/* Dùng chung cho bai-tap-doc-not.html (khóa Fa – tay trái) và bai-tap-khoa-sol.html (khóa Sol – tay phải) */
:root {
--bg: #f1eee6; --paper: #fff; --ink: #1e1b16; --muted: #6b645a; --line: #d9d3c4; --accent: #c2185b;
}
:root[data-theme="dark"] { --bg: #17150f; --ink: #f1ece0; --muted: #a39b8a; --line: #3a3528; --accent: #f06292; }
:root[data-theme="dark"] .controls { background: #221f17 !important; }
:root[data-theme="dark"] .controls select, :root[data-theme="dark"] .controls input[type=number] { background: #17150f !important; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.5 "Segoe UI", system-ui, -apple-system, Roboto, sans-serif; }
/* ---------- bảng điều khiển (chỉ hiện trên màn hình) ---------- */
.controls {
position: sticky; top: 0; z-index: 10; background: #fff; border-bottom: 1px solid var(--line);
padding: 10px 16px; display: flex; flex-wrap: wrap; gap: 8px 20px; align-items: center; justify-content: center;
box-shadow: 0 2px 8px rgba(0,0,0,.08);
}
@media (max-height: 560px) { .controls { position: static; } }
.controls h1 { font-size: 1.05rem; margin: 0; flex: 1 1 100%; text-align: center; }
.controls label { display: flex; align-items: center; gap: 8px; font-size: .92rem; color: var(--ink); }
.controls select, .controls input[type=number] { font: inherit; padding: 4px 8px; border-radius: 8px; border: 1px solid var(--line); background: var(--paper); color: var(--ink); }
.controls input[type=number] { width: 6.5em; }
.controls input[type=checkbox] { width: 18px; height: 18px; accent-color: var(--accent); }
.controls button { font: inherit; font-weight: 700; padding: 7px 16px; border-radius: 9px; border: 1px solid var(--accent); background: transparent; color: var(--accent); cursor: pointer; }
.controls button.primary { background: var(--accent); color: #fff; }
.controls .hint { flex: 1 1 100%; text-align: center; font-size: .82rem; color: var(--muted); margin: 0; }
a.home { display: inline-block; margin-right: 10px; padding: 3px 12px; border: 1px solid var(--line); border-radius: 9px; background: var(--bg); color: var(--accent); font-size: .85rem; font-weight: 700; text-decoration: none; }
a.home:hover { border-color: var(--accent); }
.back { font-size: .85rem; color: var(--accent); }
/* ---------- tờ giấy ---------- */
.page-wrap { padding: 18px 12px 40px; display: flex; flex-direction: column; align-items: center; gap: 22px; }
.sheet {
width: 186mm; max-width: 100%; height: 271mm; /* A4 trừ lề 12mm */
background: var(--paper); color: #000; overflow: hidden;
box-shadow: 0 2px 14px rgba(0,0,0,.18);
display: flex; flex-direction: column; justify-content: space-between;
padding: 8mm; /* khớp với PAD trong script */
}
.sheet svg { display: block; width: 100%; height: auto; overflow: visible; }
.hd { flex: 0 0 auto; }
.hd .t1 { display: flex; align-items: flex-end; gap: 8mm; font-size: 12.5pt; }
.hd .t1 b { letter-spacing: .02em; white-space: nowrap; }
.hd .t1 .nm { flex: 1; display: flex; align-items: flex-end; gap: 2mm; font-size: 11pt; }
.hd .t1 .nm i { flex: 1; border-bottom: .3mm solid #000; height: 1px; }
.hd p { margin: 2.5mm 0 0; font-size: 10.5pt; display: flex; justify-content: space-between; gap: 6mm; }
.hd .code { color: #666; font-size: 9pt; white-space: nowrap; }
.sheet.key .hd .t1 b { color: var(--key); }
.sec { flex: 0 0 auto; margin: 0; font-size: 10.5pt; font-weight: 700; }
.sheet { --key: #c2185b; }
/* ---------- trang hướng dẫn ---------- */
.guide .hd .t1 b { color: var(--key); }
.guide section { flex: 0 0 auto; }
.guide h3 { margin: 0 0 1mm; font-size: 10.5pt; }
.guide p, .guide ol { margin: 1mm 0 0; font-size: 9pt; line-height: 1.32; }
.guide ol { padding-left: 5mm; }
.guide .g2 { display: grid; grid-template-columns: 1fr 1fr; gap: 6mm; flex: 0 0 auto; }
.guide .ex { display: grid; grid-template-columns: 96mm 1fr; gap: 5mm; align-items: center; }
.guide em { font-style: normal; color: var(--key); font-weight: 700; }
/* ---------- trang luyện tập khởi động (chữ to cho bé) ---------- */
.warm h3 { font-size: 12pt; margin-bottom: 1.5mm; }
.warm p, .warm ol { font-size: 10.5pt; line-height: 1.4; margin-bottom: 1.5mm; }
.warm ol li + li { margin-top: 1mm; }
.warm .ex { grid-template-columns: 96mm 1fr; }
.warm .lead { margin: 0; }
.warm .stars { margin: 0; text-align: right; font-weight: 700; font-size: 11pt; }
.warm .big { font-size: 16pt; letter-spacing: 2mm; color: #000; }
.ribbon { flex: 0 0 auto; border: .35mm solid #000; border-radius: 3mm; padding: 2mm 3mm; }
.ribbon .rb-h { font-weight: 700; font-size: 10pt; margin-bottom: 1.5mm; }
.ribbon .rb-keys { display: grid; grid-template-columns: repeat(8, 1fr); gap: 1.5mm; }
.ribbon .rb-keys span { border: .3mm solid #555; border-radius: 2mm; text-align: center; padding: 1mm 0; line-height: 1.15; }
.ribbon .rb-keys b { display: block; font-size: 13pt; }
.ribbon .rb-keys i { font-style: normal; font-size: 9pt; color: #555; }
.ribbon .rb-keys span.on { background: #fce4ec; border-color: var(--key); color: var(--key); }
.ribbon .rb-f { display: flex; justify-content: space-between; font-size: 9pt; color: #555; margin-top: 1.2mm; }
@media print {
@page { size: A4; margin: 12mm; }
html, body { background: #fff; }
.controls { display: none !important; }
.page-wrap { padding: 0; display: block; }
.sheet { box-shadow: none; width: 186mm; height: 271mm; max-width: none; break-after: page; }
.sheet:last-child { break-after: auto; }
* { -webkit-print-color-adjust: exact; print-color-adjust: exact; }
}
/* ---------- hộp hướng dẫn phụ huynh (trang đáp án luyện tập) ---------- */
.ribbon.parent { border-color: var(--key); background: #fff8fb; }
.ribbon.parent p { margin: 0; font-size: 9.5pt; line-height: 1.35; }
.ribbon.parent p.tip { margin-top: 1mm; }
.hd .t1 .code { align-self: flex-end; }
.controls .clefTag { display: inline-block; margin-left: 6px; padding: 1px 10px; border-radius: 99px; background: var(--accent); color: #fff; font-size: .9rem; }
/* ---------- trang "Bài tập thêm": các dòng khuông chia đều chiều cao trang ---------- */
.extra .lead { margin: 0; }