/* ============================================================
   Corvus Relay — Y2K pixel-OS landing
   Two-color discipline: ONLY --c-blue, --c-white and the alpha
   tints below may appear as colors anywhere in this file.
   ============================================================ */

@font-face {
  font-family: "VT323";
  src: url("fonts/vt323-latin.woff2") format("woff2");
  font-display: swap;
}

@font-face {
  font-family: "Fusion Pixel 12";
  src: url("fonts/fusion-pixel-12-zh-subset.woff2") format("woff2");
  font-display: swap;
}

:root {
  --c-blue: #5ea6e5;
  --c-white: #ffffff;
  --blue-30: rgba(94, 166, 229, 0.3);
  --blue-20: rgba(94, 166, 229, 0.2);
  --blue-10: rgba(94, 166, 229, 0.1);
  --font-sys: "VT323", "Fusion Pixel 12", "PingFang SC", "Microsoft YaHei", sans-serif;
  --taskbar-h: 32px;
  --dither: repeating-linear-gradient(
    45deg,
    var(--c-white),
    var(--c-white) 2px,
    var(--blue-20) 2px,
    var(--blue-20) 4px
  );
}

/* ─── reset & base ─── */

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  background: var(--c-white);
}

body {
  background: var(--c-white);
  color: var(--c-blue);
  font-family: var(--font-sys);
  font-size: 18px;
  line-height: 1.45;
  image-rendering: pixelated;
  -webkit-font-smoothing: none;
}

@media (pointer: fine) {
  body {
    cursor: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 16 16"><path fill="%235EA6E5" d="M0 0h1v16H0V0zm1 1v14h1V1H1zm1 1v12h1V2H2zm1 1v10h1V3H3zm1 1v8h1V4H4zm1 1v6h1V5H5zm1 1v4h1V6H6zm1 1v2h1V7H7z"/><path fill="%23FFFFFF" d="M1 1h1v14H1V1zm1 1h1v12H2V2zm1 1h1v10H3V3zm1 1h1v8H4V4zm1 1h1v6H5V5zm1 1h1v4H6V6zm1 1h1v2H7V7z"/></svg>')
        0 0,
      auto;
  }
}

.svg-defs {
  position: absolute;
  width: 0;
  height: 0;
  overflow: hidden;
}

a {
  color: var(--c-blue);
  text-decoration: underline;
}

a:hover {
  background: var(--c-blue);
  color: var(--c-white);
}

button {
  font: inherit;
  color: var(--c-blue);
  background: var(--c-white);
  border: none;
  cursor: inherit;
}

:focus-visible {
  outline: 2px dashed var(--c-blue);
  outline-offset: 2px;
}

.window-header :focus-visible,
#start-button:focus-visible {
  outline-color: var(--c-white);
}

.skip-link {
  position: fixed;
  top: -48px;
  left: 8px;
  z-index: 200;
  border: 2px solid var(--c-blue);
  background: var(--c-white);
  padding: 4px 10px;
  transition: top 120ms steps(2);
}

.skip-link:focus {
  top: 8px;
}

/* chrome elements are not selectable; content is (config must be copyable) */
.window-header,
.window-menu,
.window-status,
.icon-label,
#taskbar,
#start-menu,
.hero-layer {
  user-select: none;
  -webkit-user-select: none;
}

/* ─── background layers ─── */

#canvas-container {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

#glcanvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* no-WebGL / noscript fallback: static dithered sky */
html.no-webgl #canvas-container {
  background:
    radial-gradient(560px 320px at 24% 22%, var(--blue-30), transparent 70%),
    radial-gradient(720px 380px at 76% 64%, var(--blue-20), transparent 72%),
    conic-gradient(var(--blue-20) 25%, transparent 0 50%, var(--blue-20) 0 75%, transparent 0) 0 0 / 4px 4px,
    var(--c-white);
}

html.no-webgl #glcanvas {
  display: none;
}

/* ─── hero ─── */

.hero-layer {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 5;
  pointer-events: none;
}

