/* SPDX-FileCopyrightText: 2026 Jake Wehmeier (BTSpaniel) <https://github.com/BTSpaniel> */
/* SPDX-License-Identifier: LicenseRef-ParticleRealms-Alpha */

:root {
  --ink: #030711;
  --ink-blue: #06101d;
  --panel: rgba(5, 12, 24, 0.88);
  --panel-strong: rgba(5, 10, 21, 0.96);
  --line: rgba(154, 205, 224, 0.16);
  --line-strong: rgba(154, 205, 224, 0.29);
  --text: #eaf7fb;
  --muted: #8ba4b2;
  --dim: #587080;
  --accent: #55d7ff;
  --accent-rgb: 85, 215, 255;
  --warm: #ff8b4a;
  --good: #64f0b4;
  --danger: #ff6e78;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  --topbar-height: 58px;
  --rail-width: 250px;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-width: 320px;
  min-height: 100%;
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  min-height: 100dvh;
  overflow: hidden;
}

button,
input,
a {
  font: inherit;
}

button,
a {
  -webkit-tap-highlight-color: transparent;
}

a {
  color: inherit;
}

button {
  color: inherit;
}

::selection {
  background: rgba(var(--accent-rgb), 0.28);
  color: #fff;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

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

.skip-link {
  position: fixed;
  z-index: 2000;
  top: 9px;
  left: 12px;
  padding: 9px 13px;
  border-radius: 7px;
  background: var(--text);
  color: var(--ink);
  font: 800 11px/1 var(--mono);
  letter-spacing: 0.06em;
  text-decoration: none;
  transform: translateY(-160%);
  transition: transform 180ms ease;
}

.skip-link:focus {
  transform: none;
}

.abyss {
  position: fixed;
  z-index: 0;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  background:
    radial-gradient(circle at 76% 58%, rgba(var(--accent-rgb), 0.09), transparent 31%),
    radial-gradient(circle at 22% 96%, rgba(255, 91, 37, 0.11), transparent 28%),
    linear-gradient(160deg, #02050b 0%, #05101c 48%, #020610 100%);
}

.abyss__mineral,
.abyss__smoke,
.abyss__rays,
.abyss__grain {
  position: absolute;
  inset: 0;
}

.abyss__mineral {
  opacity: 0.21;
  background-image:
    linear-gradient(180deg, rgba(1, 4, 10, 0.25), rgba(1, 4, 10, 0.89)),
    url("../assets/abyssal-layers/mineral-base-v4.webp");
  background-size: cover;
  background-position: center bottom;
  transform: scale(1.08);
  filter: saturate(0.7) hue-rotate(-6deg) brightness(0.5);
}

.abyss__smoke {
  width: 78vw;
  height: 75vh;
  inset: auto auto -23vh 18vw;
  background: url("../assets/abyssal-layers/smoke-far-v2.png") center bottom / contain no-repeat;
  mix-blend-mode: screen;
  opacity: 0.075;
  filter: hue-rotate(154deg) saturate(0.8) blur(2px);
  transform-origin: 50% 100%;
  animation: smoke-breathe 14s ease-in-out infinite alternate;
}

.abyss__smoke--near {
  inset: auto -16vw -34vh auto;
  width: 65vw;
  opacity: 0.05;
  transform: scaleX(-1);
  animation-duration: 19s;
  animation-delay: -7s;
}

.abyss__rays {
  inset: -35% -15% auto 24%;
  width: 65vw;
  height: 135vh;
  opacity: 0.25;
  background: conic-gradient(from 177deg at 50% 0%, transparent 0deg, rgba(var(--accent-rgb), 0.08) 5deg, transparent 11deg, transparent 18deg, rgba(var(--accent-rgb), 0.045) 25deg, transparent 32deg);
  filter: blur(8px);
  transform: rotate(-5deg);
}

.abyss__grain {
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 160 160' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.87' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='.9'/%3E%3C/svg%3E");
}

@keyframes smoke-breathe {
  from { transform: scale(1.02) translate3d(-1%, 1.5%, 0); }
  to { transform: scale(1.09) translate3d(1.5%, -1%, 0); }
}

.topbar {
  position: fixed;
  z-index: 100;
  inset: 0 0 auto;
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  gap: 23px;
  padding: 0 18px;
  border-bottom: 1px solid var(--line);
  background: rgba(3, 7, 15, 0.8);
  backdrop-filter: blur(22px) saturate(1.25);
  -webkit-backdrop-filter: blur(22px) saturate(1.25);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.25);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: 310px;
  text-decoration: none;
  white-space: nowrap;
}

.brand__signal {
  position: relative;
  display: block;
  width: 25px;
  height: 25px;
  border: 1px solid rgba(var(--accent-rgb), 0.35);
  border-radius: 50%;
  box-shadow: inset 0 0 14px rgba(var(--accent-rgb), 0.08), 0 0 18px rgba(var(--accent-rgb), 0.08);
}

.brand__signal::before,
.brand__signal::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  border: 1px solid rgba(var(--accent-rgb), 0.18);
}

.brand__signal::before { inset: 4px; }
.brand__signal::after { inset: 8px; background: var(--accent); box-shadow: 0 0 9px var(--accent); }
.brand__signal i { position: absolute; left: 11px; top: 1px; width: 1px; height: 23px; background: rgba(var(--accent-rgb), 0.18); transform: rotate(calc((var(--i, 0) - 1) * 60deg)); }
.brand__signal i:nth-child(1) { --i: 0; }
.brand__signal i:nth-child(2) { --i: 1; }
.brand__signal i:nth-child(3) { --i: 2; }

.brand__name {
  color: #dff6fd;
  font: 850 12px/1 var(--sans);
  letter-spacing: 0.09em;
}

.brand__name b { color: var(--accent); }

.brand__division {
  padding-left: 10px;
  border-left: 1px solid var(--line-strong);
  color: var(--dim);
  font: 700 9px/1 var(--mono);
  letter-spacing: 0.15em;
}

.topbar__nav {
  display: flex;
  align-items: center;
  gap: 2px;
  margin-left: auto;
}

.topbar__nav a {
  padding: 7px 10px;
  border-radius: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 650;
  text-decoration: none;
  transition: color 150ms ease, background-color 150ms ease;
}

.topbar__nav a:hover,
.topbar__nav a.is-active {
  color: #effbff;
  background: rgba(var(--accent-rgb), 0.08);
}

.topbar__nav a.is-active { color: var(--accent); }

.topbar__companion {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid rgba(var(--accent-rgb), 0.36);
  border-radius: 7px;
  background: rgba(var(--accent-rgb), 0.1);
  color: #dcf7ff;
  font: 750 10px/1 var(--mono);
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: background-color 160ms ease, border-color 160ms ease;
}

.topbar__companion:hover { border-color: rgba(var(--accent-rgb), 0.58); background: rgba(var(--accent-rgb), 0.17); }

.topbar__menu {
  display: none;
  width: 38px;
  height: 38px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: rgba(255, 255, 255, 0.025);
}

.topbar__menu span {
  display: block;
  height: 1px;
  margin: 4px 0;
  background: var(--text);
}

