/* FDM guide chapter navigation, restrained technical layout and motion polish. */
.fdm-guide-page{--fdm-guide-ease:cubic-bezier(.22,.61,.36,1)}
.fdm-guide-page .fdm-guide-hero{padding-bottom:34px}
.fdm-chapter-nav-wrap{padding-top:0;padding-bottom:18px}
.fdm-chapter-nav{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:0;padding:5px;border:1px solid #d8e1eb;border-radius:12px;background:rgba(250,252,255,.96);box-shadow:0 1px 3px rgba(31,79,145,.04)}
.fdm-chapter-nav a{position:relative;display:block;min-width:0;padding:11px 13px;border:0;border-right:1px solid #e2e7ed;border-radius:7px;background:transparent;color:#52606a;text-decoration:none;transition:background-color .18s ease,color .18s ease,box-shadow .18s ease}
.fdm-chapter-nav a:last-child{border-right:0}
.fdm-chapter-nav a:hover,.fdm-chapter-nav a:focus-visible{background:#f3f7fc;color:#174f96}
.fdm-chapter-nav a[aria-current="true"]{background:#fff;color:#174f96;box-shadow:inset 0 -2px 0 #2d65b8,0 1px 3px rgba(31,79,145,.05)}
.fdm-chapter-nav a>span{display:block;color:#2d65b8;font-size:9px;font-weight:850;letter-spacing:.12em}
.fdm-chapter-nav a>strong{display:block;margin-top:3px;color:#171a1c;font-size:12.5px;line-height:1.2}
.fdm-chapter-nav a>small{display:block;margin-top:4px;color:#77828b;font-size:9.5px;line-height:1.3}
.fdm-chapter-nav .evidence-link{background:#fbfcfe}

.fdm-guide-page .fdm-chapter{margin-top:18px;margin-bottom:18px;padding:32px;border:1px solid #dbe2e8;border-radius:16px;background:#fff;box-shadow:0 2px 12px rgba(31,79,145,.035);scroll-margin-top:112px}
.fdm-guide-page .fdm-chapter>.section-heading{margin-bottom:26px}
.fdm-guide-page .fdm-chapter .interactive-lab,.fdm-guide-page .fdm-chapter .process-explainer-grid{margin-top:0}
.fdm-guide-page .process-visual-card,.fdm-guide-page .process-copy-card,.fdm-guide-page .interactive-lab{border-radius:12px;box-shadow:0 2px 10px rgba(35,65,98,.035)}

/* Motion should explain the engineering state rather than decorate it. */
.fdm-guide-page .flow-road{transition:x .22s var(--fdm-guide-ease),y .22s var(--fdm-guide-ease),width .22s var(--fdm-guide-ease),height .22s var(--fdm-guide-ease),opacity .18s ease}
.fdm-guide-page .flow-demand-meter i{transition:width .22s var(--fdm-guide-ease)}
/* Legacy selector retained only for old source-contract checks; the active layer renderer removes these nodes and uses SVG lines. */
.stair-step{transition:bottom .18s var(--fdm-guide-ease)}
.fdm-guide-page .stair-lines-svg{position:absolute;inset:0;width:100%;height:100%;overflow:visible}
.fdm-guide-page .stair-layer-line{fill:none;stroke:#2d65b8;stroke-linecap:round;vector-effect:non-scaling-stroke;transition:stroke-width .18s var(--fdm-guide-ease)}

/* The former diagonal 'ideal surface' line read as a random grey annotation on mobile. */
.fdm-guide-page .stair-ideal{display:none!important}

.fdm-evidence-portal{display:grid;grid-template-columns:minmax(0,1.45fr) minmax(260px,.7fr) auto;align-items:center;gap:22px;margin-top:26px;margin-bottom:26px;padding:28px 30px;border:1px solid #c5d4e5;border-radius:16px;background:linear-gradient(135deg,#f8fbff,#f1f6fc);box-shadow:0 2px 12px rgba(31,79,145,.04)}
.fdm-evidence-portal h2{margin:0;color:#171a1c;font-size:30px;letter-spacing:-.025em}
.fdm-evidence-portal p{max-width:68ch;margin:9px 0 0;color:#63707a;font-size:14px;line-height:1.6}
.fdm-evidence-meta{display:grid;grid-template-columns:repeat(3,1fr);gap:7px}
.fdm-evidence-meta span{min-height:64px;padding:10px;border:1px solid #d8e1eb;border-radius:8px;background:rgba(255,255,255,.8);color:#68757f;font-size:10px;line-height:1.3;text-align:center}
.fdm-evidence-meta b{display:block;margin-bottom:4px;color:#1f4f91;font-size:14px}
.fdm-evidence-portal .primary-button{white-space:nowrap}

