:root {
  --primary: #1a3a4a;
  --secondary: #2d7d5f;
  --bg: #f4f1ec;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: var(--bg);
}

/* HEADER */
header {
  background: var(--primary);
  color: white;
  padding: 2rem;
  text-align: center;
}

/* SECCIONES */
section {
  max-width: 900px;
  margin: auto;
  padding: 2rem 1rem;
}

/* CARD DEMO */
.card {
  display: flex;
  flex-direction: column;
  border: 1px solid #ccc;
  border-radius: 10px;
  overflow: hidden;
  background: white;
}

.card .img {
  background: #ddd;
  height: 120px;
}

.card .text {
  padding: 1rem;
}

/* MOBILE FIRST */
@media (min-width: 600px) {
  .card {
    flex-direction: row;
  }

  .card .img {
    width: 150px;
    height: auto;
  }
}

/* GRID DEMO */
.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.grid div {
  background: white;
  padding: 1rem;
  border: 1px solid #ccc;
}

/* BREAKPOINTS */
@media (min-width: 600px) {
  .grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 900px) {
  .grid {
    grid-template-columns: 1fr 1fr 1fr;
  }
}

/* CLAMP */
h1 {
  font-size: clamp(1.5rem, 5vw, 3rem);
}

/* BOTÓN DEMO */
button {
  padding: 10px 20px;
  border: none;
  background: var(--secondary);
  color: white;
  cursor: pointer;
  border-radius: 6px;
}