/* SKD Industries — drawing-sheet system
   One family (Archivo, self-hosted), three widths. One saturated colour: the logo red, used only for the logo and primary buttons. */

@font-face {
  font-family: "Archivo";
  src: url("fonts/archivo-latin.woff2") format("woff2");
  font-weight: 100 900; font-stretch: 62% 125%; font-style: normal; font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Archivo";
  src: url("fonts/archivo-latin-ext.woff2") format("woff2");
  font-weight: 100 900; font-stretch: 62% 125%; font-style: normal; font-display: swap;
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

:root {
  --aluminium: #D3D8DA;   /* page ground */
  --film: #F2F4F4;        /* drawing sheet */
  --graphite: #1D2428;    /* ink, linework */
  --pencil: #5A656B;      /* dimension lines, secondary text */
  --red: #B00810;         /* logo red */
  --airframe: #E3E7E8;    /* neutral technical shading for the drone */
  --field: #FBFCFC;       /* input background */
  --error: #A4161A;

  --font: "Archivo", "Arial Narrow", Arial, sans-serif;
  --frame: min(1400px, 100% - 2 * clamp(16px, 4vw, 56px));
  --pad: clamp(20px, 4.5vw, 72px);
  --gap: clamp(16px, 2vw, 32px);
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--aluminium);
  color: var(--graphite);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.55;
  font-stretch: 100%;
  -webkit-font-smoothing: antialiased;
}

img, svg { display: block; max-width: 100%; }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a { color: inherit; text-underline-offset: .2em; text-decoration-thickness: 1px; }

:focus-visible { outline: 3px solid var(--graphite); outline-offset: 3px; }

.visually-hidden {
  position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip {
  position: absolute; left: 16px; top: -100px; z-index: 10;
  background: var(--graphite); color: var(--film); padding: 10px 16px; text-decoration: none;
}
.skip:focus { top: 12px; }

.frame-width { width: var(--frame); margin-inline: auto; }

/* ---------- type ---------- */

.display {
  margin: 0;
  font-weight: 800;
  font-stretch: 66%;
  line-height: .92;
  letter-spacing: -.01em;
  text-wrap: balance;
}
h1.display { font-size: clamp(3.25rem, 6.6vw, 7rem); }
h2.display { font-size: clamp(2.5rem, 4.6vw, 4.5rem); margin-bottom: .45em; }

.lede {
  font-size: clamp(1.125rem, 1.4vw, 1.3125rem);
  line-height: 1.5;
  max-width: 36ch;
  margin-top: 1.4em;
}

/* annotation lettering: expanded width, like drawing callouts */
.anno, .title-block, .person-role, .parts thead th, .revs thead th {
  font-stretch: 125%;
  font-weight: 400;
  letter-spacing: .01em;
}

/* ---------- buttons ---------- */

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  min-height: 48px; padding: 0 22px;
  border: 1.5px solid var(--graphite);
  background: transparent; color: var(--graphite);
  font: inherit; font-weight: 700; font-stretch: 88%; font-size: 1rem; line-height: 1.1;
  text-decoration: none; cursor: pointer;
  transition: background-color .15s ease, color .15s ease;
}
.btn:hover { background: var(--graphite); color: var(--film); }
.btn--target { background: var(--red); border-color: var(--red); color: var(--film); }
.btn--target:hover { background: var(--graphite); border-color: var(--graphite); color: var(--film); }
.btn--ink { background: var(--graphite); color: var(--film); }
.btn--ink:hover { background: transparent; color: var(--graphite); }
.btn:disabled { cursor: progress; opacity: .7; }

/* ---------- header ---------- */

.site-header {
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  padding-block: 14px;
  position: relative;
}

.wordmark { display: inline-block; line-height: 0; }
.wordmark img { height: clamp(56px, 5.4vw, 76px); width: auto; }

.nav-list {
  display: flex; align-items: center; gap: clamp(16px, 2.4vw, 32px);
  list-style: none; margin: 0; padding: 0;
}
.nav-list a:not(.btn) { text-decoration: none; font-weight: 500; }
.nav-list a:not(.btn):hover { text-decoration: underline; }

.menu-toggle {
  display: none;
  min-height: 44px; padding: 0 16px;
  border: 1.5px solid var(--graphite); background: transparent; color: var(--graphite);
  font: inherit; font-weight: 700; font-stretch: 88%; cursor: pointer;
}

