/* ===================== Base ===================== */
:root {
  --indigo: #4f46e5;
  --indigo-dark: #4338ca;
  --indigo-light: #eef2ff;
  --ink: #1e2235;
  --muted: #6b7090;
  --line: #d7dae8;
  --bg: #f5f6fb;
  --cell: #ffffff;
  --fill: #2b2f45;
  --good: #16a34a;
  --gold: #f59e0b;
  --shadow: 0 10px 30px rgba(40, 44, 80, 0.12);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
/* Subtle nonogram-cell backdrop: faint grid lines + a few "filled" cells. */
body {
  background-color: var(--bg);
  background-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg'%20width%3D'130'%20height%3D'130'%3E%3Cpath%20d%3D'M0%200H130%20M0%200V130%20M0%2026H130%20M26%200V130%20M0%2052H130%20M52%200V130%20M0%2078H130%20M78%200V130%20M0%20104H130%20M104%200V130%20M0%20130H130%20M130%200V130'%20fill%3D'none'%20stroke%3D'%234f46e5'%20stroke-opacity%3D'0.05'%2F%3E%3Cg%20fill%3D'%234f46e5'%20fill-opacity%3D'0.045'%3E%3Crect%20x%3D'26'%20y%3D'0'%20width%3D'26'%20height%3D'26'%2F%3E%3Crect%20x%3D'78'%20y%3D'26'%20width%3D'26'%20height%3D'26'%2F%3E%3Crect%20x%3D'0'%20y%3D'52'%20width%3D'26'%20height%3D'26'%2F%3E%3Crect%20x%3D'104'%20y%3D'52'%20width%3D'26'%20height%3D'26'%2F%3E%3Crect%20x%3D'52'%20y%3D'78'%20width%3D'26'%20height%3D'26'%2F%3E%3Crect%20x%3D'26'%20y%3D'104'%20width%3D'26'%20height%3D'26'%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E");
  background-size: 120px 120px;
}

button { font-family: inherit; cursor: pointer; }

.hidden { display: none !important; }

/* ===================== Top bar ===================== */
.topbar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 20px;
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  background: none;
  border: none;
  padding: 0;
  font-size: 18px;
  color: var(--ink);
}
.brand-mark {
  width: 26px;
  height: 26px;
  border-radius: 7px;
  background:
    linear-gradient(135deg, var(--indigo), #7c73f0);
  position: relative;
  flex: none;
}
.brand-mark::before,
.brand-mark::after {
  content: "";
  position: absolute;
  width: 7px; height: 7px;
  background: #fff;
  border-radius: 2px;
}
.brand-mark::before { top: 5px; left: 5px; }
.brand-mark::after { bottom: 5px; right: 5px; }
.brand-text { font-weight: 500; letter-spacing: -0.2px; }
.brand-text strong { color: var(--indigo); font-weight: 800; }
.topbar-spacer { flex: 1; }

.ghost-btn {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 9px 14px;
  font-size: 14px;
  color: var(--ink);
  font-weight: 600;
  transition: 0.15s;
}
.ghost-btn:hover { border-color: var(--indigo); color: var(--indigo); }
.ghost-btn small { color: var(--muted); font-weight: 600; }

.primary-btn {
  background: var(--indigo);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 11px 18px;
  font-size: 15px;
  font-weight: 700;
  transition: 0.15s;
}
.primary-btn:hover { background: var(--indigo-dark); }

.link-btn {
  background: none; border: none; color: var(--muted);
  font-size: 13px; text-decoration: underline; padding: 0;
}
.link-btn:hover { color: var(--indigo); }

/* ===================== Layout ===================== */
#app { max-width: 760px; margin: 0 auto; padding: 18px 18px 40px; }
.screen, .view { animation: fade 0.25s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }

