:root {
  --bg: #f4f7fb;
  --panel: #ffffff;
  --ink: #172033;
  --muted: #647089;
  --line: #d9e1ec;
  --accent: #1f6f63;
  --accent-dark: #155248;
  --gold: #d2952d;
  --danger: #d94635;
  --shadow: 0 16px 40px rgba(23, 32, 51, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  min-width: 320px;
  background: var(--bg);
}

body {
  margin: 0;
  color: var(--ink);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial,
    sans-serif;
  line-height: 1.6;
  letter-spacing: 0;
  overscroll-behavior-y: contain;
}

a {
  color: inherit;
}

button,
input {
  font: inherit;
}

.site-header {
  height: 60px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 18px;
  padding: 0 28px;
  background: #172033;
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 80;
}

.brand {
  font-size: 20px;
  font-weight: 900;
  text-decoration: none;
  white-space: nowrap;
}

.desktop-nav {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 6px;
}

.desktop-nav a {
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  padding: 0 12px;
  border-radius: 6px;
  color: rgba(255, 255, 255, 0.84);
  text-decoration: none;
}

.desktop-nav a:hover,
.desktop-nav a:focus-visible {
  color: #fff;
  background: rgba(255, 255, 255, 0.1);
  outline: none;
}

.header-download,
.mobile-menu {
  display: none;
}

main {
  padding: 28px 18px 0;
}

.game-shell {
  width: min(1160px, 100%);
  margin: 0 auto;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.game-top {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 18px;
  align-items: center;
  padding: 18px;
  background: #f9fbfe;
  border-bottom: 1px solid var(--line);
}

.mode-group {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.mode-btn,
.control-bar button,
.result-card button {
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  cursor: pointer;
  font-weight: 800;
  transition:
    border-color 0.18s,
    background 0.18s,
    color 0.18s;
}

.mode-btn {
  padding: 0 16px;
}

.mode-btn.active,
.control-bar button:first-child,
.result-card button {
  color: #fff;
  background: var(--accent);
  border-color: var(--accent);
}

.mode-btn:hover,
.mode-btn:focus-visible,
.control-bar button:hover,
.control-bar button:focus-visible,
.result-card button:hover,
.result-card button:focus-visible {
  border-color: var(--accent);
  outline: none;
}

.control-bar button:disabled {
  cursor: not-allowed;
  color: #97a3b6;
  background: #eef2f7;
  border-color: var(--line);
}

.score-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(74px, 1fr));
  gap: 8px;
}

.score-grid div {
  min-height: 48px;
  display: grid;
  place-items: center;
  padding: 4px 8px;
  border-radius: 6px;
  background: #101828;
  color: #fff;
}

.score-grid span {
  color: rgba(255, 255, 255, 0.62);
  font-size: 12px;
}

.score-grid strong {
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  font-size: 18px;
  line-height: 1;
  color: #f4c95d;
  white-space: nowrap;
}

.client-notice {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 12px;
  padding: 12px 18px;
  background: #fff8e8;
  border-bottom: 1px solid #f0d39c;
  color: #68430d;
}

.client-notice.hidden {
  display: none;
}

.client-notice-icon {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 6px;
  background: #f0d392;
  color: #6b4405;
  font-size: 18px;
  font-weight: 900;
}

.client-notice p {
  margin: 0;
  display: grid;
  gap: 2px;
  min-width: 0;
}

.client-notice span {
  color: #7a5a25;
  font-size: 14px;
}

.client-notice a {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  border-radius: 6px;
  background: var(--gold);
  color: #fff;
  font-weight: 800;
  text-decoration: none;
  white-space: nowrap;
}

.client-notice-close {
  width: 34px;
  height: 34px;
  border: 0;
  border-radius: 6px;
  background: rgba(104, 67, 13, 0.1);
  color: #68430d;
  cursor: pointer;
  font-size: 20px;
  line-height: 1;
}