.hero-text {
  font-family: Georgia, "Times New Roman", serif;
  font-style: italic;
  font-size: 11vw;
  color: var(--c-white);
  text-shadow:
    2px 2px 0 var(--c-blue),
    -2px -2px 0 var(--c-blue),
    2px -2px 0 var(--c-blue),
    -2px 2px 0 var(--c-blue);
  white-space: nowrap;
  filter: url("#pixelate");
}

/* ─── desktop & icons ─── */

#desktop {
  position: relative;
  z-index: 10;
  width: 100vw;
  height: calc(100vh - var(--taskbar-h));
  padding: 16px;
}

.icon-column {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 22px;
}

.desktop-icon {
  width: 76px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  text-align: center;
  text-decoration: none;
  background: transparent;
}

.desktop-icon:hover {
  background: transparent;
}

.desktop-icon:hover .icon-label,
.desktop-icon:focus-visible .icon-label {
  background: var(--c-blue);
  color: var(--c-white);
}

.desktop-icon:active .icon-label {
  border: 1px dotted var(--c-blue);
}

.icon-graphic {
  width: 32px;
  height: 32px;
  background-size: 32px 32px;
  background-repeat: no-repeat;
  image-rendering: pixelated;
}

.icon-folder {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' shape-rendering='crispEdges'><path fill='%235EA6E5' d='M1 3h6l1 2h7v8H1z'/><path fill='%23FFFFFF' d='M2 6h12v6H2z'/></svg>");
}

.icon-file {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' shape-rendering='crispEdges'><path fill='%235EA6E5' d='M3 1h7l4 4v10H3z'/><path fill='%23FFFFFF' d='M4 2h5v4h4v8H4z'/><path fill='%235EA6E5' d='M5 8h6v1H5zM5 10h6v1H5zM5 12h4v1H5z'/></svg>");
}

.icon-key {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' shape-rendering='crispEdges'><path fill='%235EA6E5' d='M2 5h5v6H2z'/><path fill='%23FFFFFF' d='M3 6h3v4H3z'/><path fill='%235EA6E5' d='M7 7h7v2H7zM10 9h1v2h-1zM13 9h1v3h-1z'/></svg>");
}

.icon-gear {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' shape-rendering='crispEdges'><path fill='%235EA6E5' d='M7 1h2v3H7zM7 12h2v3H7zM1 7h3v2H1zM12 7h3v2h-3zM3 3h2v2H3zM11 3h2v2h-2zM3 11h2v2H3zM11 11h2v2h-2zM4 4h8v8H4z'/><path fill='%23FFFFFF' d='M6 6h4v4H6z'/></svg>");
}

.icon-book {
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' shape-rendering='crispEdges'><path fill='%235EA6E5' d='M2 2h12v12H2z'/><path fill='%23FFFFFF' d='M5 3h8v10H5z'/><path fill='%235EA6E5' d='M6 5h6v1H6zM6 7h6v1H6zM6 9h4v1H6z'/></svg>");
}

/* ─── window chrome ─── */

.window {
  position: absolute;
  background: var(--c-white);
  border: 2px solid var(--c-blue);
  box-shadow: 4px 4px 0 0 var(--blue-20);
  display: none;
  flex-direction: column;
  min-width: 300px;
}

.window[data-default-open] {
  display: flex;
}

.window-header {
  background: var(--c-blue);
  color: var(--c-white);
  padding: 4px 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  touch-action: none;
}

@media (pointer: fine) {
  .window-header {
    cursor: grab;
  }

  .window-header:active {
    cursor: grabbing;
  }
}

.window-title {
  font-size: 18px;
  letter-spacing: 1px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.window-controls {
  display: flex;
  gap: 4px;
  flex-shrink: 0;
}

.win-btn {
  width: 18px;
  height: 18px;
  background: var(--c-white);
  border: 1px solid var(--c-white);
  color: var(--c-blue);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 12px;
  line-height: 1;
  padding-bottom: 2px;
}

.win-btn:active {
  background: var(--c-blue);
  color: var(--c-white);
}

.window-menu {
  display: flex;
  border-bottom: 1px solid var(--c-blue);
  padding: 2px 6px;
  gap: 14px;
  font-size: 16px;
}