/* ===================== Main nav ===================== */
.mainnav {
  display: flex; justify-content: center; gap: 6px;
  padding: 10px 16px 0; max-width: 760px; margin: 0 auto;
}
.nav-btn {
  background: none; border: none; padding: 10px 18px; border-radius: 10px;
  font-size: 15px; font-weight: 700; color: var(--muted);
}
.nav-btn:hover { color: var(--indigo); }
.nav-btn.active { color: var(--indigo-dark); background: var(--indigo-light); }

.streak-chip {
  background: #fff7ed; border: 1px solid #fed7aa; color: #c2410c;
  border-radius: 999px; padding: 6px 11px; font-size: 13px; font-weight: 700;
}
.streak-chip b { font-variant-numeric: tabular-nums; }

/* ===================== Home ===================== */
.hero { text-align: center; margin: 8px 0 22px; }
.hero h1, .hero .hero-title { font-size: 30px; font-weight: 800; margin: 0 0 8px; letter-spacing: -0.5px; }
.hero p { color: var(--muted); margin: 0 auto; max-width: 520px; line-height: 1.5; }

.difficulty-tabs {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin-bottom: 18px;
}
.tab {
  background: #fff;
  border: 2px solid var(--line);
  border-radius: 14px;
  padding: 14px 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
  display: flex;
  flex-direction: column;
  gap: 3px;
  transition: 0.15s;
}
.tab span { font-size: 12px; color: var(--muted); font-weight: 600; }
.tab:hover { border-color: var(--indigo); }
.tab.active { border-color: var(--indigo); background: var(--indigo-light); color: var(--indigo-dark); }
.tab.active span { color: var(--indigo); }

.levels-meta {
  display: flex; align-items: center; justify-content: space-between;
  margin: 4px 4px 14px; font-size: 13px; color: var(--muted);
}
.meta-toggles { display: flex; gap: 14px; flex-wrap: wrap; }
.zen-toggle { display: flex; align-items: center; gap: 6px; cursor: pointer; user-select: none; }
.zen-toggle input { accent-color: var(--indigo); width: 15px; height: 15px; }
.reset-row { text-align: center; margin-top: 22px; }

.level-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(92px, 1fr));
  gap: 12px;
}
.level-card {
  background: rgba(255, 255, 255, 0.74);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 14px 10px 12px;
  text-align: center;
  transition: 0.15s;
  position: relative;
}
.level-card:not(.locked):hover { border-color: var(--indigo); transform: translateY(-2px); box-shadow: var(--shadow); }
.level-num { font-size: 20px; font-weight: 800; color: var(--ink); }
.level-name { font-size: 12px; color: var(--muted); margin-top: 2px; min-height: 16px; }
.level-card.locked { opacity: 0.55; cursor: not-allowed; }
.level-card.locked .level-name { color: var(--muted); }
.level-card.done { border-color: #bbf7d0; background: #f0fdf4; }
.badge {
  position: absolute; top: -8px; right: -8px;
  width: 24px; height: 24px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; color: #fff;
}
.badge.check { background: var(--good); }
.badge.lock { background: #aab; font-size: 12px; }
.level-best { font-size: 11px; color: var(--good); font-weight: 700; margin-top: 4px; }

/* ===================== Game ===================== */
.game-head { text-align: center; margin-bottom: 16px; }
.game-size { font-size: 20px; font-weight: 800; line-height: 1.1; }
.game-sub {
  display: flex; align-items: center; justify-content: center; gap: 9px;
  margin-top: 3px; font-size: 13px; color: var(--muted);
}
.game-sub .sep { color: var(--line); }
.game-timer { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--indigo); }

.board-wrap { display: flex; justify-content: center; overflow-x: auto; padding: 4px; }
.board {
  display: grid;
  gap: 0;
  user-select: none;
  -webkit-user-select: none;
  touch-action: none;
}

/* clue + cell sizing handled inline via --cs (cell size) */
.board .corner { background: transparent; }

