:root{
  --bg:#0b1020;
  --panel:#121933;
  --panel-2:#0f1530;
  --text:#ecf2ff;
  --muted:#a9b4d0;
  --accent:#7aa2f7;
  --ok:#7ce2a0;
  --warn:#f7c948;
  --danger:#ff757f;
  --neutral:#c9d1e8;

  --c1:#7aa2f7; /* tone 1 */
  --c2:#5ee1a2; /* tone 2 */
  --c3:#f7c948; /* tone 3 */
  --c4:#ff757f; /* tone 4 */
  --c0:#c9d1e8; /* neutral */

  --radius:16px;
  --shadow:0 10px 30px rgba(0,0,0,.35);
}
@media (prefers-color-scheme: light){
  :root{
    --bg:#f6f9ff;
    --panel:#ffffff;
    --panel-2:#f2f6ff;
    --text:#0b1533;
    --muted:#5b6b8c;
  }
  body{background:linear-gradient(120deg,#eff4ff, #f7fbff);}
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: ui-sans-serif, -apple-system, Segoe UI, Roboto, "Noto Sans Bengali","Noto Sans", "Helvetica Neue", Arial, "Bangla Sangam MN", "SolaimanLipi", "Kalpurush", sans-serif;
  color:var(--text);
  background: radial-gradient(1000px 600px at 80% -200px, #243056, transparent 60%), var(--bg);
}
header{
  max-width:1100px;
  margin:32px auto 12px;
  padding:20px 16px;
}
h1{
  font-size: clamp(26px, 3.2vw, 42px);
  line-height:1.1;
  margin:0 0 10px 0;
  letter-spacing:.2px;
}
.sub{
  color:var(--muted);
  font-size:clamp(14px, 1.4vw, 16px);
}
.wrap{
  max-width:1100px;
  margin:0 auto 60px;
  padding:0 16px 80px;
}
.controls{
  background:linear-gradient(180deg, var(--panel), var(--panel-2));
  border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius);
  padding:14px;
  display:grid;
  grid-template-columns: repeat(3, minmax(180px,1fr));
  gap:14px;
  box-shadow: var(--shadow);
  position: sticky;
  top:8px;
  z-index:5;
}
.ctrl{
  display:flex;
  gap:10px;
  align-items:center;
  background:rgba(255,255,255,.03);
  border-radius:12px;
  padding:10px 12px;
}
.ctrl label{ font-size:13px; color:var(--muted); min-width:88px;}
.ctrl output{ font-variant-numeric: tabular-nums; color:var(--accent); font-weight:700}
input[type="range"]{ width:100% }
.grid{
  margin-top:18px;
  display:grid;
  grid-template-columns: repeat(2, minmax(260px, 1fr));
  gap:18px;
}
@media (max-width:900px){
  .grid{ grid-template-columns: 1fr }
  .controls{ grid-template-columns: 1fr; top:0 }
}
.card{
  background:linear-gradient(180deg, var(--panel), var(--panel-2));
  border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius);
  padding:14px;
  box-shadow: var(--shadow);
  position:relative;
  overflow:hidden;
  isolation:isolate;
}
.tone-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
  margin-bottom:10px;
}
.tone-title{
  display:flex; align-items:center; gap:10px;
  font-weight:800; letter-spacing:.2px;
}
.badge{
  font-size:12px; padding:4px 8px; border-radius:999px; color:#0b1020; font-weight:800;
  background:linear-gradient(180deg, #fff, #ddd);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.8), 0 6px 20px rgba(0,0,0,.2);
}
.badge.t1{ color:#0b1b42; background: linear-gradient(180deg, #bcd3ff, #9bbcff)}
.badge.t2{ color:#05381f; background: linear-gradient(180deg, #bff5d8, #9eebc7)}
.badge.t3{ color:#5a3a00; background: linear-gradient(180deg, #ffe9a6, #ffd66b)}
.badge.t4{ color:#4a0d12; background: linear-gradient(180deg, #ffc2c7, #ffa2aa)}
.badge.t0{ color:#1b2342; background: linear-gradient(180deg, #e3e9ff, #cfd7f5)}

.desc{ color:var(--muted); font-size:14px }
.examples{ display:flex; flex-wrap:wrap; gap:8px; margin:10px 0 8px}
.ex{
  background: rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.08);
  border-radius:10px; padding:6px 10px; font-size:14px
}
.svg-wrap{
  background:linear-gradient(180deg, rgba(255,255,255,.03), rgba(255,255,255,.02));
  border:1px dashed rgba(255,255,255,.08);
  border-radius:12px; padding:8px; margin-top:8px
}
svg{ width:100%; height:160px; display:block}
.axis text{ fill:var(--muted); font-size:10px }
.axis line{ stroke:rgba(255,255,255,.08) }
.tone-path{ fill:none; stroke-width:4; filter: drop-shadow(0 1px 0 rgba(255,255,255,.15)) }
.tone-dot{ stroke:#fff; stroke-width:2; filter: drop-shadow(0 2px 6px rgba(0,0,0,.35))}
.t1{ stroke: var(--c1) }
.t2{ stroke: var(--c2) }
.t3{ stroke: var(--c3) }
.t4{ stroke: var(--c4) }
.t0{ stroke: var(--c0); stroke-dasharray: 6 6 }

.controls-row{
  display:flex; gap:8px; flex-wrap:wrap; align-items:center; margin-top:10px
}
button{
  appearance:none; border:0; cursor:pointer; border-radius:10px; padding:10px 12px; font-weight:700;
  background:linear-gradient(180deg, #2a3a6b, #1c2850); color:#e9f0ff; border:1px solid rgba(255,255,255,.08)
}
button.secondary{ background:linear-gradient(180deg, #1f2a4f, #151c36) }
button:disabled{ opacity:.55; cursor:not-allowed }
.mini{
  font-size:12px; color:var(--muted)
}
.legend{
  display:flex; flex-wrap:wrap; gap:8px; margin-top:16px; font-size:13px; color:var(--muted)
}
.dot{
  width:10px; height:10px; border-radius:50%; display:inline-block; vertical-align:middle; margin-right:6px
}

details{
  background:linear-gradient(180deg, var(--panel), var(--panel-2));
  border:1px solid rgba(255,255,255,.08);
  border-radius:var(--radius); padding:12px; margin-top:18px
}
details[open]{ box-shadow: var(--shadow) }
summary{ cursor:pointer; font-weight:800 }
.tips li{ margin-bottom:8px }
.footnote{ color:var(--muted); font-size:12px; margin-top:16px }

.hero-sample{
  display:flex; gap:6px; flex-wrap:wrap; margin-top:8px
}
.pill{
  padding:8px 12px; border-radius:999px; font-weight:800; color:#0b1020;
  background:#fff; border:1px solid rgba(0,0,0,.06)
}
.pill.t1{ background:#bcd3ff }
.pill.t2{ background:#bff5d8 }
.pill.t3{ background:#ffe9a6 }
.pill.t4{ background:#ffc2c7 }
.pill.t0{ background:#e3e9ff }
.muted{ color:var(--muted) }

.kbd{
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: rgba(255,255,255,.06);
  border:1px solid rgba(255,255,255,.12);
  padding:2px 6px; border-radius:6px; font-size:12px
}