/* Web edition of the teacher guide. Colours are the book's (config/colors.tex). */
@font-face {
  font-family: 'Noto Sans Khmer Local';
  src: url('../fonts/NotoSansKhmer.woff') format('woff');
  font-weight: 100 900;
  font-display: swap;
}
/* Khmer M1 / M2 (LIM Sovanvichet, GNU LGPL 2.1): only the minister's quotation page uses them */
@font-face {
  font-family: 'Khmer M1 Web';
  src: local('Khmer M1'), url('../fonts/KhmerM1.woff') format('woff');
  font-display: swap;
}
@font-face {
  font-family: 'Khmer M2 Web';
  src: local('Khmer M2'), url('../fonts/KhmerM2.woff') format('woff');
  font-display: swap;
}
:root {
  --dark: #102a43;
  --blue: #17365d;
  --teal: #4d7c78;
  --green: #5d8065;
  --orange: #b7793e;
  --red: #a84a4a;
  --amber: #b7833e;
  --light-blue: #e9f0f5;
  --light-gray: #f0f2f2;
  --mid-gray: #68757f;
  --ink: #1f2a33;
  --page: #fbfaf7;
  --body: 'Battambang', 'Noto Sans Khmer Local', 'Khmer OS Battambang', serif;
  --head: 'Noto Sans Khmer Local', 'Noto Sans Khmer', sans-serif;
  --side-w: 290px;
  --top-h: 54px;
}
* { box-sizing: border-box; }
html { scroll-padding-top: calc(var(--top-h) + 12px); }
body { margin: 0; font-family: var(--body); font-size: 17px; line-height: 1.95; color: var(--ink); background: var(--page); }
a { color: var(--blue); }
a:hover { color: var(--teal); }
:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; }

/* ---- top bar ---- */
.top {
  position: fixed; inset: 0 0 auto 0; z-index: 30; height: var(--top-h);
  display: flex; align-items: center; gap: 12px; padding: 0 16px;
  background: var(--dark); color: #fff; font-family: var(--head);
}
.top .brand { color: #fff; text-decoration: none; font-weight: 700; font-size: 16px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.top .top-link { margin-left: auto; color: #cfe3ef; font-size: 14px; white-space: nowrap; }
.menu-btn { display: none; background: none; border: 1px solid rgba(255,255,255,.4); color: #fff; font-size: 20px; border-radius: 6px; width: 40px; height: 36px; cursor: pointer; }
.draft-tag { font-family: var(--head); font-size: 12px; background: var(--amber); color: #fff; padding: 1px 10px; border-radius: 999px; white-space: nowrap; }

/* ---- layout ---- */
.layout { display: flex; padding-top: var(--top-h); }
.side {
  position: fixed; top: var(--top-h); bottom: 0; left: 0; width: var(--side-w); overflow-y: auto;
  background: #fff; border-right: 1px solid #e2e6ea; font-family: var(--head); font-size: 14.5px; line-height: 1.6;
}
.side-inner { padding: 14px 10px 40px; }
.side-home { display: block; padding: 4px 10px; font-weight: 700; text-decoration: none; }
.side-group { margin: 14px 10px 4px; font-size: 12.5px; font-weight: 700; color: var(--mid-gray); letter-spacing: .02em; }
.side ul { list-style: none; margin: 0; padding: 0; }
.side li a { display: flex; gap: 8px; padding: 5px 10px; border-radius: 6px; text-decoration: none; color: var(--ink); }
.side li a:hover { background: var(--light-blue); }
.side li.cur > a { background: var(--light-blue); color: var(--blue); font-weight: 700; }
.side .n { flex: none; min-width: 1.4em; color: var(--teal); font-weight: 700; }
.side .sub { margin: 2px 0 8px 22px; border-left: 2px solid var(--light-blue); }
.side .sub a { font-size: 13.5px; padding: 3px 10px; color: var(--mid-gray); }
.side .sub a.here { color: var(--blue); font-weight: 700; }
.content { flex: 1; min-width: 0; margin-left: var(--side-w); padding: 28px 40px 60px; max-width: calc(var(--side-w) + 900px); }

