/* Indice HTML del portfolio: leggibile anche senza il carosello JavaScript. */
.concept-index {
  padding: clamp(40px, 6vw, 80px) var(--container-padding, 24px);
  border-top: 1px solid var(--line);
  background: var(--bg);
}
.concept-index-inner { max-width: 1120px; margin: 0 auto; }
.concept-index h2 {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 34px);
  line-height: 1.4;
  margin: 0 0 20px;
}
.concept-index p { color: var(--ui-copy); line-height: 1.75; max-width: 80ch; }
.concept-index a { color: var(--accent-primary); text-decoration: underline; text-underline-offset: 4px; }
.concept-index a:hover { color: var(--text-primary); }
.concept-index a:focus-visible, .concept-index summary:focus-visible {
  outline: 2px solid var(--accent-primary); outline-offset: 5px;
}
.concept-index-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px 24px; margin: 32px 0; }
.concept-index details { min-width: 0; border: 1px solid var(--line); padding: 18px 20px; align-self: start; scroll-margin-top: 100px; }
.concept-index summary { color: var(--text-primary); font-weight: 600; line-height: 1.5; }
.concept-index details p { margin: 16px 0 0; font-size: 15px; }
@media (max-width: 640px) { .concept-index-grid { grid-template-columns: 1fr; } }