
  
  --bg-body: #f4f6f8; /* Nền chính: Xám nhạt */
  --bg-section-alt: #ffffff; /* Nền phụ: Trắng */
  --bg-card: #ffffff; /* Nền thẻ: Trắng */
  
  --text-main: #2c3e50;
  --text-muted: #7f8c8d;
  
  --border-light: #e1e4e8;
  --shadow-card: 0 10px 20px rgba(0, 0, 0, 0.05); /* Bóng mờ nhẹ */
  --shadow-hover: 0 15px 30px rgba(0, 102, 204, 0.15);
  
  --radius: 12px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: 'Barlow', sans-serif;
  background-color: var(--bg-body);
  color: var(--text-main);
  line-height: 1.6;
}

h1, h2, h3, .logo, .eyebrow {
  font-family: 'Orbitron', sans-serif;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

a { text-decoration: none; color: inherit; transition: var(--transition); }
ul { list-style: none; }
img { max-width: 100%; display: block; }

.container { max-width: 1240px; margin: 0 auto; padding: 0 20px; }
.btn {
  padding: 10px 28px; border: none; border-radius: 50px; cursor: pointer;
  font-weight: 700; text-transform: uppercase; font-size: 0.9rem;
  transition: var(--transition); display: inline-block;
}

/* --- 2. HEADER --- */
header {
  position: sticky; top: 0; width: 100%; z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 15px rgba(0,0,0,0.05);
  border-bottom: 1px solid var(--border-light);
}

.header-top { display: flex; justify-content: space-between; align-items: center; padding: 12px 0; }

.logo { 
  font-size: 1.8rem; font-weight: 800; color: var(--primary); 
  background: -webkit-linear-gradient(45deg, var(--primary), #2980b9);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.header-search input {
  background: var(--bg-body);
  border: 1px solid var(--border-light);
  padding: 10px 20px; border-radius: 50px;
  color: var(--text-main); width: 350px; outline: none; transition: var(--transition);
}
.header-search input:focus { border-color: var(--primary); background: #fff; box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.1); }

.header-actions { display: flex; gap: 15px; align-items: center; }
.btn-cart { background: var(--bg-body); color: var(--text-main); display: flex; align-items: center; gap: 5px; }
.btn-cart:hover { background: var(--primary); color: #fff; }

.nav { border-top: 1px solid var(--border-light); background: #fff; }
.nav-links { display: flex; justify-content: center; gap: 40px; padding: 12px 0; }
.nav-links a { font-weight: 600; color: var(--text-main); font-size: 0.95rem; position: relative; }
.nav-links a:hover { color: var(--primary); }
.nav-links a::after {
  content: ''; position: absolute; bottom: -5px; left: 0; width: 0%; height: 2px;
  background: var(--primary); transition: var(--transition);
}
.nav-links a:hover::after { width: 100%; }

/* --- 3. HERO SECTION --- */
/* --- 3. HERO SECTION (UPDATED: FULL BLACK) --- */
.hero {
  padding: 120px 0 100px; /* Tăng độ cao một chút cho thoáng */
  
  /* Đổi sang nền đen. Dùng Gradient đen-xám nhẹ để tạo chiều sâu thay vì đen kịt */
  background: radial-gradient(circle at center, #1a1a1a 0%, #000000 100%);
  
  color: #fff; 
  text-align: center; 
  position: relative;
  
  /* Giữ lại đường cắt chéo (clip-path) nhưng làm nó nhẹ hơn 
     để cảm giác "full" màn hình hơn nhưng vẫn giữ nét Gundam */
  
  /* Hoặc nếu bạn muốn đen vuông vức 100% không cắt chéo, 
     hãy xóa dòng clip-path ở trên đi */
}

/* Cập nhật màu nút bấm trong Hero cho hợp nền đen */
.btn-hero-primary { 
  background: #fff; /* Nút trắng nổi bật trên nền đen */
  color: #000; 
  padding: 12px 35px; 
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.3); /* Hiệu ứng phát sáng nhẹ (Glow) */
}

.btn-hero-primary:hover { 
  transform: translateY(-3px); 
  background: var(--primary); /* Hover vào chuyển sang màu xanh chủ đạo */
  color: #fff;
  box-shadow: 0 0 30px var(--primary);
}
/* --- 4. SECTIONS --- */
.section { padding: 80px 0; }

.section-title { text-align: center; margin-bottom: 50px; }
.section-title h2 { font-size: 2.2rem; color: var(--text-main); margin-bottom: 10px; position: relative; display: inline-block; }
.section-title h2::before { 
  content: ''; position: absolute; bottom: -5px; left: 0; width: 40px; height: 4px; background: var(--primary); border-radius: 2px; 
}
.section-title h2::after { 
  content: ''; position: absolute; bottom: -5px; left: 45px; width: 10px; height: 4px; background: var(--secondary); border-radius: 2px; 
}

