:root {
  --bg: #eef3f9;
  --ink: #1f1f1f;
  --muted: #5f6368;
  --accent: #1a73e8;
  --accent-2: #174ea6;
  --page-countdown-darkness: 0;
  --page-countdown-vignette: 0;
  --widget-card-radius: 6px;
  --widget-challenge-radius: 8px;
  --widget-control-radius: 10px;
  font-family: Arial, Helvetica, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  position: relative;
  isolation: isolate;
  color: var(--ink);
  background:
    radial-gradient(circle at top right, rgba(26, 115, 232, 0.08), transparent 24%),
    linear-gradient(180deg, #f7faff 0%, #edf3fb 100%);
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  will-change: opacity;
}

body::before {
  background: #000;
  opacity: var(--page-countdown-darkness);
}

body::after {
  background: radial-gradient(
    circle at center,
    rgba(0, 0, 0, 0) 22%,
    rgba(0, 0, 0, 0.12) 50%,
    rgba(0, 0, 0, 0.34) 72%,
    rgba(0, 0, 0, 0.68) 100%
  );
  opacity: var(--page-countdown-vignette);
}

body > * {
  position: relative;
  z-index: 1;
}

.embed-page {
  min-height: 0;
  background: transparent;
}

.embed-page::before,
.embed-page::after {
  display: none;
}

.embed-page > * {
  position: static;
  z-index: auto;
}

.embed-shell {
  width: 100%;
  padding: 0.75rem;
}

.landing-page,
.copy-page {
  width: min(960px, calc(100vw - 2rem));
  margin: 0 auto;
}

.landing-page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 1.25rem 0 1rem;
}

.copy-page {
  padding: 3rem 0 4rem;
}

.register-page {
  display: grid;
  gap: 1.5rem;
  padding-top: 1.25rem;
}

.register-lead {
  max-width: 44rem;
  margin: -0.35rem 0 0;
  color: #42576d;
  font-size: 1rem;
  line-height: 1.65;
}

.register-card {
  display: grid;
  gap: 1rem;
}

.register-card-header {
  display: grid;
  gap: 0.45rem;
}

.register-card-header h2,
.register-card-header p {
  margin: 0;
}

.register-form,
.register-snippet {
  display: grid;
  gap: 1rem;
}

.register-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.register-form-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.register-form-status {
  margin: 0;
  min-height: 1.25rem;
}

.register-form-status-error {
  color: #b3261e;
}

.register-secret-note {
  max-width: 44rem;
  margin: -0.35rem 0 0;
  font-weight: 400;
  line-height: 1.55;
}

.register-copy-surface {
  position: relative;
  display: block;
  border-radius: 12px;
  cursor: pointer;
}

.register-copy-surface[data-copy-disabled="true"] {
  cursor: default;
}

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

.register-copy-surface input {
  cursor: inherit;
}

.register-copy-surface pre {
  transition: box-shadow 160ms ease, transform 160ms ease;
}

.register-copy-surface input {
  padding-right: 3rem;
  transition: border-color 160ms ease, box-shadow 160ms ease, background-color 160ms ease;
}

.register-copy-surface-dark pre {
  padding-right: 3rem;
}

.register-copy-surface:not([data-copy-disabled="true"]):hover pre {
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.24), 0 8px 20px rgba(17, 24, 39, 0.12);
}

.register-copy-surface-light:not([data-copy-disabled="true"]):hover input {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.12);
  background: #fff;
}

.register-copy-icon {
  position: absolute;
  top: 0.85rem;
  right: 0.9rem;
  width: 1.1rem;
  height: 1.1rem;
  opacity: 0.58;
  pointer-events: none;
  transition: opacity 160ms ease, transform 160ms ease;
}

.register-copy-surface-dark .register-copy-icon {
  filter: invert(1);
}

.register-copy-surface:not([data-copy-disabled="true"]):hover .register-copy-icon {
  opacity: 0.95;
  transform: translateY(-1px);
}

