/* Course teaching diagrams (public/teach-diagrams.js). Brand tokens only (/brand.css), mixed with color-mix; phone first. */
.td { --td-low: color-mix(in srgb, var(--primary) 18%, var(--card)); --td-high: var(--primary);
  --td-m1: color-mix(in srgb, var(--primary) 22%, transparent); --td-m1-line: var(--primary);
  --td-m2: color-mix(in srgb, var(--accent) 20%, transparent); --td-m2-line: var(--accent-text);
  --td-m3: color-mix(in srgb, var(--ok) 22%, transparent); --td-m3-line: var(--ok);
  --td-m4: color-mix(in srgb, var(--text-muted) 22%, transparent); --td-m4-line: var(--text-muted);
  margin: 18px 0; padding: clamp(14px, 3vw, 20px); border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); color: var(--text); }
.td-cap { font-weight: 700; color: var(--heading); font-size: 16px; margin: 0 0 12px; }
.td-note { font-size: 14px; color: var(--text-muted); margin: 12px 0 0; }
.td-icon { width: 22px; height: 22px; flex: 0 0 auto; color: var(--primary); vertical-align: -5px; margin-right: 6px; }
.td-num { display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--primary); color: var(--on-primary);
  font-weight: 700; font-size: 15px; flex: 0 0 auto; }

/* flow */
.td-flow-list { list-style: none; margin: 0; padding: 0; }
.td-step { display: flex; gap: 12px; align-items: flex-start; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px; }
.td-step-body { min-width: 0; }
.td-step-body strong { color: var(--heading); font-size: 16px; }
.td-step-body span { display: block; margin-top: 4px; font-size: 15px; line-height: 1.6; color: var(--text); }
.td-link { display: flex; padding-left: 14px; height: 24px; color: var(--border-strong); }
.td-arrow { width: 20px; height: 24px; }

/* decision */
.td-ask { display: flex; align-items: center; margin: 0; padding: 10px 12px; background: var(--card); border: 2px solid var(--primary); border-radius: var(--radius-sm);
  font-weight: 700; color: var(--heading); }
.td-branches { list-style: none; margin: 0 0 0 16px; padding: 4px 0 0 0; border-left: 2px solid var(--border-strong); }
.td-branch { position: relative; padding: 10px 0 2px 22px; }
.td-branch::before { content: ''; position: absolute; left: 0; top: 24px; width: 16px; border-top: 2px solid var(--border-strong); }
.td-edge { display: inline-block; font-size: 14px; font-weight: 700; color: var(--text-muted); background: var(--surface-2); border-radius: 999px; padding: 2px 10px; margin-right: 8px; }
.td-result { display: inline-flex; align-items: center; font-weight: 700; padding: 4px 12px; border-radius: 999px; border: 2px solid; margin-top: 4px; }
.td-result .td-icon { width: 18px; height: 18px; margin-right: 4px; color: inherit; vertical-align: 0; }
.td-yes, .td-good { color: var(--ok); border-color: var(--ok); background: var(--ok-bg); }
.td-no, .td-bad { color: var(--accent-text); border-color: var(--accent-text); background: var(--warn-bg); }
.td-neutral { color: var(--heading); border-color: var(--border-strong); background: var(--card); }
.td-branch-note { display: block; font-size: 14px; color: var(--text-muted); margin-top: 4px; }
.td-branch .td-node { margin-top: 8px; }

/* compare */
.td-cols { display: grid; gap: 10px; grid-template-columns: 1fr; }
@media (min-width: 560px) { .td-cols-2 { grid-template-columns: 1fr 1fr; } .td-cols-3 { grid-template-columns: repeat(3, 1fr); } }
.td-col { border: 2px solid; border-radius: var(--radius-sm); padding: 10px 12px; }
.td-col.td-neutral { background: var(--card); }
.td-col-title { display: flex; align-items: center; font-weight: 700; margin: 0 0 6px; }
.td-col-title .td-icon { color: inherit; }
.td-col ul { margin: 0; padding-left: 1.2em; color: var(--text); }
.td-col li { margin: 4px 0; line-height: 1.55; }

/* annotate */
.td-ann-row { display: grid; grid-template-columns: 1fr; gap: 4px; margin: 0 0 10px; }
@media (min-width: 560px) { .td-ann-row { grid-template-columns: 84px 1fr; gap: 12px; } }
.td-ann-label { font-size: 13px; font-weight: 700; color: var(--text-muted); padding-top: 6px; }
.td-ann-text { margin: 0; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 10px 12px; line-height: 2.1; overflow-wrap: anywhere; }
.td-mark { -webkit-box-decoration-break: clone; box-decoration-break: clone; color: inherit; padding: 2px 3px; border-radius: 4px; border-bottom: 2px solid; }
.td-mark-1 { background: var(--td-m1); border-color: var(--td-m1-line); }
.td-mark-2 { background: var(--td-m2); border-color: var(--td-m2-line); }
.td-mark-3 { background: var(--td-m3); border-color: var(--td-m3-line); }
.td-mark-4 { background: var(--td-m4); border-color: var(--td-m4-line); }
.td-tag { white-space: nowrap; font-size: 11px; font-weight: 700; margin-left: 3px; color: var(--text-muted); }
.td-legend { list-style: none; padding: 0; margin: 6px 0 0; display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: 14px; }
.td-legend li { display: flex; align-items: center; gap: 6px; }
.td-swatch { display: inline-block; width: 16px; height: 16px; border-radius: 4px; border: 2px solid; flex: 0 0 auto; }