/* ---------- drawing sheets ---------- */

.sheet {
  position: relative;
  width: var(--frame);
  margin: 0 auto clamp(20px, 3vw, 40px);
  padding: var(--pad) var(--pad) calc(var(--pad) + 72px);
  background: var(--film);
  border: 1px solid var(--pencil);
}
.sheet::before {               /* inner drawing frame */
  content: "";
  position: absolute; inset: 10px;
  border: 2px solid var(--graphite);
  pointer-events: none;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  column-gap: var(--gap);
}

.title-block {
  position: absolute; right: 10px; bottom: 10px;
  display: grid; grid-template-columns: minmax(0, auto) auto;
  border-top: 2px solid var(--graphite); border-left: 2px solid var(--graphite);
  font-size: .75rem; line-height: 1.3;
  background: var(--film);
}
.title-block span { padding: 7px 14px; border-right: 1px solid var(--pencil); border-bottom: 1px solid var(--pencil); }
.title-block span:nth-child(2n) { border-right: 0; }
.title-block span:nth-child(n+3) { border-bottom: 0; }
.title-block span:first-child { font-weight: 700; font-stretch: 100%; }

/* ---------- drawings ---------- */

.drawing { margin: 0; }
.drawing svg { width: 100%; height: auto; overflow: visible; }

.drawing .chain { stroke: var(--pencil); stroke-width: 1; stroke-dasharray: 22 5 3 5; }
.drawing .airframe-fill,
.drawing .airframe-solid { fill: var(--airframe); }
.drawing .airframe-line,
.drawing .airframe-solid { fill: none; stroke: var(--graphite); stroke-width: 2; stroke-linejoin: round; }
.drawing .airframe-solid { fill: var(--airframe); }
.drawing .ln, .drawing .ln-static { fill: none; stroke: var(--graphite); stroke-width: 1.6; stroke-linejoin: round; }
.drawing .thin { stroke-width: 1; }
.drawing .heavy { stroke-width: 4; stroke-linecap: square; }
.drawing .fin, .drawing .hub { fill: var(--film); }
.drawing .solid, .drawing .arrow, .drawing .dot { fill: var(--graphite); }
.drawing .leader { fill: none; stroke: var(--graphite); stroke-width: 1; }
.drawing .balloon { fill: var(--film); stroke: var(--graphite); stroke-width: 1.5; }
.drawing text { font-family: var(--font); fill: var(--graphite); }
.drawing .anno { font-size: 13px; }
.drawing .balloon-num { font-size: 14px; font-weight: 700; text-anchor: middle; }

/* one orchestrated load moment: linework draws in, then shading floods the airframe */
.anim .hero-drawing .ln { stroke-dasharray: 1; stroke-dashoffset: 1; }
.anim .hero-drawing .chain,
.anim .hero-drawing .callout { opacity: 0; }
.anim .hero-drawing .flood { transform: scaleX(0); transform-box: fill-box; transform-origin: right center; }

.anim.drawn .hero-drawing .ln { stroke-dashoffset: 0; transition: stroke-dashoffset 1.2s cubic-bezier(.6, 0, .2, 1) .2s; }
.anim.drawn .hero-drawing .chain { opacity: 1; transition: opacity .5s ease; }
.anim.drawn .hero-drawing .flood { transform: scaleX(1); transition: transform .75s cubic-bezier(.7, 0, .3, 1) 1.25s; }
.anim.drawn .hero-drawing .callout { opacity: 1; transition: opacity .5s ease 1.9s; }

/* ---------- sheet 1: hero ---------- */

.hero { align-items: center; row-gap: 40px; }
.hero-text { grid-column: 1 / span 5; }
.hero-drawing { grid-column: 6 / -1; margin-right: calc(-.4 * var(--pad)); }

.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 36px; }

.why {
  margin-top: clamp(48px, 6vw, 88px);
  padding-top: 28px;
  border-top: 1px solid var(--pencil);
  row-gap: 16px;
}
.why p { font-size: clamp(1.125rem, 1.35vw, 1.25rem); line-height: 1.55; max-width: 58ch; }
.why p:first-child { grid-column: 6 / span 5; margin: 0; }
.why p:last-child { grid-column: 6 / span 5; color: var(--pencil); }

