/* ---------- Design tokens ---------- */
:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #eef0f7;
  --text: #1d2033;
  --muted: #5d6280;
  --border: #dde0ee;
  --primary: #6c5ce7;
  --primary-strong: #5546d6;
  --on-primary: #ffffff;
  --success: #00a37a;
  --danger: #d6455d;
  --warning: #d99a00;
  --info: #0984e3;
  --node: #ffffff;
  --node-stroke: #6c5ce7;
  --edge: #8d92b3;
  --shadow: 0 1px 2px rgb(20 20 50 / 6%), 0 8px 24px rgb(20 20 50 / 6%);
  --radius: 14px;
  --font: system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --mono: ui-monospace, 'Cascadia Code', 'SF Mono', Menlo, Consolas, monospace;
  color-scheme: light;
}

:root[data-theme='dark'] {
  --bg: #12131c;
  --surface: #1b1d2b;
  --surface-2: #252839;
  --text: #e9eaf4;
  --muted: #a1a5c2;
  --border: #30344a;
  --primary: #8b7dff;
  --primary-strong: #a397ff;
  --on-primary: #12131c;
  --success: #2fd3a3;
  --danger: #ff6f86;
  --warning: #ffc94d;
  --info: #4db3ff;
  --node: #222538;
  --node-stroke: #8b7dff;
  --edge: #6f7496;
  --shadow: 0 1px 2px rgb(0 0 0 / 30%), 0 8px 24px rgb(0 0 0 / 25%);
  color-scheme: dark;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg: #12131c;
    --surface: #1b1d2b;
    --surface-2: #252839;
    --text: #e9eaf4;
    --muted: #a1a5c2;
    --border: #30344a;
    --primary: #8b7dff;
    --primary-strong: #a397ff;
    --on-primary: #12131c;
    --node: #222538;
    --node-stroke: #8b7dff;
    --edge: #6f7496;
    color-scheme: dark;
  }
}

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

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

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.55;
  transition: background-color 0.25s ease, color 0.25s ease;
}

h1,
h2,
h3 {
  line-height: 1.2;
  margin: 0 0 0.5em;
}

p {
  margin: 0 0 0.8em;
}

a {
  color: var(--primary);
}

code {
  font-family: var(--mono);
  font-size: 0.9em;
}

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

[hidden] {
  display: none !important;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 8px;
  z-index: 100;
  padding: 8px 12px;
  background: var(--surface);
  border-radius: 8px;
}

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

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

.small {
  font-size: 0.875rem;
}

.eyebrow {
  margin: 0 0 0.3em;
  color: var(--primary);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lead {
  font-size: 1.1rem;
  color: var(--muted);
}

/* ---------- Layout ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 10px 16px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none;
}

.brand-mark {
  width: 28px;
  height: 28px;
  fill: var(--primary);
  stroke: var(--primary);
  stroke-width: 2.5;
}

.site-nav {
  display: flex;
  gap: 4px;
  flex: 1;
}

.site-nav a {
  padding: 6px 12px;
  border-radius: 999px;
  color: var(--muted);
  font-weight: 600;
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--text);
  background: var(--surface-2);
}

.header-actions,
.account-slot {
  display: flex;
  align-items: center;
  gap: 8px;
}

.account-chip {
  display: flex;
  flex-direction: column;
  padding: 2px 12px;
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--text);
  text-decoration: none;
  line-height: 1.2;
}

.account-rank {
  font-size: 0.7rem;
  color: var(--primary);
  font-weight: 700;
  text-transform: uppercase;
}

.account-name {
  font-size: 0.85rem;
  font-weight: 600;
}

.icon-button {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

.icon-button svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.page {
  flex: 1;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 16px 48px;
  outline: none;
}

.page > * + * {
  margin-top: 20px;
}

.site-footer {
  padding: 20px 16px;
  text-align: center;
  color: var(--muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--border);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}

.page-header h1 {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
}

.two-column {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.notice {
  padding: 12px 16px;
  border-radius: 10px;
  background: var(--surface-2);
}

.notice-error {
  color: var(--danger);
}

/* ---------- Buttons and inputs ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 9px 16px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface-2);
  color: var(--text);
  font: inherit;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.1s ease, background-color 0.2s ease, border-color 0.2s ease;
}

.btn:hover {
  border-color: var(--primary);
}

.btn:active {
  transform: translateY(1px);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--on-primary);
}