.academy {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: var(--rail-width) minmax(0, 1fr);
  width: 100%;
  height: 100dvh;
  padding-top: var(--topbar-height);
}

.lesson-rail {
  position: relative;
  display: flex;
  min-height: 0;
  flex-direction: column;
  padding: 25px 17px 17px;
  border-right: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(3, 8, 17, 0.86), rgba(4, 9, 18, 0.7));
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.lesson-rail::after {
  content: "";
  position: absolute;
  top: 0;
  right: -1px;
  width: 1px;
  height: 24%;
  background: linear-gradient(180deg, transparent, var(--accent), transparent);
  opacity: 0.7;
}

.kicker {
  margin: 0;
  color: var(--accent);
  font: 750 9px/1 var(--mono);
  letter-spacing: 0.2em;
}

.lesson-rail__heading { padding: 2px 8px 21px; }
.lesson-rail__heading h1 { margin: 9px 0 5px; color: #f3fcff; font-size: 24px; line-height: 1.06; letter-spacing: -0.045em; }
.lesson-rail__heading > p:last-child { max-width: 190px; margin: 0; color: var(--muted); font-size: 11px; line-height: 1.55; }

.course-progress {
  margin: 0 8px 14px;
}

.course-progress__copy {
  display: flex;
  justify-content: space-between;
  color: var(--dim);
  font: 700 8px/1 var(--mono);
  letter-spacing: 0.12em;
}

.course-progress__track {
  height: 2px;
  margin-top: 8px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.07);
}

.course-progress__track i {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #d9f8ff);
  box-shadow: 0 0 9px var(--accent);
  transition: width 350ms ease;
}

.lesson-list {
  display: grid;
  min-height: 0;
  gap: 3px;
  margin: 0;
  padding: 0 1px 12px;
  overflow: auto;
  list-style: none;
  scrollbar-color: rgba(var(--accent-rgb), 0.25) transparent;
  scrollbar-width: thin;
}

.lesson-button {
  position: relative;
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr) 13px;
  align-items: center;
  gap: 8px;
  width: 100%;
  min-height: 46px;
  padding: 5px 8px;
  border: 1px solid transparent;
  border-radius: 8px;
  background: transparent;
  text-align: left;
  cursor: pointer;
  transition: color 170ms ease, border-color 170ms ease, background-color 170ms ease;
}

/* Never translate a hovered control: moving its hitbox under an edge pointer
   can alternate :hover on and off and look like vibration. */
.lesson-button:hover { border-color: rgba(var(--accent-rgb), 0.16); background: rgba(255, 255, 255, 0.035); }
.lesson-button[aria-current="step"] { border-color: rgba(var(--accent-rgb), 0.22); background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.13), rgba(var(--accent-rgb), 0.025)); }
.lesson-button[aria-current="step"]::before { content: ""; position: absolute; inset: 7px auto 7px -2px; width: 2px; border-radius: 3px; background: var(--accent); box-shadow: 0 0 12px var(--accent); }

.lesson-button__index {
  display: grid;
  place-items: center;
  width: 29px;
  height: 29px;
  border: 1px solid var(--line);
  border-radius: 50%;
  color: var(--dim);
  font: 750 9px/1 var(--mono);
}

.lesson-button[aria-current="step"] .lesson-button__index { border-color: var(--accent); color: #021016; background: var(--accent); box-shadow: 0 0 18px rgba(var(--accent-rgb), 0.32); }

.lesson-button__copy { overflow: hidden; }
.lesson-button__copy strong { display: block; overflow: hidden; color: #a9bfca; font-size: 11px; font-weight: 680; line-height: 1.25; text-overflow: ellipsis; white-space: nowrap; }
.lesson-button__copy span { display: block; margin-top: 2px; overflow: hidden; color: var(--dim); font: 650 8px/1.2 var(--mono); letter-spacing: 0.08em; text-overflow: ellipsis; white-space: nowrap; }
.lesson-button[aria-current="step"] .lesson-button__copy strong { color: #f0fbff; }
.lesson-button__check { color: transparent; font-size: 10px; }
.lesson-button.is-complete .lesson-button__check { color: var(--good); }

.lesson-rail__foot {
  display: flex;
  align-items: center;
  gap: 7px;
  margin-top: auto;
  padding: 13px 8px 0;
  border-top: 1px solid var(--line);
  color: var(--dim);
  font: 650 8px/1 var(--mono);
  letter-spacing: 0.07em;
}

.status-light {
  display: inline-block;
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--good);
  box-shadow: 0 0 9px rgba(100, 240, 180, 0.68);
}

.lesson-stage {
  position: relative;
  display: grid;
  min-width: 0;
  min-height: 0;
  grid-template-rows: auto minmax(0, 1fr) auto auto auto;
  gap: 11px;
  padding: 19px 22px 14px;
  overflow: hidden;
}

.slide-heading {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 30px;
  min-height: 74px;
}

.slide-heading__copy { min-width: 0; }
.slide-heading__eyebrow { margin: 0 0 5px; color: var(--accent); font: 750 9px/1 var(--mono); letter-spacing: 0.17em; }
.slide-heading h2 { max-width: 850px; margin: 0; color: #f4fcff; font-size: clamp(22px, 2.2vw, 34px); font-weight: 760; line-height: 1.02; letter-spacing: -0.045em; text-wrap: balance; }
.slide-heading__copy #lesson-summary { max-width: 760px; margin: 6px 0 0; color: var(--muted); font-size: 12px; line-height: 1.45; text-wrap: pretty; }
.slide-heading__copy .slide-heading__outcome { margin-top: 4px; color: rgba(var(--accent-rgb), 0.75); font: 650 9px/1.4 var(--mono); letter-spacing: 0.015em; }

.slide-heading__meta {
  display: flex;
  flex: 0 0 auto;
  align-items: center;
  gap: 7px;
  padding-bottom: 2px;
}

.slide-heading__meta span,
.slide-heading__meta button {
  min-height: 25px;
  padding: 7px 9px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: rgba(255, 255, 255, 0.02);
  color: var(--dim);
  font: 700 8px/1 var(--mono);
  letter-spacing: 0.1em;
}

.slide-heading__meta button { cursor: pointer; }
.slide-heading__meta button:hover { border-color: rgba(var(--accent-rgb), 0.4); color: var(--accent); }

.workbench {
  position: relative;
  display: grid;
  min-height: 0;
  grid-template-columns: minmax(330px, 0.88fr) minmax(430px, 1.34fr);
  gap: 11px;
}

.presentation-director {
  position: absolute;
  z-index: 40;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  opacity: 1;
  transition: opacity 180ms ease;
}

.presentation-director.is-hidden { opacity: 0; }

.presentation-director__focus {
  position: absolute;
  left: 0;
  top: 0;
  width: var(--director-width, 120px);
  height: var(--director-height, 32px);
  border: 1px solid rgba(var(--accent-rgb), 0.72);
  border-radius: 7px;
  background: rgba(var(--accent-rgb), 0.025);
  box-shadow:
    0 0 0 1px rgba(1, 5, 12, 0.84),
    0 0 28px rgba(var(--accent-rgb), 0.2),
    inset 0 0 22px rgba(var(--accent-rgb), 0.045);
  transform: translate3d(var(--director-left, 0), var(--director-top, 0), 0) scale(1.018);
  transform-origin: center;
  transition: transform 620ms cubic-bezier(0.22, 0.76, 0.22, 1), width 620ms cubic-bezier(0.22, 0.76, 0.22, 1), height 620ms cubic-bezier(0.22, 0.76, 0.22, 1);
}

