* { box-sizing: border-box; }
body { margin: 0; line-height: 1.7; }
.topbar { display: flex; align-items: center; gap: 24px; padding: 16px max(24px, calc((100vw - 1220px) / 2)); border-bottom: 1px solid var(--line); }
.brand { font-size: 1.2rem; font-weight: 700; text-decoration: none; }
.topbar nav { display: flex; gap: 20px; flex: 1; }
.topbar nav a { font-size: .9rem; }
main { max-width: 1268px; margin: 0 auto; padding: 28px 24px 48px; }
h2 { font-size: 1.12rem; line-height: 1.6; margin: 0; }
h3 { font-size: 1rem; margin: 0 0 12px; }
p { margin: 8px 0 16px; }
button, input, select, textarea { font-size: 1rem; }
button { border: 1px solid var(--line); border-radius: 8px; padding: 9px 14px; cursor: pointer; line-height: 1.5; }
button:disabled { opacity: .55; }
input, select, textarea { display: block; width: 100%; min-width: 0; border: 1px solid var(--control-border); border-radius: 8px; padding: 10px 11px; line-height: 1.5; margin-top: 5px; }
textarea { resize: vertical; min-height: 80px; }
label { display: block; font-size: .9rem; font-weight: 600; margin: 0 0 16px; }
label .optional { font-size: .8rem; font-weight: 400; color: var(--muted); margin-left: 6px; }
.workflow { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px; list-style: none; padding: 0; margin: 24px 0; }
.workflow li { display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: var(--panel); border: 1px solid var(--line); border-radius: var(--radius); }
.workflow b { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 50%; flex: 0 0 30px; background: var(--panel-strong); }
.workflow [aria-current="step"] { border-color: var(--accent); }
.workflow [aria-current="step"] b { background: var(--accent); color: var(--on-accent); }
.workflow small { display: block; font-size: .78rem; }
.workspace-grid { display: grid; grid-template-columns: minmax(280px, 340px) minmax(0, 1fr); gap: 24px; align-items: start; }
.card { border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; min-width: 0; }
.section-heading { display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.field-pair { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 12px; }
.check-label { display: flex; align-items: start; gap: 8px; font-weight: 400; }
.check-label input[type="checkbox"] { width: 18px; height: 18px; flex: 0 0 18px; margin-top: 5px; padding: 0; }
.full-width { width: 100%; }
.generation-settings { margin: 16px 0; }
summary { cursor: pointer; font-size: .9rem; }
.generation-settings label { margin-top: 12px; }
.draft-column { display: grid; gap: 20px; min-width: 0; }
.history-bar { display: flex; gap: 12px; align-items: end; padding: 16px 20px; }
.history-bar label { flex: 1; min-width: 0; margin: 0; }
.history-bar button { flex-shrink: 0; margin-bottom: 1px; }
.empty-state { padding: 56px 32px; text-align: center; }
.paper-symbol { font-size: 2.5rem; color: var(--accent); }
.empty-state p { max-width: 440px; margin: 16px auto 0; }
.badge { display: inline-block; font-size: .78rem; padding: 3px 10px; border: 1px solid var(--line); border-radius: 16px; }
.badge.unsaved { color: var(--yellow); background: var(--warm); }
.problem-editor { padding-top: 24px; border-top: 1px solid var(--line); margin-top: 24px; }
.problem-editor textarea { line-height: 1.8; }
.problem-editor .question-field { min-height: 116px; }
.problem-editor .answer-fields { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.25fr); gap: 16px; }
.formula-details { margin: -4px 0 16px; }
.formula-details label { margin: 12px 0 8px; }
.formula-details input { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; }
.figure-editor { margin-bottom: 24px; padding: 16px; border: 1px solid var(--line); border-radius: 8px; }
.figure-editor h4, .grading-criteria h4 { font-size: .95rem; margin: 0 0 12px; }
.figure-preview { max-width: 520px; margin: 0 auto 16px; }
.figure-preview svg { display: block; width: 100%; height: auto; }
.figure-preview img { display: block; max-width: 100%; max-height: 360px; object-fit: contain; margin: auto; }
.figure-caption { font-size: .85rem; text-align: center; white-space: pre-wrap; overflow-wrap: anywhere; }
.figure-grid { stroke: var(--line); stroke-width: 1; }
.figure-frame { fill: none; stroke: var(--control-border); }
.figure-axis { stroke: var(--text); stroke-width: 1.5; }
.figure-tick { fill: var(--muted); font-size: 12px; }
.figure-label { fill: var(--text); font-size: 14px; }
.figure-series, .figure-segment { fill: none; stroke: var(--accent); stroke-width: 2; }
.figure-point { fill: var(--accent); }
.figure-legend { display: flex; flex-wrap: wrap; gap: 8px 20px; padding: 4px 16px; font-size: .8rem; overflow-wrap: anywhere; }
