:root {
  --bg: #0a1017; --panel: #101822; --panel2: #162130; --text: #e3e9f0; --muted: #94a3b5;
  --border: #243142; --border-strong: #35465b; --accent: #3d8fe6; --accent-ink: #04101e; --focus: #ffd24a;
  --ok: #38b27a; --ok-bg: #0d2619; --warn: #d9a31a; --warn-bg: #2b2208; --bad: #f0626a; --bad-bg: #331417;
  --banner-bg: #2b2208; --banner-border: #d9a31a; --banner-text: #f5e3b0;
  --canvas: #070b10; --link: #7db8f2;
}
:root[data-theme="light"] {
  --bg: #f2f5f8; --panel: #ffffff; --panel2: #ebeff4; --text: #111d2b; --muted: #475567;
  --border: #c8d1dc; --border-strong: #9fb0c2; --accent: #0a58b6; --accent-ink: #ffffff; --focus: #8a5a00;
  --ok: #17692b; --ok-bg: #e0f2e7; --warn: #7a5200; --warn-bg: #fbf0d3; --bad: #b00020; --bad-bg: #fbe3e6;
  --banner-bg: #fbf0d3; --banner-border: #7a5200; --banner-text: #3d2900;
  --canvas: #e6ebf2; --link: #0a4a9e;
}
* { box-sizing: border-box; }
html { color-scheme: dark; }
:root[data-theme="light"] { color-scheme: light; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans Arabic", "Noto Naskh Arabic", Tahoma, sans-serif;
}
a { color: var(--link); }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; border-radius: 3px; }
.skip { position: absolute; inset-inline-start: 8px; top: -60px; background: var(--accent); color: var(--accent-ink); padding: 8px 12px; z-index: 50; }
.skip:focus { top: 8px; }

.top { display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; align-items: flex-end; padding: 12px 16px 10px; border-block-end: 1px solid var(--border); background: var(--panel); margin-block-end: 14px; }
.brand h1 { margin: 0; font-size: 1.25rem; font-weight: 650; letter-spacing: .01em; }
.tagline { margin: 0; color: var(--muted); font-size: .9rem; max-inline-size: 60ch; }
.top-controls { display: flex; flex-wrap: wrap; gap: 8px; align-items: flex-end; }
.meta { color: var(--muted); font-size: .85rem; align-self: center; }
.field { display: flex; flex-direction: column; gap: 2px; font-size: .8rem; color: var(--muted); }
select, .btn, input[type=range] { font: inherit; }
select { background: var(--panel2); color: var(--text); border: 1px solid var(--border); border-radius: 3px; padding: 6px 8px; min-inline-size: 12rem; max-inline-size: 100%; }
.btn { background: var(--panel2); color: var(--text); border: 1px solid var(--border); border-radius: 3px; padding: 6px 12px; cursor: pointer; text-decoration: none; display: inline-block; min-block-size: 34px; }
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 600; min-inline-size: 7rem; }
.seg { display: inline-flex; border: 1px solid var(--border); border-radius: 3px; overflow: hidden; }
.seg .btn { border: 0; border-radius: 0; border-inline-end: 1px solid var(--border); }
.seg .btn:last-child { border-inline-end: 0; }
.seg .btn[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); font-weight: 600; }

.banner { margin: 4px 16px 10px; padding: 10px 14px; background: var(--banner-bg); border: 2px solid var(--banner-border); border-inline-start-width: 8px; border-radius: 3px; color: var(--banner-text); }
.banner strong { text-transform: uppercase; letter-spacing: .06em; font-size: .85rem; }
.banner p { margin: 2px 0 0; font-size: 1.02rem; font-weight: 600; }
.banner .banner-orig { font-size: .8rem; font-weight: 400; opacity: .9; }
.error { margin: 8px 16px; padding: 10px 14px; background: var(--bad-bg); border: 1px solid var(--bad); border-radius: 3px; }
.error code { background: rgba(127,127,127,.25); padding: 1px 4px; border-radius: 3px; direction: ltr; unicode-bidi: isolate; }

