:root {
  --ink: #1c2430;
  --muted: #5b6573;
  --paper: #f7f1e6;
  --card: #fffdf8;
  --line: #e6dccb;
  --a: #e06a4a;
  --a-soft: #fde8e1;
  --b: #2f8f6b;
  --b-soft: #e3f4eb;
  --c: #2b6cb0;
  --c-soft: #e4eefb;
  --d: #c9891a;
  --d-soft: #f8ecd2;
  --shadow: 0 10px 28px rgba(48, 36, 20, 0.08);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: "Be Vietnam Pro", "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(900px 420px at 8% -10%, #ffe7c2 0%, transparent 55%),
    radial-gradient(700px 380px at 100% 0%, #d7ecff 0%, transparent 50%),
    var(--paper);
  line-height: 1.62;
  font-size: 16.5px;
}

a { color: inherit; }

.topbar {
  background: rgba(255, 253, 248, 0.94);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 8;
  backdrop-filter: blur(8px);
}

.topbar-inner {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  font-size: 13px;
  font-weight: 600;
}

.topbar a { text-decoration: none; color: #5b5346; }
.topbar a:hover { text-decoration: underline; }

.wrap {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  padding: 22px 0 80px;
}

.book {
  background: var(--card);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  border-radius: 28px;
}

.cover {
  padding: 28px 34px 26px;
  background: linear-gradient(160deg, #fff 0%, #fff7ea 58%, #e8f4ee 100%);
  border-radius: 28px 28px 0 0;
}

.cover img {
  width: 100%;
  border-radius: 20px;
  border: 1px solid var(--line);
  display: block;
  margin-bottom: 18px;
}

.eyebrow {
  display: inline-flex;
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #8a5a18;
  background: #fff3d8;
  border-radius: 999px;
  padding: 6px 12px;
  margin-bottom: 10px;
}

.cover h1 {
  font-family: Nunito, "Be Vietnam Pro", sans-serif;
  font-size: clamp(30px, 5vw, 44px);
  line-height: 1.12;
  margin-bottom: 8px;
}

.cover .sub {
  font-size: 20px;
  font-weight: 700;
  color: #2f8f6b;
  margin-bottom: 10px;
}

.cover .lead { color: var(--muted); max-width: 62ch; }

.meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.pill {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 600;
}

.inner { padding: 8px 34px 40px; }

h2 {
  font-family: Nunito, sans-serif;
  font-size: 26px;
  margin: 28px 0 10px;
}

h3 {
  font-size: 18.5px;
  margin: 18px 0 8px;
}

p { margin: 0 0 10px; }

ul, ol { margin: 0 0 12px 1.2em; }
li { margin: 4px 0; }

.howto, .note, .remember, .mr, .warn {
  border-radius: 16px;
  padding: 14px 16px;
  margin: 14px 0 18px;
}

.howto { background: #fff7ea; border: 1px dashed #d9c9a8; }
.note { background: #f3eee4; color: #4d4334; font-size: 14.5px; }
.remember { background: var(--b-soft); border-left: 6px solid var(--b); }
.warn { background: var(--a-soft); border-left: 6px solid var(--a); }
.mr { background: var(--d-soft); border-left: 6px solid var(--d); }

.remember strong, .howto strong, .mr strong, .warn strong { display: block; margin-bottom: 4px; }

.toc { display: grid; gap: 10px; margin: 16px 0 8px; }
.toc a {
  display: grid;
  grid-template-columns: 52px 1fr auto;
  gap: 12px;
  align-items: center;
  text-decoration: none;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 10px 12px;
}
.toc a:hover { border-color: #cbb892; }
.toc .n {
  width: 44px; height: 44px; border-radius: 12px;
  display: grid; place-items: center;
  color: #fff; font-family: Nunito, sans-serif; font-weight: 900; font-size: 18px;
}
.toc .n.a { background: var(--a); }
.toc .n.b { background: var(--b); }
.toc .n.c { background: var(--c); }
.toc .n.d { background: var(--d); }
.toc small { color: var(--muted); font-size: 13px; }
.toc .codes { font-size: 12px; font-weight: 700; color: #7a5408; }