.colclue, .rowclue {
  display: flex;
  color: var(--ink);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}
.colclue {
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
  padding-bottom: 4px;
  gap: 1px;
  line-height: 1.05;
}
.rowclue {
  flex-direction: row;
  justify-content: flex-end;
  align-items: center;
  padding-right: 6px;
  gap: 5px;
}
.colclue.satisfied, .rowclue.satisfied { color: var(--muted); opacity: 0.45; }

.cell {
  background: var(--cell);
  border: 1px solid var(--line);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}
/* thicker guide lines every 5 cells */
.cell.b-left { border-left: 2px solid #b9bdd4; }
.cell.b-top { border-top: 2px solid #b9bdd4; }
.cell.b-right { border-right: 2px solid #b9bdd4; }
.cell.b-bottom { border-bottom: 2px solid #b9bdd4; }

.cell.filled { background: var(--fill); border-color: var(--fill); }
.cell.marked::after {
  content: "✕";
  color: #c2c6da;
  font-size: 0.8em;
  font-weight: 700;
}
.cell.flash { animation: pop 0.4s ease; }
@keyframes pop { 0% { transform: scale(0.4); } 60% { transform: scale(1.12); } 100% { transform: scale(1); } }

/* ===================== Toolbar ===================== */
.toolbar {
  display: flex; align-items: center; justify-content: center;
  gap: 10px; margin-top: 18px; flex-wrap: wrap;
}
.tool-group { display: flex; background: #fff; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.tool {
  display: flex; align-items: center; gap: 7px;
  background: #fff; border: none; padding: 10px 16px;
  font-weight: 700; font-size: 14px; color: var(--muted);
}
.tool.active { background: var(--indigo); color: #fff; }
.tool-ico {
  width: 16px; height: 16px; display: inline-flex; align-items: center; justify-content: center;
  border-radius: 3px;
}
.fill-ico { background: currentColor; }
.mark-ico { font-size: 13px; }
.tool-help { text-align: center; color: var(--muted); font-size: 12.5px; margin: 12px auto 0; max-width: 460px; line-height: 1.5; }
@media (hover: none) { .tool-help { display: none; } }

/* ===================== Modals ===================== */
.modal {
  position: fixed; inset: 0;
  background: rgba(25, 28, 50, 0.55);
  display: flex; align-items: center; justify-content: center;
  z-index: 50; padding: 20px;
  animation: fade 0.2s ease;
}
.modal-card {
  background: #fff; border-radius: 20px; padding: 28px 26px;
  max-width: 380px; width: 100%; text-align: center; box-shadow: var(--shadow);
  animation: rise 0.25s ease;
}
@keyframes rise { from { transform: translateY(18px); opacity: 0; } to { transform: none; opacity: 1; } }
.win-burst { font-size: 44px; }
.modal-card h2 { margin: 6px 0 4px; font-size: 24px; }
.win-pic { color: var(--muted); margin: 0 0 18px; font-weight: 600; }
.win-stats { display: flex; gap: 12px; justify-content: center; margin-bottom: 22px; }
.win-stats div {
  background: var(--indigo-light); border-radius: 12px; padding: 12px 20px;
  display: flex; flex-direction: column;
}
.win-stats span { font-size: 22px; font-weight: 800; color: var(--indigo-dark); font-variant-numeric: tabular-nums; }
.win-stats small { color: var(--muted); font-size: 12px; }
.modal-actions { display: flex; gap: 10px; justify-content: center; }

.how-card { text-align: left; max-width: 440px; }
.how-card h2 { text-align: center; }
.how-card ul { padding-left: 20px; line-height: 1.6; color: var(--ink); }
.how-card li { margin-bottom: 6px; }
.how-card code { background: var(--indigo-light); padding: 1px 6px; border-radius: 5px; font-weight: 700; color: var(--indigo-dark); }
.how-controls { background: #f7f8fc; border-radius: 10px; padding: 12px 14px; font-size: 14px; color: var(--muted); }
.how-card .modal-actions { margin-top: 8px; }

