@import url('https://fonts.googleapis.com/css2?family=Audiowide&family=Space+Grotesk:wght@400;500;700&display=swap');

:root {
  /* Core surfaces — gold-charcoal */
  --background: oklch(6% 0.008 76);
  --foreground: oklch(96% 0.008 76);
  --surface: oklch(9% 0.01 76);
  --border: oklch(18% 0.02 76);

  /* Accent — gold */
  --accent: oklch(78% 0.15 76);
  --accent-foreground: oklch(11% 0.03 76);

  /* Supporting tokens */
  --muted: oklch(70% 0.02 76);
  --danger: oklch(62% 0.22 25);

  /* Surface variants for panels / inputs / code */
  --panel-bg: oklch(8% 0.009 76);
  --input-bg: oklch(5% 0.008 76);
  --code-bg: oklch(10% 0.01 76);

  /* Translucent accent for canvas connections & subtle borders */
  --accent-subtle: oklch(78% 0.15 76 / 0.16);

  /* Background grid pattern */
  --grid-color: oklch(78% 0.15 76 / 0.055);

  /* Easing & timing */
  --ease-spring: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 0.15s;
  --duration-base: 0.18s;
  --duration-slow: 0.22s;

  /* Font stacks */
  --font-display: "Audiowide", system-ui, sans-serif;
  --font-body: "Space Grotesk", system-ui, sans-serif;

  /* Accent glow shadows (alpha ramps) */
  --accent-glow-sm: 0 0  8px oklch(78% 0.15 76 / 0.20); /* search focus shadow   */
  --accent-glow-md: 0 0 10px oklch(78% 0.15 76 / 0.18); /* list-item hover        */
  --accent-glow-lg: 0 0 10px oklch(78% 0.15 76 / 0.20); /* chip / bar hover       */
  --accent-glow-xl: 0 0 10px oklch(78% 0.15 76 / 0.25); /* node-link active       */

  /* Accent alpha ramps */
  --accent-focus: oklch(78% 0.15 76 / 0.40); /* focus-visible outline colour */
}

/* ====== Base Resets ====== */
* {
  box-sizing: border-box;
  border-color: var(--border);
}

html,
body,
#app {
  height: 100%;
}

body {
  margin: 0;
  background-color: var(--background);
  color: var(--foreground);
  font-family: var(--font-body);
  font-size: 15px;
  background-image:
    linear-gradient(var(--grid-color) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-color) 1px, transparent 1px);
  background-size: 48px 48px;
  /* overflow: hidden removed — allows browser zoom/reflow fallback (WCAG 1.4.10) */
}

h1,
h2,
h3,
h4 {
  font-family: var(--font-display);
  letter-spacing: 0.06em;
  margin: 0;
}

::selection {
  background: var(--accent);
  color: var(--accent-foreground);
}

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

.hidden {
  display: none !important;
}

/* ====== Shell layout ====== */
.shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 0;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  transition: grid-template-columns 0.35s var(--ease-spring);
}

.shell--panel-open.shell--preview-open {
  grid-template-columns: minmax(0, 1fr) minmax(320px, 46vw);
}

.shell--panel-open.shell--about-open {
  grid-template-columns: minmax(0, 1fr) minmax(320px, 500px);
}

.shell__main {
  position: relative;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.shell__bar {
  position: relative;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--background); /* solid fallback for unsupported browsers */
}

@supports (backdrop-filter: blur(0)) {
  .shell__bar {
    background: oklch(6% 0.008 76 / 0.88);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
  }
}

.shell__brand {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-logo {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border: 1px solid var(--accent);
  padding: 3px;
  background: var(--input-bg);
  flex-shrink: 0;
}

.brand-name {
  font-size: 1.4rem;
  letter-spacing: 0.18em;
  color: var(--foreground);
}

/* .brand-tag removed — class unused in HTML (L4) */

.shell__chips {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.chip {
  appearance: none;
  background: transparent;
  border: 1px solid var(--accent);
  color: var(--foreground);
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  padding: 10px 18px;
  min-height: 44px;
  cursor: pointer;
  text-transform: uppercase;
  transition:
    background-color 0.18s var(--ease-spring),
    color 0.18s var(--ease-spring),
    border-color 0.18s var(--ease-spring),
    box-shadow 0.18s var(--ease-spring);
}

.chip:hover {
  border-color: var(--foreground);
  color: var(--accent);
  box-shadow: var(--accent-glow-lg);
}

.chip[aria-pressed="true"] {
  background: var(--accent);
  color: var(--accent-foreground);
  border-color: var(--accent);
}

