:root {
  --gb-bg: #f3f4f6;
  --gb-surface: #ffffff;
  --gb-border: #d7dce3;
  --gb-text: #16181d;
  --gb-text-soft: #5d6777;
  --gb-accent: #111827;
  --gb-accent-contrast: #ffffff;
  --gb-danger-bg: #fff1f2;
  --gb-danger-border: #fecdd3;
  --gb-danger-text: #9f1239;
  --gb-radius: 14px;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background:
    radial-gradient(circle at top left, rgba(17, 24, 39, 0.06), transparent 28%),
    radial-gradient(circle at top right, rgba(17, 24, 39, 0.04), transparent 22%),
    linear-gradient(180deg, #f8fafc 0%, var(--gb-bg) 100%);
  color: var(--gb-text);
  font: 400 16px/1.5 system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
input,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

textarea {
  resize: none;
}

[hidden] {
  display: none !important;
}

.gb-shell {
  width: 100%;
  max-width: 840px;
  margin: 0 auto;
  padding: 18px;
}

.gb-auth-shell {
  width: 100%;
  max-width: 480px;
  min-height: 100vh;
  margin: 0 auto;
  padding: 32px 18px;
  display: grid;
  align-items: center;
}

.gb-topbar,
.gb-setup,
.gb-scene,
.gb-composer,
.gb-alert {
  width: 100%;
  border: 1px solid var(--gb-border);
  border-radius: var(--gb-radius);
  background: var(--gb-surface);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.05);
}

.gb-topbar {
  padding: 18px;
  margin-bottom: 14px;
}

.gb-kicker {
  margin: 0 0 6px;
  color: var(--gb-text-soft);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.gb-title {
  margin: 0;
  font-size: clamp(1.8rem, 6vw, 2.4rem);
  line-height: 1.05;
}

.gb-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.gb-topbar-actions {
  margin-top: 12px;
}

.gb-account-panel,
.gb-account-card,
.gb-session-card,
.gb-story-card {
  width: 100%;
  border: 1px solid var(--gb-border);
  border-radius: var(--gb-radius);
  background: var(--gb-surface);
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.05);
}

.gb-account-panel,
.gb-setup,
.gb-scene,
.gb-composer {
  margin-bottom: 14px;
}

.gb-auth-shell .gb-account-panel {
  margin-bottom: 0;
}

.gb-auth-panel {
  border: 0;
  background: transparent;
  box-shadow: none;
}

.gb-account-card.gb-auth-card {
  padding: 24px;
  border-radius: 20px;
  box-shadow: 0 18px 44px rgba(15, 23, 42, 0.08);
}

.gb-auth-head {
  gap: 10px;
  margin-bottom: 4px;
}

.gb-account-card,
.gb-session-card {
  padding: 16px;
}

.gb-session-card.is-selected {
  border-color: var(--gb-accent);
  box-shadow: 0 0 0 1px rgba(17, 24, 39, 0.16) inset, 0 10px 30px rgba(15, 23, 42, 0.05);
}

.gb-auth-tabs,
.gb-cabinet-grid {
  display: grid;
  gap: 12px;
}

.gb-auth-tabs {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-bottom: 16px;
  padding: 4px;
  border: 1px solid rgba(215, 220, 227, 0.9);
  border-radius: 14px;
  background: #f8fafc;
}

.gb-auth-tab {
  min-height: 46px;
  padding: 12px 14px;
  border: 1px solid transparent;
  border-radius: 12px;
  background: transparent;
  color: var(--gb-text-soft);
  font-weight: 700;
  text-align: center;
  transition:
    background 0.12s ease,
    color 0.12s ease,
    border-color 0.12s ease,
    box-shadow 0.12s ease;
}

.gb-auth-tab:hover {
  color: var(--gb-text);
}

.gb-auth-tab.is-active {
  border-color: var(--gb-accent);
  background: var(--gb-accent);
  color: var(--gb-accent-contrast);
  box-shadow: 0 8px 18px rgba(17, 24, 39, 0.18);
}

.gb-auth-form {
  gap: 14px;
}

.gb-auth-form .gb-field {
  gap: 8px;
}

.gb-auth-form .gb-input {
  min-height: 50px;
  padding: 13px 14px;
}

.gb-auth-submit {
  min-height: 50px;
  margin-top: 4px;
  justify-content: center;
  text-align: center;
}