/* ---- headings ---- */
.chap-head { margin: 8px 0 26px; padding-bottom: 14px; border-bottom: 3px solid var(--teal); }
.chap-num { font-family: var(--head); color: var(--teal); font-weight: 700; font-size: 15px; }
h1, h2, h3, h4, h5 { font-family: var(--head); color: var(--dark); line-height: 1.55; }
h1 { font-size: 30px; margin: 4px 0; }
.chap-en { font-family: Georgia, serif; font-style: italic; color: var(--mid-gray); font-size: 17px; }
h2 { font-size: 23px; margin: 38px 0 10px; padding-bottom: 4px; border-bottom: 1px solid #dde3e8; }
h3 { font-size: 19.5px; margin: 28px 0 8px; color: var(--blue); }
h4 { font-size: 17.5px; margin: 22px 0 6px; }
h5 { font-size: 16.5px; margin: 18px 0 4px; }
h2 .num, h3 .num { color: var(--teal); margin-right: 4px; }
.chap-inline { font-size: 24px; }
p { margin: 0 0 .8em; }
ul, ol { margin: .2em 0 .9em; padding-left: 1.6em; }
li { margin: .15em 0; }
li.lbl { list-style: none; margin-left: -1.2em; }
.li-lbl { font-weight: 700; margin-right: 4px; }
ul.options { list-style: none; padding-left: 1em; }
blockquote { margin: .6em 0 1em; padding: 8px 18px; background: #f5f7f9; border-left: 4px solid var(--teal); }
.center { text-align: center; }
.center p { text-align: center; }
.right { text-align: right; }
.right p { text-align: right; }
code { font-size: .9em; background: #eef1f3; padding: 0 4px; border-radius: 3px; }
.eng { font-family: Georgia, serif; font-style: italic; color: var(--mid-gray); font-size: .86em; }
.pts { float: right; font-family: var(--head); font-size: 13.5px; font-weight: 700; color: var(--mid-gray); }
.comp { color: var(--teal); }
.hr-fill { display: inline-block; min-width: 40%; border-bottom: 1px solid #aab4bd; }
sup.fn a { text-decoration: none; font-weight: 700; }
.footnotes { margin-top: 36px; padding-top: 10px; border-top: 1px solid #dde3e8; font-size: 14.5px; }
a.xref { font-weight: 700; text-decoration: none; }

/* ---- figures and images ---- */
figure { margin: 22px 0; text-align: center; }
img.fig, img.photo { max-width: 100%; height: auto; }
img.fig { background: #fff; }
img.fig.wide { width: 100%; max-width: 900px; }
.tbl.plain th, .tbl.plain td { border: none; }
.tbl.plain tbody tr:nth-child(even) { background: none; }
.caption { font-size: 14.5px; color: var(--mid-gray); margin-top: 6px; text-align: center; line-height: 1.7; }
.cap-lbl { font-weight: 700; color: var(--dark); }
.mini { display: inline-block; vertical-align: top; min-width: 240px; padding: 0 6px; }
.img-slot { margin: 10px auto; padding: 18px; max-width: 520px; border: 2px dashed #b9c3cb; border-radius: 6px; color: var(--mid-gray); text-align: center; font-size: 14.5px; background: var(--light-gray); }
.math-d { margin: .8em 0; overflow-x: auto; overflow-y: hidden; text-align: center; }

/* ---- tables ---- */
.tbl { overflow-x: auto; margin: 14px 0 18px; }
.tbl table { border-collapse: collapse; margin: 0 auto; font-size: 15.5px; line-height: 1.7; }
.tbl th, .tbl td { border: 1px solid #cfd8de; padding: 5px 10px; vertical-align: top; text-align: left; }
.tbl thead th { background: var(--light-blue); color: var(--dark); font-family: var(--head); }
.tbl tbody tr:nth-child(even) { background: #f7f9fa; }
.tbl td p, .tbl th p { margin: 0; text-align: left; }
table.spec { border-collapse: collapse; width: 100%; margin: 10px 0 18px; font-size: 14.5px; line-height: 1.7; }
table.spec th, table.spec td { border: 1px solid #cfd8de; padding: 4px 10px; text-align: left; vertical-align: top; }
table.spec th { width: 32%; background: var(--light-gray); font-family: var(--head); }

/* ---- boxes (tcolorbox environments) ---- */
.box { margin: 18px 0; padding: 12px 18px 6px; border-radius: 8px; border: 1.5px solid var(--teal); background: #f4f8f7; }
.box-title { font-family: var(--head); font-weight: 700; color: #fff; background: var(--teal); display: inline-block; margin: -12px 0 10px -18px; padding: 3px 16px; border-radius: 8px 0 8px 0; font-size: 15px; }
.box-learningobjectives { border-color: var(--blue); background: #f2f6fb; }
.box-learningobjectives .box-title { background: var(--blue); }
.box-teachernote, .box-teachersnote { border-color: var(--green); background: #f3f7f3; }
.box-teachernote .box-title, .box-teachersnote .box-title { background: var(--green); }
.box-misconceptionbox, .box-commonmistake { border-color: var(--red); background: #fbf4f4; }
.box-misconceptionbox .box-title, .box-commonmistake .box-title { background: var(--red); }
.box-importantnote { border-color: var(--amber); background: #fcf7ef; }
.box-importantnote .box-title { background: var(--amber); }
.box-stimulus { border-color: var(--dark); background: #fff; }
.box-stimulus .box-title { background: var(--dark); }
.box-scoringbox, .box-solutionbox { border-color: var(--orange); background: #fcf8f2; }
.box-scoringbox .box-title, .box-solutionbox .box-title { background: var(--orange); }
.screenkey { margin: 10px 0 18px; padding: 8px 14px; background: #eef6ee; border-left: 4px solid var(--green); border-radius: 4px; }
.fignote { font-style: italic; color: var(--mid-gray); font-size: 15px; }