.btn-primary:hover {
  background: var(--primary-strong);
}

.btn-ghost {
  background: transparent;
}

.btn-danger {
  color: var(--danger);
}

.btn-danger:hover {
  border-color: var(--danger);
}

.btn-small {
  padding: 5px 10px;
  font-size: 0.875rem;
}

.btn-large {
  padding: 13px 22px;
  font-size: 1.05rem;
}

.btn-block {
  width: 100%;
}

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

.pulse {
  animation: pulse 1.6s ease-in-out infinite;
}

@keyframes pulse {
  50% {
    box-shadow: 0 0 0 6px color-mix(in srgb, var(--primary) 25%, transparent);
  }
}

.input {
  width: 100%;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--text);
  font: inherit;
}

.input-small {
  width: 5.5rem;
  padding: 5px 8px;
  font-size: 0.9rem;
}

.chip {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--surface-2);
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 600;
}

/* ---------- Home ---------- */
.hero {
  padding: 32px 0 8px;
  max-width: 760px;
}

.hero-title {
  font-size: clamp(2rem, 6vw, 3.2rem);
  letter-spacing: -0.02em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 12px;
}

.feature-grid,
.structure-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.feature h3 {
  color: var(--primary);
}

.path-list {
  padding-left: 1.2rem;
}

.path-list li {
  margin-bottom: 10px;
}

.path-list .chip {
  margin-left: 8px;
}

/* ---------- Story ---------- */
.rank-card {
  display: flex;
  align-items: center;
  gap: 18px;
}

.rank-emblem {
  width: 60px;
  height: 60px;
  flex: none;
  display: grid;
  place-items: center;
  border-radius: 16px;
  background: linear-gradient(135deg, var(--primary), var(--info));
  color: #fff;
  font-size: 1.6rem;
  font-weight: 800;
}

.rank-info {
  flex: 1;
}

.rank-name {
  margin: 0 0 6px;
  font-size: 1.25rem;
  font-weight: 800;
}

.xp-bar {
  height: 10px;
  border-radius: 999px;
  background: var(--surface-2);
  overflow: hidden;
  margin-bottom: 6px;
}

.xp-bar-fill {
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--primary), var(--success));
  transition: width 0.8s ease;
}

.act-head {
  margin-bottom: 12px;
}

.mission-path {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(230px, 1fr));
  gap: 12px;
}

.mission-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  height: 100%;
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  text-decoration: none;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

a.mission-link:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
}

.mission-number {
  width: 40px;
  height: 40px;
  flex: none;
  display: grid;
  place-items: center;
  border-radius: 50%;
  border: 2px solid var(--primary);
  font-weight: 800;
  color: var(--primary);
}

.mission-done .mission-number {
  background: var(--primary);
  color: var(--on-primary);
}

.mission-locked {
  opacity: 0.5;
}

.mission-locked .mission-number {
  border-color: var(--border);
  color: var(--muted);
}

.mission-open .mission-link {
  border-color: var(--primary);
  background: color-mix(in srgb, var(--primary) 7%, transparent);
}

.mission-text {
  display: flex;
  flex-direction: column;
  flex: 1;
}

.mission-title {
  font-weight: 700;
}

.stars {
  white-space: nowrap;
  letter-spacing: 2px;
}

.star {
  color: var(--border);
}

.star-on {
  color: var(--warning);
}

/* ---------- Mission ---------- */
.mission-layout {
  display: grid;
  grid-template-columns: minmax(300px, 400px) 1fr;
  gap: 20px;
  align-items: start;
}

.mission-layout-single {
  grid-template-columns: minmax(0, 720px);
  justify-content: center;
}

.story-panel {
  position: sticky;
  top: 76px;
}

.mission-heading {
  font-size: 1.5rem;
}

.step-dots {
  list-style: none;
  padding: 0;
  margin: 0 0 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.dot {
  width: 22px;
  height: 6px;
  border-radius: 999px;
  background: var(--surface-2);
}

.dot-done {
  background: var(--success);
}

.dot-current {
  background: var(--primary);
}

.step-body {
  min-height: 220px;
  outline: none;
}

.step {
  animation: step-in 0.35s ease;
}

@keyframes step-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
}

.speaker {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.avatar {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--info));
  color: #fff;
  font-weight: 800;
}

.speaker-name {
  font-weight: 700;
  color: var(--muted);
}

.key-points {
  padding-left: 1.2rem;
}

.key-points li::marker {
  color: var(--primary);
}

.task-text {
  font-size: 1.1rem;
  font-weight: 600;
}

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

.step-task-done .task-status {
  color: var(--success);
  font-weight: 700;
}

.hint {
  padding: 10px 12px;
  border-left: 3px solid var(--warning);
  background: var(--surface-2);
  border-radius: 6px;
}

.options {
  display: grid;
  gap: 8px;
}

.option {
  text-align: left;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
  cursor: pointer;
}

