/* course.css - stylesheet dùng chung cho mọi bài học & tài liệu tham khảo.
   Bố cục kiểu Tufte: một cột hẹp, chữ serif, in ra giấy vẫn đẹp.
   Phông: Literata (thân bài) + Bitter (tiêu đề, bảng, nhãn). */

/* vietnamese */
@font-face {
  font-family: 'Bitter';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/bitter-400-italic-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Bitter';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/bitter-400-italic-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Bitter';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/bitter-400-italic-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/bitter-400-normal-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/bitter-400-normal-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/bitter-400-normal-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url(fonts/bitter-600-normal-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url(fonts/bitter-600-normal-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url(fonts/bitter-600-normal-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(fonts/bitter-700-normal-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(fonts/bitter-700-normal-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Bitter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(fonts/bitter-700-normal-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Literata';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/literata-400-italic-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Literata';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/literata-400-italic-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Literata';
  font-style: italic;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/literata-400-italic-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/literata-400-normal-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/literata-400-normal-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url(fonts/literata-400-normal-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url(fonts/literata-600-normal-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url(fonts/literata-600-normal-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url(fonts/literata-600-normal-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* vietnamese */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(fonts/literata-700-normal-vietnamese.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}

/* latin-ext */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(fonts/literata-700-normal-latin-ext.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF;
}

/* latin */
@font-face {
  font-family: 'Literata';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url(fonts/literata-700-normal-latin.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

:root {
  --ink: #1a1a1a;
  --ink-soft: #4a4a4a;
  --ink-faint: #7a7a7a;
  --rule: #d8d4cc;
  --paper: #fdfcf9;
  --accent: #8a3324;        /* đỏ gạch */
  --accent-soft: #f5ece9;
  --good: #2d6a4f;
  --good-soft: #eaf3ee;
  --bad: #9b2226;
  --bad-soft: #f9ebeb;
  --sans: "Bitter", "Segoe UI", system-ui, -apple-system, sans-serif;
  --serif: "Literata", "Iowan Old Style", Palatino, Georgia, serif;
  --display: "Bitter", "Iowan Old Style", Palatino, Georgia, serif;
  --mono: "SF Mono", "Cascadia Mono", Consolas, monospace;
}

* { box-sizing: border-box; }

html { font-size: 17.5px; }

body {
  margin: 0;
  padding: 3rem 1.5rem 6rem;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-optical-sizing: auto;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.wrap { max-width: 46rem; margin: 0 auto; }

/* ---------- Kiểu chữ ---------- */

h1 {
  font-family: var(--display);
  font-size: 2.05rem;
  line-height: 1.22;
  font-weight: 700;
  letter-spacing: -0.018em;
  margin: 0 0 0.5rem;
}

h2 {
  font-family: var(--display);
  font-size: 1.26rem;
  font-weight: 600;
  margin: 3rem 0 0.75rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  letter-spacing: -0.008em;
}

h3 {
  font-family: var(--display);
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0.005em;
  margin: 2rem 0 0.5rem;
  color: var(--ink);
}

p { margin: 0 0 1rem; }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { background: var(--accent-soft); }

strong { font-weight: 600; }

em { font-style: italic; }

code, .mono {
  font-family: var(--mono);
  font-size: 0.86em;
  background: #f0ede6;
  padding: 0.1em 0.35em;
  border-radius: 3px;
}

hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }

/* ---------- Phần dẫn nhập ---------- */

.kicker {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.6rem;
}

.dek {
  font-size: 1.04rem;
  color: var(--ink-soft);
  font-style: italic;
  line-height: 1.65;
  margin-bottom: 2rem;
}

.meta {
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--ink-faint);
  margin-top: -1.2rem;
  margin-bottom: 2rem;
}

/* ---------- Hộp ---------- */

.box {
  border-left: 3px solid var(--accent);
  background: #faf7f2;
  padding: 1rem 1.2rem;
  margin: 1.5rem 0;
  font-size: 0.96rem;
}

.box > :last-child { margin-bottom: 0; }

.box .label {
  font-family: var(--sans);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 0.4rem;
}

.box.plain { border-left-color: var(--rule); background: #f7f6f3; }
.box.plain .label { color: var(--ink-faint); }

.box.warn { border-left-color: var(--bad); background: var(--bad-soft); }
.box.warn .label { color: var(--bad); }

