* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: Arial;
  color: white;
  background: black;
}

/* FONDO */
.hero {
  position: fixed;
  width: 100%;
  height: 100vh;
  background: url('img/fondo.jpg') center/cover no-repeat;
  z-index: -1;
}

/* CENTRADO */
.overlay {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

/* CAJA */
.reserva-box {
  width: 100%;
  max-width: 420px;
  background: rgba(20,20,20,0.9);
  padding: 25px;
  border-radius: 20px;
  text-align: center;

  display: flex;
  flex-direction: column;
  gap: 15px;
}

/* TITULO */
h1 {
  font-size: 24px;
}

/* CALENDARIO */
.mini-calendario {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 10px;
}

.dia {
  padding: 15px;
  background: #222;
  border-radius: 10px;
  cursor: pointer;
}

.dia:hover {
  background: #333;
}

.dia.activo {
  background: red;
}

/* FECHA */
.fecha {
  background: #111;
  padding: 10px;
  border-radius: 8px;
}

/* FORM */
select {
  width: 100%;
  padding: 12px;
  border-radius: 8px;
  border: none;
  background: #222;
  color: white;
}

/* BOTÓN */
.btn {
  padding: 14px;
  background: red;
  border: none;
  border-radius: 10px;
  color: white;
  cursor: pointer;
}

/* MÓVIL */
@media (max-width: 600px) {
  .overlay {
    align-items: flex-start;
    padding-top: 60px;
  }

  .dia {
    padding: 18px;
  }
}