.oos-lesson-page { max-width: 1120px; }
.oos-intro .lede { max-width: 900px; }
.oos-core-rule {
  margin-top: 18px;
  padding: 16px 18px;
  border-radius: 15px;
  background: var(--dark);
  color: #fff;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 13px;
  align-items: center;
}
.oos-core-rule span,
.oos-card-label {
  display: inline-flex;
  width: fit-content;
  padding: 5px 8px;
  border-radius: 7px;
  background: var(--accent);
  color: var(--dark);
  font-size: .64rem;
  font-weight: 900;
  letter-spacing: .08em;
}
.oos-core-rule strong { font-size: .98rem; line-height: 1.42; }
.oos-jump { position: sticky; top: 10px; z-index: 4; box-shadow: 0 7px 22px rgba(28,33,26,.05); }

.oos-two-col {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  gap: 15px;
  align-items: stretch;
}
.oos-two-col-wide-visual { grid-template-columns: minmax(0, 1.2fr) minmax(300px, .8fr); }
.oos-copy-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #f8f9f5;
}
.oos-copy-card h3 { margin: 0 0 10px; font-size: 1.18rem; }
.oos-copy-card p { margin: 0 0 12px; color: var(--muted); line-height: 1.58; font-size: .88rem; }
.oos-copy-card p:last-child { margin-bottom: 0; }
.oos-check-list,
.oos-number-list {
  margin: 0;
  padding-left: 1.15rem;
  display: grid;
  gap: 9px;
  color: var(--muted);
  line-height: 1.5;
  font-size: .87rem;
}
.oos-check-list strong,
.oos-number-list strong { color: var(--text); }
.oos-small-note {
  margin-top: 14px !important;
  padding: 11px 12px;
  border-left: 4px solid var(--accent);
  background: #fff;
  border-radius: 0 10px 10px 0;
}

.oos-svg { background: #f8f9f5; }
.oos-svg .oos-room { fill: #fff; stroke: #1c211a; stroke-width: 4; }
.oos-svg .oos-grid-soft line { stroke: #c6cbc1; stroke-width: 1.5; }
.oos-svg .oos-grid-dark line,
.oos-grid-dark line { stroke: #7d8478; stroke-width: 2; }
.oos-svg .oos-center-line { stroke: #1c211a; stroke-width: 3; stroke-dasharray: 8 7; }
.oos-svg .oos-accent-line { stroke: #b9ca35; stroke-width: 8; }
.oos-svg .oos-fixture { fill: #e5ff50; stroke: #8b982b; stroke-width: 2; }
.oos-svg .oos-svg-label,
.oos-svg-label { fill: #20231f; font-size: 15px; font-weight: 900; text-anchor: middle; letter-spacing: .03em; }
.oos-svg .oos-svg-sub,
.oos-svg-sub { fill: #6d716a; font-size: 14px; font-weight: 760; text-anchor: middle; }
.oos-svg .oos-dim-line,
.oos-dim-line { stroke: #6d716a; stroke-width: 2; }
.oos-svg .oos-witness,
.oos-witness { stroke: #a4aaa0; stroke-width: 1.5; }
.oos-svg .oos-dim-text,
.oos-dim-text { fill: #181a17; font-size: 17px; font-weight: 900; text-anchor: middle; }
.oos-svg .oos-square-line { stroke: #1c211a; stroke-width: 4; }
.oos-svg .oos-runout { stroke: #a35b4a; stroke-width: 5; }
.oos-svg .oos-right-angle,
.oos-right-angle { fill: none; stroke: #1c211a; stroke-width: 3; }
.oos-svg .oos-door { stroke: #1c211a; stroke-width: 5; }
.oos-svg .oos-door-swing { fill: none; stroke: #8f958b; stroke-width: 2.5; stroke-dasharray: 7 6; }
.oos-svg .oos-sightline { fill: none; stroke: #a8b82f; stroke-width: 4; stroke-dasharray: 8 7; }
.oos-svg .oos-desk { fill: #d9dcd5; stroke: #7d8478; stroke-width: 2; }
.oos-svg .oos-chair { fill: #fff; stroke: #1c211a; stroke-width: 3; }
.oos-svg .oos-view-arrow { fill: none; stroke: #a8b82f; stroke-width: 5; marker-end: none; }
.oos-svg .oos-crooked-wall { stroke: #a35b4a; stroke-width: 8; }
.oos-svg .oos-control-line { stroke: #1c211a; stroke-width: 4; stroke-dasharray: 10 8; }
.oos-svg .oos-border-accent,
.oos-border-accent { fill: #e5ff50; stroke: #b6c738; stroke-width: 2; }

