* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; font-family: system-ui, Arial, sans-serif; }
img { max-width: 100%; display: block; }
.app { padding: 16px; }
:root { --gap: 12px; }

/* 1 */
.full { display:flex; justify-content:center; align-items:center; min-height:100vh; }
.card { padding:24px; border:1px solid #ddd; border-radius:12px; }

/* 2 */
.nav { display:flex; align-items:center; gap: var(--gap); padding:12px 16px; border-bottom:1px solid #eee; }
.menu { display:flex; gap: var(--gap); justify-content:center; flex:1; }
.cta { padding:8px 12px; border-radius:8px; border:1px solid #ddd; background:#fff; }

/* 3 */
.cards { display:flex; flex-wrap:wrap; gap: var(--gap); }
.cards .card { flex:1 1 220px; padding:20px; border:1px solid #eee; border-radius:10px; text-align:center; }

/* 4 */
.layout { display:flex; gap: var(--gap); min-height:70vh; }
.sidebar { width:240px; border:1px solid #eee; border-radius:12px; padding:12px; }
.content { flex:1; border:1px solid #eee; border-radius:12px; padding:16px; }

/* 5 */
.pricing { display:flex; gap:24px; }
.price { font-size:18px; display:flex; gap:6px; align-items:baseline; }
.amount { font-size:48px; font-weight:700; }

/* 6 */
.grid3 { display:grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); }
.grid3 > * { border:1px solid #eee; border-radius:10px; padding:16px; text-align:center; }

/* 7 */
.page { display:grid; grid-template-columns: 240px 1fr; grid-template-rows: auto 1fr auto; gap: var(--gap);
  grid-template-areas:
    "hdr hdr"
    "sbr mn"
    "ftr ftr"; min-height:70vh; }
.hdr { grid-area: hdr; }
.sbr { grid-area: sbr; }
.mn { grid-area: mn; }
.ftr { grid-area: ftr; }
.page > * { border:1px solid #eee; border-radius:10px; padding:12px; }

/* 8 */
.auto { display:grid; gap: var(--gap); grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.auto .card { padding:20px; border:1px solid #eee; border-radius:12px; text-align:center; }

/* 9 */
.galeria { display:grid; gap: var(--gap); grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); }
.galeria img { width:100%; aspect-ratio:1; object-fit:cover; border-radius:12px; }

/* 10 */
.hero { display:grid; place-items:center; min-height:40vh; }
.hero > * { grid-area:1 / 1; }
.hero h1 { background: rgba(0,0,0,.45); color:#fff; padding:16px 24px; border-radius:12px; }

/* 11 */
.mf { display:grid; gap: var(--gap); grid-template-columns: 1fr; }
@media (min-width: 768px){ .mf { grid-template-columns: repeat(3, 1fr); } }
.mf > * { border:1px solid #eee; border-radius:10px; padding:16px; text-align:center; }

/* 12 */
.rnav { display:flex; justify-content:space-between; align-items:center; padding:8px 12px; border-bottom:1px solid #eee; }
.menu nav { display:flex; flex-direction:column; gap:8px; padding:8px 0; }
@media (min-width: 768px){
  .menu > summary { display:none; }
  .menu nav { display:flex; flex-direction:row; gap:16px; }
  .menu[open] > nav, .menu > nav { display:flex; }
}

/* 13 */
.title { font-size: clamp(1.5rem, 2.5vw + 1rem, 3rem); line-height:1.15; }

/* 14 */
.rf { display:grid; gap: var(--gap); grid-template-columns: 1fr; max-width:720px; }
.rf label { display:flex; flex-direction:column; gap:6px; }
.rf input { padding:10px; border:1px solid #ddd; border-radius:8px; }
.rf button { padding:12px; border:0; border-radius:10px; background:#111; color:#fff; }
@media (min-width: 640px){
  .rf { grid-template-columns: 1fr 1fr; }
  .rf button { grid-column: 1 / -1; }
}