:root {
  color-scheme: light dark;
  --color-base: #ff4757;
  --color-base-strong: #ff6b81;
  --color-secondary: #2ed573;
  --color-tertiary: #5f70ff;
  --color-background: #f4f5f8;
  --color-surface: #ffffff;
  --color-surface-alt: rgba(255, 255, 255, 0.88);
  --color-panel: rgba(255, 255, 255, 0.82);
  --color-border: rgba(0, 0, 0, 0.08);
  --color-border-strong: rgba(0, 0, 0, 0.16);
  --color-text-primary: #1e1e24;
  --color-text-secondary: #4b4f5c;
  --color-text-muted: #7b7f8c;
  --color-success: #2ed573;
  --color-warning: #ffa502;
  --color-danger: #ff3b30;
  --shadow-sm: 0 6px 16px -10px rgba(15, 18, 22, 0.25);
  --shadow-md: 0 20px 40px -22px rgba(15, 18, 22, 0.32);
  --shadow-lg: 0 40px 60px -24px rgba(15, 18, 22, 0.42);
  --focus-outline: rgba(255, 71, 87, 0.55);

  --tetris-board-bg: #f9fafc;
  --tetris-grid-color: rgba(12, 16, 28, 0.08);
  --tetris-preview-bg: #111218;
  --tetris-preview-grid: rgba(255, 255, 255, 0.12);

  --font-display: 'Press Start 2P', cursive;
  --font-sans: 'Inter', 'Noto Sans KR', 'Apple SD Gothic Neo', 'Malgun Gothic', -apple-system,
    BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'Roboto Mono', SFMono-Regular, Consolas, monospace;

  --space-unit: 8px;
  --space-0: 0;
  --space-1: calc(var(--space-unit) * 1);
  --space-2: calc(var(--space-unit) * 2);
  --space-3: calc(var(--space-unit) * 3);
  --space-4: calc(var(--space-unit) * 4);
  --space-5: calc(var(--space-unit) * 5);
  --space-6: calc(var(--space-unit) * 6);
  --space-7: calc(var(--space-unit) * 7);
  --space-8: calc(var(--space-unit) * 8);
  --space-9: calc(var(--space-unit) * 9);
  --space-10: calc(var(--space-unit) * 10);

  --radius-sm: 12px;
  --radius-md: 20px;
  --radius-lg: 28px;
  --radius-xl: 32px;

  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-background: #111214;
    --color-surface: #181a1f;
    --color-surface-alt: rgba(24, 26, 31, 0.88);
    --color-panel: rgba(30, 32, 39, 0.86);
    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-strong: rgba(255, 255, 255, 0.18);
    --color-text-primary: #f8f8f8;
    --color-text-secondary: rgba(255, 255, 255, 0.78);
    --color-text-muted: rgba(255, 255, 255, 0.55);
    --shadow-sm: 0 6px 16px -10px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 24px 44px -20px rgba(0, 0, 0, 0.58);
    --shadow-lg: 0 50px 70px -24px rgba(0, 0, 0, 0.72);
    --tetris-board-bg: #151922;
    --tetris-grid-color: rgba(255, 255, 255, 0.12);
    --tetris-preview-bg: #0d101a;
    --tetris-preview-grid: rgba(255, 255, 255, 0.2);
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background:
    radial-gradient(circle at top right, rgba(255, 71, 87, 0.08), transparent 55%),
    radial-gradient(circle at bottom left, rgba(46, 213, 115, 0.08), transparent 52%),
    var(--color-background);
  color: var(--color-text-primary);
  transition: background 220ms ease, color 220ms ease;
}

body.is-modal-open {
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  font: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

.app-shell {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(var(--space-2), 3vw, var(--space-3));
  padding: clamp(var(--space-3), 3vw, var(--space-5)) clamp(var(--space-3), 5vw, var(--space-6));
  background: color-mix(in srgb, var(--color-panel) 92%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.brand__logo {
  width: 48px;
  height: 48px;
  border-radius: 18px;
  display: grid;
  place-items: center;
  font-size: 20px;
  background: radial-gradient(circle at 35% 30%, rgba(255, 71, 87, 0.45), transparent 70%), rgba(255, 255, 255, 0.06);
  border: 1px solid color-mix(in srgb, var(--color-base) 45%, transparent);
  box-shadow: 0 0 32px -18px rgba(255, 71, 87, 0.6);
}

.brand__identity {
  display: flex;
  flex-direction: column;
  gap: calc(var(--space-unit) * 0.5);
}

.brand__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.brand__tagline {
  margin: 0;
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.app-header__nav {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: clamp(var(--space-2), 4vw, var(--space-3));
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.topbar__link {
  position: relative;
  padding-bottom: calc(var(--space-unit) * 0.5);
  color: var(--color-text-secondary);
  transition: color 160ms ease;
}

.topbar__link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 2px;
  background: var(--color-base);
  transform-origin: left;
  transform: scaleX(0);
  transition: transform 180ms ease;
}

.topbar__link:hover,
.topbar__link:focus-visible {
  color: var(--color-base);
}

.topbar__link:hover::after,
.topbar__link:focus-visible::after {
  transform: scaleX(1);
}

.app-header__actions {
  display: inline-flex;
  align-items: center;
  gap: clamp(var(--space-2), 3vw, var(--space-3));
}