.gb-session-select {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--gb-text-soft);
  font-size: 0.92rem;
}

.gb-session-title {
  margin: 0;
  font-size: 1.02rem;
}

.gb-story-card {
  overflow: hidden;
}

.gb-story-card summary {
  display: grid;
  gap: 4px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

.gb-story-card summary::-webkit-details-marker {
  display: none;
}

.gb-story-body {
  padding: 0 16px 16px;
}

.gb-story-content {
  margin: 10px 0 0;
  padding: 12px;
  border-radius: 12px;
  background: #f8fafc;
  color: var(--gb-text);
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.gb-cabinet-grid {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.gb-composer-actions {
  display: grid;
  gap: 10px;
}

.gb-stack,
.gb-setup-grid,
.gb-feed,
.gb-composer-grid,
.gb-options,
.gb-field,
.gb-fieldset,
.gb-legacy-body {
  display: grid;
  gap: 12px;
}

.gb-panel-head {
  display: grid;
  gap: 8px;
}

.gb-label {
  font-weight: 700;
}

.gb-hint {
  margin: 0;
  color: var(--gb-text-soft);
  font-size: 0.92rem;
  line-height: 1.45;
}

.gb-fieldset {
  padding: 0;
  margin: 0;
  border: 0;
}

.gb-fieldset > legend {
  grid-column: 1 / -1;
}

.gb-choice {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  padding: 14px;
  border: 1px solid var(--gb-border);
  border-radius: 12px;
  background: linear-gradient(180deg, #fff, #fbfcfe);
}

.gb-choice:hover {
  border-color: #b8c0cc;
}

.gb-choice:has(input:checked) {
  border-color: var(--gb-accent);
  box-shadow: 0 0 0 1px var(--gb-accent) inset;
}

.gb-choice input {
  margin-top: 4px;
  accent-color: var(--gb-accent);
}

.gb-choice-copy {
  display: grid;
  gap: 4px;
}

.gb-choice-title {
  font-weight: 700;
}

.gb-choice-text {
  color: var(--gb-text-soft);
  font-size: 0.92rem;
  line-height: 1.45;
}

.gb-legacy {
  border: 1px dashed var(--gb-border);
  border-radius: 12px;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.7);
}

.gb-legacy summary {
  cursor: pointer;
  font-weight: 700;
}

.gb-legacy-body {
  padding-top: 12px;
}

.gb-scene-title {
  margin: 0;
  font-size: clamp(1.3rem, 5vw, 1.8rem);
  line-height: 1.15;
}

.gb-setup,
.gb-scene,
.gb-composer {
  padding: 16px;
}

.gb-input,
.gb-textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--gb-border);
  border-radius: 12px;
  background: var(--gb-surface);
  color: var(--gb-text);
}

.gb-textarea-large {
  min-height: 150px;
}

.gb-textarea {
  min-height: 110px;
}

.gb-button,
.gb-option {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--gb-border);
  border-radius: 12px;
  background: var(--gb-surface);
  color: var(--gb-text);
  text-align: left;
  transition:
    transform 0.12s ease,
    border-color 0.12s ease,
    box-shadow 0.12s ease,
    background 0.12s ease;
}

.gb-button-primary {
  background: var(--gb-accent);
  border-color: var(--gb-accent);
  color: var(--gb-accent-contrast);
  text-align: center;
}

.gb-button:hover:not(:disabled),
.gb-option:hover:not(:disabled) {
  border-color: #b8c0cc;
  transform: translateY(-1px);
}

.gb-button:disabled,
.gb-option:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.gb-alert {
  padding: 12px 14px;
  background: var(--gb-danger-bg);
  border-color: var(--gb-danger-border);
  color: var(--gb-danger-text);
}

.gb-player-action {
  margin: 0 0 12px;
  color: var(--gb-text-soft);
  font-size: 0.95rem;
}

.gb-copy {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
}

.gb-copy + .gb-copy {
  margin-top: 10px;
}

.gb-option {
  display: block;
  white-space: normal;
  overflow-wrap: anywhere;
  word-break: break-word;
  line-height: 1.35;
}

.gb-input {
  min-height: 44px;
}

@media (min-width: 720px) {
  .gb-fieldset {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .gb-composer-grid {
    grid-template-columns: 1fr auto;
    align-items: end;
  }

  .gb-composer-actions {
    width: 180px;
  }
}