.option:hover:not(:disabled) {
  border-color: var(--primary);
}

.option:disabled {
  cursor: default;
}

.option-correct {
  border-color: var(--success);
  background: color-mix(in srgb, var(--success) 15%, transparent);
  font-weight: 700;
}

.option-wrong {
  border-color: var(--danger);
  background: color-mix(in srgb, var(--danger) 12%, transparent);
  animation: shake 0.35s ease;
}

@keyframes shake {
  25% {
    transform: translateX(-5px);
  }
  75% {
    transform: translateX(5px);
  }
}

.quiz-explain {
  margin-top: 12px;
  padding: 10px 12px;
  border-radius: 8px;
}

.quiz-explain-good {
  background: color-mix(in srgb, var(--success) 12%, transparent);
}

.quiz-explain-bad {
  background: color-mix(in srgb, var(--danger) 10%, transparent);
}

.story-actions {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  margin-top: 16px;
}

/* ---------- Simulator ---------- */
.sim {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-width: 0;
}

.sim-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.sim-title {
  margin: 0;
  font-size: 1.2rem;
}

.chip-cost {
  font-family: var(--mono);
}

.sim-stage {
  border: 1px solid var(--border);
  border-radius: 12px;
  background-color: var(--bg);
  background-image: radial-gradient(var(--border) 1px, transparent 1px);
  background-size: 22px 22px;
  overflow: hidden;
}

.sim-canvas {
  display: block;
  width: 100%;
  height: clamp(260px, 42vh, 420px);
}

.sim-narration {
  min-height: 3.2em;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--surface-2);
}

.sim-step {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
}

.sim-message {
  margin: 0;
}

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

.sim-speed {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: 0.875rem;
}

.sim-ops {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 8px;
}

.op-form {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
}

.op-name {
  font-weight: 700;
  flex: 1 1 100%;
}

.op-cost {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--muted);
}

/* SVG scene */
.node-body {
  fill: var(--node);
  stroke: var(--node-stroke);
  stroke-width: 2.5;
  transition: fill 0.3s ease, stroke 0.3s ease;
}

.node-label {
  fill: var(--text);
  font: 700 15px var(--font);
  pointer-events: none;
}

.node-caption {
  fill: var(--muted);
  font: 600 11px var(--mono);
}

.node.state-active .node-body {
  fill: var(--primary);
  stroke: var(--primary-strong);
}

.node.state-active .node-label,
.node.state-found .node-label,
.node.state-removed .node-label,
.node.state-new .node-label,
.node.state-visited .node-label {
  fill: #fff;
}

.node.state-compare .node-body {
  fill: color-mix(in srgb, var(--warning) 30%, var(--node));
  stroke: var(--warning);
}

.node.state-found .node-body {
  fill: var(--success);
  stroke: var(--success);
}

.node.state-new .node-body {
  fill: var(--info);
  stroke: var(--info);
}

.node.state-removed .node-body {
  fill: var(--danger);
  stroke: var(--danger);
}

.node.state-visited .node-body {
  fill: color-mix(in srgb, var(--primary) 55%, var(--node));
  stroke: var(--primary);
}

.node.variant-bucket .node-body {
  fill: var(--surface-2);
  stroke: var(--edge);
  stroke-dasharray: 4 3;
}

.node.variant-terminal .node-body {
  stroke-width: 5;
  stroke: var(--success);
}

.edge {
  stroke: var(--edge);
  stroke-width: 2.5;
  transition: stroke 0.3s ease;
}

.edge.state-path {
  stroke: var(--success);
  stroke-width: 4;
}

.edge.state-removed {
  stroke: var(--danger);
  stroke-dasharray: 6 4;
}

.edge-arrow {
  fill: var(--edge);
}

.tag-bg {
  fill: var(--surface-2);
  stroke: var(--border);
}

.tag-text {
  fill: var(--text);
  font: 600 12px var(--font);
}

.tag.kind-pointer .tag-bg {
  fill: var(--primary);
  stroke: none;
}

.tag.kind-pointer .tag-text {
  fill: var(--on-primary);
}

.tag.kind-accent .tag-bg {
  fill: var(--warning);
  stroke: none;
}

.tag.kind-accent .tag-text {
  fill: #1d2033;
}

.tag.kind-index .tag-bg,
.tag.kind-muted .tag-bg {
  fill: none;
  stroke: none;
}

.tag.kind-index .tag-text,
.tag.kind-muted .tag-text {
  fill: var(--muted);
  font-family: var(--mono);
}

/* ---------- Sandbox, history, profile ---------- */
.tier-title {
  font-size: 1rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.structure-card {
  color: var(--text);
  text-decoration: none;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.structure-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary);
}