.register-snippet pre {
  min-height: 16rem;
}

.register-examples {
  display: grid;
  gap: 1rem;
}

.register-language-switcher {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  width: fit-content;
  padding: 0.25rem;
  border: 1px solid #cddff8;
  border-radius: var(--widget-control-radius);
  background: rgba(255, 255, 255, 0.62);
}

.register-language-switcher button {
  padding: 0.45rem 0.7rem;
  border: 0;
  border-radius: calc(var(--widget-control-radius) - 2px);
  background: transparent;
  color: #42576d;
  font: 400 0.9rem/1 "IBM Plex Sans", "Avenir Next", "Segoe UI", sans-serif;
  cursor: pointer;
}

.register-language-switcher button.is-active {
  background: var(--accent);
  color: #fff;
}

.register-language-switcher button:focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 2px;
}

.register-example {
  display: grid;
  gap: 0.6rem;
}

.register-example h3 {
  margin: 0;
  font-size: 1rem;
}

.register-snippet pre,
.register-example pre {
  margin: 0;
  padding: 0.95rem 1rem;
  border-radius: 12px;
  background: #111827;
  color: #f3f4f6;
  overflow-x: auto;
  font: 400 0.88rem/1.55 "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.register-example code {
  font: inherit;
}

.widget-shell {
  width: min(100%, 640px);
  margin: 0 auto;
}

.message-board-drawer {
  display: grid;
  gap: 1rem;
  width: min(100%, 760px);
  margin: 3.75rem auto 0;
}

.message-board-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  justify-self: center;
  padding: 0;
  border: 0;
  background: transparent;
  color: #42576d;
  font: 400 0.95rem/1 Arial, Helvetica, sans-serif;
  cursor: pointer;
}

.message-board-toggle:hover,
.message-board-toggle:focus-visible {
  color: #17324d;
}

.message-board-toggle-caret {
  width: 0.45rem;
  height: 0.45rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: translateY(-0.15rem) rotate(45deg);
}

.message-board-toggle[aria-expanded="true"] .message-board-toggle-caret {
  transform: translateY(0.15rem) rotate(225deg);
}

.message-board-panel {
  display: grid;
  gap: 1rem;
  padding-bottom: 3.75rem;
}

.landing-header {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  width: min(100%, 640px);
  margin: 0 auto;
  margin-bottom: 3.75rem;
  padding: 0;
}

.landing-header-mark {
  width: 28px;
  height: 28px;
  flex: 0 0 auto;
}

.landing-header-title,
.landing-footer-line {
  margin: 0;
}

.landing-header-title {
  font-size: clamp(1.3rem, 3vw, 1.65rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: #17324d;
}

.landing-header-title a {
  color: inherit;
  text-decoration: none;
}

.landing-header-title a:hover,
.landing-header-title a:focus-visible {
  text-decoration: underline;
}

.landing-header-register {
  position: fixed;
  top: 1rem;
  right: 1rem;
  z-index: 2;
  color: var(--accent-2);
  font: 400 0.95rem/1.2 "IBM Plex Sans", "Avenir Next", "Segoe UI", sans-serif;
  text-decoration: underline;
}

.landing-header-register:hover,
.landing-header-register:focus-visible {
  color: #42576d;
}

.landing-footer a {
  color: #5f7287;
  font: 600 0.95rem/1.2 "IBM Plex Sans", "Avenir Next", "Segoe UI", sans-serif;
  text-decoration: none;
}

.landing-footer a:hover {
  color: #42576d;
  text-decoration: underline;
}

.landing-footer {
  width: min(100%, 960px);
  margin: auto auto 0;
  padding: 0;
  color: #6a7b8e;
  text-align: center;
}

.landing-footer-line {
  font-size: 0.92rem;
  line-height: 1.5;
}

.landing-footer-line a {
  display: inline;
  margin-left: 0.55rem;
  vertical-align: baseline;
}

.landing-footer-line a:first-of-type {
  margin-left: 0;
}

.eyebrow {
  margin: 0 0 0.75rem;
  color: var(--accent-2);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.75rem;
  font-weight: 700;
}

.copy-title {
  margin: 0;
  max-width: 42rem;
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1.05;
}

