:root {
  --bg: #07111f;
  --bg-soft: rgba(13, 24, 40, 0.82);
  --line: rgba(255,255,255,0.08);
  --text: #eaf2ff;
  --muted: #96a6c2;
  --primary: #6ee7b7;
  --primary-strong: #34d399;
  --accent: #60a5fa;
  --shadow: 0 20px 60px rgba(0,0,0,0.35);
}
* { box-sizing: border-box; margin: 0; }
html, body { min-height: 100%; }
canvas, .control-btn { touch-action: none; }
body {
  font-family: 'Inter', system-ui, sans-serif;
  color: var(--text);
  overflow-x: hidden;
  background:
    radial-gradient(circle at top left, rgba(96,165,250,.18), transparent 30%),
    radial-gradient(circle at top right, rgba(110,231,183,.14), transparent 25%),
    linear-gradient(135deg, #040814 0%, #07111f 45%, #0a1626 100%);
}
.mobile-only { display: none; }

/* ===== Desktop ===== */
.app-shell { max-width: 1180px; margin: 0 auto; padding: 20px 16px 32px; }
.hero, .panel, .board-panel {
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  background: var(--bg-soft); border: 1px solid var(--line); box-shadow: var(--shadow);
}
.hero { border-radius: 24px; padding: 22px; display: flex; justify-content: space-between; gap: 16px; align-items: center; margin-bottom: 20px; }
.eyebrow { margin: 0 0 8px; color: var(--primary); font-weight: 700; text-transform: uppercase; letter-spacing: .18em; font-size: 12px; }
h1 { font-size: clamp(30px, 4vw, 48px); line-height: 1.05; }
.subtitle { margin: 10px 0 0; color: var(--muted); font-size: 15px; max-width: 520px; line-height: 1.7; }
.stats-card { min-width: 240px; display: grid; gap: 10px; }
.stat { border: 1px solid var(--line); border-radius: 18px; padding: 12px 14px; background: rgba(255,255,255,.03); }
.stat span { display: block; font-size: 12px; color: var(--muted); margin-bottom: 6px; }
.stat strong { font-size: 26px; }
.game-layout { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 20px; }
.board-panel, .panel { border-radius: 24px; }
.board-panel { padding: 18px; position: relative; overflow: hidden; }
.board-topbar { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 14px; }
.status-pill { display: inline-flex; align-items: center; padding: 10px 14px; border-radius: 999px; background: rgba(96,165,250,.15); color: #d9e7ff; border: 1px solid rgba(96,165,250,.18); }
.actions { display: flex; gap: 10px; }
.btn { border: 0; border-radius: 14px; padding: 12px 16px; font-size: 14px; font-weight: 700; cursor: pointer; transition: transform .15s ease, background .2s ease; }
.btn.primary { background: linear-gradient(135deg, var(--primary), var(--primary-strong)); color: #062217; }
.btn.secondary { background: rgba(255,255,255,.08); color: var(--text); border: 1px solid var(--line); }
.btn.large { width: 100%; padding: 14px 18px; font-size: 16px; }
.board-wrap { position: relative; border-radius: 20px; overflow: hidden; border: 1px solid rgba(255,255,255,.08); box-shadow: inset 0 1px 0 rgba(255,255,255,.06), 0 18px 40px rgba(0,0,0,.28); }
#game { display: block; width: 100%; max-width: 300px; margin: 0 auto; aspect-ratio: 1 / 2; background: linear-gradient(180deg, rgba(5,10,18,.85), rgba(8,15,25,.95)); }
#next { display: block; margin: 8px auto 0; background: transparent; }
.overlay { position: absolute; inset: 0; display: none; align-items: center; justify-content: center; background: rgba(3,8,16,.62); padding: 24px; }
.overlay.visible { display: flex; }
.overlay-card { width: min(100%, 340px); background: rgba(7,17,31,.92); border: 1px solid var(--line); border-radius: 24px; padding: 22px; text-align: center; box-shadow: var(--shadow); }
.overlay-card h2 { margin: 0 0 10px; }
.overlay-card p { margin: 0 0 18px; color: var(--muted); line-height: 1.6; }
.sidebar { display: grid; gap: 20px; align-content: start; }
.panel { padding: 18px; background: linear-gradient(180deg, rgba(12,22,36,.88), rgba(8,16,28,.92)); }
.panel h3 { margin-top: 0; margin-bottom: 12px; }
.panel ul { margin: 0; padding-left: 18px; color: var(--muted); line-height: 1.8; }
.touch-controls-area { margin-top: 14px; }
.touch-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; }
.control-btn {
  border: 1px solid var(--line); background: rgba(255,255,255,.06); color: var(--text); border-radius: 18px; min-height: 64px;
  font-size: 20px; font-weight: 800; cursor: pointer; -webkit-tap-highlight-color: transparent;
}
.control-btn.rotate, .control-btn.drop { font-size: 15px; font-weight: 700; }
.board-hint { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.board-hint span { display: inline-flex; align-items: center; padding: 8px 12px; border-radius: 999px; font-size: 13px; color: var(--muted); background: rgba(255,255,255,.04); border: 1px solid var(--line); }