/* Categories */
.categories { background-color: var(--bg-section-alt); }
.category-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 25px; }
.category-card {
  background: var(--bg-body); border-radius: var(--radius); overflow: hidden;
  position: relative; height: 260px; transition: var(--transition);
  border: 1px solid var(--border-light);
}
.category-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-hover); border-color: var(--primary); }
.category-card img { width: 100%; height: 100%; object-fit: cover; transition: 0.5s; }
.category-card:hover img { transform: scale(1.1); }
.category-info {
  position: absolute; bottom: 0; width: 100%; padding: 20px;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent); color: #fff;
}

/* Products */
.products { background-color: var(--bg-body); }
.product-layout { display: grid; grid-template-columns: 260px 1fr; gap: 40px; }

/* Filter Panel */
.filter-panel { 
  background: var(--bg-card); padding: 25px; border-radius: var(--radius); 
  box-shadow: var(--shadow-card); height: fit-content; position: sticky; top: 100px;
}
.filter-group h4 { margin-bottom: 15px; color: var(--text-main); font-size: 1.1rem; border-bottom: 2px solid var(--bg-body); padding-bottom: 5px; }
.filter-group label { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; color: var(--text-muted); cursor: pointer; }
.filter-group label:hover { color: var(--primary); }

/* Product Cards */
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 25px; }

.product-card {
  background: var(--bg-card);
  border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: var(--transition);
  display: flex; flex-direction: column;
  border: 1px solid transparent;
}

.product-card:hover { 
  transform: translateY(-8px); 
  box-shadow: 0 20px 40px rgba(0,0,0,0.1); 
  border-color: var(--primary);
}

.product-img-wrap { overflow: hidden; height: 220px; background: #f0f0f0; position: relative; }
.product-img-wrap img { width: 100%; height: 100%; object-fit: cover; transition: 0.5s; }
.product-card:hover .product-img-wrap img { transform: scale(1.08); }

.tag { 
  position: absolute; top: 10px; left: 10px; 
  padding: 4px 10px; border-radius: 4px; color: #fff; font-size: 0.75rem; font-weight: 700; text-transform: uppercase;
}
.tag-blue { background: var(--primary); }
.tag-red { background: var(--secondary); }

.product-info { padding: 20px; flex-grow: 1; display: flex; flex-direction: column; }
.product-info h3 { font-size: 1rem; margin-bottom: 8px; color: var(--text-main); font-weight: 700; line-height: 1.4; }
.product-desc { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 15px; }

.price-action { margin-top: auto; display: flex; justify-content: space-between; align-items: center; padding-top: 15px; border-top: 1px dashed var(--border-light); }
.price { color: var(--secondary); font-weight: 800; font-size: 1.1rem; }
.btn-buy { 
  width: 35px; height: 35px; border-radius: 50%; border: none; 
  background: var(--bg-body); color: var(--primary); 
  display: flex; align-items: center; justify-content: center; cursor: pointer; transition: 0.2s;
}
.btn-buy:hover { background: var(--primary); color: #fff; }

/* Promo */
.promo-section { padding: 60px 0; }
.promo-card {
  background: linear-gradient(100deg, var(--primary), #2980b9);
  border-radius: 20px; padding: 50px; color: #fff; text-align: center;
  position: relative; overflow: hidden; box-shadow: 0 20px 40px rgba(0, 102, 204, 0.2);
}
.promo-card h2 { font-size: 2.5rem; margin-bottom: 15px; }
.btn-white { background: #fff; color: var(--primary); }
.btn-white:hover { background: var(--bg-body); box-shadow: 0 5px 15px rgba(0,0,0,0.1); }

/* --- 5. FOOTER --- */
footer { background: #1a1d21; color: #fff; padding: 70px 0 30px; margin-top: 0; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 50px; }
.footer-brand h3 { color: var(--primary); font-size: 1.5rem; margin-bottom: 15px; }
.footer-brand p { color: #95a5a6; font-size: 0.9rem; margin-bottom: 20px; }
.footer-col h4 { margin-bottom: 20px; font-size: 1.1rem; }
.footer-col a { display: block; color: #95a5a6; margin-bottom: 12px; font-size: 0.95rem; }
.footer-col a:hover { color: #fff; transform: translateX(5px); }
.footer-bottom { border-top: 1px solid #34495e; padding-top: 30px; text-align: center; color: #7f8c8d; font-size: 0.9rem; }

/* --- RESPONSIVE --- */
@media (max-width: 768px) {
  .hero h1 { font-size: 2rem; }
  .product-layout { grid-template-columns: 1fr; }
  .filter-panel { display: none; }
  .header-top { flex-direction: column; gap: 10px; }
  .nav-links { flex-wrap: wrap; gap: 15px; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
}