/* ---------- Bảng ---------- */

table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--sans);
  font-size: 0.84rem;
  line-height: 1.55;
  margin: 1.5rem 0;
}

th, td {
  text-align: left;
  padding: 0.5rem 0.6rem;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}

th {
  font-weight: 600;
  font-size: 0.73rem;
  letter-spacing: 0.055em;
  text-transform: uppercase;
  color: var(--ink-soft);
  border-bottom: 1.5px solid var(--ink-soft);
}

tbody tr:hover { background: #f7f6f3; }

td a { text-decoration: none; }
td a:hover { text-decoration: underline; text-decoration-color: var(--accent); }

/* ---------- Sơ đồ quy trình ---------- */

.steps { counter-reset: step; list-style: none; padding: 0; margin: 1.5rem 0; }

.steps > li {
  counter-increment: step;
  position: relative;
  padding-left: 2.6rem;
  margin-bottom: 1.1rem;
  font-size: 0.96rem;
}

.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.05rem;
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 50%;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--sans);
  font-size: 0.8rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

.steps > li strong { display: block; font-family: var(--sans); font-size: 0.92rem; }

.steps > li .sub { color: var(--ink-soft); font-size: 0.92rem; }

/* ---------- Quiz ---------- */

.quiz { margin: 1.5rem 0 2rem; }

.q {
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1.1rem 1.2rem;
  margin-bottom: 1rem;
  background: #fff;
}

.q .stem {
  font-family: var(--display);
  font-size: 0.94rem;
  font-weight: 600;
  margin-bottom: 0.9rem;
  line-height: 1.5;
}

.q .opt {
  display: block;
  width: 100%;
  text-align: left;
  font-family: var(--sans);
  font-size: 0.88rem;
  padding: 0.55rem 0.75rem;
  margin-bottom: 0.4rem;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
  transition: background 0.12s, border-color 0.12s;
}

.q .opt:hover:not(:disabled) { background: #f2efe8; border-color: var(--ink-faint); }
.q .opt:disabled { cursor: default; }

.q .opt.correct { background: var(--good-soft); border-color: var(--good); color: var(--good); font-weight: 600; }
.q .opt.wrong   { background: var(--bad-soft); border-color: var(--bad); color: var(--bad); }
.q .opt.dim     { opacity: 0.45; }

.q .why {
  font-size: 0.88rem;
  color: var(--ink-soft);
  margin-top: 0.7rem;
  padding-top: 0.7rem;
  border-top: 1px dashed var(--rule);
  display: none;
}

.q .why.show { display: block; }

.score {
  font-family: var(--sans);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ink-soft);
}

/* ---------- Thẻ lật (retrieval practice) ---------- */

.flip {
  border: 1px solid var(--rule);
  border-radius: 6px;
  padding: 1rem 1.2rem;
  margin: 0.75rem 0;
  background: #fff;
  cursor: pointer;
}

.flip .front { font-family: var(--sans); font-size: 0.92rem; font-weight: 600; }
.flip .back  { display: none; font-size: 0.92rem; color: var(--ink-soft); margin-top: 0.6rem;
               padding-top: 0.6rem; border-top: 1px dashed var(--rule); }
.flip.open .back { display: block; }
.flip .hint { font-family: var(--sans); font-size: 0.7rem; color: var(--ink-faint);
              text-transform: uppercase; letter-spacing: 0.08em; }

/* ---------- Icon (Lucide v1.61.0, lưu cục bộ trong assets/icons/) ----------
   Dùng <i class="i i-check i-ok"></i>. Icon lấy màu từ currentColor.
   Nguồn: https://lucide.dev/api/icons/<tên>.svg */

.i {
  display: inline-block;
  width: 0.95em;
  height: 0.95em;
  vertical-align: -0.1em;
  background-color: currentColor;
  -webkit-mask-repeat: no-repeat; mask-repeat: no-repeat;
  -webkit-mask-position: center; mask-position: center;
  -webkit-mask-size: contain; mask-size: contain;
}