.profile-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 0 14px;
  height: 44px;
  border-radius: 18px;
  border: 1px solid color-mix(in srgb, var(--color-border) 70%, transparent);
  background: color-mix(in srgb, var(--color-surface-alt) 90%, transparent);
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: background 160ms ease, color 160ms ease, border 160ms ease, box-shadow 160ms ease;
}

.profile-badge:hover,
.profile-badge:focus-visible {
  background: color-mix(in srgb, var(--color-base) 14%, transparent);
  color: var(--color-base);
  border-color: color-mix(in srgb, var(--color-base) 36%, transparent);
}

.profile-badge__avatar {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: rgba(17, 22, 30, 0.08);
  font-weight: 700;
}

.profile-badge__name {
  font-size: 14px;
}

.header-toggle {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  padding: 0;
  justify-content: center;
  font-size: 18px;
}

.header-toggle:hover {
  transform: translateY(-1px);
}

.locale-switcher {
  display: inline-flex;
  align-items: center;
  padding: 6px 12px;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--color-base) 35%, transparent);
  background: rgba(255, 71, 87, 0.12);
}

.locale-switcher__select {
  border: none;
  background: transparent;
  font: inherit;
  color: var(--color-base);
  padding: 0 var(--space-1);
  appearance: none;
  cursor: pointer;
}

.locale-switcher__select:focus-visible {
  outline: 2px solid var(--focus-outline);
  outline-offset: 2px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: calc(var(--space-unit) * 1.5) calc(var(--space-unit) * 3);
  border-radius: 18px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease, color 180ms ease;
}

.button--icon {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 14px;
}

.icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  line-height: 1;
}

.button--icon .icon {
  font-size: 20px;
}

.button--primary {
  background: linear-gradient(135deg, var(--color-base), var(--color-base-strong));
  color: #ffffff;
  box-shadow: 0 14px 34px -18px rgba(255, 71, 87, 0.55);
}

.button--primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 40px -18px rgba(255, 71, 87, 0.6);
}

.button--ghost {
  border: 1px solid color-mix(in srgb, var(--color-base) 20%, transparent);
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-base);
}

.button--ghost:hover {
  transform: translateY(-1px);
  background: color-mix(in srgb, var(--color-base) 16%, transparent);
}

.profile-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: calc(var(--space-unit) * 1.25) calc(var(--space-unit) * 2.5) calc(var(--space-unit) * 1.25) calc(var(--space-unit) * 1.5);
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--color-secondary) 30%, transparent);
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-text-primary);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.profile-badge:hover {
  transform: translateY(-1px);
  box-shadow: 0 20px 32px -20px rgba(46, 213, 115, 0.42);
}

.profile-badge__avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 14px;
  background: linear-gradient(135deg, var(--color-secondary), color-mix(in srgb, var(--color-secondary) 80%, #ffffff 20%));
  color: #0f0f0f;
}

.profile-badge__name {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.app-shell__body {
  display: block;
  padding: clamp(var(--space-5), 8vw, var(--space-7)) clamp(var(--space-3), 6vw, var(--space-6)) var(--space-8);
  flex: 1 1 auto;
}

.sidebar-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(2px);
  z-index: 40;
  display: none;
}

.sidebar-overlay[hidden] {
  display: none;
}

.is-sidebar-open .sidebar-overlay {
  display: block;
}

.is-sidebar-open {
  overflow: hidden;
}

body.sidebar-collapsed .app-shell__body {
  grid-template-columns: 96px minmax(0, 1fr) 320px;
}

body.sidebar-collapsed .app-sidebar {
  width: 84px;
  padding-inline: var(--space-2);
  align-items: center;
}

body.sidebar-collapsed .sidebar__label,
body.sidebar-collapsed .sidebar__title {
  display: none;
}

body.sidebar-collapsed .sidebar__icon {
  margin: 0 auto;
}

body.sidebar-collapsed .sidebar__link {
  justify-content: center;
}

.is-game-active .app-header,
.is-game-active .app-sidebar,
.is-game-active .app-meta,
.is-game-active .app-footer,
.is-game-active .hero__cta-group {
  display: none !important;
}

.is-game-active .app-shell__body {
  grid-template-columns: minmax(0, 1fr);
  padding: var(--space-4) var(--space-3);
}

.is-game-active .app-main {
  min-height: 100vh;
}

.is-game-active #gameHost {
  min-height: calc(100vh - var(--space-4) * 2);
  padding-bottom: 0;
}

.game-utilities {
  position: fixed;
  top: clamp(var(--space-4), 6vw, var(--space-6));
  right: clamp(var(--space-3), 6vw, var(--space-5));
  display: none;
  align-items: center;
  gap: var(--space-2);
  z-index: 60;
}

.game-utilities:not([hidden]) {
  display: inline-flex;
}


.game-utilities .game-controls {
  box-shadow: 0 16px 32px -20px rgba(95, 112, 255, 0.45);
}

.game-utilities .game-exit {
  box-shadow: 0 16px 32px -20px rgba(255, 71, 87, 0.45);
}

.game-utilities .button.is-active {
  background: color-mix(in srgb, var(--color-base) 18%, transparent);
  color: var(--color-base);
}

.game-utilities .button:focus-visible {
  outline-offset: 6px;
}

.game-intro {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(48px, 12vh, 160px)
    clamp(var(--space-4), 8vw, var(--space-7))
    clamp(var(--space-4), 10vh, var(--space-9));
  background: rgba(10, 12, 18, 0.62);
  backdrop-filter: blur(10px);
  z-index: 70;
}