main { padding: 0 16px 16px; }
.views { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
@media (max-width: 860px) { .views { grid-template-columns: minmax(0, 1fr); } }
.view { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; padding: 10px; display: flex; flex-direction: column; gap: 8px; min-inline-size: 0; }
.view-head { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; }
.view h2, .panel h2 { margin: 0; font-size: 1.05rem; }
.badge { font-size: .7rem; padding: 2px 7px; border-radius: 2px; border: 1px solid; text-decoration: none; font-weight: 600; letter-spacing: .06em; text-transform: uppercase; }
.badge-ok { color: var(--ok); background: var(--ok-bg); border-color: var(--ok); }
.badge-warn { color: var(--warn); background: var(--warn-bg); border-color: var(--warn); }
.scen { flex-direction: row; align-items: center; gap: 8px; }
.scen select { flex: 1; }
.canvas-wrap { position: relative; aspect-ratio: 16 / 10; background: var(--canvas); border-radius: 3px; overflow: hidden; }
.canvas-wrap canvas { position: absolute; inset: 0; inline-size: 100%; block-size: 100%; display: block; touch-action: none; }
.overlay { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; text-align: center; padding: 16px; background: color-mix(in srgb, var(--canvas) 80%, transparent); font-weight: 600; }
.overlay:empty { display: none; }
.readouts { display: grid; grid-template-columns: repeat(auto-fit, minmax(11rem, 1fr)); gap: 6px; margin: 0; }
.readouts > div { background: var(--panel2); border-radius: 3px; padding: 6px 8px; }
.readouts dt { font-size: .72rem; color: var(--muted); letter-spacing: .02em; }
.readouts dd { margin: 0; font-size: 1.15rem; font-weight: 650; font-variant-numeric: tabular-nums; }
.readouts .unit { font-size: .8rem; font-weight: 400; color: var(--muted); }
.readouts dd.is-bad { color: var(--bad); }
.readouts > div:has(dd.is-bad) { border-inline-start: 3px solid var(--bad); }
.note { margin: 0; font-size: .8rem; color: var(--muted); }
.note-warn { color: var(--warn); font-weight: 600; }
a.num { color: inherit; text-decoration: underline dotted; text-underline-offset: 3px; }
a.num:hover { text-decoration: underline solid; color: var(--link); }

.transport { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; padding: 10px; margin-block: 12px; display: flex; flex-direction: column; gap: 8px; }
.tr-row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.time { margin-inline-start: auto; font-variant-numeric: tabular-nums; font-weight: 600; direction: ltr; unicode-bidi: isolate; }
#scrub { inline-size: 100%; direction: ltr; accent-color: var(--accent); block-size: 28px; }
.legend { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 4px 14px; font-size: .8rem; color: var(--muted); }
.legend li { display: flex; align-items: center; gap: 5px; }
.sw { inline-size: 12px; block-size: 12px; border-radius: 50%; display: inline-block; flex: none; }
.sw.line { border-radius: 0; block-size: 3px; inline-size: 18px; }
.sw.dash { border-radius: 0; block-size: 0; border-top: 3px dashed; inline-size: 18px; background: none; }
.sw.dia { border-radius: 0; transform: rotate(45deg); background: none; border: 2px solid; inline-size: 10px; block-size: 10px; }
.sw.grad { border-radius: 3px; inline-size: 36px; }