/* ---------- sheet 2: drone ---------- */

.drone-intro { grid-column: 1 / span 4; grid-row: 1 / span 2; align-self: start; }
.drone-intro p { max-width: 42ch; }
.drone-figure { grid-column: 5 / -1; margin-top: 8px; }
.parts-wrap { grid-column: 5 / -1; margin-top: 40px; overflow-x: auto; }

table { border-collapse: collapse; width: 100%; }
.parts, .revs { font-size: .9688rem; line-height: 1.45; }
.parts th, .parts td, .revs th, .revs td {
  text-align: left; vertical-align: top;
  padding: 12px 16px 12px 0;
  border-bottom: 1px solid var(--pencil);
}
.parts thead th, .revs thead th {
  font-size: .8125rem; color: var(--pencil);
  border-bottom: 2px solid var(--graphite);
  padding-top: 0;
}
.parts td:nth-child(2) { font-weight: 700; white-space: nowrap; width: 9.5rem; }
.parts tbody th { width: 3.25rem; }
.parts-group th[scope="rowgroup"] {
  padding-top: 28px; font-weight: 700; font-stretch: 88%; font-size: 1.0625rem;
  border-bottom: 2px solid var(--graphite);
}

.balloon-tag {
  display: inline-grid; place-items: center;
  width: 28px; height: 28px; border-radius: 50%;
  border: 1.5px solid var(--graphite);
  font-weight: 700; font-size: .875rem; line-height: 1;
}

.run-wrap { grid-column: 1 / -1; margin-top: clamp(56px, 7vw, 96px); }
.run-title { margin: 0 0 32px; font-weight: 700; font-stretch: 80%; font-size: clamp(1.5rem, 2vw, 1.875rem); line-height: 1.1; }

.run {
  list-style: none; margin: 0; padding: 44px 0 0;
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: var(--gap);
  counter-reset: step;
  position: relative;
}
.run::before {                 /* the flight route */
  content: ""; position: absolute; left: 0; right: 0; top: 13px;
  border-top: 2px dashed var(--graphite);
}
.run li { position: relative; counter-increment: step; max-width: 30ch; }
.run li::before {              /* waypoint */
  content: counter(step);
  position: absolute; top: -44px; left: 0;
  display: grid; place-items: center; width: 28px; height: 28px;
  background: var(--film); border: 2px solid var(--graphite);
  font-weight: 700; font-size: .875rem;
}
.run strong { display: block; font-weight: 700; font-stretch: 88%; font-size: 1.125rem; margin-bottom: 4px; }

/* ---------- sheet 3: roadmap ---------- */

.roadmap-intro { grid-column: 1 / span 5; }
.roadmap-intro p { max-width: 40ch; }
.revs-wrap { grid-column: 7 / -1; align-self: end; overflow-x: auto; }
.revs tbody th { width: 3.5rem; }
.revs td:last-child { white-space: nowrap; width: 7rem; color: var(--pencil); }
.revs .is-current td:last-child { color: var(--graphite); font-weight: 700; }

.rev-mark {                    /* drawing revision triangle */
  display: inline-grid; place-items: end center;
  width: 30px; height: 27px; padding-bottom: 3px;
  background: var(--graphite); color: var(--film);
  clip-path: polygon(50% 0, 100% 100%, 0 100%);
  font-weight: 700; font-size: .8125rem; line-height: 1;
}

/* ---------- sheet 4: team ---------- */

.team-intro { grid-column: 1 / span 4; }
.team-intro p { max-width: 38ch; }
.team { grid-column: 6 / -1; list-style: none; margin: 0; padding: 0; }
.person {
  display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 6fr); column-gap: var(--gap);
  padding: 22px 0 24px;
  border-top: 1px solid var(--pencil);
}
.person:last-child { border-bottom: 1px solid var(--pencil); }
.person:first-child { border-top: 2px solid var(--graphite); }
.person-name {
  grid-column: 1; grid-row: 1 / span 2; margin: 0;
  font-weight: 800; font-stretch: 66%; font-size: clamp(1.75rem, 2.6vw, 2.375rem); line-height: 1;
}
.person-role { grid-column: 2; margin: 0 0 8px; font-size: .8125rem; font-weight: 600; color: var(--red); }
.person p:last-child { grid-column: 2; }
.placeholder {
  display: inline-block; padding: 2px 10px 4px;
  border: 1.5px dashed var(--pencil); color: var(--pencil);
  font-weight: 600; font-stretch: 80%; font-size: .6em; line-height: 1.2;
}