.presentation-director__focus span {
  position: absolute;
  top: -17px;
  left: 5px;
  padding: 3px 6px;
  border: 1px solid rgba(var(--accent-rgb), 0.3);
  border-radius: 3px;
  background: rgba(2, 8, 17, 0.95);
  color: var(--accent);
  font: 750 6px/1 var(--mono);
  letter-spacing: 0.11em;
  white-space: nowrap;
}

.presentation-director__cursor {
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 34px;
  filter: drop-shadow(0 3px 7px rgba(0, 0, 0, 0.7)) drop-shadow(0 0 7px rgba(var(--accent-rgb), 0.42));
  transform: translate3d(var(--director-x, 0), var(--director-y, 0), 0);
  transition: transform 720ms cubic-bezier(0.2, 0.78, 0.2, 1);
}

.presentation-director__cursor svg { display: block; width: 100%; height: 100%; overflow: visible; }
.presentation-director__cursor path { fill: #f6fcff; stroke: rgba(2, 8, 16, 0.95); stroke-width: 2; stroke-linejoin: round; }
.presentation-director__cursor i {
  position: absolute;
  left: 7px;
  top: 7px;
  width: 7px;
  height: 7px;
  border: 1px solid var(--accent);
  border-radius: 50%;
  opacity: 0;
  animation: director-click 2.4s ease-out infinite;
}

.is-director-focus { position: relative; z-index: 3; }

@keyframes director-click {
  0%, 72% { opacity: 0; transform: scale(0.4); }
  78% { opacity: 0.9; transform: scale(0.6); }
  100% { opacity: 0; transform: scale(3.2); }
}

.workbench.is-code-phase {
  grid-template-columns: minmax(430px, 1.18fr) minmax(360px, 0.82fr);
}

.code-panel,
.runtime-panel {
  position: relative;
  min-width: 0;
  min-height: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  box-shadow: 0 24px 70px rgba(0, 0, 0, 0.32), inset 0 1px rgba(255, 255, 255, 0.025);
}

.code-panel { display: grid; grid-template-rows: 47px minmax(0, 1fr) 27px; }
.runtime-panel { display: grid; grid-template-rows: 47px minmax(0, 1fr); }

.panel-bar {
  position: relative;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 0 12px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(13, 25, 40, 0.88), rgba(6, 13, 25, 0.82));
}

.panel-bar__identity { display: flex; align-items: center; gap: 10px; min-width: 0; }
.panel-bar__identity > div { min-width: 0; }
.panel-bar__label { display: block; margin-bottom: 2px; color: var(--dim); font: 700 7px/1 var(--mono); letter-spacing: 0.15em; }
.panel-bar__identity strong { display: block; overflow: hidden; color: #cfe3eb; font: 650 10px/1.1 var(--mono); text-overflow: ellipsis; white-space: nowrap; }

.panel-bar__lights { display: flex; gap: 4px; }
.panel-bar__lights i { display: block; width: 6px; height: 6px; border-radius: 50%; background: #243748; }
.panel-bar__lights i:first-child { background: #f36e72; }
.panel-bar__lights i:nth-child(2) { background: #e8af58; }
.panel-bar__lights i:nth-child(3) { background: #64dca1; }

.panel-bar__actions { display: flex; align-items: center; gap: 4px; }
.panel-bar__actions a,
.panel-bar__actions button {
  padding: 6px 7px;
  border: 0;
  border-radius: 4px;
  background: transparent;
  color: var(--dim);
  font: 700 8px/1 var(--mono);
  letter-spacing: 0.08em;
  text-decoration: none;
  cursor: pointer;
}
.panel-bar__actions a:hover,
.panel-bar__actions button:hover { color: var(--accent); background: rgba(var(--accent-rgb), 0.06); }
.panel-bar__actions button:disabled { color: #3a4c58; cursor: not-allowed; background: transparent; }

.code-window {
  min-height: 0;
  overflow: auto;
  padding: 12px 0 18px;
  background:
    linear-gradient(90deg, rgba(var(--accent-rgb), 0.022) 1px, transparent 1px) 0 0 / 28px 100%,
    linear-gradient(145deg, rgba(3, 8, 17, 0.94), rgba(6, 15, 28, 0.91));
  scrollbar-color: rgba(var(--accent-rgb), 0.24) transparent;
  scrollbar-width: thin;
  counter-reset: source-line;
}

.code-line {
  position: relative;
  display: grid;
  grid-template-columns: 43px minmax(max-content, 1fr);
  min-height: 20px;
  padding: 1px 14px 1px 0;
  color: #9db4c0;
  font: 500 10.5px/1.65 var(--mono);
  white-space: pre;
  counter-increment: source-line;
  transition: color 100ms ease, background-color 100ms ease;
}

.code-line::before {
  content: counter(source-line, decimal-leading-zero);
  padding-right: 12px;
  color: #3c5262;
  text-align: right;
  user-select: none;
}

.code-line.is-active {
  color: #eaf9ff;
  background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.13), rgba(var(--accent-rgb), 0.018));
}

.code-line.is-active::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 2px;
  background: var(--accent);
  box-shadow: 0 0 9px var(--accent);
}

.code-line.is-future { color: #354b59; }
.code-line.is-error { color: #ffd7da; background: linear-gradient(90deg, rgba(255, 85, 98, 0.18), rgba(255, 85, 98, 0.025)); }
.code-line.is-error::after { content: ""; position: absolute; inset: 0 auto 0 0; width: 2px; background: var(--danger); box-shadow: 0 0 9px var(--danger); }
.code-line__text::after { content: ""; display: inline-block; width: 0; height: 1.1em; vertical-align: -0.2em; }
.code-line.is-typing .code-line__text::after { width: 1px; margin-left: 1px; background: var(--accent); animation: cursor-blink 700ms steps(1) infinite; }
@keyframes cursor-blink { 0%, 49% { opacity: 1; } 50%, 100% { opacity: 0; } }

.tok-comment { color: #577483; font-style: italic; }
.tok-string { color: #9de3a8; }
.tok-keyword { color: #d699ff; }
.tok-number { color: #f5bd78; }
.tok-function { color: #70dcff; }

.code-panel__status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 11px;
  border-top: 1px solid var(--line);
  color: var(--dim);
  font: 650 7px/1 var(--mono);
  letter-spacing: 0.1em;
}
.code-panel__status > span:first-child { display: flex; align-items: center; gap: 5px; }
.code-panel__status .status-light { width: 4px; height: 4px; }

.runtime-mark {
  width: 23px;
  height: 23px;
  border: 1px solid rgba(var(--accent-rgb), 0.34);
  border-radius: 4px 50% 50%;
  background: radial-gradient(circle at 62% 38%, rgba(var(--accent-rgb), 0.5), transparent 25%), rgba(var(--accent-rgb), 0.05);
  transform: rotate(45deg);
  box-shadow: 0 0 14px rgba(var(--accent-rgb), 0.12);
}