.panels { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
@media (max-width: 860px) { .panels { grid-template-columns: minmax(0, 1fr); } }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; padding: 12px; min-inline-size: 0; }
.panel h3 { margin: 14px 0 4px; font-size: .92rem; }
.verdict { display: inline-flex; align-items: center; gap: 8px; font-weight: 700; font-size: 1.1rem; letter-spacing: .06em; padding: 3px 12px; border-radius: 2px; border: 1px solid; }
.verdict.pass { color: var(--ok); background: var(--ok-bg); border-color: var(--ok); }
.verdict.fail { color: var(--bad); background: var(--bad-bg); border-color: var(--bad); }
.kv { display: grid; grid-template-columns: minmax(8rem, 40%) 1fr; gap: 4px 12px; margin: 10px 0 0; }
.kv dt { color: var(--muted); font-size: .85rem; }
.kv dd { margin: 0; font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.kv code, code.hash { direction: ltr; unicode-bidi: isolate; font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .85rem; }
.hash-full { margin-block-start: 4px; word-break: break-all; }
.tbl { inline-size: 100%; border-collapse: collapse; font-size: .85rem; font-variant-numeric: tabular-nums; }
.tbl th, .tbl td { text-align: start; padding: 3px 6px; border-bottom: 1px solid var(--border); }
.tbl th { font-weight: 500; color: var(--muted); }
.list { margin: 4px 0; padding-inline-start: 1.2rem; font-size: .88rem; }
.list li { margin-block: 3px; }
.list.en-only, [lang="en"].keep { direction: ltr; text-align: left; }
.assumed { background: var(--warn-bg); border: 1px solid var(--warn); color: var(--text); border-radius: 3px; padding: 8px 10px; font-size: .88rem; }
.chip { font-size: .72rem; color: var(--warn); border: 1px solid var(--warn); border-radius: 2px; padding: 0 6px; margin-inline-start: 4px; }
.ev-btn { font-size: .78rem; padding: 2px 8px; min-block-size: 26px; margin-inline-start: 6px; }
.foot { padding: 10px 16px 24px; color: var(--muted); font-size: .8rem; }

/* methods page */
.doc { max-inline-size: 78ch; margin: 0 auto; padding: 8px 16px 48px; }
.doc h1 { font-size: 1.6rem; }
.doc h2 { margin-block-start: 2rem; padding-block-start: .5rem; border-block-start: 1px solid var(--border); font-size: 1.25rem; scroll-margin-block-start: 12px; }
.doc h3 { font-size: 1.02rem; scroll-margin-block-start: 12px; }
.doc :target > h2, .doc h2:target, .doc h3:target { background: color-mix(in srgb, var(--accent) 22%, transparent); }
.doc p, .doc li { overflow-wrap: anywhere; }
.doc .ar-sum { background: var(--panel2); border-radius: 3px; padding: 8px 12px; }
html[lang="en"] .ar, html[lang="ar"] .en { display: none; }
.doc .en-detail { direction: ltr; text-align: left; }
html[dir="rtl"] .doc .en-detail ul { padding-inline-start: 0; padding-inline-end: 1.2rem; }
.doc .en-detail li, .doc .en-detail p { text-align: left; }
.toc { columns: 2 16rem; font-size: .92rem; }
.doc code { font-family: ui-monospace, Menlo, Consolas, monospace; font-size: .9em; background: var(--panel2); padding: 0 4px; border-radius: 3px; direction: ltr; unicode-bidi: isolate; }
.doc .callout { background: var(--warn-bg); border: 1px solid var(--warn); border-radius: 3px; padding: 8px 12px; }
.doc .nav { display: flex; gap: 8px; flex-wrap: wrap; padding: 12px 0; align-items: center; }

@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; scroll-behavior: auto !important; } }

.scen-ph { min-block-size: 34px; display: flex; align-items: center; }

/* transport: media controls and the timeline keep left-to-right order in Arabic (time runs left to right) */
.media { display: inline-flex; gap: 8px; }
.en-block { display: block; text-align: left; }
.ico-back::before { content: "\25C0\25C0"; }
.ico-fwd::before { content: "\25B6\25B6"; }
.tbl-wrap { overflow-x: auto; max-inline-size: 100%; }