/* ===================== Footer ===================== */
.sitefoot {
  max-width: 640px; margin: 10px auto 30px; padding: 0 20px;
  text-align: center; color: var(--muted); font-size: 12.5px; line-height: 1.6;
}
.made-with {
  display: inline-flex; align-items: center; gap: 7px;
  margin-top: 14px; font-weight: 800; color: var(--ink);
  letter-spacing: 0.2px;
}
.pixel-heart {
  width: 16px; height: 16px; flex: none;
  transform-origin: center; animation: heartbeat 1.7s ease-in-out infinite;
}
.pixel-heart rect { fill: #ef4444; }
@keyframes heartbeat {
  0%, 70%, 100% { transform: scale(1); }
  35% { transform: scale(1.18); }
  50% { transform: scale(1.05); }
}

/* ===================== Daily ===================== */
.daily-card {
  background: #fff; border: 1px solid var(--line); border-radius: 18px;
  padding: 20px; box-shadow: var(--shadow); max-width: 480px; margin: 0 auto;
}
.daily-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 16px; }
.daily-num { font-size: 18px; font-weight: 800; display: block; }
.daily-date { font-size: 13px; color: var(--muted); }

/* streak hero */
.streak-hero {
  max-width: 480px; margin: 0 auto 16px;
  background: linear-gradient(135deg, #fff7ed, #ffedd5);
  border: 1px solid #fed7aa; border-radius: 18px; padding: 20px;
  display: flex; align-items: center; gap: 20px;
}
.streak-big { text-align: center; flex: none; min-width: 110px; }
.streak-flame { font-size: 30px; line-height: 1; }
.streak-num { font-size: 52px; font-weight: 900; color: #c2410c; line-height: 1; font-variant-numeric: tabular-nums; }
.streak-word { font-size: 13px; color: #9a3412; font-weight: 700; }
.streak-side { flex: 1; display: flex; flex-direction: column; gap: 8px; }
.streak-stat { display: flex; justify-content: space-between; font-size: 13px; color: #7c2d12; }
.streak-stat b { font-weight: 800; font-variant-numeric: tabular-nums; }
.streak-countdown {
  margin-top: 2px; background: rgba(255,255,255,0.7); border-radius: 10px; padding: 8px 10px;
  text-align: center; font-size: 12px; color: #9a3412; font-weight: 700;
}
.streak-countdown b { font-variant-numeric: tabular-nums; font-size: 14px; }

/* streak calendar */
.streak-cal { max-width: 480px; margin: 0 auto 16px; }
.streak-cal-title { font-size: 12px; color: var(--muted); font-weight: 700; margin: 0 0 8px 2px; }
.streak-cal-row { display: flex; gap: 5px; }
.cal-day {
  flex: 1; aspect-ratio: 1; border-radius: 7px; background: var(--line);
  display: flex; align-items: center; justify-content: center; font-size: 9px; color: transparent;
  position: relative; max-width: 30px;
}
.cal-day.done { background: var(--good); color: #fff; }
.cal-day.miss { background: #fde2e2; }
.cal-day.freeze { background: #dbeafe; }
.cal-day.today { outline: 2px solid var(--indigo); outline-offset: 1px; }
.cal-day.today.done { outline-color: var(--good); }

.daily-progress { display: flex; gap: 6px; margin-bottom: 16px; }
.daily-pip { flex: 1; height: 7px; border-radius: 4px; background: var(--line); }
.daily-pip.done { background: var(--good); }

.daily-row {
  display: flex; align-items: center; gap: 12px; padding: 12px 4px;
  border-top: 1px solid var(--line);
}
.daily-row-ico {
  width: 44px; height: 44px; border-radius: 10px; flex: none;
  background: var(--indigo-light); color: var(--indigo-dark);
  display: flex; align-items: center; justify-content: center; font-weight: 800; font-size: 13px;
}
.daily-row.done .daily-row-ico { background: #dcfce7; color: var(--good); }
.daily-row-info { flex: 1; }
.daily-row-info b { display: block; font-size: 15px; }
.daily-row-info small { color: var(--muted); font-size: 12px; }
.daily-row .primary-btn, .daily-row .ghost-btn { padding: 9px 16px; }
.daily-row-done { color: var(--good); font-weight: 800; font-size: 14px; }