/* Default (off) state: gold border + muted text — clearly different from active gold-fill */
.chip--accent {
  border-color: var(--accent);
  color: var(--muted);
}

.chip--accent:hover {
  background: var(--accent-subtle);
  color: var(--accent);
  border-color: var(--accent);
}

/* Active (on) state: full gold fill — distinct from off state */
.chip--accent[aria-pressed="true"] {
  background: var(--accent);
  color: var(--accent-foreground);
  border-color: var(--accent);
}

.shell__stage {
  position: relative;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

/* ====== Sphere scene ====== */
.scene-host {
  position: absolute;
  inset: 0;
  overflow: hidden;
  transition: opacity 0.22s var(--ease-spring);
}

.shell--list-open .scene-host {
  pointer-events: none;
  opacity: 0.25;
}

.scene-container {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 0;
  height: 0;
  overflow: visible;
}

.scene-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

/* Merged from two duplicate .node-link blocks (M3) */
.node-link {
  position: absolute;
  transform-style: preserve-3d;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 10px;
  will-change: transform, opacity;
  background-color: var(--surface);
  border: 1px solid var(--accent);
  color: var(--foreground);
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.05em;
  white-space: nowrap;
  text-decoration: none;
  transition:
    background-color 0.15s var(--ease-spring),
    border-color 0.15s var(--ease-spring),
    color 0.15s var(--ease-spring),
    box-shadow 0.15s var(--ease-spring);
}

/* Hover: white border + gold text + whisper glow */
.node-link:hover,
.node-link:focus-visible,
.node-link.is-active {
  background-color: var(--input-bg);
  border-color: var(--foreground);
  color: var(--accent);
  box-shadow: var(--accent-glow-xl);
  z-index: 9999 !important;
  outline: none;
}

/* Sizing based on Project Importance (Visual Hierarchy) */
.node-link--big {
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 700;
  border-width: 2px;
}

.node-link--medium {
  padding: 6px 10px;
  font-size: 11px;
}

.node-link--small {
  padding: 4px 8px;
  font-size: 9px;
  opacity: 0.75;
}
.node-link--small:hover {
  opacity: 1;
}

/* ====== Side panels ====== */
.side-panel {
  border-left: 1px solid var(--border);
  background: var(--surface);
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100vh;
  animation: panel-in 0.32s var(--ease-spring) both;
}

@keyframes panel-in {
  from {
    transform: translateX(8px);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 14px 18px;
  border-bottom: 1px solid var(--accent);
  background: var(--background);
  color: var(--foreground);
  flex-wrap: wrap;
}

.panel-title {
  font-size: 0.95rem;
  letter-spacing: 0.12em;
  margin: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  min-width: 0;
  max-width: 32ch;
  color: var(--accent);
}

.panel-controls {
  display: flex;
  gap: 8px;
  align-items: center;
  flex-wrap: wrap;
}

.panel-btn {
  appearance: none;
  border: 1px solid var(--accent);
  color: var(--muted);
  background: transparent;
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  padding: 10px 16px;
  min-height: 44px;
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition:
    background-color 0.18s var(--ease-spring),
    color 0.18s var(--ease-spring),
    border-color 0.18s var(--ease-spring);
}

.panel-btn:hover:not(:disabled):not(.is-disabled) {
  background: var(--accent-subtle);
  border-color: var(--foreground);
  color: var(--accent);
}

.panel-btn:disabled,
.panel-btn.is-disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.panel-btn--close {
  padding: 0;
  width: 44px;
  height: 44px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.panel-content {
  position: relative;
  flex: 1;
  min-height: 0;
  background: var(--panel-bg);
  overflow: auto;
}

.preview-panel .panel-content {
  overflow: hidden;
}

.panel-frame {
  width: 100%;
  height: 100%;
  border: none;
  background: #ffffff;
  opacity: 0;
  transition: opacity 0.2s ease;
}

.panel-content.state-loaded .panel-frame {
  opacity: 1;
}

.frame-status {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.18em;
  text-align: center;
  padding: 24px;
  transition: opacity 0.25s ease, visibility 0.25s ease;
}

.panel-content.state-loaded .frame-status {
  opacity: 0;
  pointer-events: none;
  visibility: hidden;
}

.frame-status .status-bar {
  width: 160px;
  height: 2px;
  background: var(--border);
  position: relative;
  overflow: hidden;
}

.frame-status .status-bar::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--accent);
  transform: translateX(-100%);
  animation: status-sweep 1.1s linear infinite;
}