@media (max-width: 768px) {
  .game-intro {
    align-items: flex-end;
    padding: clamp(32px, 6vh, 64px)
      clamp(var(--space-3), 6vw, var(--space-6))
      clamp(var(--space-3), 12vh, var(--space-8));
  }
}

.game-intro[hidden] {
  display: none;
}

.game-intro__dialog {
  width: min(94vw, 420px);
  padding: clamp(var(--space-5), 7vw, var(--space-7));
  border-radius: 28px;
  border: 1px solid color-mix(in srgb, var(--color-base) 18%, transparent);
  background: color-mix(in srgb, var(--color-surface) 92%, rgba(255, 255, 255, 0.08));
  box-shadow: var(--shadow-lg);
  display: grid;
  gap: var(--space-4);
  text-align: center;
}

.game-intro__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(20px, 4vw, 28px);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-base);
}

.game-intro__body {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 16px;
  line-height: 1.6;
}

.game-intro__actions {
  display: flex;
  justify-content: center;
  gap: var(--space-3);
}

.game-intro__options {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: var(--space-3);
}

.game-intro__skip {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: 14px;
  color: var(--color-text-secondary);
}

.game-intro__skip input {
  width: 18px;
  height: 18px;
  accent-color: var(--color-base);
}

.game--intro-open .game__body > :not(.game-intro),
.game--intro-open .tetris-touch-controls {
  filter: blur(2px);
  pointer-events: none;
  user-select: none;
}

.game--intro-open .game-intro {
  filter: none;
  pointer-events: auto;
  user-select: auto;
}

.app-sidebar {
  display: grid;
  gap: var(--space-4);
  align-content: start;
  background: color-mix(in srgb, var(--color-panel) 94%, transparent);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.sidebar__section + .sidebar__section {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-4);
}

.sidebar__title {
  margin: 0 0 var(--space-3);
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.sidebar__list {
  display: grid;
  gap: var(--space-2);
}

.sidebar__icon {
  font-size: 18px;
}

.sidebar__label {
  flex: 1 1 auto;
}

.sidebar__link {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: 14px;
  color: var(--color-text-secondary);
  font-weight: 600;
  transition: background 160ms ease, color 160ms ease;
}

.sidebar__link:hover,
.sidebar__link:focus-visible {
  color: var(--color-base);
  background: rgba(255, 71, 87, 0.12);
}

.sidebar__link--active {
  color: var(--color-base);
  background: rgba(255, 71, 87, 0.15);
}

.app-main {
  display: grid;
  gap: clamp(var(--space-6), 7vw, var(--space-8));
  min-width: 0;
  max-width: 1100px;
  margin: 0 auto;
}

.portal-layout {
  display: grid;
  gap: clamp(var(--space-5), 6vw, var(--space-7));
}

.portal-layout__intro {
  display: grid;
}

.portal-layout__list {
  display: grid;
  gap: clamp(var(--space-4), 5vw, var(--space-6));
}

@media (min-width: 960px) {
  .portal-layout {
    grid-template-columns: minmax(260px, 360px) minmax(0, 1fr);
    align-items: start;
    gap: clamp(var(--space-5), 5vw, var(--space-7));
  }

  .portal-hero {
    text-align: left;
  }

  .portal-hero__actions {
    justify-content: flex-start;
  }
}

.portal-hero {
  display: grid;
  gap: var(--space-4);
  max-width: 100%;
  text-align: center;
}

.portal-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(26px, 4vw, 36px);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.portal-hero__subtitle {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 16px;
  line-height: 1.7;
}

.portal-hero__actions {
  display: flex;
  justify-content: center;
}

.game-grid__empty {
  margin: clamp(var(--space-6), 10vw, var(--space-9)) auto 0;
  max-width: 520px;
  padding: clamp(var(--space-5), 7vw, var(--space-7));
  text-align: center;
  border-radius: var(--radius-lg);
  background: radial-gradient(ellipse at 50% 40%, color-mix(in srgb, var(--color-surface) 100%, transparent), color-mix(in srgb, var(--color-surface) 92%, transparent) 70%);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  animation: fadeInUp 500ms 200ms ease-out backwards;
}

.game-grid__empty::before {
  content: '+';
  position: absolute;
  top: 20px;
  left: 20px;
  font-size: 200px;
  font-weight: 100;
  line-height: 1;
  color: color-mix(in srgb, var(--color-border) 50%, transparent);
  transform: rotate(20deg);
  opacity: 0.5;
}

.game-grid__empty-title {
  margin: 0 0 var(--space-2);
  font-size: 20px;
  font-weight: 600;
  position: relative;
  z-index: 1;
}

.game-grid__empty-copy {
  margin: 0;
  color: var(--color-text-secondary);
  position: relative;
  z-index: 1;
}

.portal-next {
  margin: clamp(var(--space-7), 10vw, var(--space-10)) auto 0;
  max-width: 760px;
  padding: clamp(var(--space-5), 7vw, var(--space-7));
  background: linear-gradient(145deg, color-mix(in srgb, var(--color-surface) 90%, rgba(255, 71, 87, 0.08)), rgba(255, 255, 255, 0.02));
  border-radius: var(--radius-lg);
  border: 1px solid color-mix(in srgb, var(--color-border) 50%, transparent);
  box-shadow: var(--shadow-md);
  display: grid;
  gap: var(--space-4);
  text-align: center;
}