.copy-back {
  margin-top: 1.25rem;
}

.copy-back a,
.brand-links a {
  color: var(--accent-2);
}

.copy-back a:hover,
.brand-links a:hover {
  text-decoration: underline;
}

.muted {
  color: var(--muted);
}

.message-board-composer,
.message-board-list-section {
  display: grid;
  gap: 1rem;
}

.message-board-form,
.message-board-list {
  display: grid;
  gap: 1rem;
}

.message-board-more {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.message-board-list-header h2,
.message-board-item p {
  margin: 0;
}

.message-board-label {
  display: grid;
  gap: 0.45rem;
  font-weight: 600;
}

.message-board-label input,
.message-board-label textarea {
  width: 100%;
  padding: 0.85rem 1rem;
  border: 1px solid #c9ced6;
  border-radius: var(--widget-control-radius);
  background: rgba(255, 255, 255, 0.96);
  font: inherit;
  font-weight: 400;
  color: inherit;
}

.register-copy-surface input {
  padding-right: 3rem;
}

.message-board-label textarea {
  min-height: 7.5rem;
  resize: vertical;
}

.message-board-form-row,
.message-board-list-header,
.message-board-item-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.message-board-form-row {
  align-items: flex-start;
}

.message-board-form-status {
  margin: 0;
  min-height: 1.25rem;
}

.message-board-more-status {
  margin: 0;
  min-height: 1.25rem;
}

.message-board-form-error {
  color: #b3261e;
}

.message-board-more-status-error {
  color: #b3261e;
}

.message-board-form-disabled {
  opacity: 0.65;
}

.message-board-item {
  display: grid;
  gap: 0.7rem;
  padding: 1rem 1.1rem;
  border: 1px solid #dce3ec;
  border-radius: var(--widget-challenge-radius);
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.98) 0%, rgba(246, 250, 255, 0.95) 100%);
}

.message-board-item-meta {
  flex-wrap: wrap;
  color: #3d556d;
  font-family: Arial, Helvetica, sans-serif;
  font-size: 0.92rem;
}

.message-board-item-meta strong,
.message-board-item-meta time {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.message-board-verification {
  display: flex;
  flex-wrap: wrap;
  gap: 0.27rem;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.492rem;
  line-height: 1.1;
}

.message-board-verification span {
  padding: 0.168rem 0.27rem;
  border: 1px solid #d5e2f0;
}

.message-board-verification span:nth-child(1) {
  background: rgba(232, 240, 254, 0.72);
  color: #31516f;
}

.message-board-verification span:nth-child(2) {
  border-color: #d7ead3;
  background: rgba(230, 244, 234, 0.72);
  color: #2f6033;
}

.message-board-verification span:nth-child(3) {
  border-color: #f4dfb8;
  background: rgba(254, 247, 224, 0.78);
  color: #795400;
}

.message-board-verification span:nth-child(4) {
  border-color: #ead4e9;
  background: rgba(253, 231, 246, 0.72);
  color: #71356f;
}

.widget-card {
  --widget-accent: #1a73e8;
  --widget-status-color: #b3261e;
  display: flex;
  align-items: center;
  justify-content: space-between;
  align-content: center;
  padding: 1.45rem 1.4rem 1.2rem;
  border: 1px solid #c9ced6;
  border-radius: var(--widget-card-radius);
  background: #f9f9f9;
  box-shadow: 0 1px 2px rgba(60, 64, 67, 0.2);
}

.widget-card-interactive {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  grid-template-rows: 1fr auto;
  align-items: center;
}

.widget-visible-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  min-height: 0;
}

.widget-main {
  display: flex;
  align-items: center;
  gap: 1.1rem;
}

.widget-checkbox {
  position: relative;
  display: inline-flex;
  cursor: pointer;
}

.widget-checkbox input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.fake-check {
  width: 34px;
  height: 34px;
  border: 2px solid #b8bcc2;
  border-radius: 3px;
  background: white;
  box-shadow: inset 0 1px 1px rgba(0, 0, 0, 0.04);
}

.widget-checkbox input:checked + .fake-check {
  border-color: var(--widget-accent);
  background: linear-gradient(180deg, #ffffff 0%, #f1f7ff 100%);
}