.window-menu a {
  text-decoration: none;
  padding: 0 2px;
}

.window-content {
  padding: 14px 16px;
  flex-grow: 1;
  overflow-y: auto;
  max-height: calc(100vh - 230px);
  font-size: 18px;
  scrollbar-width: thin;
  scrollbar-color: var(--c-blue) var(--c-white);
}

.window-content p {
  margin-bottom: 10px;
}

.window-status {
  border-top: 1px solid var(--c-blue);
  padding: 2px 8px;
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-size: 14px;
}

/* ─── window default positions (desktop) ─── */

#win-welcome {
  top: 8%;
  left: 50%;
  transform: translateX(-50%);
  width: 620px;
  max-width: 92vw;
}

#win-terminal {
  top: 14%;
  left: calc(100vw - 500px);
  width: 470px;
  max-width: 92vw;
}

#win-setup {
  top: 55%;
  left: 4%;
  width: 430px;
  max-width: 92vw;
}

#win-why {
  top: 20%;
  left: 8%;
  width: 400px;
  max-width: 92vw;
}

#win-control {
  top: 30%;
  left: 32%;
  width: 470px;
  max-width: 92vw;
}

/* ─── window content modules ─── */

.pixel-banner {
  width: 100%;
  height: 96px;
  border: 1px solid var(--c-blue);
  margin-bottom: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--dither);
  letter-spacing: 2px;
}

.window-content h1 {
  font-size: 30px;
  line-height: 1.2;
  margin-bottom: 10px;
  font-weight: normal;
}

.kicker {
  font-size: 15px;
  letter-spacing: 1px;
  border-bottom: 1px solid var(--c-blue);
  padding-bottom: 4px;
  margin-bottom: 12px;
}

.retro-list {
  list-style: none;
  margin: 0 0 14px;
}

.retro-list li {
  margin-bottom: 4px;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 12px 0;
}

.px-btn {
  display: inline-flex;
  align-items: center;
  background: var(--c-white);
  color: var(--c-blue);
  border: 2px solid var(--c-blue);
  padding: 3px 14px;
  font-size: 18px;
  text-decoration: none;
  box-shadow: 2px 2px 0 0 var(--c-blue);
}

.px-btn:hover {
  background: var(--dither);
  color: var(--c-blue);
}

.px-btn:active {
  transform: translate(2px, 2px);
  box-shadow: none;
}

.px-btn-primary {
  background: var(--c-blue);
  color: var(--c-white);
}

.px-btn-primary:hover {
  background: var(--c-blue);
  color: var(--c-white);
}

.px-btn-small {
  font-size: 14px;
  padding: 0 8px;
  border-width: 1px;
  box-shadow: 1px 1px 0 0 var(--c-blue);
}

.px-btn-small:active {
  transform: translate(1px, 1px);
}

.dotted-rule {
  border: none;
  border-top: 1px dotted var(--c-blue);
  margin: 10px 0;
}

.fine-print {
  font-size: 15px;
  opacity: 0.85;
}

.link-row {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.meta-data {
  font-size: 13px;
  opacity: 0.7;
}

.term-block {
  border: 1px solid var(--c-blue);
  margin-bottom: 12px;
}

.term-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 3px 8px;
  border-bottom: 1px solid var(--c-blue);
  background: var(--blue-10);
  font-size: 15px;
  letter-spacing: 1px;
  user-select: none;
  -webkit-user-select: none;
}

.term-code {
  display: block;
  padding: 10px 12px;
  font-family: var(--font-sys);
  font-size: 16px;
  line-height: 1.6;
  white-space: pre;
  overflow-x: auto;
  user-select: text;
  -webkit-user-select: text;
}

.term-code::selection {
  background: var(--c-blue);
  color: var(--c-white);
}

.wizard-step,
.why-item {
  border: 1px solid var(--c-blue);
  padding: 8px 10px;
  margin-bottom: 10px;
}

.wizard-tag {
  display: inline-block;
  background: var(--c-blue);
  color: var(--c-white);
  font-size: 13px;
  letter-spacing: 1px;
  padding: 0 6px;
  margin-bottom: 4px;
}