.portal-next__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 3.6vw, 30px);
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.portal-next__copy {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 16px;
  line-height: 1.6;
}

.portal-next__actions {
  display: flex;
  justify-content: center;
  gap: var(--space-2);
}

.hero {
  display: grid;
  gap: var(--space-4);
  text-align: center;
  background: color-mix(in srgb, var(--color-surface) 85%, rgba(255, 255, 255, 0.05));
  border-radius: var(--radius-lg);
  padding: clamp(var(--space-5), 7vw, var(--space-8));
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at top, rgba(255, 71, 87, 0.15), transparent 65%),
    radial-gradient(circle at bottom, rgba(46, 213, 115, 0.14), transparent 65%);
  pointer-events: none;
  opacity: 0.9;
}

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

.hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(24px, 5vw, 36px);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--color-base);
}

.hero__subtitle {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 18px;
}

.hero__cta-group {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
}

.game-grid {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: repeat(2, 1fr);
}

@media (max-width: 640px) {
  .game-grid {
    grid-template-columns: 1fr;
  }
}

.game-card {
  position: relative;
  display: block;
  border-radius: var(--radius-lg);
  background: linear-gradient(160deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0)) padding-box,
    var(--color-border) border-box;
  border: 1px solid transparent;
  box-shadow: var(--shadow-sm);
  transition: transform 250ms ease-out, box-shadow 250ms ease-out, border-color 250ms ease-out;
  overflow: hidden;
}

.game-card::after {
  content: '';
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  border: 2px solid color-mix(in srgb, var(--color-base) 35%, transparent);
  opacity: 0;
  transition: opacity 250ms ease-out;
}

.game-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-md);
}

.game-card:hover::after {
  opacity: 1;
}

.game-card__image {
  padding-top: 100%;
  position: relative;
  background-size: cover;
  background-position: center;
  transition: transform 300ms ease-out;
}

.game-card:hover .game-card__image {
  transform: scale(1.1);
}

.game-card__image[data-game-thumb='memoryFlip'] {
  background: linear-gradient(135deg, #a8bfff, #e2e8ff);
}

.game-card__image[data-game-thumb='tetris'] {
  background: linear-gradient(135deg, #ffafbd, #ffc3a0);
}

.game-card__image::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.8) 0%, rgba(0, 0, 0, 0.1) 60%, rgba(0, 0, 0, 0) 100%);
  opacity: 0.9;
  transition: opacity 250ms ease-out;
}

.game-card:hover .game-card__image::before {
  opacity: 1;
}

.game-card__title {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  margin: 0;
  padding: var(--space-4) var(--space-3) var(--space-3);
  font-size: 18px;
  font-weight: 700;
  color: #ffffff;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6);
  transform: translateY(10px);
  opacity: 0.8;
  transition: transform 250ms ease-out, opacity 250ms ease-out;
}

.game-card:hover .game-card__title {
  transform: translateY(0);
  opacity: 1;
}

.info-panel {
  display: grid;
  gap: var(--space-3);
  padding: clamp(var(--space-4), 6vw, var(--space-6));
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface) 88%, rgba(255, 255, 255, 0.04));
  box-shadow: var(--shadow-sm);
}

.info-panel--accent {
  background: linear-gradient(150deg, rgba(255, 71, 87, 0.12), rgba(46, 213, 115, 0.12));
  border-color: color-mix(in srgb, var(--color-base) 24%, transparent);
}

.info-panel__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 18px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.info-panel__copy {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 16px;
}

/* Accessibility */
:focus-visible {
  outline: 2px solid var(--focus-outline);
  outline-offset: 2px;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.view {
  display: none;
}

.view--active {
  display: block;
  animation: fadeInUp 350ms ease-out;
}

#gameHost {
  width: 100%;
  padding-bottom: var(--space-6);
}

.game {
  background: color-mix(in srgb, var(--color-panel) 96%, transparent);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-md);
  width: 100%;
  max-width: 920px;
  margin: 0 auto;
  overflow: hidden;
}

.game__header {
  padding: clamp(var(--space-3), 4vw, var(--space-4));
  border-bottom: 1px solid var(--color-border);
  background: rgba(255, 255, 255, 0.02);
}

.game__header h2 {
  margin: 0 0 var(--space-2);
  font-size: 24px;
  font-family: var(--font-display);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.game__header p {
  margin: 0;
  color: var(--color-text-secondary);
}

.game__header--visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.game__body {
  padding: clamp(var(--space-3), 4vw, var(--space-4));
  display: grid;
  gap: var(--space-5);
}

.player-stats {
  display: grid;
  gap: var(--space-3);
}

.player-stats__item {
  display: flex;
  justify-content: space-between;
}

.player-stats__label {
  color: var(--color-text-muted);
  font-size: 14px;
}

.player-stats__value {
  font-family: var(--font-mono);
  font-weight: 600;
}

.meta-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  border-radius: 999px;
  padding: 6px 14px;
  background: rgba(255, 71, 87, 0.12);
  color: var(--color-base);
  font-weight: 600;
  font-size: 13px;
}

