/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: 14px;
  padding: 0.8rem 1.25rem;
  cursor: pointer;
  font-size: 0.95rem;
  transition:
    background 0.18s ease,
    color 0.18s ease,
    border-color 0.18s ease,
    box-shadow 0.18s ease,
    transform 0.08s ease,
    filter 0.18s ease;
  text-decoration: none;
  color: var(--text);
  will-change: transform;
}
.btn:active {
  transform: translateY(1px) scale(0.98);
}
.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-primary {
  background: linear-gradient(
    135deg,
    var(--brand) 0%,
    var(--brand-strong) 100%
  );
  color: var(--on-brand);
  box-shadow: var(--shadow-brand);
  border-color: color-mix(in srgb, var(--brand-strong) 65%, transparent);
  position: relative;
  overflow: hidden;
}
/* Diagonal sheen that sweeps across the button on hover. The pseudo
   sits off-screen by default and translates across when the parent is
   hovered, giving the primary CTA a tactile, premium feel. */
.btn-primary::before {
  content: "";
  position: absolute;
  top: 0;
  left: -120%;
  width: 60%;
  height: 100%;
  background: linear-gradient(
    100deg,
    transparent 0%,
    color-mix(in srgb, #ffffff 35%, transparent) 50%,
    transparent 100%
  );
  transform: skewX(-20deg);
  transition: left 0.6s ease;
  pointer-events: none;
}
.btn-primary:hover::before {
  left: 130%;
}
.btn-primary:hover {
  color: var(--on-brand);
  text-decoration: none;
  filter: brightness(1.05);
  box-shadow:
    0 12px 28px -8px color-mix(in srgb, var(--brand) 60%, transparent),
    0 2px 6px -2px color-mix(in srgb, var(--brand) 40%, transparent);
  transform: translateY(-1px);
}
.btn-primary:active {
  transform: translateY(0) scale(0.99);
  filter: brightness(1);
}

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border);
}
.btn-secondary:hover {
  background: var(--surface-2);
  border-color: color-mix(in srgb, var(--border) 60%, var(--text-muted));
}

.btn-danger {
  background: var(--danger);
  color: #fff;
  box-shadow: 0 8px 20px -8px color-mix(in srgb, var(--danger) 50%, transparent);
}
.btn-danger:hover {
  filter: brightness(1.06);
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.5rem 0.9rem;
  font-size: 0.88rem;
  border-radius: 12px;
}

/* Circular icon CTAs (Send / Stop) - premium, balances the textarea pill. */
.btn-icon {
  width: 46px;
  height: 46px;
  padding: 0;
  border-radius: 50%;
  flex: 0 0 auto;
}
.btn-icon svg {
  transition: transform 0.18s ease;
}
.btn-icon:hover svg {
  transform: scale(1.08);
}
.btn-icon.btn-primary svg {
  transform: translate(-1px, 1px);
}
.btn-icon.btn-primary:hover svg {
  transform: translate(-1px, 1px) scale(1.08);
}