.wizard-step strong,
.why-item strong,
.cpl-item strong {
  display: block;
  margin-bottom: 2px;
}

.wizard-step p,
.why-item p,
.cpl-item p {
  margin-bottom: 0;
  font-size: 16px;
}

.cpl-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-bottom: 6px;
}

.cpl-item {
  border: 1px solid var(--c-blue);
  padding: 8px 10px;
}

/* ─── taskbar ─── */

#taskbar {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100vw;
  height: var(--taskbar-h);
  background: var(--c-white);
  border-top: 2px solid var(--c-blue);
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 4px;
}

#start-button {
  border: 2px solid var(--c-blue);
  padding: 0 14px;
  height: 24px;
  font-size: 18px;
  display: flex;
  align-items: center;
  box-shadow: 2px 2px 0 0 var(--c-blue);
  flex-shrink: 0;
}

#start-button:active,
#start-button[aria-expanded="true"] {
  transform: translate(2px, 2px);
  box-shadow: none;
  background: var(--dither);
}

.taskbar-items {
  display: flex;
  flex-grow: 1;
  gap: 4px;
  overflow: hidden;
}

.taskbar-item {
  border: 1px solid var(--c-blue);
  padding: 0 12px;
  height: 24px;
  display: flex;
  align-items: center;
  font-size: 15px;
  max-width: 170px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.taskbar-item.active {
  background: var(--dither);
  box-shadow: inset 2px 2px 0 0 var(--blue-30);
}

.taskbar-item.minimized {
  opacity: 0.6;
}

.sys-tray {
  border: 1px solid var(--c-blue);
  padding: 0 10px;
  height: 24px;
  display: flex;
  align-items: center;
  font-size: 16px;
  flex-shrink: 0;
}

/* ─── start menu ─── */

#start-menu {
  position: fixed;
  left: 4px;
  bottom: calc(var(--taskbar-h) + 4px);
  z-index: 110;
  background: var(--c-white);
  border: 2px solid var(--c-blue);
  box-shadow: 4px 4px 0 0 var(--blue-20);
  min-width: 200px;
  display: flex;
  flex-direction: column;
  padding: 4px;
}

#start-menu[hidden] {
  display: none;
}

#start-menu a,
#start-menu button {
  text-align: left;
  text-decoration: none;
  padding: 4px 10px;
  font-size: 17px;
}

#start-menu a:hover,
#start-menu button:hover,
#start-menu a:focus-visible,
#start-menu button:focus-visible {
  background: var(--c-blue);
  color: var(--c-white);
}

.start-tagline {
  font-size: 13px;
  opacity: 0.7;
  padding: 4px 10px;
}

/* ─── motion & a11y ─── */

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

/* ─── desktop mode ─── */

@media (min-width: 761px) {
  body {
    overflow: hidden;
  }
}

@media (min-width: 761px) and (max-width: 1100px) {
  #win-terminal {
    top: 48%;
    left: calc(100vw - 480px);
  }

  #win-setup {
    top: 52%;
  }
}

/* ─── mobile transformation (≤760px): windows become stacked cards ─── */

@media (max-width: 760px) {
  body {
    overflow: auto;
  }

  #desktop {
    height: auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding: 12px 12px calc(var(--taskbar-h) + 20px);
  }

  .hero-layer {
    position: static;
    transform: none;
    padding: 18px 12px 0;
  }

  .hero-text {
    font-size: clamp(52px, 16vw, 100px);
    white-space: normal;
    line-height: 1.05;
  }

  .icon-column {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 10px;
    order: 99;
  }

  .desktop-icon {
    width: 72px;
  }

  .window {
    position: static !important;
    transform: none !important;
    width: auto !important;
    max-width: none;
    display: flex !important;
  }

  .window[data-minimized] {
    display: flex !important;
  }

  .window-controls {
    display: none;
  }

  .window-content {
    max-height: none;
  }

  /* stack order: welcome → why → setup → terminal → control → icons */
  #win-welcome { order: 1; }
  #win-why { order: 2; }
  #win-setup { order: 3; }
  #win-terminal { order: 4; }
  #win-control { order: 5; }

  .taskbar-items {
    display: none;
  }

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