/* Tutor Core CSS — shared across all subject modules (statics, diffeq, circuits, etc.)
   Extracted from proven homework styling to ensure visual consistency across all homework files */

:root {
  /* Dark theme palette — aligned to forged-kit (arath.site) tokens.
     --green intentionally held back: semantic completion/success marker. */
  --bg: #030201;                       /* fk-bg */
  --card: rgba(13, 11, 10, 0.6);       /* fk-card-bg */
  --border: rgba(255, 136, 0, 0.12);   /* fk-border-soft */
  --accent: #FF8800;                   /* fk-accent */
  --accent2: var(--fk-accent-dim);     /* was purple; requires forged.css loaded */
  --green: #4ade80;
  --text: #e0e0e0;                     /* fk-text */
  --dim: #9ca3af;                      /* fk-text-dim */
  --answer-bg: rgba(255, 136, 0, 0.06);
  --answer-border: rgba(255, 136, 0, 0.35); /* fk-border-strong */
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  padding: 2rem;
  max-width: 900px;
  margin: 0 auto;
}

h1 {
  font-size: 1.8rem;
  color: var(--accent);
  border-bottom: 2px solid var(--accent);
  padding-bottom: 0.5rem;
  margin-bottom: 0.3rem;
}

.subtitle {
  color: var(--dim);
  margin-bottom: 2rem;
  font-size: 0.95rem;
}

.section-header {
  color: var(--accent);
  font-size: 1.4rem;
  margin: 2rem 0 1rem 0;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}

.question-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.8rem;
  margin-bottom: 1.5rem;
}

.question-card h2 {
  color: var(--accent2);
  font-size: 1.2rem;
  margin-bottom: 0.8rem;
}

.problem-statement {
  background: #090706; /* fk-surface */
  border-left: 3px solid var(--accent);
  padding: 1rem 1.2rem;
  margin-bottom: 1.2rem;
  border-radius: 0 8px 8px 0;
  font-size: 0.95rem;
}

.step {
  margin: 0.8rem 0;
  padding-left: 1rem;
}

.step-label {
  color: var(--green);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
}

.why-box {
  background: #0d0b0a;
  border-left: 3px solid var(--accent2);
  padding: 0.6rem 1rem;
  margin: 0.5rem 0;
  border-radius: 0 6px 6px 0;
  font-size: 0.9rem;
  color: #ffcf9e;
}

.why-box strong {
  color: var(--accent2);
}

.answer-box {
  background: var(--answer-bg);
  border: 1px solid var(--answer-border);
  border-radius: 8px;
  padding: 0.8rem 1.2rem;
  margin-top: 1rem;
}

.answer-box .label {
  color: var(--green);
  font-weight: 700;
  margin-right: 0.4rem;
}

.sub-problem {
  border-top: 1px solid var(--border);
  padding-top: 1rem;
  margin-top: 1rem;
}

.sub-problem:first-of-type {
  border-top: none;
  padding-top: 0;
  margin-top: 0;
}

.note {
  color: var(--dim);
  font-style: italic;
  font-size: 0.9rem;
  margin-top: 0.6rem;
}

.status-badge {
  display: inline-block;
  background: #1a2e1a;
  border: 1px solid #2d5c30;
  color: var(--green);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-left: 0.8rem;
  vertical-align: middle;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}

th, td {
  padding: 0.6rem 1rem;
  text-align: left;
  border: 1px solid var(--border);
}

th {
  background: #090706; /* fk-surface */
  color: var(--accent);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

td {
  font-size: 0.95rem;
}

.katex {
  font-size: 1.1em !important;
}

.solution-divider {
  border: none;
  border-top: 1px dashed var(--border);
  margin: 1.2rem 0;
}

canvas {
  display: block;
  margin: 1rem auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #090706; /* fk-surface */
}

.plot-label {
  text-align: center;
  color: var(--dim);
  font-size: 0.85rem;
  margin-top: 0.3rem;
  margin-bottom: 1rem;
}

p { margin: 0.6rem 0; }
ul, ol { padding-left: 1.5rem; margin: 0.6rem 0; }
li { margin: 0.3rem 0; }