.runtime-backend {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 8px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--dim);
  font: 700 7px/1 var(--mono);
  letter-spacing: 0.1em;
}
.runtime-backend i { width: 5px; height: 5px; border-radius: 50%; background: #788a95; box-shadow: 0 0 6px currentColor; }
.runtime-backend[data-state="webgpu"] { border-color: rgba(100, 240, 180, 0.25); color: var(--good); }
.runtime-backend[data-state="verified"] { border-color: rgba(100, 240, 180, 0.25); color: var(--good); }
.runtime-backend[data-state="canvas2d"] { border-color: rgba(255, 184, 98, 0.25); color: #ffb862; }
.runtime-backend[data-state="error"] { border-color: rgba(255, 110, 120, 0.3); color: var(--danger); }

.runtime-viewport {
  position: relative;
  min-height: 0;
  overflow: hidden;
  isolation: isolate;
  background: #020713;
}

.runtime-live {
  position: absolute;
  z-index: 0;
  inset: 0;
  opacity: 1;
  visibility: visible;
  transition: opacity 420ms ease, visibility 420ms step-start;
}

.runtime-viewport[data-revealed="false"] .runtime-live,
.runtime-viewport[data-revealed="preview"] .runtime-live {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

/* The WGSL chapter presents the exact compiled shader without Academy HUD
   decoration or unrelated ECS/runtime overlays. */
.runtime-viewport[data-output="shader"]::before,
.runtime-viewport[data-output="shader"]::after,
.runtime-viewport[data-output="shader"] .sonar,
.runtime-viewport[data-output="shader"] .depth-scale,
.runtime-viewport[data-output="shader"] .runtime-titlecard,
.runtime-viewport[data-output="shader"] .lab-controls,
.runtime-viewport[data-output="shader"] .runtime-receipt,
.runtime-viewport[data-output="shader"] .runtime-hint {
  display: none;
}

.runtime-viewport[data-output="shader"] #engine-canvas { cursor: default; }

#engine-canvas {
  position: absolute;
  z-index: 0;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  cursor: crosshair;
}

.engine-canvas-fallback {
  position: absolute;
  z-index: 0;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
}

.runtime-gate {
  position: absolute;
  z-index: 12;
  inset: 0;
  display: grid;
  align-content: center;
  justify-items: center;
  padding: clamp(24px, 5vw, 64px);
  overflow: hidden;
  background:
    radial-gradient(circle at 50% 42%, rgba(var(--accent-rgb), 0.09), transparent 34%),
    linear-gradient(rgba(var(--accent-rgb), 0.025) 1px, transparent 1px) 0 0 / 100% 31px,
    linear-gradient(90deg, rgba(var(--accent-rgb), 0.018) 1px, transparent 1px) 0 0 / 31px 100%,
    #030914;
  text-align: center;
}

.runtime-gate[hidden] { display: none; }

.runtime-gate.has-preview {
  align-content: stretch;
  justify-items: stretch;
  padding: clamp(14px, 2.2vw, 24px);
  text-align: left;
}

.runtime-gate.has-preview > :not(.runtime-gate__beam, .runtime-gate__preview, .runtime-gate__error) {
  display: none;
}

.runtime-gate__preview {
  position: relative;
  z-index: 2;
  display: grid;
  min-width: 0;
  min-height: 0;
}

.runtime-gate__preview[hidden] { display: none; }

.preview-console {
  display: grid;
  min-width: 0;
  min-height: 0;
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
  border: 1px solid rgba(var(--accent-rgb), 0.22);
  border-radius: 9px;
  background: rgba(1, 5, 11, 0.92);
  box-shadow: inset 0 1px rgba(255, 255, 255, 0.025), 0 20px 60px rgba(0, 0, 0, 0.34);
}

.preview-console--powershell { background: #080a0c; border-color: rgba(112, 231, 194, 0.25); }

.preview-console__bar {
  display: flex;
  min-height: 39px;
  align-items: center;
  gap: 9px;
  padding: 0 12px;
  border-bottom: 1px solid rgba(var(--accent-rgb), 0.14);
  color: #b9d1da;
  font: 680 8px/1 var(--mono);
  letter-spacing: 0.08em;
}

.preview-console__lights { display: inline-flex; gap: 4px; }
.preview-console__lights i { width: 6px; height: 6px; border-radius: 50%; background: #ff7278; }
.preview-console__lights i:nth-child(2) { background: #f1bd67; }
.preview-console__lights i:nth-child(3) { background: #63e0aa; }
.preview-console__bar output { margin-left: auto; color: var(--dim); font: inherit; }
.preview-console[data-state="running"] .preview-console__bar output { color: var(--good); }

.preview-console__body {
  min-height: 0;
  margin: 0;
  padding: clamp(17px, 2.5vw, 28px);
  overflow: auto;
  color: #c9dbe2;
  font: 570 clamp(10px, 1.02vw, 13px)/1.75 var(--mono);
  white-space: pre-wrap;
  scrollbar-color: rgba(var(--accent-rgb), 0.28) transparent;
  scrollbar-width: thin;
}

.preview-console--powershell .preview-console__body { color: #e2e2e2; }
.preview-console__prompt { color: #70e7c2; }
.preview-console__command { color: #f3f7f8; }
.preview-console__muted { color: #66808d; }
.preview-console__success { color: var(--good); }
.preview-console__tree-root { color: var(--accent); font-weight: 760; }
.preview-console__tree-branch { color: #637b87; }
.preview-console__tree-name { color: #e1f3f8; }
.preview-console__tree-role { color: #78909b; }

.preview-console__foot {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 9px 12px;
  border-top: 1px solid rgba(var(--accent-rgb), 0.12);
  color: var(--dim);
  font: 680 7px/1.3 var(--mono);
  letter-spacing: 0.08em;
}

.preview-study {
  display: grid;
  min-width: 0;
  min-height: 0;
  grid-template-rows: auto minmax(130px, 1fr) auto auto;
  overflow: hidden;
  border: 1px solid rgba(var(--accent-rgb), 0.22);
  border-radius: 9px;
  background:
    radial-gradient(circle at 25% 40%, rgba(var(--accent-rgb), 0.09), transparent 32%),
    rgba(2, 7, 15, 0.92);
  box-shadow: inset 0 1px rgba(255, 255, 255, 0.025), 0 20px 60px rgba(0, 0, 0, 0.3);
}

.preview-study__bar,
.preview-study > footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 38px;
  padding: 0 13px;
  border-bottom: 1px solid rgba(var(--accent-rgb), 0.12);
  color: var(--dim);
  font: 700 7px/1.3 var(--mono);
  letter-spacing: 0.11em;
}

.preview-study__bar output { color: var(--accent); font: inherit; }
.preview-study > footer { min-height: 35px; border-top: 1px solid rgba(var(--accent-rgb), 0.12); border-bottom: 0; }

