.model-builder { margin-top: 56px; padding-top: 36px; border-top: 1px solid var(--line); scroll-margin-top: 24px; }
.builder-heading { max-width: 800px; }
.builder-heading h2 { font-size: clamp(30px, 4vw, 46px); margin-bottom: 14px; }
.builder-heading > p:last-child { color: var(--muted); font-size: 17px; }
.builder-steps { display: flex; flex-wrap: wrap; gap: 12px 32px; margin: 24px 0; padding-left: 22px; color: var(--accent); font-size: 13px; }
.builder-layout { display: grid; grid-template-columns: minmax(280px, 1fr) minmax(0, 1.2fr); border: 1px solid var(--line); }
.builder-input, .builder-output { padding: 26px; min-width: 0; }
.builder-input { background: var(--surface); }
.builder-output { background: white; }
.model-builder label { display: block; font-size: 13px; font-weight: 650; line-height: 1.5; margin: 16px 0 7px; }
.model-builder textarea, .model-builder select { width: 100%; padding: 10px; border: 1px solid #8ca89d; border-radius: 0; background: var(--paper); color: var(--ink); font: inherit; font-size: 14px; }
.model-builder textarea { resize: vertical; min-height: 70px; }
.model-builder textarea:focus-visible, .model-builder select:focus-visible, .model-builder input:focus-visible, .model-builder button:focus-visible, .model-builder summary:focus-visible { outline: 3px solid #ac7841; outline-offset: 3px; }
.model-builder button { font: inherit; font-size: 13px; padding: 10px 12px; border: 1px solid var(--accent); color: var(--accent); background: white; cursor: pointer; }
.model-builder button.primary { color: white; background: var(--accent); }
.model-builder button:disabled { opacity: .55; cursor: not-allowed; }
.builder-actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 16px 0; }
.model-builder .lab-button { width: auto; margin: 0; }
.builder-guidance { border-top: 1px solid #bdcfc2; margin-top: 24px; padding-top: 16px; }
.model-builder summary { cursor: pointer; font-size: 14px; font-weight: 650; color: var(--accent); }
.builder-guidance p, .builder-guidance a { font-size: 12px; line-height: 1.6; }
.builder-guidance a { display: inline-block; margin-top: 16px; text-decoration: underline; text-underline-offset: 3px; }
.model-builder .builder-privacy, .model-builder .builder-note, #model-availability, #solver-availability { font-size: 12px; color: var(--muted); line-height: 1.7; margin: 16px 0; }
.builder-examples { padding-bottom: 12px; border-bottom: 1px solid #bdcfc2; margin-bottom: 22px; font-size: 13px; }
.builder-empty { color: var(--muted); max-width: 450px; padding: 20px 0; }
.builder-linearization { border: 1px solid var(--line); background: var(--surface); padding: 16px; margin: 14px 0; }
.builder-linearization pre { white-space: pre-wrap; overflow-wrap: anywhere; font-size: 13px; line-height: 1.7; }
.builder-linearization strong, .builder-linearizations a { font-size: 12px; }
.builder-linearization-kind { font-weight: 650; color: var(--accent); }
#model-status { font-size: 13px; color: var(--accent); line-height: 1.6; }
#model-review h3, #model-solution h3 { font-size: 25px; line-height: 1.3; margin: 18px 0 12px; }
#model-review h4 { font-size: 14px; margin: 24px 0 10px; }
#model-review p, #model-review li, #model-solution p { font-size: 13px; line-height: 1.7; overflow-wrap: anywhere; }
.builder-table { max-width: 100%; overflow-x: auto; margin: 12px 0; }
.builder-table table { width: 100%; border-collapse: collapse; font-size: 12px; }
.builder-table th, .builder-table td { padding: 9px; border: 1px solid #bdcfc2; text-align: left; vertical-align: top; }
.builder-table th { background: var(--surface); }
#model-lp { white-space: pre; overflow-x: auto; font-size: 12px; background: var(--surface); padding: 14px; }
#model-controls { border-top: 1px solid var(--line); padding-top: 20px; margin-top: 24px; }
.model-builder .builder-check { display: flex; gap: 10px; align-items: flex-start; font-weight: 400; margin: 20px 0; }
.builder-check input { width: 18px; height: 18px; flex: 0 0 18px; accent-color: var(--accent); }
.builder-solve { display: flex; gap: 16px; align-items: end; flex-wrap: wrap; }
.builder-solve label { margin-top: 0; }
#model-solution { border-top: 1px solid var(--line); margin-top: 20px; }
.model-builder [hidden] { display: none; }
.lab-entry-actions { display: flex; gap: 12px 24px; align-items: center; flex-wrap: wrap; margin: 20px 0; }
.lab-entry-actions a { font-size: 14px; text-decoration: underline; text-underline-offset: 4px; }
@media (max-width: 850px) { .builder-layout { grid-template-columns: 1fr; } .builder-input, .builder-output { padding: 20px; } }