.frame-status .status-bar.error::after {
  animation: none;
  background: var(--danger);
  transform: translateX(0);
}

.frame-status .status-bar.error {
  background: oklch(62% 0.22 25 / 0.2);
}

@keyframes status-sweep {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(100%);
  }
}

/* ====== About panel markdown ====== */
.about-markdown {
  padding: 28px 28px 56px;
  color: var(--foreground);
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.8;
  max-width: min(720px, 60ch);
}

.about-markdown h1,
.about-markdown h2,
.about-markdown h3 {
  color: var(--accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-top: 1.8em;
  margin-bottom: 0.6em;
}

.about-markdown h1 {
  font-size: 1.6rem;
  margin-top: 0;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0.4em;
}

.about-markdown h2 {
  font-size: 1.1rem;
}

.about-markdown h3 {
  font-size: 0.95rem;
}

.about-markdown p {
  color: var(--foreground);
}

.about-markdown a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.about-markdown a:hover {
  background: var(--accent);
  color: var(--accent-foreground);
}

.about-markdown ul {
  list-style: none;
  padding: 0;
  margin: 1.5em 0;
}

.about-markdown li {
  position: relative;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  padding: 14px 18px;
  margin-bottom: 12px;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--foreground);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.about-markdown li:hover {
  border-color: var(--accent);
  background: var(--code-bg);
}

.about-markdown li strong {
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 0.9rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 4px;
}

.about-markdown ol {
  padding-left: 1.4em;
}

.about-markdown code {
  background: var(--code-bg);
  color: var(--accent);
  padding: 2px 6px;
  border: 1px solid var(--border);
  font-size: 0.85em;
  font-family: ui-monospace, monospace;
}

.about-markdown pre {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  padding: 14px;
  overflow: auto;
}

.about-markdown pre code {
  background: transparent;
  border: none;
  padding: 0;
}

.about-markdown hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2em 0;
}

/* ====== List sheet ====== */
.list-sheet {
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 16px;
  max-height: 62vh;
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--accent);
  /* Subtle shadow to lift the panel off the sphere visually */
  box-shadow: 0 -4px 32px oklch(0% 0 0 / 0.55), 0 0 0 1px var(--accent);
  z-index: 1000;
  animation: panel-in 0.22s var(--ease-spring) both;
}

/* .list-sheet .panel-header — inherits base dark background + gold accent border */

.list-search {
  appearance: none;
  background: var(--input-bg);
  border: 1px solid var(--accent);
  color: var(--accent);
  font-family: var(--font-display);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  padding: 6px 10px;
  flex: 1;
  min-width: 0;
  transition: border-color 0.18s var(--ease-spring),
              box-shadow 0.18s var(--ease-spring);
}

.list-search:focus-visible {
  border-color: var(--foreground);
  outline: 2px solid var(--accent-focus);
  outline-offset: -1px;
  box-shadow: var(--accent-glow-sm);
}

.list-sheet .panel-btn--close {
  background: transparent;
  color: var(--accent);
  border-color: var(--accent);
}

.list-grid {
  list-style: none;
  margin: 0;
  padding: 12px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 10px;
  overflow: auto;
}

.list-item {
  width: 100%;
  appearance: none;
  background: var(--panel-bg);
  border: 1px solid var(--accent);
  color: var(--foreground);
  padding: 14px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  font-family: var(--font-body);
  text-align: left;
  transition:
    border-color 0.18s var(--ease-spring),
    background-color 0.18s var(--ease-spring),
    color 0.18s var(--ease-spring),
    box-shadow 0.18s var(--ease-spring);
}

/* Hover: white border + gold text + whisper glow — matches node-link hover */
.list-item:hover,
.list-item.is-active {
  border-color: var(--foreground);
  background: var(--input-bg);
  color: var(--accent);
  box-shadow: var(--accent-glow-md);
}

.list-item-text {
  font-size: 0.9rem;
  letter-spacing: 0.02em;
  line-height: 1.25;
  white-space: normal;
  min-width: 0;
}

.list-item-arrow {
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.list-empty {
  grid-column: 1 / -1;
  text-align: center;
  padding: 40px;
  color: var(--muted);
  font-family: var(--font-display);
  letter-spacing: 0.18em;
  font-size: 0.85rem;
}

/* ====== Responsive ====== */
@media (max-width: 980px) {
  .shell,
  .shell--panel-open.shell--preview-open,
  .shell--panel-open.shell--about-open {
    grid-template-columns: 1fr !important;
    grid-template-rows: 1fr !important;
  }

