/* ==========================================================================
   Truong Thanh Gia Thinh — Mechanical & Piping Engineer
   Layout and theme. Dark is the default; light is opt-in via data-theme.
   ========================================================================== */

/* ---------- tokens ---------- */
:root {
  --bg:          #0a0f1c;
  --bg-2:        #0d1424;
  --panel:       #111a2e;
  --panel-2:     #16203a;
  --line:        #1f2b46;
  --line-2:      #2b3a5c;

  --fg:          #e9eef8;
  --fg-2:        #9fb0cb;
  --fg-3:        #64748b;

  --flame:       #f5a524;   /* natural gas */
  --flame-2:     #ffc860;
  --steel:       #4fb3d9;   /* carbon steel pipe */
  --weld:        #34d399;

  --grid:        rgba(120, 160, 220, 0.055);
  --sym:         rgba(120, 160, 220, 0.10);
  --shadow:      0 18px 50px -18px rgba(0, 0, 0, 0.75);

  --sans: 'Space Grotesk', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, 'Cascadia Code', Consolas, monospace;

  --maxw: 1080px;
  --nav-h: 62px;
  --r: 12px;
}

:root[data-theme="light"] {
  --bg:      #f6f7fa;
  --bg-2:    #eef1f6;
  --panel:   #ffffff;
  --panel-2: #f3f5f9;
  --line:    #dde3ed;
  --line-2:  #c6d0e0;

  --fg:      #101828;
  --fg-2:    #4a5a73;
  --fg-3:    #7b8aa3;

  --flame:   #b96b00;
  --flame-2: #8a5100;
  --steel:   #12708f;
  --weld:    #0e7f5c;

  --grid:    rgba(30, 70, 130, 0.06);
  --sym:     rgba(30, 70, 130, 0.11);
  --shadow:  0 14px 38px -18px rgba(20, 40, 80, 0.28);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 18px);
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--fg);
  font-size: 15.5px;
  line-height: 1.68;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
svg { display: block; }
::selection { background: var(--flame); color: #0a0f1c; }

/* ---------- page background: isometric grid + P&ID symbols ---------- */
.bg {
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
}
.bg svg { width: 100%; height: 100%; }

.bg-glow {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(60rem 40rem at 78% -8%,  rgba(245, 165, 36, 0.10), transparent 62%),
    radial-gradient(52rem 36rem at 6% 14%,   rgba(79, 179, 217, 0.09), transparent 60%),
    radial-gradient(70rem 50rem at 50% 108%, rgba(52, 211, 153, 0.06), transparent 65%);
}
:root[data-theme="light"] .bg-glow {
  background:
    radial-gradient(60rem 40rem at 78% -8%,  rgba(245, 165, 36, 0.13), transparent 62%),
    radial-gradient(52rem 36rem at 6% 14%,   rgba(79, 179, 217, 0.12), transparent 60%);
}

/* ---------- shell ---------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: 20px;
}

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 60;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 84%, transparent);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}
.nav .wrap {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.brand .mark {
  width: 26px;
  height: 26px;
  flex: none;
  color: var(--flame);
}
.brand .dim { color: var(--fg-3); font-weight: 400; }

.nav-links {
  display: flex;
  gap: 2px;
  margin-left: auto;
  list-style: none;
}
.nav-links a {
  display: block;
  /* the Vietnamese labels are longer and were wrapping onto a second line */
  white-space: nowrap;
  padding: 7px 10px;
  border-radius: 8px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--fg-2);
  transition: color .18s, background .18s;
}
.nav-links a:hover { color: var(--fg); background: var(--panel-2); }
.nav-links a.on { color: var(--flame); }

.nav-tools {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-left: 6px;
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.icon-btn {
  width: 32px;
  height: 32px;
  display: grid;
  place-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--fg-2);
  cursor: pointer;
  transition: color .18s, border-color .18s, transform .18s;
}
.icon-btn:hover {
  color: var(--flame);
  border-color: var(--line-2);
  transform: translateY(-1px);
}
.icon-btn svg { width: 15px; height: 15px; }

.lang-btn {
  /* .icon-btn is a grid, which would stack EN / . / VI vertically */
  display: flex;
  align-items: center;
  white-space: nowrap;
  width: auto;
  padding-inline: 9px;
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .04em;
}
.lang-btn .on { color: var(--flame); }
.lang-btn .off { color: var(--fg-3); }

.burger { display: none; }

/* ---------- hero ---------- */
.hero { padding: 62px 0 54px; position: relative; }

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 290px;
  gap: 46px;
  align-items: center;
}