.play-area {
  display: grid;
  grid-template-columns: minmax(320px, 1fr) 300px;
  gap: 18px;
  align-items: stretch;
  padding: 18px;
  background:
    linear-gradient(90deg, rgba(31, 111, 99, 0.055) 1px, transparent 1px),
    linear-gradient(rgba(31, 111, 99, 0.055) 1px, transparent 1px), #edf2f8;
  background-size: 18px 18px;
}

.board-panel,
.side-panel {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.board-panel {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 360px;
  padding: 14px;
  overflow: hidden;
}

#boardCanvas {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: inset 0 0 0 1px rgba(62, 43, 24, 0.22);
  touch-action: none;
}

.result-overlay {
  position: absolute;
  inset: 14px;
  display: grid;
  place-items: center;
  padding: 20px;
  border-radius: 8px;
  background: rgba(16, 24, 40, 0.62);
}

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

.result-card {
  width: min(280px, 100%);
  display: grid;
  gap: 10px;
  padding: 22px;
  border-radius: 8px;
  background: #fff;
  text-align: center;
  box-shadow: var(--shadow);
}

.result-card strong {
  font-size: 24px;
  line-height: 1.2;
}

.result-card span {
  color: var(--muted);
}

.result-card button {
  width: 100%;
}

.side-panel {
  display: grid;
  grid-template-rows: auto auto auto minmax(0, 1fr);
  gap: 12px;
  padding: 14px;
  min-width: 0;
}

.status-card {
  min-height: 70px;
  display: grid;
  align-content: center;
  gap: 4px;
  padding: 12px;
  border-radius: 8px;
  background: #f8fafc;
  border: 1px solid var(--line);
}

.status-card span,
.move-list h2 {
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.status-card strong {
  overflow-wrap: anywhere;
  font-size: 18px;
  line-height: 1.3;
}

.move-list {
  min-height: 0;
  padding: 12px;
  border-radius: 8px;
  background: #f8fafc;
  border: 1px solid var(--line);
  overflow: hidden;
}

.move-list h2 {
  margin: 0 0 8px;
}

.move-list ol {
  min-height: 0;
  max-height: 320px;
  display: grid;
  gap: 5px;
  margin: 0;
  padding-left: 20px;
  overflow: auto;
}

.move-list li {
  color: var(--muted);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
}

.control-bar {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.content-page {
  width: min(980px, 100%);
  margin: 28px auto 0;
  padding: 0 18px;
}

.content-page article {
  margin-bottom: 18px;
  padding: 28px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
}

.content-page h1,
.content-page h2 {
  margin: 0 0 10px;
  line-height: 1.25;
}

.content-page h1 {
  font-size: 32px;
}

.content-page h2 {
  margin-top: 24px;
  font-size: 23px;
}

.content-page p,
.content-page li {
  color: var(--muted);
}

.content-page a {
  color: var(--accent-dark);
  font-weight: 800;
}

.game-card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 14px;
}

.game-card {
  min-height: 78px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 12px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fafc;
  color: var(--ink);
  text-decoration: none;
}

.game-card:hover,
.game-card:focus-visible {
  border-color: var(--accent);
  outline: none;
}

.game-card-icon {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 8px;
  color: #fff;
  font-size: 18px;
  font-weight: 900;
}

.game-card-icon.snake,
.game-card-icon.spider {
  background: #1f7a5c;
}

.game-card-icon.tile {
  background: #2563eb;
  font-size: 13px;
}

.game-card-icon.block {
  background: #172033;
}

.game-card strong {
  color: var(--ink);
  font-size: 18px;
  line-height: 1.2;
}

.game-card-icon.jump {
  background: #d93a2f;
}

.game-card-icon.sudoku {
  background: #2f6f9f;
}

.site-footer {
  margin-top: 34px;
  padding: 22px 18px;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid var(--line);
}

.site-footer p {
  margin: 6px 0;
}

.site-footer a {
  color: var(--accent-dark);
  font-weight: 800;
  text-decoration: none;
}