.preview-study__stage {
  display: grid;
  grid-template-columns: minmax(118px, 0.42fr) minmax(220px, 1fr);
  align-items: center;
  gap: clamp(18px, 3vw, 42px);
  padding: clamp(18px, 3vw, 34px);
}

.preview-study__stage p { margin: 0 0 7px; color: var(--accent); font: 760 8px/1 var(--mono); letter-spacing: 0.16em; }
.preview-study__stage h3 { margin: 0; color: #eefaff; font-size: clamp(18px, 2vw, 28px); letter-spacing: -0.04em; }
.preview-study__stage small { display: block; margin-top: 8px; color: var(--muted); font-size: 10px; line-height: 1.5; }

.preview-study__signal {
  position: relative;
  display: grid;
  width: min(100%, 180px);
  aspect-ratio: 1;
  place-items: center;
  justify-self: end;
  border: 1px solid rgba(var(--accent-rgb), 0.25);
  border-radius: 50%;
  background: radial-gradient(circle, rgba(var(--accent-rgb), 0.12), transparent 58%);
  box-shadow: inset 0 0 45px rgba(var(--accent-rgb), 0.05), 0 0 35px rgba(var(--accent-rgb), 0.06);
}

.preview-study__signal::before,
.preview-study__signal::after,
.preview-study__signal i { content: ""; position: absolute; inset: 17%; border: 1px solid rgba(var(--accent-rgb), 0.18); border-radius: inherit; }
.preview-study__signal::after { inset: 35%; }
.preview-study__signal i:nth-child(1) { inset: 50% 8% auto; border: 0; border-top: 1px solid rgba(var(--accent-rgb), 0.2); }
.preview-study__signal i:nth-child(2) { inset: 8% auto 8% 50%; border: 0; border-left: 1px solid rgba(var(--accent-rgb), 0.2); }
.preview-study__signal i:nth-child(3) { inset: 50%; width: 5px; height: 5px; border: 0; background: var(--accent); box-shadow: 0 0 13px var(--accent); }
.preview-study__signal strong { position: relative; color: #dff7fd; font: 760 8px/1 var(--mono); letter-spacing: 0.12em; }

.preview-study[data-study="surface-flow"] .preview-study__signal { aspect-ratio: 16 / 10; border-radius: 6px; }
.preview-study[data-study="surface-flow"] .preview-study__signal::before { inset: 12%; border-radius: 3px; }
.preview-study[data-study="surface-flow"] .preview-study__signal::after { inset: 25%; border-radius: 2px; }
.preview-study[data-study="shader-flow"] .preview-study__signal { border-radius: 10px; clip-path: polygon(50% 3%, 97% 92%, 3% 92%); }
.preview-study[data-study="frame-flow"] .preview-study__signal { border-radius: 50% 8px 50% 8px; }
.preview-study[data-study="ship-flow"] .preview-study__signal { border-radius: 8px; transform: rotate(45deg); }
.preview-study[data-study="ship-flow"] .preview-study__signal > * { transform: rotate(-45deg); }

.preview-study__cards {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
  margin: 0;
  padding: 0 13px 13px;
  list-style: none;
}

.preview-study__cards li {
  position: relative;
  min-width: 0;
  min-height: 76px;
  padding: 10px 10px 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.18);
  color: var(--dim);
}

.preview-study__cards span { display: block; font: 700 6px/1 var(--mono); letter-spacing: 0.12em; }
.preview-study__cards strong { display: block; margin-top: 8px; overflow: hidden; font: 750 8px/1.2 var(--mono); letter-spacing: 0.07em; text-overflow: ellipsis; white-space: nowrap; }
.preview-study__cards small { display: block; margin-top: 5px; overflow: hidden; font: 600 7px/1.35 var(--mono); text-overflow: ellipsis; }
.preview-study__cards i { position: absolute; right: 9px; bottom: 8px; left: 9px; height: 1px; background: rgba(255, 255, 255, 0.06); }
.preview-study__cards li.is-active { border-color: rgba(var(--accent-rgb), 0.4); color: #e7f8fd; background: rgba(var(--accent-rgb), 0.07); }
.preview-study__cards li.is-active i { background: var(--accent); box-shadow: 0 0 8px var(--accent); }
.preview-study__cards li.is-complete { color: var(--good); border-color: rgba(100, 240, 180, 0.18); }
.preview-study__cards li.is-complete i { background: var(--good); }

.runtime-gate__beam {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, transparent 0%, rgba(var(--accent-rgb), 0.07) 49%, rgba(var(--accent-rgb), 0.16) 50%, transparent 52%);
  background-size: 100% 160px;
  animation: gate-scan 6s linear infinite;
  opacity: 0.5;
}

@keyframes gate-scan {
  from { background-position: 0 -160px; }
  to { background-position: 0 calc(100% + 160px); }
}

.runtime-gate__kicker {
  position: relative;
  margin: 0 0 10px;
  color: var(--accent);
  font: 760 8px/1 var(--mono);
  letter-spacing: 0.2em;
}

.runtime-gate h3 {
  position: relative;
  margin: 0;
  color: #effbff;
  font-size: clamp(19px, 2vw, 28px);
  letter-spacing: -0.04em;
}

.runtime-gate > p:not(.runtime-gate__kicker, .runtime-gate__error) {
  position: relative;
  max-width: 500px;
  margin: 9px 0 20px;
  color: var(--muted);
  font-size: 11px;
  line-height: 1.55;
  text-wrap: balance;
}

.runtime-gate__stages {
  position: relative;
  display: grid;
  width: min(100%, 430px);
  grid-template-columns: repeat(3, 1fr);
  gap: 5px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.runtime-gate__stages li {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  gap: 4px 7px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(0, 0, 0, 0.18);
  color: var(--dim);
  text-align: left;
}

.runtime-gate__stages li i { grid-row: 1 / 3; width: 6px; height: 6px; border-radius: 50%; background: #334955; }
.runtime-gate__stages li span { font: 680 6px/1 var(--mono); letter-spacing: 0.12em; }
.runtime-gate__stages li strong { font: 750 8px/1 var(--mono); letter-spacing: 0.1em; }
.runtime-gate__stages li.is-active { border-color: rgba(var(--accent-rgb), 0.32); color: #e7f8fd; background: rgba(var(--accent-rgb), 0.07); }
.runtime-gate__stages li.is-complete { color: var(--good); }
.runtime-gate__stages li.is-active i { background: var(--accent); box-shadow: 0 0 10px var(--accent); }
.runtime-gate__stages li.is-complete i { background: var(--good); box-shadow: 0 0 8px rgba(100, 240, 180, 0.5); }

.runtime-gate__progress {
  position: relative;
  width: min(100%, 430px);
  height: 2px;
  margin-top: 11px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.07);
}

.runtime-gate__progress i { display: block; width: 0; height: 100%; background: var(--accent); box-shadow: 0 0 9px var(--accent); transition: width 120ms linear; }

.runtime-gate__receipt {
  position: relative;
  display: flex;
  width: min(100%, 430px);
  justify-content: space-between;
  margin-top: 8px;
  color: var(--dim);
  font: 680 7px/1 var(--mono);
  letter-spacing: 0.09em;
}