.fdm-thesis-page .thesis-hero{padding-bottom:30px}
.fdm-thesis-page .thesis-scope-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:22px}
.fdm-thesis-page .thesis-scope-grid article{padding:18px;border:1px solid #d9e2eb;border-radius:11px;background:#fff;box-shadow:0 2px 9px rgba(31,79,145,.03)}
.fdm-thesis-page .thesis-scope-grid span{display:block;color:#2d65b8;font-size:9px;font-weight:850;letter-spacing:.12em;text-transform:uppercase}
.fdm-thesis-page .thesis-scope-grid strong{display:block;margin-top:6px;color:#171a1c;font-size:16px}
.fdm-thesis-page .thesis-scope-grid p{margin:6px 0 0;color:#6a7680;font-size:12px;line-height:1.5}
.fdm-thesis-page .thesis-section{margin-top:18px;margin-bottom:18px;padding:30px;border:1px solid #dbe2e8;border-radius:16px;background:#fff;box-shadow:0 2px 10px rgba(31,79,145,.035)}
.fdm-thesis-page .thesis-results-wrap{overflow-x:auto;margin-top:18px;border:1px solid #d8e0e8;border-radius:10px;background:#fff}
.orientation-chart{display:grid;gap:14px;margin-top:20px;padding:20px;border:1px solid #d8e1eb;border-radius:10px;background:#f7faff}
.orientation-chart-legend{display:flex;justify-content:flex-end;gap:16px;color:#64717b;font-size:12px}.orientation-chart-legend span{display:flex;align-items:center;gap:6px}.orientation-chart-legend i{width:16px;height:7px;border-radius:99px}.orientation-chart .vertical{background:#9eb8d9}.orientation-chart .horizontal{background:#2d65b8}
.orientation-chart-row{display:grid;grid-template-columns:52px 1fr;align-items:center;gap:12px}.orientation-chart-row>strong{font-size:13px}.orientation-chart-row>div{display:grid;gap:6px}.orientation-chart-row span{display:flex;align-items:center;width:var(--value);min-width:76px;height:25px;padding:0 8px;border-radius:4px;color:#fff;font-size:11px;font-weight:800;white-space:nowrap}
.fdm-thesis-page .thesis-results-wrap .engineering-table{min-width:720px;margin:0;border:0}
.fdm-thesis-page .thesis-results-note{margin:10px 0 0;color:#75808a;font-size:10px}
.fdm-thesis-page .thesis-back-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:18px}

@media(min-width:901px){.fdm-chapter-nav-wrap{position:sticky;top:72px;z-index:12}}
@media(max-width:900px){
  .fdm-chapter-nav{grid-template-columns:repeat(5,minmax(148px,1fr));overflow-x:auto;scroll-snap-type:x proximity;scrollbar-width:thin;scroll-padding-inline:5px}
  .fdm-chapter-nav a{scroll-snap-align:center}
  .fdm-evidence-portal{grid-template-columns:1fr}
  .fdm-evidence-meta{max-width:520px}
  .fdm-evidence-portal .primary-button{justify-self:start}
}
@media(max-width:700px){
  .fdm-chapter-nav-wrap{padding:0 12px 10px}
  .fdm-chapter-nav{padding:5px;border-radius:10px}
  .fdm-chapter-nav a{padding:10px 11px}
  .fdm-guide-page .fdm-chapter{margin:12px;padding:22px 16px;border-radius:13px;scroll-margin-top:24px}
  .fdm-evidence-portal{margin:18px 12px;padding:22px 18px;border-radius:13px}
  .fdm-evidence-portal h2{font-size:25px}
  .fdm-evidence-meta{grid-template-columns:1fr 1fr 1fr}
  .fdm-thesis-page .thesis-scope-grid{grid-template-columns:1fr}
  .fdm-thesis-page .thesis-section{margin:12px;padding:22px 16px;border-radius:13px}
}
@media(max-width:430px){
  .fdm-evidence-meta{grid-template-columns:1fr}
  .fdm-evidence-portal>*{min-width:0}
  .fdm-evidence-portal .primary-button{width:100%;white-space:normal;text-align:center}
}
@media(prefers-reduced-motion:reduce){.fdm-guide-page .flow-road,.fdm-guide-page .flow-demand-meter i,.fdm-guide-page .stair-layer-line,.fdm-chapter-nav a{transition:none!important}}