.app-meta {
  display: grid;
  gap: var(--space-4);
  align-content: start;
}

.app-meta[hidden] {
  display: none !important;
}

.app-meta-mobile {
  display: none;
  gap: var(--space-3);
  align-content: start;
}

.app-meta-mobile:not([hidden]) {
  display: grid;
}

.meta-mobile__tabs {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  padding: 6px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface-alt) 94%, transparent);
  box-shadow: var(--shadow-sm);
  overflow-x: auto;
  scrollbar-width: thin;
}

.meta-mobile__tabs::-webkit-scrollbar {
  height: 6px;
}

.meta-mobile__tabs::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--color-text-muted) 45%, transparent);
  border-radius: 999px;
}

.meta-mobile__tabs::-webkit-scrollbar-track {
  background: transparent;
}

.meta-mobile__tab {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  background: transparent;
  color: var(--color-text-secondary);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 160ms ease, color 160ms ease, border-color 160ms ease, box-shadow 160ms ease;
}

.meta-mobile__tab:hover,
.meta-mobile__tab:focus-visible {
  color: var(--color-text-primary);
}

.meta-mobile__tab:focus-visible {
  outline-offset: 4px;
}

.meta-mobile__tab--active {
  color: var(--color-text-primary);
  border-color: color-mix(in srgb, var(--color-base) 28%, transparent);
  background: color-mix(in srgb, var(--color-surface) 92%, transparent);
  box-shadow: 0 10px 24px -18px rgba(15, 18, 22, 0.6);
}

.meta-mobile__panels {
  display: grid;
  gap: var(--space-3);
}

.meta-mobile__panel {
  display: none;
  padding: var(--space-4);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface-alt) 96%, transparent);
  box-shadow: var(--shadow-sm);
}

.meta-mobile__panel--active {
  display: grid;
  gap: var(--space-3);
}

.meta-panel {
  padding: var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface-alt) 96%, transparent);
  box-shadow: var(--shadow-sm);
}

.meta-panel[open] {
  padding-bottom: var(--space-4);
}

.meta-panel__summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  cursor: pointer;
  list-style: none;
}

.meta-panel__summary:focus-visible {
  outline-offset: 6px;
}

.meta-panel__summary::-webkit-details-marker {
  display: none;
}

.meta-panel__summary::after {
  content: '⌄';
  font-size: 14px;
  color: var(--color-text-muted);
  transition: transform 160ms ease;
}

.meta-panel[open] .meta-panel__summary::after {
  transform: rotate(180deg);
}

.meta-panel__summary span:first-child {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.meta-panel__body,
.meta-panel__cta,
.player-stats,
.leaderboard-list,
.meta-list {
  margin-top: var(--space-3);
}

.meta-panel__meta {
  font-size: 12px;
  color: var(--color-text-muted);
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.meta-panel__body {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 15px;
}

.meta-panel__cta {
  width: fit-content;
}

.leaderboard-list {
  display: grid;
  gap: var(--space-2);
}

.leaderboard-list li {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: 15px;
}

.leaderboard-list__rank {
  color: var(--color-text-muted);
}

.leaderboard-list__score {
  font-weight: 600;
}

.meta-list {
  display: grid;
  gap: var(--space-2);
}

.meta-list__name {
  font-weight: 600;
  color: var(--color-text-secondary);
}

.meta-list__tag {
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-base);
}

.meta-panel--chat {
  background: linear-gradient(160deg, rgba(95, 112, 255, 0.12), rgba(255, 71, 87, 0.12));
  border-color: color-mix(in srgb, var(--color-tertiary) 24%, transparent);
}

.ad-slot {
  min-height: 96px;
  display: grid;
  place-items: center;
  border-radius: var(--radius-md);
  border: 1px dashed color-mix(in srgb, var(--color-base) 35%, transparent);
  background: rgba(255, 255, 255, 0.05);
  font-size: 14px;
  color: var(--color-text-muted);
}

.app-footer {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-6);
  padding: var(--space-6) clamp(var(--space-3), 6vw, var(--space-6));
  border-top: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-panel) 92%, transparent);
  box-shadow: 0 -18px 36px -32px rgba(0, 0, 0, 0.35);
}

.app-footer__section {
  display: grid;
  gap: var(--space-2);
}

.app-footer__section h3,
.app-footer__section h4 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-display);
  font-size: 14px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.app-footer__description {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 14px;
}

.app-footer__list {
  display: grid;
  gap: var(--space-1);
  font-size: 14px;
}

.app-footer__list a {
  color: var(--color-text-secondary);
}

.app-footer__list a:hover {
  color: var(--color-base);
}

/* Memory Flip */
.memory-info {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

.memory-stats {
  display: flex;
  gap: var(--space-3);
  color: var(--color-text-muted);
  font-weight: 500;
}

.memory-timer {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 10px 18px;
  border-radius: 999px;
  background: rgba(255, 71, 87, 0.12);
  color: var(--color-base);
  font-weight: 600;
}

.memory-timer--warning {
  background: color-mix(in srgb, var(--color-warning) 18%, transparent);
  color: var(--color-warning);
}

.memory-timer--expired {
  background: color-mix(in srgb, var(--color-danger) 18%, transparent);
  color: var(--color-danger);
}

.memory-timer--complete {
  background: color-mix(in srgb, var(--color-success) 16%, transparent);
  color: var(--color-success);
}