/* ---------- request a trial ---------- */

.request { padding-block: clamp(48px, 7vw, 104px) clamp(40px, 5vw, 72px); }
.request-intro { grid-column: 1 / span 4; }
.request-intro p { max-width: 36ch; }

.form-panel {
  grid-column: 6 / -1;
  background: var(--film);
  border: 2px solid var(--graphite);
  padding: clamp(20px, 3vw, 40px);
}

.field { margin: 0 0 20px; padding: 0; border: 0; min-width: 0; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0 20px; }

.field label, .field legend { display: block; font-weight: 600; font-size: .9375rem; margin-bottom: 6px; padding: 0; }
.optional { font-weight: 400; color: var(--pencil); }

input[type="text"], input[type="email"], textarea {
  width: 100%; min-height: 48px; padding: 10px 12px;
  border: 1.5px solid var(--graphite); border-radius: 0;
  background: var(--field); color: var(--graphite);
  font: inherit; font-size: 1rem;
}
textarea { resize: vertical; min-height: 120px; }
input[aria-invalid="true"] { border-color: var(--error); box-shadow: inset 0 0 0 1px var(--error); }

.field-error { margin: 6px 0 0; color: var(--error); font-size: .875rem; font-weight: 600; }
.field-error:empty { display: none; }

.choices { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.choice {
  display: flex !important; align-items: center; gap: 10px;
  min-height: 52px; padding: 10px 14px; margin: 0 !important;
  border: 1.5px solid var(--pencil); background: var(--field);
  font-weight: 500 !important; cursor: pointer;
}
.choice input { width: 18px; height: 18px; margin: 0; accent-color: var(--graphite); flex: none; }
.choice:has(input:checked) { border-color: var(--graphite); box-shadow: inset 0 0 0 1px var(--graphite); font-weight: 700 !important; }

.form-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 16px; margin-top: 8px; }
.form-status { margin: 0; font-size: .9375rem; font-weight: 600; color: var(--error); }
.form-status:empty { display: none; }

.form-done h3 { margin: 0 0 12px; font-weight: 800; font-stretch: 66%; font-size: 2.25rem; line-height: 1; }
.form-done .btn { margin-top: 12px; }
.form-done:focus { outline: none; }
.local-note { color: var(--pencil); font-size: .9375rem; }

/* ---------- footer ---------- */

.site-footer {
  display: grid; grid-template-columns: repeat(4, auto); justify-content: space-between; gap: 12px 24px;
  padding: 20px 0 40px;
  border-top: 2px solid var(--graphite);
  font-size: .8125rem; font-stretch: 125%; color: var(--pencil);
}
.footer-logo { height: 96px; width: auto; grid-row: span 2; align-self: start; }

/* ---------- responsive ---------- */

@media (max-width: 1100px) {
  .hero-text { grid-column: 1 / span 6; }
  .hero-drawing { grid-column: 7 / -1; }
  .why p:first-child, .why p:last-child { grid-column: 4 / -1; }
  .drone-intro, .roadmap-intro, .team-intro, .request-intro { grid-column: 1 / span 5; }
  .drone-figure, .parts-wrap { grid-column: 6 / -1; }
  .revs-wrap, .team, .form-panel { grid-column: 6 / -1; }
}

@media (max-width: 860px) {
  .hero-text, .hero-drawing,
  .why p:first-child, .why p:last-child,
  .drone-intro, .drone-figure, .parts-wrap,
  .roadmap-intro, .revs-wrap,
  .team-intro, .team,
  .request-intro, .form-panel { grid-column: 1 / -1; }

  .hero-drawing { margin-right: 0; }
  .drone-intro { grid-row: auto; }
  .drone-figure, .revs-wrap, .team, .form-panel { margin-top: 28px; }
  .run { grid-template-columns: 1fr 1fr; row-gap: 56px; }
  .run::before { display: none; }
  .run li::before { top: -38px; }
  .run { padding-top: 38px; }
  .site-footer { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 760px) {
  .menu-toggle { display: inline-flex; align-items: center; }
  .nav-list {
    display: none;
    position: absolute; left: 0; right: 0; top: 100%; z-index: 5;
    flex-direction: column; align-items: stretch; gap: 0;
    background: var(--film); border: 2px solid var(--graphite);
  }
  .nav-list.is-open { display: flex; }
  .nav-list li { border-bottom: 1px solid var(--pencil); }
  .nav-list li:last-child { border-bottom: 0; padding: 12px; }
  .nav-list a:not(.btn) { display: block; padding: 14px 16px; }
  .nav-list .btn { width: 100%; }
}

