:root {
  --color-labor-blue: #0F52BA;
  --color-labor-blue-light: #4169E1;
  --color-warning-orange: #FF7F00;
  --color-paper: #FDF9F1; /* Giấy ngả vàng */
  --color-text-main: #1E293B;
  --color-text-muted: #64748B;
  --color-border: #CBD5E1;
  
  --shadow-clipboard: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

body {
  background-color: #E2E8F0;
  color: var(--color-text-main);
  background-image: repeating-linear-gradient(45deg, #E2E8F0 0, #E2E8F0 2px, transparent 2px, transparent 8px);
}

.hero {
  padding: 6rem 1rem 4rem;
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.hero-content h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  color: var(--color-labor-blue);
}

.hero-content p {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 2rem;
  max-width: 500px;
}

/* Clipboard Metaphor */
.hero-visual {
  display: flex;
  justify-content: center;
}

.clipboard {
  width: 320px;
  background: var(--color-paper);
  box-shadow: var(--shadow-clipboard);
  border-radius: 4px;
  position: relative;
  padding: 3rem 2rem 2rem;
  transform: rotate(2deg);
}

.clip {
  position: absolute;
  top: -15px;
  left: 50%;
  transform: translateX(-50%);
  width: 120px;
  height: 40px;
  background: #94A3B8;
  border-radius: 8px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.2);
}

.clip::after {
  content: '';
  position: absolute;
  top: 15px;
  left: 20px;
  right: 20px;
  height: 10px;
  border-radius: 5px;
  background: #64748B;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.3);
}

.checklist-title {
  font-size: 1.25rem;
  font-weight: 800;
  text-transform: uppercase;
  border-bottom: 2px solid var(--color-labor-blue);
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
  text-align: center;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  font-family: monospace;
  font-size: 1rem;
}

.check-box {
  width: 20px;
  height: 20px;
  border: 2px solid var(--color-labor-blue);
  border-radius: 3px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.check-box.checked::after {
  content: '✓';
  color: var(--color-warning-orange);
  font-weight: bold;
}

.check-text.checked {
  text-decoration: line-through;
  color: var(--color-text-muted);
}

/* Features */
.features {
  max-width: 1200px;
  margin: 0 auto 6rem;
  padding: 0 1rem;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  background: white;
  padding: 2.5rem 2rem;
  border-radius: 8px;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
  border-left: 4px solid var(--color-labor-blue);
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 1rem 0 0.5rem;
}

.feature-card p {
  color: var(--color-text-muted);
  line-height: 1.6;
}

.btn-primary {
  background: var(--color-warning-orange);
  color: white;
  padding: 1rem 2rem;
  border-radius: 4px;
  font-weight: 700;
  text-decoration: none;
  display: inline-block;
  box-shadow: 0 4px 0px #CC6600;
  transition: transform 0.1s, box-shadow 0.1s;
}

.btn-primary:active {
  transform: translateY(4px);
  box-shadow: 0 0px 0px #CC6600;
}

@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
    text-align: center;
    padding-top: 4rem;
  }
  .hero-content p {
    margin: 0 auto 2rem;
  }
  .features {
    grid-template-columns: 1fr;
  }
}