.structure-card h3 {
  color: var(--primary);
}

.sandbox-head {
  display: flex;
  justify-content: space-between;
}

.sandbox-layout {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 20px;
  align-items: start;
}

.cost-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.cost-table th,
.cost-table td {
  padding: 6px 4px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.history-list {
  display: grid;
  gap: 12px;
}

.history-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

.history-meta {
  min-width: 0;
}

.history-meta h2 {
  font-size: 1.1rem;
  margin: 0;
}

.history-ops {
  margin: 0;
  overflow-wrap: anywhere;
  color: var(--muted);
}

.history-footer {
  display: flex;
  justify-content: flex-end;
}

.empty-state {
  text-align: center;
}

.badge-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
  gap: 12px;
}

.badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 12px 8px;
  border: 1px dashed var(--border);
  border-radius: 12px;
  text-align: center;
  color: var(--muted);
}

.badge-mark {
  width: 48px;
  height: 48px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--surface-2);
  font-weight: 800;
  font-size: 1.2rem;
}

.badge-earned {
  border-style: solid;
  border-color: var(--warning);
  color: var(--text);
}

.badge-earned .badge-mark {
  background: linear-gradient(135deg, var(--warning), #ff9f43);
  color: #1d2033;
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--warning) 25%, transparent);
}

.badge-name {
  font-size: 0.85rem;
  font-weight: 600;
}

.setting {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}

.setting .input {
  width: auto;
}

.setting input[type='checkbox'] {
  width: 20px;
  height: 20px;
  accent-color: var(--primary);
}

/* ---------- Auth and prose ---------- */
.auth {
  max-width: 420px;
  margin: 24px auto 0;
}

.form {
  display: grid;
  gap: 8px;
  margin: 16px 0;
}

.form label {
  font-weight: 600;
  margin-top: 6px;
}

.form-error {
  color: var(--danger);
  font-weight: 600;
}

.prose {
  max-width: 760px;
}

.prose h2 {
  margin-top: 1.2em;
  font-size: 1.2rem;
}

/* ---------- Modal, toasts, confetti ---------- */
.modal {
  width: min(460px, calc(100vw - 32px));
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 20px 60px rgb(0 0 0 / 35%);
}

.modal::backdrop {
  background: rgb(10 10 25 / 55%);
  backdrop-filter: blur(2px);
}

.modal[open] {
  animation: pop 0.35s cubic-bezier(0.2, 1.4, 0.4, 1);
}

@keyframes pop {
  from {
    opacity: 0;
    transform: scale(0.85);
  }
}

.modal-body {
  display: grid;
  gap: 10px;
}

.modal-body label {
  display: grid;
  gap: 6px;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.modal-celebrate {
  text-align: center;
}

.modal-celebrate .modal-title {
  font-size: 1.8rem;
}

.modal-celebrate .modal-actions {
  justify-content: center;
}

.celebrate-stars {
  font-size: 2.6rem;
}

.celebrate-stars .star-on {
  display: inline-block;
  animation: star-pop 0.5s cubic-bezier(0.2, 1.6, 0.4, 1) both;
}

.celebrate-stars .star-on:nth-child(2) {
  animation-delay: 0.15s;
}

.celebrate-stars .star-on:nth-child(3) {
  animation-delay: 0.3s;
}

@keyframes star-pop {
  from {
    transform: scale(0) rotate(-40deg);
  }
}

.xp-gain {
  font-size: 2rem;
  font-weight: 800;
  color: var(--success);
}

.badge-large {
  border-style: solid;
}

.rank-up {
  font-weight: 800;
  color: var(--primary);
}

.toasts {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 60;
  display: grid;
  gap: 8px;
  max-width: min(360px, calc(100vw - 32px));
}

.toast {
  padding: 12px 16px;
  border-radius: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 4px solid var(--info);
  box-shadow: var(--shadow);
  animation: step-in 0.25s ease;
  transition: opacity 0.3s ease;
}

.toast-success {
  border-left-color: var(--success);
}

.toast-error {
  border-left-color: var(--danger);
}

.toast-leaving {
  opacity: 0;
}

.confetti {
  position: fixed;
  inset: 0;
  z-index: 1000;
  pointer-events: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .mission-layout,
  .sandbox-layout {
    grid-template-columns: 1fr;
  }

  .story-panel {
    position: static;
  }
}

@media (max-width: 640px) {
  .site-header-inner {
    flex-wrap: wrap;
  }

  .site-nav {
    order: 3;
    flex-basis: 100%;
    justify-content: space-between;
  }

  .header-actions {
    margin-left: auto;
  }

  .rank-card {
    align-items: flex-start;
  }

  .history-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .sim-speed {
    margin-left: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}