.runtime-gate__error {
  position: relative;
  max-width: 520px;
  margin: 16px 0 0;
  padding: 9px 11px;
  border: 1px solid rgba(255, 110, 120, 0.3);
  border-radius: 6px;
  background: rgba(33, 5, 10, 0.72);
  color: #ffd7da;
  font: 650 9px/1.45 var(--mono);
}

.runtime-gate__error[hidden] { display: none; }

.runtime-viewport::before {
  content: "";
  position: absolute;
  z-index: 1;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(rgba(var(--accent-rgb), 0.024) 1px, transparent 1px) 0 0 / 100% 36px,
    linear-gradient(90deg, rgba(var(--accent-rgb), 0.018) 1px, transparent 1px) 0 0 / 36px 100%,
    radial-gradient(circle at 50% 45%, transparent 30%, rgba(1, 4, 10, 0.25) 85%);
}

.runtime-viewport::after {
  content: "";
  position: absolute;
  z-index: 2;
  inset: 0;
  pointer-events: none;
  border: 1px solid rgba(var(--accent-rgb), 0.06);
  box-shadow: inset 0 0 80px rgba(0, 0, 0, 0.4);
}

.sonar {
  position: absolute;
  z-index: 2;
  top: 13%;
  right: 10%;
  width: min(22vw, 220px);
  aspect-ratio: 1;
  opacity: 0.23;
  pointer-events: none;
  border: 1px solid rgba(var(--accent-rgb), 0.25);
  border-radius: 50%;
}
.sonar::before,
.sonar::after,
.sonar i { content: ""; position: absolute; inset: 18%; border: 1px solid rgba(var(--accent-rgb), 0.2); border-radius: 50%; }
.sonar::after { inset: 37%; }
.sonar i:first-child { inset: 49% 0 auto; border: 0; border-top: 1px solid rgba(var(--accent-rgb), 0.2); border-radius: 0; }
.sonar i:nth-child(2) { inset: 0 auto 0 49%; border: 0; border-left: 1px solid rgba(var(--accent-rgb), 0.2); border-radius: 0; }
.sonar i:nth-child(3) { inset: 49%; width: 3px; height: 3px; border: 0; background: var(--accent); box-shadow: 0 0 9px var(--accent); }

.depth-scale {
  position: absolute;
  z-index: 3;
  top: 16px;
  right: 12px;
  bottom: 75px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding-right: 8px;
  border-right: 1px solid rgba(var(--accent-rgb), 0.17);
  color: rgba(var(--accent-rgb), 0.43);
  font: 650 7px/1 var(--mono);
  letter-spacing: 0.08em;
  pointer-events: none;
}

.depth-scale span::after { content: ""; display: inline-block; width: 7px; margin-left: 5px; border-top: 1px solid rgba(var(--accent-rgb), 0.2); vertical-align: middle; }

.runtime-titlecard {
  position: absolute;
  z-index: 4;
  top: 19px;
  left: 19px;
  max-width: 55%;
  pointer-events: none;
}
.runtime-titlecard span { display: block; margin-bottom: 4px; color: var(--accent); font: 750 8px/1 var(--mono); letter-spacing: 0.19em; text-shadow: 0 0 13px rgba(var(--accent-rgb), 0.45); }
.runtime-titlecard strong { display: block; color: rgba(233, 250, 255, 0.91); font-size: clamp(14px, 1.4vw, 20px); font-weight: 690; letter-spacing: -0.025em; text-shadow: 0 2px 20px #000; }

.lab-controls {
  position: absolute;
  z-index: 6;
  left: 15px;
  bottom: 69px;
  display: flex;
  align-items: flex-end;
  gap: 8px;
  max-width: calc(100% - 30px);
  padding: 7px 9px;
  border: 1px solid rgba(var(--accent-rgb), 0.15);
  border-radius: 7px;
  background: rgba(2, 8, 16, 0.64);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.lab-controls label { display: grid; grid-template-columns: minmax(80px, 1fr) auto; align-items: center; gap: 5px 7px; }
.lab-controls label:first-child { grid-template-columns: minmax(92px, 145px) 28px; }
.lab-controls label > span { grid-column: 1 / -1; color: var(--dim); font: 700 6px/1 var(--mono); letter-spacing: 0.13em; }
.lab-controls input { width: 100%; height: 14px; margin: 0; accent-color: var(--accent); cursor: pointer; }
.lab-controls output { color: var(--accent); font: 700 8px/1 var(--mono); text-align: right; }
.lab-controls select { min-width: 92px; height: 23px; padding: 0 22px 0 7px; border: 1px solid rgba(var(--accent-rgb), 0.19); border-radius: 4px; background: #071321; color: #cde5ed; font: 650 8px/1 var(--mono); cursor: pointer; }

.runtime-receipt {
  position: absolute;
  z-index: 4;
  right: 15px;
  bottom: 14px;
  left: 15px;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  border: 1px solid rgba(var(--accent-rgb), 0.15);
  border-radius: 7px;
  background: rgba(2, 8, 16, 0.67);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.runtime-receipt > div { display: grid; grid-template-columns: auto 1fr; align-items: baseline; gap: 3px 7px; min-width: 0; padding: 7px 9px; border-right: 1px solid rgba(var(--accent-rgb), 0.1); }
.runtime-receipt > div:last-child { border-right: 0; }
.runtime-receipt span { grid-column: 1 / -1; color: var(--dim); font: 700 6px/1 var(--mono); letter-spacing: 0.14em; }
.runtime-receipt strong { overflow: hidden; color: #e5f9ff; font: 760 15px/1 var(--mono); text-overflow: ellipsis; }
.runtime-receipt small { color: var(--dim); font: 650 6px/1 var(--mono); letter-spacing: 0.08em; }

.runtime-hint {
  position: absolute;
  z-index: 4;
  right: 15px;
  top: 17px;
  padding: 5px 7px;
  color: rgba(188, 218, 228, 0.48);
  font: 650 7px/1 var(--mono);
  letter-spacing: 0.06em;
  pointer-events: none;
  transform: translateY(31px);
}

.runtime-error {
  position: absolute;
  z-index: 8;
  inset: 50% auto auto 50%;
  max-width: 80%;
  padding: 12px 15px;
  border: 1px solid rgba(255, 110, 120, 0.35);
  border-radius: 7px;
  background: rgba(26, 5, 9, 0.86);
  color: #ffd7da;
  font: 650 10px/1.5 var(--mono);
  text-align: center;
  transform: translate(-50%, -50%);
}

.lesson-feedback {
  display: grid;
  min-width: 0;
  grid-template-columns: minmax(330px, 0.88fr) minmax(430px, 1.34fr);
  gap: 8px;
}

.lesson-feedback:has(.caption-card[hidden]) .execution-bridge { grid-column: 1 / -1; }

.execution-bridge {
  display: grid;
  min-width: 0;
  min-height: 39px;
  grid-template-columns: auto minmax(15px, 1fr) auto minmax(15px, 1fr) auto;
  align-items: center;
  gap: 7px;
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: rgba(2, 7, 15, 0.82);
  color: var(--dim);
}