@media (max-width: 900px) {
  .game-top,
  .play-area {
    grid-template-columns: 1fr;
  }

  .score-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .side-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    grid-template-rows: auto auto auto;
  }

  .control-bar {
    grid-column: 1 / -1;
  }

  .move-list {
    grid-column: 1 / -1;
  }

  .move-list ol {
    max-height: 120px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 700px) {
  .site-header {
    height: 48px;
    grid-template-columns: minmax(0, 1fr) auto 40px;
    gap: 6px;
    padding: 0 8px;
  }

  .brand {
    font-size: 17px;
  }

  .desktop-nav {
    display: none;
  }

  .header-download {
    min-height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0 10px;
    border-radius: 6px;
    background: #fff8e8;
    color: #68430d;
    border: 1px solid #e5c16b;
    font-size: 13px;
    font-weight: 800;
    line-height: 1;
    text-decoration: none;
    white-space: nowrap;
  }

  .mobile-menu {
    display: block;
    position: relative;
  }

  .mobile-menu summary {
    width: 40px;
    height: 40px;
    display: grid;
    place-items: center;
    gap: 4px;
    padding: 10px;
    border-radius: 6px;
    background: rgba(255, 255, 255, 0.1);
    cursor: pointer;
    list-style: none;
  }

  .mobile-menu summary::-webkit-details-marker {
    display: none;
  }

  .mobile-menu span {
    width: 18px;
    height: 2px;
    display: block;
    border-radius: 2px;
    background: #fff;
  }

  .mobile-menu nav {
    position: fixed;
    top: 48px;
    right: 8px;
    z-index: 20;
    width: min(220px, calc(100vw - 16px));
    display: grid;
    gap: 4px;
    padding: 10px;
    border-radius: 8px;
    background: #172033;
    box-shadow: var(--shadow);
  }

  .mobile-menu:not([open]) nav {
    display: none;
  }

  .mobile-menu nav a {
    min-height: 42px;
    display: flex;
    align-items: center;
    padding: 0 12px;
    border-radius: 6px;
    color: #fff;
    text-decoration: none;
  }

  main {
    padding: 8px 8px 0;
  }

  .game-top {
    gap: 10px;
    padding: 10px;
  }

  .mode-group {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 6px;
  }

  .mode-btn {
    min-height: 34px;
    padding: 0 6px;
    font-size: 13px;
  }

  .score-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 6px;
  }

  .score-grid div {
    min-height: 42px;
    padding: 3px 4px;
  }

  .score-grid span {
    font-size: 11px;
  }

  .score-grid strong {
    font-size: 14px;
  }

  .client-notice {
    display: none;
  }

  .play-area {
    gap: 8px;
    padding: 8px;
  }

  .board-panel {
    min-height: 310px;
    padding: 8px;
  }

  .result-overlay {
    inset: 8px;
    padding: 14px;
  }

  .result-card {
    padding: 18px;
  }

  .result-card strong {
    font-size: 22px;
  }

  .side-panel {
    gap: 8px;
    padding: 8px;
  }

  .status-card {
    min-height: 54px;
    padding: 8px;
  }

  .status-card span,
  .move-list h2 {
    font-size: 12px;
  }

  .status-card strong {
    font-size: 14px;
  }

  .move-list {
    display: none;
  }

  .control-bar {
    gap: 8px;
  }

  .control-bar button {
    min-height: 38px;
    font-size: 14px;
  }

  .content-page {
    margin-top: 14px;
    padding: 0 10px;
  }

  .content-page article {
    padding: 20px;
  }

  .game-card-grid {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .game-card {
    min-height: 64px;
    padding: 10px;
  }

  .game-card-icon {
    width: 38px;
    height: 38px;
    font-size: 17px;
  }

  .game-card-icon.tile {
    font-size: 12px;
  }

  .game-card strong {
    font-size: 17px;
  }

  .site-footer {
    margin-top: 20px;
    padding: 18px 12px;
    font-size: 13px;
  }
}