:root {
  --bg: #071015;
  --panel: rgba(11, 25, 31, 0.92);
  --panel-soft: rgba(14, 32, 38, 0.74);
  --line: rgba(119, 235, 255, 0.22);
  --line-strong: rgba(119, 235, 255, 0.42);
  --text: #e7fbff;
  --muted: rgba(231, 251, 255, 0.68);
  --cyan: #58e6ff;
  --amber: #ffd166;
  --pink: #ff6f91;
}
* { box-sizing: border-box; }
html { background: var(--bg); color: var(--text); }
body.utility-lab {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at 20% 0%, rgba(47, 160, 170, 0.16), transparent 32rem),
    radial-gradient(circle at 80% 10%, rgba(255, 111, 145, 0.11), transparent 34rem),
    linear-gradient(180deg, #08141b, #05090d 70%);
  overflow-x: hidden;
}
a { color: var(--cyan); }
.utility-shell { width: min(1120px, calc(100% - 28px)); margin: 0 auto; }
.utility-hero { padding: 34px 0 20px; }
.utility-eyebrow { margin: 0 0 10px; color: var(--cyan); letter-spacing: .12em; font-size: .76rem; font-weight: 800; }
.utility-hero h1 { margin: 0; font-size: clamp(2rem, 6vw, 4.2rem); line-height: 1.02; letter-spacing: 0; }
.utility-lead { max-width: 760px; color: var(--muted); font-size: 1.02rem; line-height: 1.85; }
.utility-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(300px, .85fr); gap: 18px; align-items: start; }
.utility-panel,
.utility-card,
.utility-comments,
.utility-tail-link { background: var(--panel); border: 1px solid var(--line); box-shadow: 0 0 0 1px rgba(255,255,255,.025) inset, 0 18px 54px rgba(0,0,0,.24); border-radius: 10px; }
.utility-panel { padding: 18px; }
.utility-card { padding: 16px; margin: 16px 0; }
.utility-card h2,
.utility-card h3,
.utility-panel h2 { margin-top: 0; letter-spacing: 0; }
.tool-form { display: grid; gap: 14px; }
.tool-row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.tool-field { display: grid; gap: 7px; }
.tool-field label { color: var(--muted); font-weight: 700; font-size: .88rem; }
.tool-field input,
.tool-field select,
.tool-field textarea { width: 100%; border: 1px solid var(--line-strong); background: rgba(2, 8, 11, .88); color: var(--text); border-radius: 8px; padding: 12px; min-height: 46px; font: inherit; }
.tool-field textarea { min-height: 120px; resize: vertical; }
.quick-buttons,
.tool-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.utility-btn,
.quick-buttons button,
.tool-actions button,
.buzzer-pad button { border: 1px solid var(--line-strong); background: linear-gradient(180deg, rgba(88,230,255,.2), rgba(8,29,36,.92)); color: var(--text); border-radius: 999px; padding: 10px 14px; font-weight: 800; cursor: pointer; }
.utility-btn.secondary,
.tool-actions button.secondary { background: rgba(255,255,255,.06); }
.result-board { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-top: 16px; }
.result-cell { background: var(--panel-soft); border: 1px solid rgba(255,255,255,.08); border-radius: 8px; padding: 12px; min-height: 78px; }
.result-cell span { display: block; color: var(--muted); font-size: .76rem; letter-spacing: .08em; font-weight: 800; }
.result-cell strong { display: block; margin-top: 6px; font-size: clamp(1.35rem, 4vw, 2.5rem); color: var(--amber); overflow-wrap: anywhere; }
.notice { color: var(--muted); font-size: .92rem; line-height: 1.7; }
.series-links { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.series-links a { display: block; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: rgba(255,255,255,.045); text-decoration: none; }
.utility-comments { padding: 16px; margin: 18px 0; }
.utility-comments .app-comments,
.utility-comments .app-comment-form-section,
.utility-comments .app-comment-form { background: rgba(8, 18, 24, .86) !important; color: var(--text) !important; border-color: var(--line) !important; }
.utility-comments input,
.utility-comments textarea,
.utility-comments select { background: rgba(2, 8, 11, .9) !important; color: var(--text) !important; border: 1px solid var(--line-strong) !important; }
.tail-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin: 18px 0 28px; }
.utility-tail-link { padding: 13px; color: var(--muted); }
.utility-tail-link span { display: block; color: var(--muted); font-size: .8rem; font-weight: 800; letter-spacing: .1em; }
.utility-tail-link a { display: inline-block; margin: 4px 0; font-size: 1.05rem; font-weight: 900; text-decoration: none; }
.utility-footer { padding: 20px 0 34px; text-align: center; color: rgba(231,251,255,.46); font-size: .86rem; }
.buzzer-pad { display: grid; gap: 12px; }
.buzzer-pad button.big-buzzer { min-height: 150px; border-radius: 16px; font-size: clamp(1.4rem, 5vw, 3rem); background: radial-gradient(circle at top, rgba(255,209,102,.28), rgba(255,111,145,.16) 50%, rgba(8,29,36,.95)); }
.player-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; }
.player-grid button { min-height: 150px; border-radius: 14px; font-size: clamp(1.2rem, 4vw, 2.4rem); }
.classroom-buttons { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.classroom-buttons button { min-height: 92px; border-radius: 12px; font-size: 1.1rem; }
.history-list { margin: 10px 0 0; padding-left: 1.2em; color: var(--muted); line-height: 1.7; max-height: 210px; overflow: auto; }
@media (max-width: 760px) {
  .utility-shell { width: min(100% - 18px, 1120px); }
  .utility-grid,
  .tool-row,
  .result-board,
  .series-links,
  .tail-grid,
  .player-grid,
  .classroom-buttons { grid-template-columns: 1fr; }
  .utility-panel { padding: 14px; }
  .buzzer-pad button.big-buzzer,
  .player-grid button { min-height: 124px; }
}