@media (max-width: 600px) {
  body { font-size: 1rem; }
  .sheet { padding-bottom: var(--pad); }
  .sheet::before { inset: 6px; }
  .title-block { position: static; margin: 32px calc(-1 * var(--pad) + 8px) calc(-1 * var(--pad) + 8px); }
  .actions .btn { flex: 1 1 100%; }
  .person { grid-template-columns: 1fr; }
  .person-name { grid-row: auto; margin-bottom: 10px; }
  .person-role, .person p:last-child { grid-column: 1; }
  .field-row, .choices { grid-template-columns: 1fr; }
  .run { grid-template-columns: 1fr; }
  .parts td:nth-child(2) { white-space: normal; width: auto; }
  .site-footer { grid-template-columns: 1fr; }
}

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

/* ---------- refinements after preview ---------- */

.rev-mark { width: 34px; height: 30px; font-size: .875rem; padding-bottom: 4px; }

.drawing-key { display: none; }
.drawing-key ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 10px 20px; font-size: .875rem; }
.drawing-key li { display: inline-flex; align-items: center; gap: 8px; }
.drawing-key .balloon-tag { width: 24px; height: 24px; font-size: .75rem; }

@media (max-width: 600px) {
  /* drawings: keep balloons legible, move labels into a key */
  .hero-drawing { margin-inline: calc(-1 * var(--pad) + 14px); }
  .hero-drawing .anno { display: none; }
  .drawing .bal { transform: scale(2); transform-box: fill-box; transform-origin: center; }
  .drawing-key { display: block; margin-top: 16px; }

  /* parts list and roadmap: stack each row */
  .parts thead, .revs thead {
    position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0);
  }
  .parts tbody, .revs tbody { display: block; }
  .parts tr, .revs tr {
    display: grid; grid-template-columns: 40px minmax(0, 1fr); column-gap: 10px;
    padding: 14px 0; border-bottom: 1px solid var(--pencil);
  }
  .parts th, .parts td, .revs th, .revs td { padding: 0; border: 0; width: auto; }
  .parts td:nth-child(3), .revs td:nth-child(3) { grid-column: 2; margin-top: 4px; }
  .parts .parts-group th[scope="rowgroup"] { grid-column: 1 / -1; padding-top: 18px; border-bottom: 0; }
  .parts-group tr:first-child { border-bottom: 2px solid var(--graphite); padding-top: 0; }
  .revs td:last-child { white-space: normal; font-size: .875rem; }

  /* training run: the route runs down the left */
  .run { padding-top: 0; row-gap: 28px; }
  .run::before {
    display: block; top: 6px; bottom: 6px; left: 13px; right: auto;
    border-top: 0; border-left: 2px dashed var(--graphite);
  }
  .run li { padding-left: 48px; max-width: none; }
  .run li::before { top: 0; }
}

/* easter egg: click the drone to spin its propeller */
.drawing .spinnable { cursor: pointer; }
.drawing .prop { transform-box: fill-box; transform-origin: center; }
.drawing .prop-blur {
  fill: none; stroke: var(--pencil); stroke-width: 10; stroke-linecap: round;
  opacity: 0; transition: opacity .35s ease;
}
.drawing svg.is-spinning .prop-blur { opacity: .3; }

/* ---------- hero 3D stage ---------- */

.hero-3d { margin: 0; }
.stage { position: relative; aspect-ratio: 16 / 10; }
.stage canvas {
  position: absolute; inset: 0; width: 100%; height: 100%; display: block;
  touch-action: pan-y; cursor: grab;
}
.stage canvas:active { cursor: grabbing; }
.stage canvas:focus-visible { outline-offset: -3px; }
.is-playing .stage canvas { cursor: default; }

.stage-status {
  position: absolute; left: 0; right: 0; top: 50%; margin: 0; text-align: center;
  font-size: .8125rem; font-stretch: 125%; color: var(--pencil);
}
.hero-3d:not(.is-loading) .stage-status { display: none; }