.execution-bridge > i { height: 1px; background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.18), var(--accent), rgba(var(--accent-rgb), 0.18)); opacity: 0.45; }
.execution-bridge__node { font: 700 6px/1 var(--mono); letter-spacing: 0.12em; }
.execution-bridge strong { color: var(--accent); font: 780 8px/1 var(--mono); letter-spacing: 0.12em; }
.execution-bridge small { display: -webkit-box; grid-column: 1 / -1; overflow: hidden; color: var(--dim); font: 620 7px/1.35 var(--mono); -webkit-box-orient: vertical; -webkit-line-clamp: 2; }
.execution-bridge[data-state="validating"] strong { color: #f5bd78; }
.execution-bridge[data-state="running"] { border-color: rgba(100, 240, 180, 0.22); }
.execution-bridge[data-state="running"] strong { color: var(--good); }
.execution-bridge[data-state="fallback"] { border-color: rgba(255, 184, 98, 0.3); }
.execution-bridge[data-state="fallback"] strong { color: #ffb862; }
.execution-bridge[data-state="error"] { border-color: rgba(255, 110, 120, 0.3); }
.execution-bridge[data-state="error"] strong { color: var(--danger); }

.caption-card {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  min-width: 0;
  min-height: 39px;
  padding: 9px 12px;
  border: 1px solid rgba(var(--accent-rgb), 0.2);
  border-radius: 7px;
  background: rgba(2, 7, 15, 0.82);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}
.caption-card[hidden] { display: none; }
.caption-card__speaker { flex: 0 0 auto; padding-top: 2px; color: var(--accent); font: 750 7px/1 var(--mono); letter-spacing: 0.13em; }
.caption-card p { margin: 0; color: #dcecf2; font-size: 11px; line-height: 1.4; }

.lesson-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  min-height: 34px;
  padding: 0 2px;
}
.lesson-actions p { max-width: 720px; margin: 0; color: var(--muted); font-size: 10.5px; line-height: 1.4; }
.lesson-actions > div { display: flex; flex: 0 0 auto; gap: 7px; }
.action-link { display: inline-flex; align-items: center; min-height: 29px; padding: 7px 10px; border: 1px solid var(--line); border-radius: 5px; color: #a8c0cb; font: 700 8px/1 var(--mono); letter-spacing: 0.05em; text-decoration: none; transition: border-color 150ms ease, color 150ms ease, background-color 150ms ease; }
.action-link:hover { border-color: rgba(var(--accent-rgb), 0.45); color: #ecfbff; }
.action-link--primary { border-color: rgba(var(--accent-rgb), 0.36); background: rgba(var(--accent-rgb), 0.1); color: var(--accent); }

.transport {
  display: grid;
  grid-template-areas: "controls timeline tools";
  grid-template-columns: auto minmax(180px, 1fr) auto;
  align-items: center;
  gap: 14px;
  min-height: 54px;
  padding: 6px 8px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(3, 8, 16, 0.82);
  box-shadow: 0 13px 38px rgba(0, 0, 0, 0.25);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.transport button {
  min-width: 40px;
  height: 40px;
  padding: 0 8px;
  border: 1px solid transparent;
  border-radius: 5px;
  background: transparent;
  color: var(--muted);
  font: 750 9px/1 var(--mono);
  cursor: pointer;
  transition: color 140ms ease, background-color 140ms ease, border-color 140ms ease;
}
.transport button:hover { color: #fff; background: rgba(255, 255, 255, 0.04); border-color: var(--line); }
.transport__cluster,
.transport__tools { display: flex; align-items: center; gap: 2px; }
.transport__cluster { grid-area: controls; }
.transport__tools { grid-area: tools; }
.transport .transport__play { width: 44px; border-color: rgba(var(--accent-rgb), 0.34); background: rgba(var(--accent-rgb), 0.1); color: var(--accent); }
.transport button[aria-pressed="true"] { color: var(--accent); background: rgba(var(--accent-rgb), 0.08); }

.transport__timeline {
  display: grid;
  grid-area: timeline;
  grid-template-columns: 34px minmax(90px, 1fr) 34px;
  align-items: center;
  gap: 8px;
  color: var(--dim);
  font: 650 8px/1 var(--mono);
}
.transport__timeline > span { text-align: right; }
.transport__timeline input { width: 100%; height: 44px; margin: 0; appearance: none; -webkit-appearance: none; background: transparent; cursor: pointer; }
.transport__timeline input::-webkit-slider-runnable-track { height: 2px; border-radius: 3px; background: linear-gradient(90deg, var(--accent) var(--scrub, 0%), rgba(255, 255, 255, 0.1) var(--scrub, 0%)); }
.transport__timeline input::-moz-range-track { height: 2px; border-radius: 3px; background: rgba(255, 255, 255, 0.1); }
.transport__timeline input::-moz-range-progress { height: 2px; background: var(--accent); }
.transport__timeline input::-webkit-slider-thumb { width: 9px; height: 9px; margin-top: -3.5px; appearance: none; -webkit-appearance: none; border: 2px solid #06101c; border-radius: 50%; background: var(--accent); box-shadow: 0 0 9px rgba(var(--accent-rgb), 0.7); }
.transport__timeline input::-moz-range-thumb { width: 7px; height: 7px; border: 2px solid #06101c; border-radius: 50%; background: var(--accent); box-shadow: 0 0 9px rgba(var(--accent-rgb), 0.7); }

.transcript {
  position: fixed;
  z-index: 300;
  top: calc(var(--topbar-height) + 12px);
  right: 12px;
  bottom: 12px;
  display: grid;
  width: min(390px, calc(100vw - 24px));
  grid-template-rows: auto minmax(0, 1fr) auto;
  overflow: hidden;
  border: 1px solid rgba(var(--accent-rgb), 0.26);
  border-radius: 11px;
  background: rgba(4, 10, 20, 0.95);
  box-shadow: 0 30px 100px #000c;
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}
.transcript[hidden] { display: none; }
.transcript > header { display: flex; align-items: center; justify-content: space-between; padding: 17px 17px 14px; border-bottom: 1px solid var(--line); }
.transcript h2 { margin: 6px 0 0; font-size: 19px; letter-spacing: -0.035em; }
.transcript header button { width: 31px; height: 31px; border: 1px solid var(--line); border-radius: 50%; background: transparent; color: var(--muted); font-size: 21px; line-height: 1; cursor: pointer; }
.transcript ol { min-height: 0; margin: 0; padding: 13px 17px 20px; overflow: auto; list-style: none; }
.transcript li { display: grid; grid-template-columns: 38px 1fr; gap: 10px; padding: 11px 0; border-bottom: 1px solid rgba(255, 255, 255, 0.055); }
.transcript time { color: var(--accent); font: 700 8px/1.5 var(--mono); }
.transcript__cue { margin: -5px; padding: 5px; border: 0; border-radius: 5px; background: transparent; color: #bdd0d8; font-size: 11px; line-height: 1.55; text-align: left; cursor: pointer; }
.transcript__cue:hover { background: rgba(var(--accent-rgb), 0.06); color: #f2fbff; }
.transcript li.is-current .transcript__cue { color: #f2fbff; }
.transcript li.is-current { background: linear-gradient(90deg, rgba(var(--accent-rgb), 0.06), transparent); }
.transcript > footer { padding: 12px 17px; border-top: 1px solid var(--line); }
.transcript > footer p { margin: 0; color: var(--dim); font: 650 8px/1.5 var(--mono); }