.daily-allnote {
  margin-top: 16px; background: #f0fdf4; border: 1px solid #bbf7d0; color: #15803d;
  border-radius: 12px; padding: 14px; text-align: center; font-weight: 700;
}
.daily-allnote small { display: block; color: var(--muted); font-weight: 600; margin-top: 4px; }
.daily-share-btn { width: 100%; margin-top: 12px; }

/* ===================== Themes ===================== */
.theme-chips { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 18px; }
.theme-chip {
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 8px 16px; font-size: 14px; font-weight: 700; color: var(--muted); text-transform: capitalize;
}
.theme-chip:hover { border-color: var(--indigo); color: var(--indigo); }
.theme-chip.active { background: var(--indigo); border-color: var(--indigo); color: #fff; }

/* ===================== Zoom ===================== */
.zoom-group .tool { padding: 8px 15px; font-size: 19px; font-weight: 800; line-height: 1; color: var(--ink); }
.zoom-group .tool:hover { color: var(--indigo); }

/* ===================== Streak nudge ===================== */
.streak-nudge {
  max-width: 480px; margin: 0 auto 14px;
  background: #fffbeb; border: 1px solid #fde68a; color: #92400e;
  border-radius: 14px; padding: 12px 16px; text-align: center; font-weight: 700; font-size: 14px;
}

/* ===================== Logic badge ===================== */
.logic-badge {
  text-align: center; background: #eef2ff; color: var(--indigo-dark);
  border: 1px solid #c7d2fe; border-radius: 10px; padding: 7px 12px;
  font-size: 12.5px; font-weight: 700; margin: 0 auto 14px; max-width: 360px;
}
.level-card .mini-badge {
  position: absolute; bottom: 6px; left: 50%; transform: translateX(-50%);
  font-size: 10px; color: var(--indigo); font-weight: 700;
}

/* ===================== Album ===================== */
.album-meta { text-align: center; color: var(--muted); font-size: 14px; margin-bottom: 16px; font-weight: 600; }
.album-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(96px, 1fr)); gap: 14px;
}
.album-item { text-align: center; }
.album-thumb {
  width: 100%; aspect-ratio: 1; border-radius: 12px; border: 1px solid var(--line);
  background: #fff; display: block; image-rendering: pixelated;
}
.album-item.locked .album-thumb { background: repeating-linear-gradient(45deg,#f0f1f6,#f0f1f6 6px,#e8e9f2 6px,#e8e9f2 12px); }
.album-name { font-size: 12px; color: var(--ink); margin-top: 6px; font-weight: 600; }
.album-item.locked .album-name { color: var(--muted); }

/* ===================== Win extras ===================== */
.win-streak {
  background: #fff7ed; border: 1px solid #fed7aa; color: #c2410c;
  border-radius: 10px; padding: 10px; font-weight: 700; margin: -6px 0 16px;
}

/* ===================== Toast ===================== */
.toast {
  position: fixed; bottom: 26px; left: 50%; transform: translateX(-50%);
  background: var(--ink); color: #fff; padding: 12px 20px; border-radius: 12px;
  font-size: 14px; font-weight: 600; z-index: 80; box-shadow: var(--shadow);
  animation: toastIn 0.2s ease;
}
@keyframes toastIn { from { opacity: 0; transform: translate(-50%, 10px); } to { opacity: 1; transform: translate(-50%, 0); } }

/* ===================== Icon button (gear) ===================== */
.icon-btn {
  background: #fff; border: 1px solid var(--line); border-radius: 10px;
  width: 38px; height: 38px; font-size: 18px; display: flex; align-items: center; justify-content: center;
}
.icon-btn:hover { border-color: var(--indigo); }