.steps-list {
  list-style: none;
  padding: 0;
  margin: 1rem 0;
}

.progress-container {
  background: #090706; /* fk-surface */
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  margin-bottom: 2rem;
}

.progress-label {
  font-size: 0.9rem;
  color: var(--dim);
  margin-bottom: 0.5rem;
}

.progress-bar {
  background: var(--border);
  border-radius: 4px;
  height: 6px;
  overflow: hidden;
  margin-bottom: 0.5rem;
}

.progress-fill {
  background: linear-gradient(90deg, #994400, #FF8800); /* fk-accent-deep → fk-accent */
  height: 100%;
  transition: width 0.3s ease;
}

.progress-text {
  font-size: 0.85rem;
  color: var(--text);
  display: flex;
  justify-content: space-between;
}

.reset-progress-btn {
  background: var(--border);
  border: 1px solid var(--border);
  color: var(--dim);
  padding: 0.4rem 0.8rem;
  border-radius: 4px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
  margin-top: 0.5rem;
}

.reset-progress-btn:hover {
  background: #f87171;
  border-color: #f87171;
  color: white;
}

.toc {
  background: #090706; /* fk-surface */
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.5rem;
  margin-bottom: 2rem;
}

.toc h3 {
  color: var(--accent);
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.toc ol {
  list-style: decimal;
  padding-left: 1.5rem;
}

.toc li {
  margin: 0.3rem 0;
  font-size: 0.92rem;
}

.toc a {
  color: var(--accent2);
  text-decoration: none;
}

.toc a:hover {
  text-decoration: underline;
}

.toc .sec {
  color: var(--dim);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 0.8rem;
  font-weight: 700;
}

.toc-check {
  color: var(--green);
  margin-right: 0.4rem;
}

.badge-label {
  display: inline-block;
  background: rgba(255, 136, 0, 0.08); /* fk-chip-bg */
  border: 1px solid rgba(255, 136, 0, 0.35);
  color: var(--accent);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-left: 0.8rem;
  vertical-align: middle;
}

.mark-complete-label {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  color: var(--dim);
  font-size: 0.9rem;
  user-select: none;
}

.quiz-toggle-btn {
  background: var(--border);
  border: 1px solid var(--border);
  color: var(--dim);
  padding: 0.3rem 0.6rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.quiz-toggle-btn:hover {
  background: var(--accent2);
  color: var(--bg);
  border-color: var(--accent2);
}

.card-header-right {
  display: flex;
  gap: 0.6rem;
  align-items: center;
  font-size: 0.9rem;
}

.step-reveal-btn {
  background: none;
  border: none;
  color: var(--green);
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 700;
  cursor: pointer;
  padding: 0;
  transition: color 0.2s;
}

.step-reveal-btn:hover {
  color: var(--accent);
}

.step-body.hidden {
  display: none;
}

.answer-box.hidden {
  display: none;
}

.reference-box {
  background: #0d0b0a;
  border: 1px solid rgba(255, 136, 0, 0.2);
  border-left: 4px solid var(--accent2);
  border-radius: 0 10px 10px 0;
  margin: 1.2rem 0;
  padding: 1rem 1.2rem;
}

.reference-box .title {
  display: block;
  color: var(--accent2);
  font-weight: 700;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.5rem;
}

strong {
  color: #fff;
}

.legend {
  background: #090706; /* fk-surface */
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.2rem;
  margin-bottom: 2rem;
  font-size: 0.9rem;
}

.legend h3 {
  color: var(--accent);
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.legend .item {
  margin: 0.3rem 0;
}

.companion-link {
  padding: 12px;
  margin: 20px 0;
  text-align: center;
  font-size: 0.95em;
  border-top: 2px solid var(--accent);
  padding-top: 20px;
}

.companion-link a {
  color: var(--accent);
  text-decoration: none;
  font-weight: bold;
}

.companion-link a:hover {
  text-decoration: underline;
}