  .side-panel {
    position: fixed;
    inset: 0;
    width: 100vw;
    height: 100vh;
    z-index: 100;
    border: none;
    animation: panel-in-mobile 0.3s var(--ease-spring) both;
  }

  @keyframes panel-in-mobile {
    from {
      transform: translateY(30px);
      opacity: 0;
    }
    to {
      transform: translateY(0);
      opacity: 1;
    }
  }

  .shell__bar {
    padding: 10px 12px;
  }

  .brand-tag {
    display: none;
  }

  .list-grid {
    grid-template-columns: 1fr;
  }
}

/* ====== Mobile Layout Adaptation ====== */
@media (max-width: 600px) {
  .shell__stage,
  #btn-list-toggle,
  #btn-list-close {
    display: none !important;
  }

  .shell__bar {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    gap: 8px;
  }

  .shell__brand {
    justify-content: flex-start;
  }

  .brand-name {
    font-size: 1.1rem;
    letter-spacing: 0.1em;
  }

  .brand-logo {
    width: 32px;
    height: 32px;
  }

  .shell__chips {
    justify-content: flex-end;
    width: auto;
    gap: 8px;
  }

  .chip {
    padding: 8px 12px;
    font-size: 0.7rem;
    letter-spacing: 0.08em;
    min-height: 44px; /* restored to WCAG 2.5.5 minimum (H1) */
  }

  .list-sheet {
    position: static !important;
    display: flex !important; /* overrides .hidden */
    max-height: none !important;
    height: auto !important;
    flex: 1;
    border: none !important;
    background: transparent !important;
    animation: none !important;
    box-shadow: none !important;
  }

  .list-sheet .panel-header {
    background: transparent !important;
    border-bottom: 1px solid var(--border) !important;
    padding: 10px 16px !important;
  }

  .list-search {
    min-width: 0; /* prevent horizontal overflow on narrow screens (L1) */
    flex: 1;
  }

  .about-markdown {
    padding: 16px 16px 36px;
  }
}

/* ====== Onboard hint ====== */
.onboard-hint {
  position: absolute;
  left: 50%;
  bottom: 44px;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--surface);
  border: 1px solid var(--accent);
  padding: 12px 20px;
  z-index: 15;
  pointer-events: all;
  max-width: calc(100vw - 32px);
  animation: hint-in 0.45s var(--ease-spring) 0.8s both;
}

.onboard-hint--hiding {
  animation: hint-out 0.28s ease forwards;
}

.onboard-hint__tips {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.onboard-hint__tips li {
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
  white-space: nowrap;
}

.onboard-hint__tips li::before {
  content: "·";
  margin-right: 8px;
  color: var(--accent);
}

.onboard-hint__tips li:first-child::before {
  display: none;
}

.onboard-hint__btn {
  appearance: none;
  background: var(--accent);
  color: var(--accent-foreground);
  border: none;
  font-family: var(--font-display);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  padding: 10px 18px;
  min-height: 44px;
  cursor: pointer;
  text-transform: uppercase;
  white-space: nowrap;
  transition: opacity 0.15s ease;
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.onboard-hint__btn:hover {
  opacity: 0.82;
}

@keyframes hint-in {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

@keyframes hint-out {
  from {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
  to {
    opacity: 0;
    transform: translateX(-50%) translateY(6px);
  }
}

@media (max-width: 980px) {
  .onboard-hint {
    flex-direction: column;
    gap: 12px;
    bottom: 16px;
    text-align: center;
    padding: 14px 16px;
  }

  .onboard-hint__tips {
    flex-direction: column;
    gap: 6px;
    align-items: center;
  }

  .onboard-hint__tips li:not(:first-child) {
    display: none;
  }

  .onboard-hint__tips li::before {
    display: none;
  }
}

/* ====== Init Error State ====== */
.init-error {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  padding: 32px;
  text-align: center;
  z-index: 10;
}

.init-error__msg {
  font-family: var(--font-display);
  font-size: 0.9rem;
  letter-spacing: 0.16em;
  color: var(--danger);
  text-transform: uppercase;
  max-width: 36ch;
}

.init-error__sub {
  font-family: var(--font-body);
  font-size: 0.85rem;
  color: var(--muted);
  margin: 0;
  max-width: 36ch;
}

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

@media (prefers-reduced-motion: reduce) {
  * {
    animation-delay: -1ms !important;
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0s !important;
    scroll-behavior: auto !important;
  }
}