.memory-message {
  margin: 0;
  min-height: 28px;
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 14px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: color-mix(in srgb, var(--color-border) 35%, transparent);
  transition: background 180ms ease, color 180ms ease, box-shadow 180ms ease;
}

.memory-message::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.8;
}

.memory-message--info {
  background: color-mix(in srgb, var(--color-border) 48%, transparent);
  color: var(--color-text-secondary);
}

.memory-message--positive {
  background: color-mix(in srgb, var(--color-success) 18%, transparent);
  color: var(--color-success);
}

.memory-message--warning {
  background: color-mix(in srgb, var(--color-warning) 18%, transparent);
  color: var(--color-warning);
}

.memory-message--danger {
  background: color-mix(in srgb, var(--color-danger) 18%, transparent);
  color: var(--color-danger);
}

.memory-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(72px, 1fr));
  gap: var(--space-3);
}

.memory-card {
  position: relative;
  padding-top: 100%;
  border-radius: 22px;
  background: linear-gradient(160deg, rgba(255, 255, 255, 0.08), rgba(255, 255, 255, 0)) padding-box,
    color-mix(in srgb, var(--color-border) 50%, transparent) border-box;
  border: 1px solid transparent;
  box-shadow: var(--shadow-sm);
  transition: transform 160ms ease, box-shadow 160ms ease, border 160ms ease;
}

.memory-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.memory-card:focus-visible {
  outline: 2px solid var(--focus-outline);
  outline-offset: 4px;
}

.memory-card.solved {
  background: color-mix(in srgb, var(--color-success) 14%, transparent);
  border-color: color-mix(in srgb, var(--color-success) 35%, transparent);
}

.memory-card__inner {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-size: 30px;
}

.memory-card.cover .memory-card__inner {
  opacity: 0;
  transition: opacity 140ms ease;
}

.memory-card.cover::after {
  content: '?';
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--color-text-muted);
  font-size: 24px;
  font-weight: 600;
}

.memory-card--matched {
  animation: memory-match-pop 280ms ease;
}

@keyframes memory-match-pop {
  0% {
    transform: scale(1);
  }
  55% {
    transform: scale(1.08);
  }
  100% {
    transform: scale(1);
  }
}

.game-actions {
  display: flex;
  justify-content: flex-end;
}

@media (max-width: 640px) {
  .memory-info {
    justify-content: center;
  }
  .memory-stats span > span {
    display: none;
  }
}

/* Tetris */
.tetris-layout {
  display: grid;
  gap: var(--space-5);
  grid-template-columns: minmax(0, 1fr) minmax(220px, 1fr);
  align-items: start;
}

.tetris-board-wrapper {
  position: relative;
  border-radius: 20px;
  background: color-mix(in srgb, var(--color-panel) 94%, transparent);
  padding: clamp(var(--space-2), 4vw, var(--space-3));
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  width: min(100%, 360px);
  margin: 0 auto;
}

.tetris-next-canvas {
  width: min(100%, 140px);
  aspect-ratio: 1 / 1;
  border-radius: 14px;
  border: 1px solid color-mix(in srgb, var(--color-base) 18%, transparent);
  background: var(--tetris-preview-bg);
}

.tetris-next {
  justify-items: center;
}

.tetris-canvas {
  width: 100%;
  height: auto;
  display: block;
  background:
    radial-gradient(circle at 20% 0%, rgba(255, 71, 87, 0.12), transparent 55%),
    radial-gradient(circle at 80% 100%, rgba(46, 213, 115, 0.12), transparent 58%),
    linear-gradient(160deg, rgba(0, 229, 255, 0.08), transparent 60%),
    #101521;
  border-radius: 16px;
  border: 1px solid color-mix(in srgb, var(--color-base) 22%, transparent);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.02), 0 28px 40px -25px rgba(13, 17, 30, 0.6);
}

.tetris-sidebar {
  display: grid;
  gap: var(--space-3);
}

.tetris-brand {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3);
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, rgba(255, 71, 87, 0.12), rgba(46, 213, 115, 0.12));
  border: 1px solid color-mix(in srgb, var(--color-base) 22%, transparent);
  box-shadow: var(--shadow-sm);
}

.tetris-brand__logo {
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-base);
}

.tetris-brand__badge-list {
  display: flex;
  gap: var(--space-2);
}

.tetris-badge {
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid color-mix(in srgb, var(--color-secondary) 35%, transparent);
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-secondary);
}

.tetris-panel {
  background: color-mix(in srgb, var(--color-surface) 88%, rgba(255, 255, 255, 0.04));
  border-radius: var(--radius-md);
  padding: var(--space-3);
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  display: grid;
  gap: var(--space-2);
}

.tetris-panel--compact {
  gap: var(--space-3);
  padding: var(--space-3);
}

.tetris-panel h3 {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.tetris-stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tetris-stat-chip {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border-radius: 16px;
  background: color-mix(in srgb, var(--color-border) 45%, transparent);
  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--color-border) 60%, transparent);
}

.tetris-stat-chip__label {
  font-size: 13px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.tetris-stat-chip__value {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 16px;
  color: var(--color-base);
}

.tetris-next {
  justify-items: center;
}

.tetris-next canvas {
  width: min(100%, 140px);
  aspect-ratio: 1 / 1;
  border-radius: 14px;
  border: 1px solid color-mix(in srgb, var(--color-base) 18%, transparent);
  background: var(--tetris-preview-bg);
}