.series-0 { stroke: var(--accent); fill: var(--accent); color: var(--accent); }
.series-1 { stroke: var(--cyan); fill: var(--cyan); color: var(--cyan); }
.series-2 { stroke: var(--purple); fill: var(--purple); color: var(--purple); }
.series-3 { stroke: var(--red); fill: var(--red); color: var(--red); }
.figure-series { fill: none; }
.figure-actions { display: flex; flex-wrap: wrap; align-items: start; gap: 12px; }
.figure-actions label { min-width: 0; flex: 1 1 220px; }
.figure-upload { max-width: 100%; padding: 8px; font-size: .8rem; }
.figure-upload::file-selector-button { background: var(--panel-strong); color: var(--text); border: 1px solid var(--line); border-radius: 6px; padding: 6px; margin-right: 8px; }
.figure-actions button { margin-top: 26px; }
.figure-details label { margin-top: 12px; }
.figure-json { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: .85rem; }
.grading-criteria { border-top: 1px solid var(--line); padding-top: 16px; margin: 8px 0 24px; }
.grading-criteria > label { max-width: 180px; }
.grading-criteria > label:first-of-type { max-width: 520px; }
.equivalence-help { padding: 10px 12px; background: var(--panel-strong); border-radius: 7px; }
.rubric-settings { margin-top: 18px; }
.rubric-settings > label { max-width: 180px; }
.criterion-row { display: grid; grid-template-columns: minmax(0, 1fr) 86px auto; gap: 10px; align-items: center; }
.criterion-row label { min-width: 0; }
.criterion-row button { padding: 8px; }
.criterion-row textarea { min-height: 80px; }
.grading-settings { border: 1px solid var(--line); background: var(--panel-strong); border-radius: 8px; padding: 16px; margin: 20px 0; }
.grading-next { border-top: 1px solid var(--line); padding-top: 20px; margin-top: 20px; }
.grading-link { display: inline-block; padding: 12px 16px; border-radius: 8px; background: var(--accent); color: var(--on-accent); font-weight: 600; text-decoration: none; }
.grading-next .ui-help { margin: 12px 0 0; }
.review-actions { padding-top: 20px; border-top: 1px solid var(--line); }
.review-actions > label { margin-top: 20px; max-width: 360px; }
.review-actions > .ui-help { margin-bottom: 0; }
.actions { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.job-panel { display: flex; gap: 16px; justify-content: space-between; align-items: center; margin: 0 0 20px; }
.job-panel .ui-help { margin: 4px 0 0; }
.notice, #message { background: var(--warm); border: 1px solid var(--line); border-radius: 8px; padding: 12px 16px; margin: 0 0 20px; overflow-wrap: anywhere; }
#message.error { border-color: var(--red); }
.output-section { border-color: var(--accent); }
.output-file { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; border-top: 1px solid var(--line); padding: 14px 0; }
.output-file strong { flex: 1 1 180px; overflow-wrap: anywhere; font-size: .9rem; }
.output-file a { border: 1px solid var(--line); border-radius: 8px; padding: 8px 12px; font-size: .9rem; }
.output-file .preview-link { background: var(--accent); color: var(--on-accent); border-color: var(--accent); }
.editable-data { margin-top: 16px; }
.editable-data summary { padding: 8px 0; }
#output-warning { margin-top: 16px; }
footer { max-width: 1268px; padding: 0 24px 24px; margin: auto; font-size: .8rem; }
@media (max-width: 900px) {
  .workspace-grid { grid-template-columns: minmax(260px, 300px) minmax(0, 1fr); gap: 16px; }
  .card { padding: 20px; }
  .problem-editor .answer-fields { grid-template-columns: minmax(0, 1fr); gap: 0; }
  .history-bar { align-items: stretch; flex-direction: column; }
  .history-bar button { align-self: start; }
}
@media (max-width: 680px) {
  main { padding: 20px 16px 32px; }
  .workspace-grid { grid-template-columns: minmax(0, 1fr); }
  .workflow { gap: 6px; margin: 20px 0; }
  .workflow li { display: block; padding: 12px 8px; font-size: .8rem; }
  .workflow b { width: 26px; height: 26px; margin-bottom: 8px; }
  .workflow small { display: none; }
  .card { padding: 18px; }
  .topbar nav { gap: 12px; }
  .topbar .brand { font-size: 1rem; }
  .topbar nav a { font-size: .8rem; }
  .empty-state { padding: 32px 20px; }
  .job-panel { align-items: start; flex-direction: column; }
  .review-actions > button { width: 100%; }
  .output-file { gap: 10px; }
  .output-file strong { flex-basis: 100%; }
  .figure-editor { padding: 12px; }
  .figure-actions button { margin-top: 0; }
  .criterion-row { grid-template-columns: minmax(0, 1fr) auto; gap: 0 10px; }
  .criterion-row label:first-child { grid-column: 1 / -1; }
  .criterion-row label:nth-child(2) { max-width: 140px; }
}