/* scale */
.td-scale { color: var(--primary); }
.td-scale-ends { display: flex; justify-content: space-between; font-size: 13px; font-weight: 700; color: var(--text-muted); }
.td-scale-bar { display: block; width: 100%; height: 30px; margin: 4px 0; }
.td-scale-points { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(var(--n), 1fr); gap: 4px; text-align: center; color: var(--text); }
.td-scale-points strong { display: block; color: var(--heading); font-size: 14px; overflow-wrap: anywhere; }
.td-scale-points span { display: block; font-size: 12px; color: var(--text-muted); line-height: 1.4; margin-top: 2px; }

/* stack */
.td-stack-bar { display: block; width: 100%; height: 26px; margin-bottom: 12px; }
.td-fill-1 { fill: var(--primary); background: var(--primary); border-color: var(--primary); }
.td-fill-2 { fill: color-mix(in srgb, var(--primary) 55%, var(--card)); background: color-mix(in srgb, var(--primary) 55%, var(--card)); border-color: var(--primary); }
.td-fill-3 { fill: color-mix(in srgb, var(--primary) 28%, var(--card)); background: color-mix(in srgb, var(--primary) 28%, var(--card)); border-color: var(--primary); }
/* Maple red stays an accent (marketing framework §8.1): only the fourth block, and only as a light tint. */
.td-fill-4 { fill: color-mix(in srgb, var(--accent) 35%, var(--card)); background: color-mix(in srgb, var(--accent) 35%, var(--card)); border-color: var(--accent); }
.td-stack-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.td-stack-list li { display: flex; gap: 10px; align-items: flex-start; }
.td-stack-list .td-swatch { margin-top: 4px; }
.td-stack-list strong { color: var(--heading); }
.td-stack-list span { display: block; font-size: 15px; line-height: 1.55; }

/* otter-steps (young learners) */
.td-otter-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; }
.td-otter-step { display: flex; gap: 12px; align-items: center; background: var(--card); border: 2px solid var(--border); border-radius: 18px; padding: 10px 14px 10px 10px; }
.td-otter-step img { width: 88px; height: 88px; object-fit: contain; flex: 0 0 auto; }
.td-otter-step:nth-child(even) { flex-direction: row-reverse; }
.td-otter-step > div { min-width: 0; }
.td-otter-step strong { display: inline; font-size: 17px; color: var(--heading); margin-left: 6px; }
.td-otter-step span:not(.td-num) { display: block; margin-top: 6px; font-size: 16px; line-height: 1.6; }
@media (max-width: 400px) { .td-otter-step img { width: 72px; height: 72px; } }

/* The unit's own approach steps, drawn as a numbered path instead of a bare list (every course). */
.course-approach { list-style: none; margin: 8px 0 14px; padding: 0; counter-reset: ap; }
.course-approach li { counter-increment: ap; position: relative; padding: 10px 12px 10px 48px; margin: 0 0 8px; background: var(--surface); border-radius: var(--radius-sm); line-height: 1.65; }
.course-approach li::before { content: counter(ap); position: absolute; left: 10px; top: 10px; width: 28px; height: 28px; border-radius: 50%; display: grid; place-items: center;
  background: var(--primary); color: var(--on-primary); font-weight: 700; font-size: 15px; }
.course-approach li:not(:last-child)::after { content: ''; position: absolute; left: 23px; top: 40px; bottom: -10px; border-left: 2px dashed var(--border-strong); }
.course-approach .ap-key { font-weight: 700; color: var(--heading); }
/* Legend swatches take their mark's colour (the .td-swatch border shorthand above would otherwise reset it). */
.td-swatch.td-mark-1 { border-color: var(--td-m1-line); } .td-swatch.td-mark-2 { border-color: var(--td-m2-line); }
.td-swatch.td-mark-3 { border-color: var(--td-m3-line); } .td-swatch.td-mark-4 { border-color: var(--td-m4-line); }
.td-stack-list .td-swatch.td-fill-1, .td-stack-list .td-swatch.td-fill-2, .td-stack-list .td-swatch.td-fill-3 { border-color: var(--primary); }
.td-stack-list .td-swatch.td-fill-4 { border-color: var(--accent); }