.tetris-controls ul,
.tetris-controls-modal__body ul {
  margin: 0;
  padding-left: var(--space-3);
  color: var(--color-text-secondary);
  font-size: 14px;
  display: grid;
  gap: var(--space-1);
}

.tetris-controls-modal {
  position: fixed;
  inset: 0;
  display: grid;
  place-items: center;
  z-index: 55;
  backdrop-filter: blur(4px);
  background: rgba(8, 10, 14, 0.35);
}

.tetris-controls-modal[hidden] {
  display: none;
}

.tetris-controls-modal__backdrop {
  position: absolute;
  inset: 0;
}

.tetris-controls-modal__dialog {
  position: relative;
  z-index: 1;
  width: min(92vw, 440px);
  max-height: min(80vh, 540px);
  display: grid;
  grid-template-rows: auto 1fr;
  background: color-mix(in srgb, var(--color-surface) 90%, rgba(255, 255, 255, 0.06));
  border-radius: 24px;
  border: 1px solid color-mix(in srgb, var(--color-base) 18%, transparent);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.tetris-controls-modal__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border);
}

.tetris-controls-modal__body {
  padding: var(--space-4);
  display: grid;
  gap: var(--space-3);
  overflow-y: auto;
}

.tetris-controls-modal__close {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid color-mix(in srgb, var(--color-base) 24%, transparent);
  background: rgba(255, 255, 255, 0.05);
  color: var(--color-text-secondary);
  display: grid;
  place-items: center;
  transition: background 160ms ease, color 160ms ease, border 160ms ease;
}

.tetris-controls-modal__close:hover {
  background: color-mix(in srgb, var(--color-base) 16%, transparent);
  color: var(--color-base);
  border-color: color-mix(in srgb, var(--color-base) 32%, transparent);
}

.tetris-controls-modal__tabs {
  display: inline-flex;
  gap: var(--space-2);
  padding: 6px;
  border-radius: 999px;
  border: 1px solid var(--color-border);
  background: color-mix(in srgb, var(--color-surface-alt) 92%, transparent);
}

.tetris-controls-tab {
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px solid transparent;
  background: transparent;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease, box-shadow 150ms ease;
}

.tetris-controls-tab--active {
  color: var(--color-text-primary);
  border-color: color-mix(in srgb, var(--color-base) 30%, transparent);
  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
  box-shadow: 0 12px 28px -18px rgba(15, 18, 22, 0.55);
}

.tetris-controls-modal__content {
  display: grid;
  gap: var(--space-3);
}

.tetris-controls__section h4 {
  margin: 0 0 var(--space-2);
  font-size: 14px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--color-text-primary);
}

.tetris-touch-controls {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    background: color-mix(in srgb, var(--color-surface) 90%, rgba(255, 255, 255, 0.05));
  }

  .tetris-touch-button {  padding: var(--space-2) 0;
  border-radius: 14px;
  background: color-mix(in srgb, var(--color-surface) 88%, rgba(255, 255, 255, 0.04));
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text-primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  user-select: none;
  transition: background 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.tetris-touch-button:hover,
.tetris-touch-button:focus-visible {
  background: color-mix(in srgb, var(--color-base) 12%, transparent);
  box-shadow: 0 0 0 4px rgba(255, 71, 87, 0.14);
}

.tetris-touch-button:active {
  background: color-mix(in srgb, var(--color-base) 16%, transparent);
  transform: translateY(1px);
}

.tetris-touch-controls--highlight .tetris-touch-button {
  animation: tetrisTouchPulse 1.4s ease-in-out infinite;
}

@keyframes tetrisTouchPulse {
  0% {
    box-shadow: 0 0 0 0 rgba(255, 71, 87, 0.32);
    transform: scale(1);
  }
  50% {
    box-shadow: 0 0 0 10px rgba(255, 71, 87, 0.08);
    transform: scale(1.04);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(255, 71, 87, 0);
    transform: scale(1);
  }
}

.tetris-message {
  margin: 0;
  min-height: 20px;
  color: var(--color-text-muted);
  font-size: 14px;
}

.tetris-overlay {
  position: absolute;
  inset: clamp(10px, 3vw, 14px);
  display: grid;
  place-items: center;
  background: rgba(17, 25, 40, 0.72);
  color: #ffffff;
  border-radius: 14px;
  font-size: clamp(18px, 4vw, 24px);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms ease;
}

.tetris-overlay--visible {
  opacity: 1;
}

/* Intro modal */
.intro-modal {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: clamp(var(--space-3), 6vw, var(--space-6));
  z-index: 50;
  animation: fadeIn 300ms ease-out;
}

.intro-modal[hidden] {
  display: none;
}

.intro-modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
}

.intro-modal__dialog {
  position: relative;
  z-index: 1;
  width: min(92vw, 520px);
  padding: clamp(var(--space-5), 7vw, var(--space-8));
  border-radius: var(--radius-xl);
  border: 1px solid color-mix(in srgb, var(--color-base) 22%, transparent);
  background: color-mix(in srgb, var(--color-surface) 90%, rgba(255, 255, 255, 0.06));
  box-shadow: var(--shadow-lg);
  animation: scaleIn 350ms 100ms ease-out backwards;
}