/* ---- pager, footer ---- */
.pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 48px; padding-top: 16px; border-top: 1px solid #dde3e8; font-family: var(--head); }
.pager a { display: inline-block; max-width: 48%; padding: 8px 16px; border: 1.5px solid var(--teal); border-radius: 8px; text-decoration: none; }
.pager a:hover { background: var(--light-blue); }
.pager .next { text-align: right; margin-left: auto; }
.foot { margin-left: var(--side-w); padding: 18px 40px 40px; font-size: 13.5px; color: var(--mid-gray); border-top: 1px solid #dde3e8; }
.foot p { margin: 0 0 4px; text-align: left; }
.en-note { font-size: 13.5px; font-style: italic; color: var(--mid-gray); }

/* ---- home ---- */
.hero { display: flex; gap: 32px; align-items: center; margin: 10px 0 24px; }
.hero .cover { width: 260px; max-width: 42%; box-shadow: 0 8px 26px rgba(16,42,67,.25); border-radius: 4px; }
.hero h1 { font-size: 34px; }
.hero .sub { font-size: 19px; margin: 6px 0; text-align: left; }
.hero .by { font-family: var(--head); color: var(--mid-gray); text-align: left; }
.btn { display: inline-block; margin: 8px 8px 0 0; padding: 9px 22px; border-radius: 8px; background: var(--teal); color: #fff; font-family: var(--head); font-weight: 700; text-decoration: none; }
.btn:hover { color: #fff; filter: brightness(1.08); }
.btn.ghost { background: #fff; color: var(--teal); border: 1.5px solid var(--teal); }
.toc-list { list-style: none; padding: 0; }
.toc-list a { display: flex; gap: 10px; padding: 6px 4px; border-bottom: 1px solid #eef1f3; text-decoration: none; font-family: var(--head); }
.toc-list .n { min-width: 1.6em; color: var(--teal); font-weight: 700; }

/* ---- minister's quotation (front matter) ---- */
.quote-page { max-width: 780px; margin: 0 auto; color: var(--dark); }
.quote-portrait { margin: 8px 0 36px; }
.quote-portrait img.fig { width: 460px; max-width: 100%; background: none; }
.quote-text { font-family: 'Khmer M2 Web', 'Khmer M2', var(--head); }
.content .quote-lead { max-width: 700px; margin: 0 auto 20px; font-size: 23px; line-height: 2.05; text-align: center; }
.quote-points { list-style: none; width: fit-content; max-width: 100%; margin: 0 auto; padding: 0; font-size: 19px; line-height: 2.1; }
.quote-points li { display: flex; gap: .45em; margin: 0; }
.quote-points .qn { flex: none; color: var(--amber); }
.quote-sign { width: 62%; margin: 44px 0 0 auto; text-align: center; }
.content .quote-sign p { margin: 0; text-align: center; }
.content .sign-intro, .content .sign-office { color: var(--mid-gray); }
.content .sign-name { margin: 6px 0 2px; font-family: 'Khmer M1 Web', 'Khmer M1', var(--head); font-size: 21px; color: var(--dark); }
.sign-rule { width: 84px; margin: 8px auto 10px; border: 0; border-top: 1.5px solid var(--amber); }

/* ---- small screens ---- */
@media (max-width: 900px) {
  .menu-btn { display: inline-block; }
  .side { transform: translateX(-100%); transition: transform .2s ease; z-index: 25; box-shadow: 4px 0 18px rgba(0,0,0,.15); }
  body.menu-open .side { transform: none; }
  .content, .foot { margin-left: 0; padding-left: 16px; padding-right: 16px; }
  .top .top-link { display: none; }
  h1 { font-size: 25px; }
  .hero { flex-direction: column; align-items: flex-start; }
  .hero .cover { max-width: 60%; }
  .content .quote-lead { font-size: 20px; }
  .quote-points { font-size: 17px; }
  .quote-sign { width: 100%; }
  body { font-size: 16.5px; }
}
@media print {
  .top, .side, .pager, .foot { display: none; }
  .content { margin: 0; padding: 0; }
}