/* ---- engineering skin and guided layer ---- */
.show-line { flex-basis: 100%; margin: 0; font-size: .85rem; color: var(--muted); }
.show-line .meta { margin-inline-start: 10px; font-variant-numeric: tabular-nums; }
.field span { text-transform: uppercase; letter-spacing: .08em; font-size: .68rem; }
.view h2, .panel h2, .why h2 { font-size: .8rem; text-transform: uppercase; letter-spacing: .1em; color: var(--muted); font-weight: 650; }
.panel h3 { font-size: .85rem; }
.btn { transition: none; }
.btn:hover { border-color: var(--accent); background: color-mix(in srgb, var(--accent) 12%, var(--panel2)); }
.btn-primary:hover { background: var(--accent); filter: brightness(1.08); }

body.classic .guide-only { display: none !important; }
body:not(.classic) .classic-only { display: none; }

.guide { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; padding: 12px 14px; margin-block-end: 12px; display: grid; gap: 10px; }
.intro { margin: 0; max-inline-size: 90ch; color: var(--text); }
.steps { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0; border: 1px solid var(--border); border-radius: 3px; overflow: hidden; counter-reset: st; }
.steps li { display: contents; }
.step-btn { text-align: start; background: var(--panel2); color: var(--muted); border: 0; border-inline-end: 1px solid var(--border); padding: 8px 10px; cursor: pointer; font: inherit; font-size: .85rem; display: flex; gap: 8px; align-items: baseline; min-block-size: 40px; }
.steps li:last-child .step-btn { border-inline-end: 0; }
.step-btn .no { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--accent); }
.step-btn:hover { color: var(--text); }
.step-btn[aria-current="step"] { background: var(--accent); color: var(--accent-ink); font-weight: 600; }
.step-btn[aria-current="step"] .no { color: inherit; }
.tour-card { display: flex; flex-wrap: wrap; gap: 8px 16px; align-items: center; justify-content: space-between; min-block-size: 44px; }
.tour-body { flex: 1 1 28rem; min-inline-size: 0; }
.tour-body h3 { margin: 0 0 2px; font-size: .95rem; }
.tour-body p { margin: 0; font-size: .92rem; max-inline-size: 90ch; }
.tour-body .step-no { font-size: .7rem; text-transform: uppercase; letter-spacing: .1em; color: var(--muted); }
.tour-nav { display: flex; gap: 8px; flex-wrap: wrap; }

.views-bar { display: flex; justify-content: flex-end; margin-block-end: 8px; }
.vcard { border: 1px solid var(--border); border-inline-start-width: 4px; border-radius: 3px; padding: 8px 10px; background: var(--panel2); display: grid; gap: 2px; }
.vcard.ok { border-inline-start-color: var(--ok); }
.vcard.bad { border-inline-start-color: var(--bad); }
.vcard .vc-t { font-size: 1rem; font-weight: 650; }
.vcard.ok .vc-t { color: var(--ok); }
.vcard.bad .vc-t { color: var(--bad); }
.vcard p { margin: 0; font-size: .86rem; }
.vcard .vc-n { font-size: .75rem; color: var(--muted); }
.vcard .btn { justify-self: start; margin-block-start: 4px; font-size: .8rem; min-block-size: 28px; padding: 3px 10px; }
.pair-label { position: absolute; transform: translate(-50%, -140%); pointer-events: none; font-size: .78rem; font-weight: 650; font-variant-numeric: tabular-nums; padding: 1px 6px; border-radius: 2px; background: color-mix(in srgb, var(--canvas) 82%, transparent); color: var(--text); border: 1px solid var(--border-strong); white-space: nowrap; direction: ltr; unicode-bidi: isolate; }
.pair-label.bad { color: var(--bad); border-color: var(--bad); }

