:root {
  --bg: #f4f6fb;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --border: #dde3ee;
  --primary: #2563eb;
  --primary-text: #ffffff;
  --highlight: #fde68a;
  --warn-bg: #fff7e6;
  --warn-border: #f5c26b;
  --radius: 14px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --card: #1e293b;
    --text: #e5e7eb;
    --muted: #94a3b8;
    --border: #334155;
    --primary: #3b82f6;
    --highlight: #854d0e;
    --warn-bg: #3a2a0c;
    --warn-border: #a16207;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
}

.top { text-align: center; padding: 20px 16px 4px; }
.top h1 { margin: 0; font-size: 1.6rem; }
.top p { margin: 6px 0 0; color: var(--muted); }

main { max-width: 860px; margin: 0 auto; padding: 12px 14px 8px; }

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  margin-bottom: 14px;
}

.drop {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 16px;
  display: flex; flex-wrap: wrap; gap: 10px;
  align-items: center; justify-content: center;
  color: var(--muted);
  transition: border-color .15s, background .15s;
}
.drop.over { border-color: var(--primary); background: color-mix(in srgb, var(--primary) 8%, transparent); }

textarea {
  width: 100%;
  min-height: 180px;
  margin-top: 10px;
  padding: 12px;
  font: inherit;
  font-size: 1rem;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  resize: vertical;
}

.row { display: flex; justify-content: space-between; align-items: center; margin-top: 8px; }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px 16px;
}
.grid label { display: flex; flex-direction: column; gap: 4px; font-size: .92rem; }
select, input[type="range"] { width: 100%; }
select {
  font: inherit;
  padding: 8px;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
}
input[type="range"] { accent-color: var(--primary); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  font: inherit;
  font-size: 1rem;
  padding: 9px 16px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text);
  cursor: pointer;
  user-select: none;
  min-height: 44px;
}
.btn:hover { border-color: var(--primary); }
.btn:disabled { opacity: .45; cursor: default; }
.btn.primary {
  background: var(--primary); color: var(--primary-text); border-color: var(--primary);
  min-width: 150px; font-weight: 600;
}
.btn.ghost { background: transparent; }

.hint { color: var(--muted); font-size: .88rem; margin: 6px 0 0; }
.message { text-align: center; color: var(--muted); min-height: 1.2em; }

.warning {
  background: var(--warn-bg);
  border: 1px solid var(--warn-border);
  border-radius: 10px;
  padding: 10px 12px;
  margin-top: 10px;
  font-size: .9rem;
}
.warning ul { margin: 6px 0 0; padding-left: 20px; }

#reader {
  position: relative;
  max-height: 45vh;
  overflow-y: auto;
  font-size: 1.08rem;
  line-height: 1.7;
  padding-right: 4px;
}
#reader p { margin: 0 0 .8em; }
#reader span { cursor: pointer; border-radius: 4px; transition: background .2s; }
#reader span:hover { background: color-mix(in srgb, var(--primary) 12%, transparent); }
#reader span.current { background: var(--highlight); }

.controls {
  position: sticky;
  bottom: 0;
  background: var(--card);
  border-top: 1px solid var(--border);
  padding: 8px 12px calc(10px + env(safe-area-inset-bottom));
  text-align: center;
  box-shadow: 0 -4px 16px rgba(0,0,0,.06);
}
.controls .buttons { display: flex; justify-content: center; gap: 8px; margin-top: 8px; }
.progress { height: 5px; background: var(--border); border-radius: 3px; overflow: hidden; max-width: 860px; margin: 0 auto; }
#progressBar { height: 100%; width: 0; background: var(--primary); transition: width .3s; }

footer {
  max-width: 860px; margin: 0 auto;
  padding: 14px 16px 24px;
  color: var(--muted); font-size: .8rem; text-align: center;
}