/* ===================== Play-nav cards ===================== */
.play-nav { display: flex; gap: 12px; max-width: 480px; margin: 22px auto 0; }
.nav-card {
  flex: 1; display: flex; align-items: center; gap: 12px;
  background: rgba(255,255,255,0.82); border: 1px solid var(--line); border-radius: 14px;
  padding: 14px 16px; text-align: left; transition: 0.15s;
}
.nav-card:hover { border-color: var(--indigo); transform: translateY(-2px); box-shadow: var(--shadow); }
.nav-card-ic { font-size: 24px; flex: none; }
.nav-card-txt { display: flex; flex-direction: column; font-weight: 800; font-size: 16px; color: var(--ink); }
.nav-card-txt small { font-weight: 600; color: var(--muted); font-size: 12px; }

.subnav { max-width: 760px; margin: 0 auto 4px; }

/* ===================== Settings ===================== */
.set-row { display: flex; align-items: center; justify-content: space-between; padding: 14px 2px; border-top: 1px solid var(--line); text-align: left; cursor: pointer; }
.set-row span { display: flex; flex-direction: column; font-weight: 700; }
.set-row span small { font-weight: 500; color: var(--muted); font-size: 12px; margin-top: 2px; }
.set-row input { accent-color: var(--indigo); width: 18px; height: 18px; flex: none; }
.set-links { display: flex; justify-content: space-between; align-items: center; margin: 16px 0 4px; }

/* ===================== Collection tiles ===================== */
.coll-item { text-align: center; background: none; border: none; padding: 0; cursor: pointer; }
.coll-item .album-thumb { display: flex; align-items: center; justify-content: center; }
.coll-item:hover .album-thumb { border-color: var(--indigo); }
.coll-item.locked .album-thumb { background: repeating-linear-gradient(45deg,#f0f1f6,#f0f1f6 6px,#e8e9f2 6px,#e8e9f2 12px); }
.coll-q { font-size: 22px; font-weight: 800; color: #aab; }
.coll-meta { font-weight: 800; color: var(--indigo-dark); margin-top: 6px; }

/* ===================== SEO article ===================== */
.seo {
  max-width: 720px; margin: 40px auto 0; padding-top: 30px;
  border-top: 1px solid var(--line);
}
.seo-article h1 { font-size: 26px; font-weight: 800; margin: 0 0 12px; letter-spacing: -0.4px; }
.seo-article h2 { font-size: 22px; margin: 30px 0 10px; letter-spacing: -0.3px; }
.seo-article h3 { font-size: 17px; margin: 22px 0 8px; }
.seo-article p { line-height: 1.7; color: #3a3f55; margin: 0 0 14px; }
.seo-article ul { line-height: 1.8; color: #3a3f55; padding-left: 22px; margin: 0 0 14px; }
.seo-article code { background: var(--indigo-light); color: var(--indigo-dark); padding: 1px 7px; border-radius: 5px; font-weight: 700; }
.faq-q { font-weight: 800; color: var(--ink); margin-bottom: 4px; }
.faq p:not(.faq-q) { margin-bottom: 16px; }

/* interactive demo */
.demo {
  display: flex; gap: 22px; align-items: center; flex-wrap: wrap;
  background: rgba(255,255,255,0.7); border: 1px solid var(--line);
  border-radius: 16px; padding: 20px; margin: 18px 0 24px;
}
.demo .board { flex: none; }
.demo-side { flex: 1; min-width: 180px; }
.demo-status { font-weight: 700; color: var(--muted); line-height: 1.5; margin: 0 0 12px; }
.demo-status.demo-won { color: var(--good); }

/* ===================== Responsive ===================== */
@media (max-width: 480px) {
  .hero h1 { font-size: 24px; }
  #app { padding: 14px 12px 30px; }
  .ghost-btn { padding: 8px 11px; font-size: 13px; }
  .nav-btn { padding: 9px 14px; font-size: 14px; }
  .play-nav { flex-direction: column; }
  .seo-article h2 { font-size: 20px; }
  .demo { justify-content: center; }
}