.oos-method-card {
  margin-top: 15px;
  padding: 19px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
  display: grid;
  grid-template-columns: minmax(0, .85fr) minmax(420px, 1.15fr);
  gap: 18px;
  align-items: center;
}
.oos-method-card h3 { margin: 3px 0 8px; font-size: 1.35rem; }
.oos-method-card p { margin: 0; color: var(--muted); line-height: 1.58; }
.oos-345-wrap { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; align-items: center; }
.oos-345-svg { border: 1px solid var(--line); border-radius: 13px; background: #f8f9f5; }
.oos-345-svg .oos-triangle { fill: #fff; stroke: #1c211a; stroke-width: 4; }
.oos-ratio-table { width: 100%; border-collapse: collapse; font-size: .78rem; }
.oos-ratio-table caption { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }
.oos-ratio-table th { padding: 8px 6px; background: var(--dark); color: #fff; font-size: .67rem; letter-spacing: .04em; }
.oos-ratio-table td { padding: 8px 6px; border: 1px solid var(--line); text-align: center; font-weight: 800; }
.oos-ratio-table tbody tr:nth-child(even) td { background: #f8f9f5; }

.oos-taper-compare { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 14px; }
.oos-taper-card { padding: 17px; border: 1px solid var(--line); border-radius: 16px; background: #f8f9f5; }
.oos-taper-card-warning { border-color: #d9c2bb; }
.oos-taper-card h3 { margin: 8px 0 5px; }
.oos-taper-svg { margin-top: 5px; border-radius: 12px; background: #fff; }
.oos-taper-svg .oos-wall-line { stroke: #1c211a; stroke-width: 5; }
.oos-taper-svg .oos-danger-text { fill: #a35b4a; }

.oos-decision-block {
  margin-top: 16px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
}
.oos-decision-block h3 { margin: 4px 0 7px; font-size: 1.35rem; }
.oos-decision-block > p { color: var(--muted); line-height: 1.55; }
.oos-option-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 11px; margin-top: 15px; }
.oos-option-card { padding: 15px; border: 1px solid var(--line); border-radius: 14px; background: #f8f9f5; }
.oos-option-card > span { width: 31px; height: 31px; display: grid; place-items: center; border-radius: 9px; background: var(--dark); color: var(--accent); font-weight: 900; }
.oos-option-card h4 { margin: 9px 0 10px; font-size: 1rem; }
.oos-option-card p { margin: 10px 0 0; color: var(--muted); font-size: .8rem; line-height: 1.45; }
.oos-option-balanced { background: var(--accent-soft); border-color: #dbe67e; }
.oos-mini-room { height: 104px; position: relative; overflow: hidden; border: 2px solid #1c211a; background: #fff; }
.oos-mini-room::before { content: ""; position: absolute; inset: 12px 15px; background: repeating-linear-gradient(90deg, transparent 0 28px, #b6bbb2 29px 30px), repeating-linear-gradient(0deg, transparent 0 28px, #c6cbc1 29px 30px); }
.oos-mini-room i { position: absolute; left: 0; top: 0; bottom: 0; width: 17px; background: var(--accent); }
.oos-mini-room b { position: absolute; right: 0; top: 0; bottom: 0; width: 8px; background: var(--accent); transform-origin: top right; }
.oos-mini-a b { transform: skewY(-14deg); width: 4px; }
.oos-mini-b i { width: 12px; transform: skewY(4deg); }
.oos-mini-b b { width: 12px; transform: skewY(-4deg); }
.oos-mini-c i { width: 5px; transform: skewY(13deg); }
.oos-mini-c b { width: 18px; }

