:root{
  --bg:#f3f6fb;
  --card:#ffffff;
  --accent:#2563eb;
  --input-border:rgb(150, 140, 140);
  --radius:12px;
  --shadow: 0 6px 20px rgba(38,99,235,0.08);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}

html,body{
  height:100%;
}

body{
  margin:0;
  background: linear-gradient(180deg, var(--bg), #eef3fb);
  align-items:center;
  justify-content:center;
}

/* tarjeta */
.card{
  width:360px;
  padding:28px;
  background:var(--card);
  border-radius:var(--radius);
  box-shadow:var(--shadow);
  text-align:center;
}

h1{
  margin:0 0 14px 0;
  font-size:18px;
  color:#0f172a;
}

p.sub{
  margin:0 0 18px 0;
  color:#475569;
  font-size:13px;
}

form{
  display:flex;
  flex-direction:column;
  gap:12px;
  align-items:center;
}

/* input */
input[type="text"]{
  width:100%;
  padding:12px 14px;
  font-size:15px;
  border:1px solid var(--input-border);
  border-radius:10px;
  outline:none;
  transition:box-shadow .15s, border-color .12s;
  box-sizing:border-box;
}

input[type="text"]:focus{
  border-color:var(--accent);
  box-shadow:0 4px 18px rgba(37,99,235,0.12);
}

/* boton */
button{
  min-width:140px;
  padding:10px 16px;
  border-radius:10px;
  border:0;
  color:rgb(255, 255, 255);
  font-weight:600;
  cursor:pointer;
  font-size:15px;
  box-shadow: 0 6px 18px rgba(37,99,235,0.12);
}
.color {
  background-color: rgb(147 118 91);
}

button:active{
  transform:translateY(1px);
}

/* Responsivo */
@media (max-height:520px){
  body{
    align-items:flex-start;
    padding-top:28px;
    padding-bottom:28px;
  }
}