.labels { list-style: none; margin: 0; padding: 0; position: absolute; inset: 0; pointer-events: none; opacity: 0; transition: opacity .4s ease; }
.show-labels .labels { opacity: 1; }
.labels li { position: absolute; left: 0; top: 0; }
.labels .dot { position: absolute; left: -3px; top: -3px; width: 6px; height: 6px; border-radius: 50%; background: var(--graphite); }
.labels li::after {
  content: ""; position: absolute; left: 0; top: 0; width: 34px;
  border-top: 1px solid var(--graphite); transform-origin: 0 0; transform: rotate(-40deg);
}
.labels .tag {
  position: absolute; left: 26px; top: -48px;
  display: inline-flex; align-items: center; gap: 6px; white-space: nowrap;
  font-size: .8125rem; font-stretch: 125%;
}
.labels .to-left::after { transform: rotate(-140deg); }
.labels .to-left .tag { left: auto; right: 26px; flex-direction: row-reverse; }
.labels .balloon-tag { width: 24px; height: 24px; font-size: .75rem; background: var(--film); }

.stage-bar {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 24px;
  margin-top: 8px; padding-top: 10px; border-top: 1px solid var(--pencil);
  font-size: .8125rem; font-stretch: 125%; color: var(--pencil);
}
.stage-specs { display: flex; flex-wrap: wrap; gap: 4px 22px; margin: 0; }
.stage-specs div { display: flex; gap: 6px; }
.stage-specs dd { margin: 0; color: var(--graphite); font-weight: 600; }
.stage-actions { display: inline-flex; align-items: center; gap: 16px; }
.stage-btn {
  min-height: 36px; padding: 0 2px; border: 0; border-bottom: 1px solid currentColor; background: none;
  color: var(--graphite); font: inherit; font-stretch: 100%; font-weight: 600; cursor: pointer;
}
.stage-btn:hover { color: var(--red); }
.is-playing .stage-hint { visibility: hidden; }

.hero-3d .fallback { display: none; }
.hero-3d.no-3d .fallback { display: block; }
.hero-3d.no-3d .stage, .hero-3d.no-3d .stage-bar { display: none; }
html:not(.js) .hero-3d .stage, html:not(.js) .hero-3d .stage-bar { display: none; }
html:not(.js) .hero-3d .fallback { display: block; }

.stage-key { display: none; }

@media (max-width: 600px) {
  .stage { aspect-ratio: 4 / 3; }
  .labels .tag { font-size: 0; gap: 0; }
  .labels .balloon-tag { font-size: .75rem; }
  .stage-key {
    display: flex; flex-wrap: wrap; gap: 6px 16px; width: 100%;
    list-style: none; margin: 0 0 4px; padding: 0; color: var(--graphite);
  }
  .stage-key li { display: inline-flex; align-items: center; gap: 6px; }
}

/* ---------- part descriptions (hero) ---------- */

.hero-3d { position: relative; }
.labels { visibility: hidden; }
.show-labels .labels { visibility: visible; }
.labels .tag {
  pointer-events: auto; cursor: pointer;
  border: 0; background: none; padding: 6px; margin: -6px;
  color: var(--graphite); font-family: inherit; line-height: 1.2;
}
.labels .tag:hover .balloon-tag,
.labels .tag[aria-expanded="true"] .balloon-tag,
.stage-key button:hover .balloon-tag,
.stage-key button[aria-expanded="true"] .balloon-tag { background: var(--graphite); color: var(--film); }
.labels .tag:hover { text-decoration: underline; text-underline-offset: .2em; }

.stage-key button {
  display: inline-flex; align-items: center; gap: 6px; min-height: 40px; padding: 0;
  border: 0; background: none; color: var(--graphite); font: inherit; cursor: pointer;
}

.part-info {
  position: absolute; left: 0; top: 0; z-index: 2;
  width: min(320px, 100%);
  padding: 16px 18px 18px;
  background: var(--film); border: 1.5px solid var(--graphite);
  font-size: .9375rem; line-height: 1.5;
  animation: part-info-in .16s ease-out;
}
@keyframes part-info-in { from { opacity: 0; transform: translateY(4px); } }
.part-info-head { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
.part-info-head .balloon-tag { background: var(--graphite); color: var(--film); flex: none; }
.part-info h3 { margin: 0; font-weight: 700; font-stretch: 88%; font-size: 1.1875rem; line-height: 1.15; flex: 1; }
.part-info-close {
  flex: none; width: 36px; height: 36px; margin: -8px -10px -8px 0;
  border: 0; background: none; color: var(--graphite); font: inherit; font-size: 1.5rem; line-height: 1; cursor: pointer;
}
.part-info-close:hover { color: var(--red); }
.part-info p { margin: 0 0 12px; }
.part-info dl { margin: 0; border-top: 1px solid var(--pencil); }
.part-info dl div { display: flex; justify-content: space-between; gap: 16px; padding: 6px 0; border-bottom: 1px solid var(--pencil); font-size: .8125rem; font-stretch: 125%; }
.part-info dt { color: var(--pencil); }
.part-info dd { margin: 0; font-weight: 600; text-align: right; }