.i-check { -webkit-mask-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMiIgc3Ryb2tlLWxpbmVjYXA9InJvdW5kIiBzdHJva2UtbGluZWpvaW49InJvdW5kIiBjbGFzcz0ibHVjaWRlIGx1Y2lkZS1jaGVjayIgYXJpYS1oaWRkZW49InRydWUiPjxwYXRoIGQ9Ik0yMCA2IDkgMTdsLTUtNSI+PC9wYXRoPjwvc3ZnPg=="); mask-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMiIgc3Ryb2tlLWxpbmVjYXA9InJvdW5kIiBzdHJva2UtbGluZWpvaW49InJvdW5kIiBjbGFzcz0ibHVjaWRlIGx1Y2lkZS1jaGVjayIgYXJpYS1oaWRkZW49InRydWUiPjxwYXRoIGQ9Ik0yMCA2IDkgMTdsLTUtNSI+PC9wYXRoPjwvc3ZnPg=="); }
.i-x { -webkit-mask-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMiIgc3Ryb2tlLWxpbmVjYXA9InJvdW5kIiBzdHJva2UtbGluZWpvaW49InJvdW5kIiBjbGFzcz0ibHVjaWRlIGx1Y2lkZS14IiBhcmlhLWhpZGRlbj0idHJ1ZSI+PHBhdGggZD0iTTE4IDYgNiAxOCI+PC9wYXRoPjxwYXRoIGQ9Im02IDYgMTIgMTIiPjwvcGF0aD48L3N2Zz4="); mask-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMiIgc3Ryb2tlLWxpbmVjYXA9InJvdW5kIiBzdHJva2UtbGluZWpvaW49InJvdW5kIiBjbGFzcz0ibHVjaWRlIGx1Y2lkZS14IiBhcmlhLWhpZGRlbj0idHJ1ZSI+PHBhdGggZD0iTTE4IDYgNiAxOCI+PC9wYXRoPjxwYXRoIGQ9Im02IDYgMTIgMTIiPjwvcGF0aD48L3N2Zz4="); }
.i-alert { -webkit-mask-image: url("data:image/svg+xml;base64,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"); mask-image: url("data:image/svg+xml;base64,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"); }
.i-dashed { -webkit-mask-image: url("data:image/svg+xml;base64,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"); mask-image: url("data:image/svg+xml;base64,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"); }
.i-arrow { -webkit-mask-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMiIgc3Ryb2tlLWxpbmVjYXA9InJvdW5kIiBzdHJva2UtbGluZWpvaW49InJvdW5kIiBjbGFzcz0ibHVjaWRlIGx1Y2lkZS1hcnJvdy1yaWdodCIgYXJpYS1oaWRkZW49InRydWUiPjxwYXRoIGQ9Ik01IDEyaDE0Ij48L3BhdGg+PHBhdGggZD0ibTEyIDUgNyA3LTcgNyI+PC9wYXRoPjwvc3ZnPg=="); mask-image: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9IiMwMDAiIHN0cm9rZS13aWR0aD0iMiIgc3Ryb2tlLWxpbmVjYXA9InJvdW5kIiBzdHJva2UtbGluZWpvaW49InJvdW5kIiBjbGFzcz0ibHVjaWRlIGx1Y2lkZS1hcnJvdy1yaWdodCIgYXJpYS1oaWRkZW49InRydWUiPjxwYXRoIGQ9Ik01IDEyaDE0Ij48L3BhdGg+PHBhdGggZD0ibTEyIDUgNyA3LTcgNyI+PC9wYXRoPjwvc3ZnPg=="); }

.i-ok   { color: var(--good); }
.i-warn { color: #a16207; }
.i-no   { color: var(--bad); }

/* ---------- Chân trang ---------- */

.footer {
  margin-top: 4rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--ink-faint);
}

.footer a { color: var(--ink-soft); }

.next {
  display: block;
  margin: 2.5rem 0 0;
  padding: 1rem 1.2rem;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  text-decoration: none;
  color: var(--ink);
  background: #fff;
}

.next .label { font-family: var(--sans); font-size: 0.7rem; font-weight: 700;
               letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent); display: block; }
.next .t { font-family: var(--sans); font-weight: 600; font-size: 0.95rem; }

/* ---------- In ---------- */

@media print {
  body { padding: 0; background: #fff; font-size: 11pt; }
  .q .opt { border: 1px solid #ccc; }
  .next, .no-print { display: none; }
  h2 { page-break-after: avoid; }
  .q, table, .box { page-break-inside: avoid; }
  a { color: #000; text-decoration: none; }
  a::after { content: " (" attr(href) ")"; font-size: 8pt; color: #666; }
}

@media (max-width: 640px) {
  html { font-size: 16.5px; }
  body { padding: 1.5rem 1rem 4rem; }
  h1 { font-size: 1.6rem; }
}