:root {
  --brand-blue: #002e5d;
  --brand-orange: #ffa94d;
}

/* Cuerpo */
body {
  background: var(--brand-blue);
  color: #fff;
  font-family: Inter, system-ui, sans-serif;
}

/*–– Botones ––*/
.btn {
  display: inline-block;
  padding: 0.75rem 1.25rem;
  border-radius: 0.5rem;
  font-weight: 600;
  text-decoration: none;
  transition: box-shadow 0.2s ease, background-color 0.2s ease, color 0.2s ease;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
  cursor: pointer;
}
.btn:hover {
  box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}
.btn:focus {
  outline: 2px solid rgba(255,255,255,0.6);
  outline-offset: 2px;
}

/* Botón principal */
.btn-primary {
  background-color: var(--brand-orange);
  color: #222;
  border: none;
}
.btn-primary:hover {
  background-color: #ee993f;
}

/* Botón secundario */
.btn-secondary {
  background-color: transparent;
  border: 2px solid var(--brand-orange);
  color: var(--brand-orange);
}
.btn-secondary:hover {
  background-color: var(--brand-orange);
  color: #222;
}

/*–– Formularios ––*/
form {
  max-width: 360px;
  margin: 0 auto;        /* centra el bloque del formulario */
  width: 100%;
}
form label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
  color: #fff;
}
form input,
form select,
form textarea {
  width: 100%;
  padding: 0.5rem 1rem;
  margin-bottom: 1rem;
  border: none;
  border-radius: 0.375rem;
  background-color: #fff;
  color: #333;
  font-size: 1rem;
  box-sizing: border-box;
}
form input:focus,
form select:focus,
form textarea:focus {
  outline: 2px solid var(--brand-orange);
  outline-offset: 2px;
}

/*–– Animaciones hero ––*/
@keyframes scaleFade {
  0% { opacity: 0; transform: scale(.7) }
  100% { opacity: 1; transform: scale(1) }
}
.hero-appear { animation: scaleFade .6s ease-out both }

/*–– Logos ––*/
.logo-big   { width: 60% }
.logo-small { width: 100px }

/*-- Texto matemático --*/
label sub,
label sup {
  font-size: 0.75em;
  vertical-align: baseline;
  position: relative;
  top: 0.25em;
}