.intro-modal__close {
  position: absolute;
  top: var(--space-2);
  right: var(--space-2);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid color-mix(in srgb, var(--color-base) 24%, transparent);
  background: rgba(255, 255, 255, 0.04);
  color: var(--color-text-secondary);
  font-size: 20px;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: background 160ms ease, color 160ms ease, border 160ms ease;
}

.intro-modal__close:hover {
  background: color-mix(in srgb, var(--color-base) 18%, transparent);
  color: var(--color-base);
  border-color: color-mix(in srgb, var(--color-base) 35%, transparent);
}

.intro-modal__content {
  display: grid;
  gap: var(--space-4);
  text-align: center;
}

.intro-modal__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 4.5vw, 32px);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-base);
}

.intro-modal__body {
  margin: 0;
  color: var(--color-text-secondary);
  font-size: 17px;
  line-height: 1.6;
}

.intro-modal__cta {
  justify-self: center;
  min-width: 200px;
}

.nickname-input {
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-strong);
  background: var(--color-surface);
  color: var(--color-text-primary);
  font-size: 18px;
  text-align: center;
  width: 100%;
  max-width: 300px;
  justify-self: center;
}

.nickname-input:focus {
  outline: 2px solid var(--focus-outline);
  outline-offset: 2px;
  border-color: var(--color-base);
}

/* Accessibility */
:focus-visible {
  outline: 2px solid var(--focus-outline);
  outline-offset: 2px;
}

.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;
}

/* Responsive */
@media (max-width: 1440px) {
  .app-shell__body {
    grid-template-columns: 220px minmax(0, 1fr) 280px;
  }
}

@media (max-width: 1200px) {
  .app-shell__body {
    grid-template-columns: 220px minmax(0, 1fr);
  }

  .app-meta {
    order: 3;
    grid-column: 1 / -1;
  }
}

@media (max-width: 960px) {
  .app-shell__body {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-3);
    padding: var(--space-4) var(--space-3) var(--space-6);
  }

  .app-header {
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-2);
    padding: clamp(var(--space-2), 3vw, var(--space-3)) clamp(var(--space-3), 6vw, var(--space-4));
  }

  .brand {
    flex: 1 1 auto;
  }

  .brand__logo {
    width: 40px;
    height: 40px;
  }

  .brand__tagline {
    display: none;
  }

  .app-header__nav {
    order: 3;
    width: 100%;
    justify-content: center;
  }

  .app-header__actions {
    justify-content: flex-end;
    flex: 1 1 auto;
  }

  .app-sidebar {
    position: fixed;
    top: 84px;
    left: 0;
    width: min(280px, 80vw);
    height: calc(100vh - 84px);
    padding: var(--space-4);
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    display: grid;
    gap: var(--space-3);
    transform: translateX(-110%);
    transition: transform 200ms ease;
    z-index: 50;
  }

  .is-sidebar-open .app-sidebar {
    transform: translateX(0);
  }

  .app-main {
    order: 2;
    width: 100%;
  }

  .app-meta {
    order: 3;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-3);
  }

  .app-meta-mobile {
    order: 3;
  }

  .app-meta-mobile:not([hidden]) .meta-mobile__panel {
    padding: var(--space-3);
  }

  .hero__cta-group {
    flex-direction: column;
    width: 100%;
  }

  .hero__cta-group .button {
    width: 100%;
  }
}

@media (max-width: 640px) {
  .app-header__nav {
    gap: var(--space-2);
  }

  .app-shell__body {
    padding: var(--space-4) var(--space-3) var(--space-6);
  }

  .hero {
    padding: var(--space-5);
  }

  .meta-panel {
    padding: var(--space-3);
  }

  .intro-modal__dialog {
    padding: var(--space-5);
  }


  .tetris-layout {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .tetris-board-wrapper {
    width: 100%;
    max-width: 360px;
    margin: 0 auto;
    padding: var(--space-2);
  }

  .tetris-sidebar {
    width: 100%;
    gap: var(--space-3);
  }

  .tetris-stats-and-next {
    display: grid;
    grid-template-columns: auto 1fr;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2);
  }

  .tetris-stats-and-next h3 {
    font-size: 14px;
    margin: 0;
    flex-shrink: 0;
    grid-column: 1 / -1; /* Span across all columns */
    text-align: center;
  }

  .tetris-next-canvas {
    width: 50px;
    height: 50px;
    flex-shrink: 0;
    justify-self: center;
  }

  .tetris-stats {
    flex-shrink: 1;
    justify-content: center;
    gap: 4px;
  }

  .tetris-message {
    grid-column: 1 / -1; /* Span across all columns */
    text-align: center;
    margin-top: var(--space-1);
  }

  .tetris-stat-chip {
    padding: 4px 8px;
    font-size: 10px;
  }
  .tetris-stat-chip__value {
    font-size: 12px;
  }

  .tetris-touch-controls {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    background: color-mix(in srgb, var(--color-surface) 90%, rgba(255, 255, 255, 0.05));
  }

  .tetris-touch-button {
    padding: var(--space-2) 0;
    font-size: 18px;
    border-radius: 16px;
  }

  .tetris-controls-modal {
    align-items: flex-end;
    justify-items: stretch;
  }

  .tetris-controls-modal__dialog {
    width: 100%;
    max-width: none;
    border-radius: 28px 28px 0 0;
    max-height: 85vh;
  }

  .tetris-controls-modal__body {
    padding: var(--space-4) var(--space-4) calc(var(--space-4) + 12px);
  }
}