@media (max-width: 600px) {
  .labels .tag { padding: 10px; margin: -10px; }
  .part-info { position: static; width: auto; margin-top: 8px; }
}

/* ---------- sheet 2: specs and side profile ---------- */

.spec-list { margin: 32px 0 0; max-width: 42ch; border-top: 2px solid var(--graphite); }
.spec-list div { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; padding: 10px 0; border-bottom: 1px solid var(--pencil); }
.spec-list dt { flex: none; color: var(--pencil); font-size: .8125rem; font-stretch: 125%; }
.spec-list dd { margin: 0; font-size: .9375rem; font-weight: 600; text-align: right; }

.profile { position: relative; margin: 0; }
.pstage { position: relative; aspect-ratio: 16 / 9; overflow: hidden; }
.pstage canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.profile:not(.is-loading) .stage-status { display: none; }
.poverlay { position: absolute; inset: 0; width: 100%; height: 100%; overflow: visible; pointer-events: none; }
.p-ext, .p-leader { stroke: var(--graphite); stroke-width: 1; }
.p-dim { stroke: var(--graphite); stroke-width: 1; }
.p-arrowhead, .p-dot { fill: var(--graphite); }
.p-dim-text { fill: var(--graphite); font-family: var(--font); font-size: 13px; font-weight: 600; font-stretch: 125%; }
.p-trail { stroke: var(--graphite); stroke-width: 1.2; stroke-dasharray: 5 5; }
.p-missile { fill: var(--graphite); }
.p-burst-ring { fill: none; stroke: var(--red); stroke-width: 2; }
.p-burst-ray { stroke: var(--red); stroke-width: 2; stroke-linecap: round; }
.p-trail, .p-missile, .p-burst { opacity: 0; }
.p-dims, .p-callouts, .pballoons { transition: opacity .3s ease; }
.is-engaging .p-dims, .is-engaging .p-callouts, .is-engaging .pballoons { opacity: 0; }
.has-pick .p-callouts g:not(.is-on) { opacity: .25; }
.pballoons { position: absolute; inset: 0; pointer-events: none; }
.pballoon {
  position: absolute; left: 0; top: 0; pointer-events: auto;
  display: grid; place-items: center; width: 28px; height: 28px; padding: 0;
  border: 1.5px solid var(--graphite); border-radius: 50%;
  background: var(--film); color: var(--graphite);
  font: inherit; font-weight: 700; font-size: .8125rem; line-height: 1; cursor: pointer;
}
.is-small .pballoon { width: 22px; height: 22px; font-size: .6875rem; }
.pballoon:hover, .pballoon.is-on { background: var(--graphite); color: var(--film); }
.has-pick .pballoon:not(.is-on) { opacity: .35; }
.is-engaging .pballoon { pointer-events: none; }
.pcaption {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 6px 20px;
  margin-top: 8px; padding-top: 10px; border-top: 1px solid var(--pencil);
  font-size: .8125rem; font-stretch: 125%; color: var(--pencil);
}
.pcaption .stage-btn:disabled { opacity: .4; cursor: default; }

.profile .fallback { display: none; width: 100%; height: auto; }
.profile.no-3d .fallback { display: block; }
.profile.no-3d .pstage { display: none; }
html:not(.js) .profile .fallback { display: block; }
html:not(.js) .profile .pstage { display: none; }

.parts button.balloon-tag { background: transparent; color: inherit; font: inherit; font-weight: 700; font-size: .875rem; padding: 0; cursor: pointer; }
.parts tr.is-on th, .parts tr.is-on td { background: #E4E8E9; }
.parts tr.is-on button.balloon-tag, .parts button.balloon-tag:hover { background: var(--graphite); color: var(--film); }

@media (max-width: 600px) {
  .pstage { aspect-ratio: 16 / 9; }
  .spec-list { max-width: none; }
}
.part-info.on-right { left: auto; right: 0; }
@media (max-width: 600px) { .part-info.on-right { right: auto; } }