.lesson {
  border-top: 1px solid var(--line);
  padding: 28px 0 8px;
  page-break-before: always;
  scroll-margin-top: 56px;
}

.lesson-head {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 8px;
}

.badge {
  min-width: 58px; height: 58px; border-radius: 18px;
  display: grid; place-items: center;
  color: #fff; font-family: Nunito, sans-serif; font-weight: 900; font-size: 22px;
}
.badge.a { background: var(--a); }
.badge.b { background: var(--b); }
.badge.c { background: var(--c); }
.badge.d { background: var(--d); }

.lesson-head h2 { margin: 0 0 4px; font-size: 24px; }
.kicker { font-size: 13px; color: var(--muted); font-weight: 600; }

.goals {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 12px 14px 6px;
  margin: 12px 0 16px;
}

.figure {
  margin: 16px 0 18px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 18px;
  overflow: hidden;
}

.figure img { width: 100%; display: block; }

.caption {
  font-size: 13.5px;
  color: var(--muted);
  padding: 10px 14px 12px;
  font-style: italic;
}

.slot {
  min-height: 180px;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 22px 16px;
  background:
    repeating-linear-gradient(-45deg, #faf6ee, #faf6ee 12px, #f3eee4 12px, #f3eee4 24px);
  color: #6a5d48;
  font-size: 14.5px;
}

.slot b { display: block; color: var(--ink); font-style: normal; margin-bottom: 6px; }

.box-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 12px 0 16px;
}

.box {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 12px 14px;
}

.box h4 { font-size: 15px; margin-bottom: 6px; }
.box.good { border-color: #b7e0c8; background: #f4fbf6; }
.box.bad { border-color: #f3c4b6; background: #fff7f4; }

.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin: 12px 0 16px;
}

.step {
  background: var(--c-soft);
  border-radius: 14px;
  padding: 12px 10px;
  text-align: center;
  font-size: 14px;
}

.step .num {
  width: 28px; height: 28px; border-radius: 50%;
  background: var(--c); color: #fff;
  display: grid; place-items: center;
  margin: 0 auto 6px;
  font-weight: 800; font-size: 13px;
}

.task {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 14px 16px;
  margin: 12px 0 16px;
}

.task h3 { margin-top: 0; }
.blank {
  display: block;
  border-bottom: 1px dotted #9a8b72;
  min-height: 28px;
  margin: 8px 0;
}

table.sheet {
  width: 100%;
  border-collapse: collapse;
  margin: 10px 0 6px;
  font-size: 14.5px;
}

table.sheet th, table.sheet td {
  border: 1px solid #d9c9a8;
  padding: 8px 10px;
  vertical-align: top;
}

table.sheet th { background: #fff3d8; text-align: left; }
table.sheet td.fill { height: 42px; }

.tf { list-style: none; margin-left: 0; }
.tf li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 10px 12px;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: center;
}
.circles { color: var(--muted); font-weight: 700; white-space: nowrap; }

.home {
  background: #fff7ea;
  border-radius: 16px;
  padding: 12px 14px;
  margin-top: 8px;
}

.nav-lesson {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-top: 18px;
  font-size: 14px;
  font-weight: 600;
}

.nav-lesson a { text-decoration: none; color: #5b5346; }
.nav-lesson a:hover { text-decoration: underline; }

.glossary dt { font-weight: 700; margin-top: 8px; }
.glossary dd { margin-left: 0; color: #3d4654; }

footer.book-foot {
  border-top: 1px solid var(--line);
  padding: 18px 34px 28px;
  color: var(--muted);
  font-size: 13.5px;
}

@media (max-width: 760px) {
  .inner, .cover { padding-left: 18px; padding-right: 18px; }
  .box-grid, .steps { grid-template-columns: 1fr 1fr; }
  .toc a { grid-template-columns: 44px 1fr; }
  .toc .codes { display: none; }
}

@media (max-width: 560px) {
  .steps { grid-template-columns: 1fr; }
  .box-grid { grid-template-columns: 1fr; }
}

@media print {
  body { background: #fff; font-size: 12.5px; }
  .topbar { display: none; }
  .book { box-shadow: none; border: none; border-radius: 0; }
  .lesson { break-before: page; }
  .cover { break-after: page; }
  a { text-decoration: none; }
}