.widget-checkbox input:checked + .fake-check::after {
  content: "";
  position: absolute;
  left: 10px;
  top: 6px;
  width: 10px;
  height: 18px;
  border-right: 3px solid var(--widget-accent);
  border-bottom: 3px solid var(--widget-accent);
  transform: rotate(38deg);
}

.widget-copy {
  display: grid;
  gap: 0.2rem;
}

.widget-title {
  margin: 0;
  font-size: clamp(1.8rem, 4vw, 2.2rem);
  line-height: 1.05;
  color: #202124;
}

.widget-subtitle {
  margin: 0;
  font-size: 0.95rem;
  color: #5f6368;
}

.widget-status {
  margin: 0;
  font-size: 0.95rem;
  color: var(--widget-status-color);
  white-space: nowrap;
}

.widget-brand {
  display: grid;
  justify-items: center;
  gap: 0.2rem;
  min-width: 120px;
  color: #5f6368;
}

.brand-mark {
  width: 52px;
  height: 52px;
}

.brand-mark svg {
  display: block;
  width: 100%;
  height: 100%;
}

.brand-title,
.brand-links {
  margin: 0;
}

.brand-links {
  font-size: 0.85rem;
}

.brand-links a {
  text-decoration: none;
}

.widget-robot-hint {
  grid-row: 2;
  margin: 0;
  padding: 0;
  font-size: 0.54rem;
  line-height: 1;
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  color: rgba(255, 255, 255, 0.04);
}

.widget-robot-hint a {
  color: rgba(255, 255, 255, 0.07);
  text-decoration: none;
}

.widget-robot-hint a:hover {
  color: rgba(255, 255, 255, 0.12);
}

.widget-expanded {
  grid-column: 1;
  display: grid;
  gap: 1rem;
  padding-top: 0.5rem;
}

.widget-progress {
  height: 6px;
  border-radius: 999px;
  overflow: hidden;
}

.widget-progress-bar {
  display: none;
}

.widget-progress-segments {
  --widget-progress-segments: 1;
  display: grid;
  grid-template-columns: repeat(var(--widget-progress-segments), minmax(0, 1fr));
  gap: 0;
  height: 100%;
}

.widget-progress-segments span {
  position: relative;
  min-width: 0;
  border-radius: 0;
  background: #e3e7ee;
  transition: background-color 180ms ease;
}

.widget-progress-segments span:first-child {
  border-radius: 999px 0 0 999px;
}

.widget-progress-segments span:last-child {
  border-radius: 0 999px 999px 0;
}

.widget-progress-segments span:only-child {
  border-radius: 999px;
}

.widget-progress-segments span:not(:last-child)::after {
  content: "";
  position: absolute;
  top: 0;
  right: -0.5px;
  z-index: 1;
  width: 1px;
  height: 100%;
  background: #f9f9f9;
  transform: skewX(-18deg);
  transform-origin: center;
}

.widget-progress-segments span.is-filled {
  background: linear-gradient(90deg, #5ca7ff 0%, #1a73e8 100%);
}

.widget-meta {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.6rem;
  border-radius: 999px;
  font-size: 0.8rem;
  background: #e9edf3;
  color: #334155;
}

.badge-accent {
  background: #e8f0fe;
  color: #174ea6;
}

.widget-challenge {
  border: 1px solid #d9dee7;
  border-radius: var(--widget-challenge-radius);
  padding: 1rem;
  background: #fbfdff;
}

.challenge-block {
  display: grid;
  gap: 0.9rem;
}

.challenge-block p {
  margin: 0;
}

.challenge-block label {
  display: grid;
  gap: 0.35rem;
}

.challenge-block input[type="text"] {
  width: 100%;
  padding: 0.75rem 0.9rem;
  border: 1px solid #c9ced6;
  border-radius: var(--widget-control-radius);
  font: inherit;
}

.chess-puzzle-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: start;
}

.challenge-chess-board {
  display: block;
  width: min(100%, 320px);
}

.chess-puzzle-copy {
  display: grid;
  gap: 0.75rem;
}

.chess-fen {
  margin: 0;
}

.chess-fen code {
  font-size: 0.88rem;
}

.chess-fen code {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  word-break: break-all;
}