/* Tablet */
@media (max-width: 920px) {
  .hero, .game-layout { grid-template-columns: 1fr; display: grid; }
  .stats-card { grid-template-columns: repeat(3, 1fr); min-width: 0; }
}

/* ===== Mobile: full rewrite ===== */
@media (max-width: 720px) {
  .desktop-only { display: none !important; }
  .mobile-only { display: flex !important; }

  html, body {
    height: 100dvh;
    overflow: hidden;
  }

  .app-shell {
    height: 100dvh;
    padding: 0;
    display: flex;
    flex-direction: column;
    overflow: hidden;
  }

  /* Mobile compact header bar */
  .mobile-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 12px;
    background: var(--bg-soft);
    border-bottom: 1px solid var(--line);
    flex-shrink: 0;
  }

  .mobile-title {
    font-weight: 800;
    font-size: 16px;
    color: var(--primary);
  }

  .mobile-stats {
    display: flex;
    gap: 14px;
  }

  .m-stat {
    text-align: center;
  }

  .m-stat span {
    display: block;
    font-size: 10px;
    color: var(--muted);
    margin-bottom: 2px;
  }

  .m-stat strong {
    font-size: 16px;
    font-weight: 800;
  }

  .btn-icon {
    border: 0;
    background: rgba(255,255,255,.08);
    color: var(--text);
    width: 36px;
    height: 36px;
    border-radius: 12px;
    font-size: 18px;
    cursor: pointer;
  }

  .mobile-bar-right {
    display: flex;
    gap: 8px;
  }

  /* Main layout fills remaining space */
  .game-layout {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-height: 0;
    padding: 8px;
    gap: 8px;
  }

  .board-panel {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-height: 0;
    padding: 0;
    border-radius: 0;
    background: none;
    border: 0;
    box-shadow: none;
    backdrop-filter: none;
  }

  /* Next preview row */
  .mobile-next-row {
    display: flex !important;
    align-items: center;
    gap: 10px;
    padding: 6px 4px;
    flex-shrink: 0;
  }

  .mobile-next-label {
    font-size: 13px;
    color: var(--muted);
    font-weight: 700;
  }

  #next-mobile {
    width: 56px;
    height: 56px;
  }

  /* Game canvas fills available space */
  .board-stage {
    flex: 1;
    min-height: 0;
    display: flex;
    flex-direction: column;
  }

  .board-wrap {
    flex: 1;
    min-height: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 14px;
  }

  #game {
    max-width: 100%;
    max-height: 100%;
    width: auto;
    height: auto;
    object-fit: contain;
  }

  /* Touch controls pinned at bottom */
  .touch-controls-area {
    flex-shrink: 0;
    margin-top: 6px;
    padding: 0 2px;
  }

  .touch-grid {
    gap: 6px;
  }

  .control-btn {
    min-height: 54px;
    border-radius: 14px;
    font-size: 18px;
  }

  .control-btn.rotate, .control-btn.drop {
    font-size: 14px;
  }
}