:root {
  --bg-main: #f5f7fb;
  --bg-card: #ffffff;

  --primary: #2f6fed;
  --primary-light: #e9f0ff;

  --success: #22c55e;
  --success-light: #eafaf1;

  --warning: #facc15;
  --warning-light: #fff8db;

  --danger: #ef4444;
  --danger-light: #fdecec;

  --text-main: #1f2937;
  --text-muted: #6b7280;

  --border-radius: 14px;
  --shadow-soft: 0 10px 30px rgba(0, 0, 0, 0.05);
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-main);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
html {
  scroll-behavior: smooth;
}

main {
  flex: 1;
  background: linear-gradient(135deg, #f5f7fa, #e4ecff);
}
.nav-bar {
  position: fixed;
  top: 0;
  left: 0;
  display: flex;
  width: 100%;
  background: linear-gradient(90deg, #2f6fed, #4f8cff);
  z-index: 1000;
  align-items: center; /* QUAN TRỌNG */
  gap: 20px;
  color: white;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.nav-bar a {
  display: block;
  color: white;
  font-size: 16px;
  text-decoration: none;
  padding: 20px 25px;
  opacity: 0.9;
  transition: color 0.3s;
}

.nav-bar a:hover {
  opacity: 1;
}
.search-box {
  margin-left: 25px;
}
.search-box input {
  background: #f9fafb;
  border: 1px solid #e5e7eb;
  border-radius: 10px;
  padding: 10px 14px;
  font-size: 14px;
  outline: none;
  width: 800px;
  transition: 0.3s;
}

.search-box input:focus {
  border-color: var(--primary);
  background: white;
  box-shadow: 0 0 0 2px rgba(79, 140, 255, 0.2);
}

.user-wrapper {
  position: relative;
}

.user-trigger {
  cursor: pointer;
}

.avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
}

/* MENU ẨN */
.user-dropdown {
  position: absolute;
  top: 50px;
  right: 0;

  width: 220px;
  background: #111;
  color: white;

  border-radius: 10px;
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.6);

  display: none;
  flex-direction: column;
  padding: 8px 0;
  z-index: 999;
}

.user-dropdown a {
  padding: 10px 16px;
  text-decoration: none;
  color: white;
  font-size: 14px;
}

.user-dropdown a:hover {
  background: #1f1f1f;
}

.user-dropdown hr {
  border: none;
  border-top: 1px solid #333;
  margin: 6px 0;
}

.content {
  max-width: 820px;
  margin: 120px auto 80px;
  padding: 48px;

  background: rgba(255, 255, 255, 0.9);
  border-radius: 20px;

  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.08);
  text-align: center;
}

.content .title {
  font-size: 40px;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 20px;
}

.content p {
  font-size: 16px;
  color: #475569;
  line-height: 1.7;
  max-width: 640px;
  margin: 0 auto 32px;
}

.features {
  display: flex;
  justify-content: center;
  gap: 30px;
  margin: 60px 0;
}

.feature {
  background: white;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 5px 20px rgba(0, 0, 0, 0.05);
}

.buy-btn {
  animation: pulse 1.2s infinite;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 10px;
  padding: 10px 18px;
  font-size: 14px;
  text-decoration: none;
  cursor: pointer;
}
.buy-btn:hover {
  background: #1f5ae0;
}
.products-section {
  padding: 80px 40px;
  background: #ffffff;
  text-align: center;
}

.products-section h2 {
  margin-bottom: 40px;
}
.product-card {
  background: #ffffff;
  border-radius: 14px;
  padding: 24px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);

  font-weight: 500;
  color: #1f2937;

  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.product-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.08);
}

.products {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(14rem, 1fr));
  gap: 25px;
}
#products {
  scroll-margin-top: 80px;
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.1);
  }
  100% {
    transform: scale(1);
  }
}
.footer {
  text-align: center;
  background: #f5f5f5;
  padding: 15px;
  font-size: 14px;
  color: #777;
  width: 100%;
}
.footer a {
  text-decoration: none;
  padding: 10px 20px;
  border-radius: 5px;
  background-color: #4da3ff;
}