/* ==========================================================================
   BOTONES
   --------------------------------------------------------------------------
   .btn            → base
   .btn--primary   → acción principal (fondo acento)
   .btn--ghost     → acción secundaria (solo borde)
   .btn--icon      → botón cuadrado solo con icono
   ========================================================================== */

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  min-height: 48px;
  padding: 0 var(--sp-5);
  border-radius: var(--radius-xs);
  font-family: var(--ff-body);
  font-size: var(--fs-base);
  font-weight: 600;
  letter-spacing: 0.01em;
  white-space: nowrap;
  overflow: hidden;
  isolation: isolate;
  transition:
    color var(--dur-fast) ease,
    background-color var(--dur-fast) ease,
    border-color var(--dur-fast) ease,
    transform var(--dur-fast) var(--ease-out);
}

.btn:active {
  transform: scale(0.97);
}

.btn svg {
  width: 1.1em;
  height: 1.1em;
  flex-shrink: 0;
  transition: transform var(--dur-med) var(--ease-out);
}

/* La flecha se desplaza al pasar el mouse */
.btn:hover svg {
  transform: translateX(3px);
}

/* ---------- Primario ---------- */
.btn--primary {
  background: var(--c-accent);
  color: var(--c-accent-ink);
  box-shadow: 0 10px 30px -10px rgba(var(--c-teal-rgb), 0.7);
}

/* Al pasar el mouse se revela el gradiente de marca */
.btn--primary::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background: var(--grad-cool);
  opacity: 0;
  transition: opacity var(--dur-med) ease;
}

.btn--primary:hover::before {
  opacity: 1;
}

.btn--primary:hover {
  box-shadow: 0 14px 36px -10px rgba(var(--c-indigo-rgb), 0.75);
}

/* ---------- Fantasma ---------- */
.btn--ghost {
  border: 1px solid var(--c-line-strong);
  color: var(--c-text);
  background: rgba(var(--c-bg-rgb), 0.35);
  backdrop-filter: blur(8px);
}

.btn--ghost:hover {
  border-color: var(--c-indigo);
  color: var(--c-indigo);
}

/* ---------- Solo icono ---------- */
.btn--icon {
  width: 40px;
  min-height: 40px;
  padding: 0;
  border: 1px solid var(--c-line);
  color: var(--c-text-muted);
}

.btn--icon:hover {
  color: var(--c-text);
  border-color: var(--c-line-strong);
}

.btn--icon:hover svg {
  transform: rotate(-20deg);
}

/* Enlace de texto con subrayado animado */
.link-underline {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-weight: 500;
  color: var(--c-text);
}

.link-underline::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--dur-med) var(--ease-out);
}

.link-underline:hover {
  color: var(--c-accent);
}

.link-underline:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}