.toast {
  position: fixed;
  z-index: 500;
  left: 50%;
  bottom: 22px;
  padding: 9px 13px;
  border: 1px solid rgba(var(--accent-rgb), 0.35);
  border-radius: 999px;
  background: rgba(4, 11, 21, 0.94);
  color: #def8ff;
  font: 700 9px/1 var(--mono);
  letter-spacing: 0.04em;
  box-shadow: 0 15px 45px #0009;
  transform: translateX(-50%);
}
.toast[hidden] { display: none; }

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

.noscript-course { position: fixed; z-index: 1000; inset: 70px 20px 20px; padding: 30px; overflow: auto; border: 1px solid var(--line); border-radius: 10px; background: #050c18; }
.noscript-course h1 { font-size: 27px; }
.noscript-course a { color: var(--accent); }

@media (max-width: 1180px) {
  :root { --rail-width: 220px; }
  .brand { min-width: 230px; }
  .brand__division { display: none; }
  .topbar__nav a { padding-inline: 7px; }
  .workbench { grid-template-columns: minmax(300px, 0.83fr) minmax(390px, 1.17fr); }
  .workbench.is-code-phase { grid-template-columns: minmax(360px, 1.08fr) minmax(330px, 0.92fr); }
  .runtime-receipt > div { padding-inline: 6px; }
  .runtime-receipt strong { font-size: 13px; }
  .transport { grid-template-areas: "controls timeline" "tools tools"; grid-template-columns: auto 1fr; }
  .transport__tools { justify-content: flex-end; }
}

@media (max-width: 920px) {
  body { overflow: auto; }
  .topbar { gap: 11px; }
  .brand { min-width: 0; margin-right: auto; }
  .topbar__nav { position: fixed; top: var(--topbar-height); right: 8px; display: none; width: 210px; flex-direction: column; align-items: stretch; padding: 8px; border: 1px solid var(--line); border-radius: 0 0 9px 9px; background: rgba(3, 8, 17, 0.97); box-shadow: 0 18px 50px #000a; }
  .topbar__nav.is-open { display: flex; }
  .topbar__nav a { padding: 10px 11px; }
  .topbar__companion { display: none; }
  .topbar__menu { display: block; }
  .academy { display: block; height: auto; min-height: 100dvh; }
  .lesson-rail { position: sticky; z-index: 30; top: var(--topbar-height); display: block; width: 100%; padding: 10px 12px; border-right: 0; border-bottom: 1px solid var(--line); }
  .lesson-rail__heading,
  .course-progress,
  .lesson-rail__foot { display: none; }
  .lesson-list { display: flex; gap: 5px; padding: 0; overflow-x: auto; }
  .lesson-list li { flex: 0 0 auto; }
  .lesson-button { width: 151px; min-height: 42px; grid-template-columns: 27px 1fr 0; }
  .lesson-button__index { width: 26px; height: 26px; }
  .lesson-button__check { display: none; }
  .lesson-stage { min-height: calc(100dvh - var(--topbar-height) - 63px); padding: 17px 14px 13px; overflow: visible; }
  .workbench { min-height: 0; grid-template-columns: 1fr; grid-template-rows: clamp(300px, 45vh, 420px) clamp(360px, 55vh, 500px); }
  .workbench.is-code-phase { grid-template-columns: 1fr; }
  .lesson-feedback { grid-template-columns: 1fr; }
  .runtime-titlecard strong { font-size: 16px; }
  .preview-study__stage { grid-template-columns: minmax(95px, 0.32fr) 1fr; }
  .preview-study__cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 650px) {
  .topbar { padding-inline: 12px; }
  .brand__name { font-size: 10px; }
  .brand__signal { width: 22px; height: 22px; }
  .brand__signal i { left: 9px; top: 1px; height: 20px; }
  .slide-heading { align-items: flex-start; }
  .slide-heading__meta span,
  .slide-heading__meta button { display: none; }
  .slide-heading h2 { font-size: 25px; }
  .lesson-stage { grid-template-rows: auto auto auto auto auto; }
  .workbench { min-height: 0; grid-template-rows: clamp(320px, 52vh, 440px) clamp(380px, 60vh, 520px); }
  .lesson-actions { align-items: flex-start; flex-direction: column; }
  .lesson-actions > div { width: 100%; flex-wrap: wrap; }
  .transport { position: static; grid-template-areas: "controls" "timeline" "tools"; grid-template-columns: minmax(0, 1fr); }
  .transport__cluster { justify-content: center; }
  .transport__timeline { grid-template-columns: 26px 1fr 26px; }
  .transport__tools { justify-content: flex-end; }
  .transport__tools button { flex: 1; }
  .runtime-receipt { grid-template-columns: repeat(2, 1fr); }
  .runtime-receipt > div:nth-child(2) { border-right: 0; }
  .runtime-receipt > div:nth-child(-n+2) { border-bottom: 1px solid rgba(var(--accent-rgb), 0.1); }
  .sonar { width: 170px; }
  .lab-controls { right: 15px; bottom: 119px; flex-wrap: wrap; }
  .runtime-gate { padding: 22px 16px; }
  .runtime-gate__stages li { padding: 8px 6px; }
  .preview-study { grid-template-rows: auto auto auto auto; }
  .preview-study__stage { grid-template-columns: 82px minmax(0, 1fr); gap: 14px; padding: 15px; }
  .preview-study__signal { width: 82px; }
  .preview-study__stage h3 { font-size: 17px; }
  .preview-study__cards li { min-height: 68px; }
  .preview-study > footer { align-items: flex-start; flex-direction: column; justify-content: center; }
  .execution-bridge { grid-template-columns: auto 1fr auto; }
  .execution-bridge > i:nth-of-type(2),
  .execution-bridge__node:last-of-type { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  .presentation-director__cursor { display: none; }
  .presentation-director__focus { transition: none; transform: translate3d(var(--director-left, 0), var(--director-top, 0), 0); }
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .abyss__smoke { transform: none; }
}

html[data-reduced-motion="true"] *,
html[data-reduced-motion="true"] *::before,
html[data-reduced-motion="true"] *::after {
  scroll-behavior: auto !important;
  animation-duration: 0.001ms !important;
  animation-iteration-count: 1 !important;
  transition-duration: 0.001ms !important;
}

html[data-reduced-motion="true"] .presentation-director__cursor { display: none; }
html[data-reduced-motion="true"] .presentation-director__focus {
  transform: translate3d(var(--director-left, 0), var(--director-top, 0), 0);
}

@media (forced-colors: active) {
  .abyss { display: none; }
  .runtime-viewport::before,
  .runtime-viewport::after { display: none; }
  .runtime-gate { border: 1px solid CanvasText; background: Canvas; color: CanvasText; }
  .lesson-button[aria-current="step"],
  .code-panel,
  .runtime-panel,
  .transport { border: 1px solid CanvasText; }
}