.choice-grid,
.choice-list {
  display: grid;
  gap: 0.75rem;
}

.choice-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.choice-card,
.choice-line {
  display: grid;
  gap: 0.35rem;
  padding: 0.85rem 0.95rem;
  border: 1px solid #c9ced6;
  border-radius: 12px;
  background: #fff;
}

.choice-line {
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: 0.85rem;
}

.choice-line input[type="radio"] {
  margin: 0.15rem 0 0;
}

.choice-card code,
.code-block {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

.choice-card code {
  white-space: pre-wrap;
  word-break: break-all;
  font-size: 0.83rem;
}

.code-block {
  margin: 0;
  padding: 0.85rem 0.95rem;
  border-radius: 12px;
  background: #111827;
  color: #f3f4f6;
  overflow-x: auto;
}

.widget-actions {
  display: flex;
}

.message-board-form-row button,
.message-board-more button,
.register-form-row button,
.widget-actions button {
  padding: 0.75rem 1rem;
  border: 0;
  border-radius: var(--widget-control-radius);
  background: var(--accent);
  color: #fff;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

.message-board-form-row button:disabled,
.message-board-more button:disabled,
.register-form-row button:disabled,
.widget-actions button:disabled {
  cursor: default;
  opacity: 0.6;
}

.widget-result {
  margin: 0;
  font-weight: 600;
}

.widget-result-success {
  color: #18794e;
}

.widget-result-error {
  color: #b3261e;
}

.robot-icon {
  stroke-width: 3;
}

.robot-blue {
  stroke: var(--widget-accent);
}

.robot-gray {
  stroke: #c7c9cc;
}

.widget-state-happy {
  --widget-accent: #16a34a;
}

.widget-state-suspicious {
  --widget-accent: #ea580c;
}

.widget-state-angry,
.widget-state-dead {
  --widget-accent: #b3261e;
}

.widget-state-happy .widget-subtitle,
.widget-state-suspicious .widget-subtitle,
.widget-state-angry .widget-subtitle,
.widget-state-dead .widget-subtitle {
  color: var(--widget-status-color);
}

.widget-state-happy .robot-eye-normal,
.widget-state-suspicious .robot-eye-normal,
.widget-state-angry .robot-eye-normal,
.widget-state-dead .robot-eye-normal,
.widget-state-normal .robot-eye-flat,
.widget-state-normal .robot-eye-happy,
.widget-state-normal .robot-eye-dead,
.widget-state-happy .robot-eye-flat,
.widget-state-happy .robot-eye-dead,
.widget-state-suspicious .robot-eye-happy,
.widget-state-suspicious .robot-eye-dead,
.widget-state-angry .robot-eye-happy,
.widget-state-angry .robot-eye-dead,
.widget-state-dead .robot-eye-flat,
.widget-state-dead .robot-eye-happy {
  display: none;
}

.widget-state-happy .robot-eye-happy,
.widget-state-suspicious .robot-eye-flat,
.widget-state-angry .robot-eye-flat,
.widget-state-dead .robot-eye-dead {
  display: block;
}

.hidden {
  display: none !important;
}

@media (max-width: 720px) {
  .landing-page {
    padding-top: 1rem;
  }

  .landing-header {
    width: min(100%, 640px);
    flex-wrap: wrap;
    justify-content: center;
  }

  .landing-header-mark {
    width: 24px;
    height: 24px;
  }

  .landing-header-register {
    top: 0.75rem;
    right: 0.75rem;
  }

  .widget-card,
  .widget-card-interactive,
  .choice-grid {
    grid-template-columns: 1fr;
  }

  .widget-main {
    align-items: start;
  }

  .widget-brand {
    justify-items: start;
    min-width: 0;
  }

  .copy-page {
    padding: 2rem 0 3rem;
  }

  .register-form-row,
  .message-board-form-row,
  .message-board-list-header,
  .message-board-item-meta {
    align-items: start;
    flex-direction: column;
  }

  .landing-footer {
    width: min(100%, 640px);
  }
}