.stage-now { margin: 0; font-size: .9rem; font-weight: 600; }
.stage-now .ph { font-weight: 400; color: var(--muted); }
.timeline { display: grid; gap: 0; }
.tl-markers { position: relative; block-size: 24px; margin-inline: 8px; }
.tl-mk { position: absolute; top: 0; transform: translateX(-50%); inline-size: 22px; block-size: 24px; padding: 0; border: 0; background: none; cursor: pointer; display: flex; align-items: center; justify-content: center; }
.tl-mk::before { content: ""; inline-size: 10px; block-size: 10px; border: 2px solid currentColor; transform: rotate(45deg); background: var(--panel); }
.tl-mk.tight-nom { color: var(--accent); }
.tl-mk.tight-str { color: var(--bad); }
.tl-mk.tight-str::before { background: currentColor; }
.tl-mk.ev { color: #d946c0; }
.tl-mk:hover::before { background: currentColor; }
.tl-band { display: flex; margin-inline: 8px; block-size: 28px; border: 1px solid var(--border-strong); border-radius: 2px; overflow: hidden; background: var(--panel2); }
.tl-seg { flex: none; min-inline-size: 0; padding: 0 4px; border: 0; border-inline-end: 1px solid var(--border-strong); background: var(--panel2); color: var(--muted); font: inherit; font-size: .7rem; cursor: pointer; overflow: hidden; white-space: nowrap; text-overflow: ellipsis; text-align: start; }
.tl-seg:last-child { border-inline-end: 0; }
.tl-seg:hover { color: var(--text); background: color-mix(in srgb, var(--accent) 14%, var(--panel2)); }
.tl-seg.cur { background: color-mix(in srgb, var(--accent) 30%, var(--panel2)); color: var(--text); font-weight: 600; }
.tl-track { position: relative; }
.tl-frames { position: absolute; inset-inline: 8px; top: 50%; block-size: 14px; transform: translateY(-50%); pointer-events: none; background: repeating-linear-gradient(to right, var(--warn) 0, var(--warn) 1px, transparent 1px, transparent calc(var(--fc-step, 1) * 1%)); }
#scrub { appearance: none; -webkit-appearance: none; background: transparent; margin: 0; padding: 0; block-size: 28px; }
#scrub::-webkit-slider-runnable-track { block-size: 4px; background: var(--border-strong); border-radius: 0; }
#scrub::-moz-range-track { block-size: 4px; background: var(--border-strong); border-radius: 0; }
#scrub::-webkit-slider-thumb { -webkit-appearance: none; inline-size: 16px; block-size: 22px; margin-block-start: -9px; background: var(--accent); border: 2px solid var(--panel); border-radius: 2px; }
#scrub::-moz-range-thumb { inline-size: 12px; block-size: 18px; background: var(--accent); border: 2px solid var(--panel); border-radius: 2px; }

.why { background: var(--panel); border: 1px solid var(--border); border-radius: 4px; padding: 12px 14px; margin-block: 12px; display: grid; gap: 8px; }
.why h2 { margin: 0; }
.why p { margin: 0; max-inline-size: 90ch; }
.why .btn[aria-pressed="true"] { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); font-weight: 600; }
.fc-out p { margin: 0 0 4px; }
.fc-out .fc-num { font-variant-numeric: tabular-nums; font-weight: 650; }
.fc-ev { border-block-start: 1px solid var(--border); padding-block-start: 8px; }
.fc-ev h3 { margin: 0 0 4px; font-size: .8rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); }
.fc-ev ul { margin: 0; padding-inline-start: 1.2rem; font-size: .88rem; }
.fc-ev li { margin-block: 3px; }

@media (max-width: 860px) {
  .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .steps li:nth-child(2) .step-btn { border-inline-end: 0; }
  .steps li:nth-child(-n+2) .step-btn { border-block-end: 1px solid var(--border); }
  .views-bar { justify-content: flex-start; }
}
[hidden] { display: none !important; }

@media (min-width: 861px) {
  .views .view { display: grid; grid-row: span 5; grid-template-rows: subgrid; row-gap: 8px; align-content: start; }
  body.classic .views .view { grid-row: span 5; }
}
@media (max-width: 860px) { .row-fill { display: none; } }
.row-fill { min-block-size: 0; }