.oos-coordinate-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 11px; }
.oos-coordinate-grid > div { padding: 16px; border: 1px solid var(--line); border-radius: 14px; background: #f8f9f5; }
.oos-coordinate-grid span { color: #969c92; font-size: .65rem; font-weight: 900; letter-spacing: .08em; }
.oos-coordinate-grid strong { display: block; margin-top: 5px; }
.oos-coordinate-grid p { margin: 5px 0 0; color: var(--muted); font-size: .8rem; line-height: 1.42; }

.oos-communication-grid { display: grid; grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr); gap: 14px; }
.oos-field-dialogue { padding: 20px; border-radius: 16px; background: var(--dark); color: #fff; }
.oos-field-dialogue > span { display: inline-flex; padding: 5px 8px; border-radius: 7px; background: var(--accent); color: var(--dark); font-size: .64rem; font-weight: 900; letter-spacing: .08em; }
.oos-field-dialogue p { margin: 14px 0 0; color: #e7e9e4; font-size: .9rem; line-height: 1.58; }
.oos-summary { margin-top: 18px; }
.oos-closing-note { margin-top: 18px; }
.oos-next-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }

@media (max-width: 900px) {
  .oos-two-col,
  .oos-two-col-wide-visual,
  .oos-method-card,
  .oos-communication-grid { grid-template-columns: 1fr; }
  .oos-method-card { gap: 13px; }
  .oos-coordinate-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .oos-option-grid { grid-template-columns: 1fr; }
}

@media (max-width: 760px) {
  .oos-jump { position: static; box-shadow: none; }
  .oos-core-rule { grid-template-columns: 1fr; gap: 9px; }
  .oos-next-grid { grid-template-columns: 1fr; }
  .oos-next-grid a { grid-template-columns: auto minmax(0, 1fr) auto; }
  .oos-next-grid a > div { min-width: 0; }
  .oos-next-grid strong,
  .oos-next-grid small { overflow-wrap: anywhere; }
  .oos-taper-compare,
  .oos-coordinate-grid { grid-template-columns: 1fr; }
  .oos-345-wrap { grid-template-columns: 1fr; }
  .oos-method-card { padding: 14px; }
  .oos-decision-block { padding: 15px; }
  .oos-field-dialogue { padding: 17px; }
  .oos-svg .oos-svg-label,
  .oos-svg-label { font-size: 17px; }
  .oos-svg .oos-svg-sub,
  .oos-svg-sub { font-size: 16px; }
  .oos-svg .oos-dim-text,
  .oos-dim-text { font-size: 19px; }
}

@media (max-width: 500px) {
  .oos-copy-card { padding: 15px; }
  .oos-coordinate-grid > div { padding: 14px; }
  .oos-core-rule strong { font-size: .92rem; }
}


/* Mobile safety override for the Keep Going resource cards. */
@media (max-width: 760px) {
  .lesson-next .lesson-next-grid.oos-next-grid {
    display: grid !important;
    grid-template-columns: minmax(0, 1fr) !important;
    gap: 10px;
  }

  .lesson-next .lesson-next-grid.oos-next-grid > a {
    width: 100%;
    min-width: 0;
    box-sizing: border-box;
    grid-template-columns: 36px minmax(0, 1fr) 24px;
    align-items: center;
  }

  .lesson-next .lesson-next-grid.oos-next-grid > a > div {
    min-width: 0;
    width: 100%;
  }

  .lesson-next .lesson-next-grid.oos-next-grid strong,
  .lesson-next .lesson-next-grid.oos-next-grid small {
    min-width: 0;
    overflow-wrap: anywhere;
    word-break: normal;
  }

  .lesson-next .lesson-next-grid.oos-next-grid b {
    justify-self: end;
  }
}