/* ---------- sheet 2: main systems view ---------- */

.profile[data-view="systems"] .poverlay,
.profile[data-view="systems"] .pballoons { opacity: 0; visibility: hidden; transition: opacity .45s ease, visibility 0s linear .45s; }
.profile[data-view="systems"].is-formed .poverlay,
.profile[data-view="systems"].is-formed .pballoons { opacity: 1; visibility: visible; transition: opacity .45s ease; }
.p-leader.is-on { stroke: var(--red); stroke-width: 1.5; }
.p-dot.is-on { fill: var(--red); }
.profile[data-view="systems"] .pballoon:hover { background: var(--graphite); color: var(--film); }
.profile[data-view="systems"] .pballoon.is-on { background: var(--red); border-color: var(--red); color: #fff; }
.parts tr[data-system].is-on button.balloon-tag { background: var(--red); border-color: var(--red); color: #fff; }
.parts tr[data-system] { cursor: default; }
.parts tr.is-arrived th, .parts tr.is-arrived td { animation: row-arrive 1.6s ease-out; }
@keyframes row-arrive { 0%, 35% { background: #F3D9DA; } 100% { background: #E4E8E9; } }
@media (prefers-reduced-motion: reduce) { .parts tr.is-arrived th, .parts tr.is-arrived td { animation: none; } }

/* ---------- sheet 2: thermal interception film ---------- */

.film {
  position: absolute; inset: 0; z-index: 3;
  background: #0E1011;
  opacity: 0; visibility: hidden;
  transition: opacity .9s ease, visibility 0s linear .9s;
}
.film-on .film { opacity: 1; visibility: visible; transition: opacity .35s ease; }
.film canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; }
.film-plate { position: absolute; left: 0; top: 0; width: 2px; height: 2px; opacity: 0; pointer-events: none; }   /* only read as a texture */
.hud { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.hud-line { fill: none; stroke: rgba(255, 255, 255, .85); stroke-width: 1.2; }
.hud-thin { stroke-width: 1; }
.hud-text, .hud-msg {
  fill: rgba(255, 255, 255, .88);
  font-family: var(--font); font-stretch: 125%; font-weight: 500;
  font-size: var(--hud-size, 12px); letter-spacing: .08em;
}
.hud-small { font-size: calc(var(--hud-size, 12px) * .9); }
.hud-msg { font-weight: 700; font-size: calc(var(--hud-size, 12px) * 1.25); letter-spacing: .16em; }
.no-film .film { display: none; }
.pcaption-actions { display: inline-flex; gap: 16px; }

/* ---------- additions for the published site ---------- */

.spec-note { margin-top: 12px; max-width: 42ch; font-size: .8125rem; line-height: 1.45; color: var(--pencil); }
.direct { margin-top: 1em; }
.direct a { font-weight: 600; overflow-wrap: anywhere; }
.form-privacy { margin: 18px 0 0; font-size: .875rem; color: var(--pencil); }
.site-footer a { color: var(--graphite); }

/* document pages (privacy notice, 404) */
.nav-list--plain { display: flex; }
.doc > :not(.title-block) { max-width: 68ch; }
.doc h1.display { font-size: clamp(2.5rem, 5vw, 4.5rem); margin-bottom: .2em; }
.doc-meta { color: var(--pencil); font-size: .875rem; font-stretch: 125%; margin-bottom: 2.2em; }
.doc h2 { margin: 2em 0 .5em; font-weight: 700; font-stretch: 80%; font-size: clamp(1.375rem, 1.8vw, 1.625rem); line-height: 1.15; }
.doc h3 { margin: 1.4em 0 .3em; font-weight: 700; font-size: 1.0625rem; }
.doc ul { padding-left: 1.2em; margin: 0 0 1em; }
.doc li { margin-bottom: .4em; }
.doc a:not(.btn) { overflow-wrap: anywhere; }
.doc--short { min-height: 60vh; }
.doc--short .btn { margin-top: 12px; }
@media (max-width: 760px) {
  .nav-list--plain { display: flex; position: static; flex-direction: row; border: 0; background: none; }
  .nav-list--plain li { border: 0; }
  .nav-list--plain li:last-child { padding: 0; }
  .nav-list--plain a:not(.btn) { padding: 0; }
  .nav-list--plain .btn { width: auto; }
}