.tag-term {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 12px 5px 9px;
  border: 1px solid var(--line-2);
  border-radius: 999px;
  background: var(--panel);
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--fg-2);
  margin-bottom: 22px;
}
.tag-term .dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--weld);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--weld) 22%, transparent);
  animation: pulse 2.6s ease-in-out infinite;
}
@keyframes pulse { 0%,100% { opacity: 1 } 50% { opacity: .45 } }
.tag-term b { color: var(--flame); font-weight: 600; }

h1.name {
  font-size: clamp(2.3rem, 6.4vw, 3.9rem);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.035em;
}
h1.name .accent {
  background: linear-gradient(100deg, var(--flame) 10%, var(--flame-2) 55%, var(--steel) 115%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.role {
  margin-top: 14px;
  font-family: var(--mono);
  font-size: clamp(.82rem, 2.1vw, .95rem);
  letter-spacing: .01em;
  color: var(--steel);
}

.lede {
  margin-top: 20px;
  max-width: 60ch;
  color: var(--fg-2);
  font-size: 15.5px;
}
.lede b { color: var(--fg); font-weight: 600; }

.cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 17px;
  border-radius: 10px;
  border: 1px solid var(--line-2);
  background: var(--panel);
  color: var(--fg);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  transition: transform .18s, border-color .18s, background .18s, box-shadow .18s;
}
.btn svg { width: 15px; height: 15px; flex: none; }
.btn:hover {
  transform: translateY(-2px);
  border-color: var(--flame);
  box-shadow: var(--shadow);
}
.btn.primary {
  background: linear-gradient(135deg, var(--flame), var(--flame-2));
  border-color: transparent;
  color: #16130a;
}
:root[data-theme="light"] .btn.primary { color: #fff; }

/* portrait */
.portrait {
  position: relative;
  justify-self: center;
  width: 250px;
}
.portrait img {
  width: 100%;
  height: auto;
  aspect-ratio: 1;
  object-fit: cover;
  border-radius: 14px;
  border: 1px solid var(--line-2);
  background: var(--panel);
  /* tranh minh hoa da duoc chinh mau san - khong ap them bo loc anh chup */
  filter: none;
}
/* drafting corner ticks */
.portrait::before,
.portrait::after {
  content: "";
  position: absolute;
  width: 26px; height: 26px;
  border: 2px solid var(--flame);
  opacity: .8;
}
.portrait::before { top: -8px;  left: -8px;  border-right: 0; border-bottom: 0; border-radius: 4px 0 0 0; }
.portrait::after  { bottom: -8px; right: -8px; border-left: 0;  border-top: 0;    border-radius: 0 0 4px 0; }

/* hero spool drawing */
.spool {
  margin-top: 46px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: linear-gradient(180deg, var(--panel), var(--bg-2));
  overflow: hidden;
  position: relative;
}
.spool .cap {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-bottom: 1px solid var(--line);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--fg-3);
}
.spool .cap .lamp { width: 8px; height: 8px; border-radius: 50%; background: var(--line-2); }
.spool .cap .lamp.a { background: var(--flame); }
.spool svg { width: 100%; height: auto; }

.flow {
  stroke-dasharray: 16 190;
  animation: flow 5.5s linear infinite;
}
@keyframes flow { to { stroke-dashoffset: -412; } }

/* ---------- stats strip ---------- */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin-top: 26px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: var(--line);
  overflow: hidden;
}
.stat { background: var(--panel); padding: 16px 18px; }
.stat .n {
  font-family: var(--mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--flame);
  line-height: 1.1;
}
.stat .k {
  margin-top: 3px;
  font-size: 11.5px;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--fg-3);
}

/* ---------- sections ---------- */
section { padding: 54px 0; scroll-margin-top: calc(var(--nav-h) + 10px); }

.sec-head { margin-bottom: 26px; }
.sec-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--flame);
}
.sec-label svg { width: 13px; height: 13px; }
.sec-head h2 {
  margin-top: 9px;
  font-size: clamp(1.5rem, 3.4vw, 2rem);
  font-weight: 700;
  letter-spacing: -0.025em;
}
.sec-head p {
  margin-top: 7px;
  max-width: 62ch;
  color: var(--fg-2);
  font-size: 14.5px;
}

/* ---------- cards ---------- */
.card {
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: var(--panel);
  padding: 20px;
  transition: border-color .2s, transform .2s, box-shadow .2s;
}
.card:hover {
  border-color: var(--line-2);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

/* ---------- experience timeline ---------- */
.tl { position: relative; padding-left: 30px; }
.tl::before {
  content: "";
  position: absolute;
  left: 8px; top: 8px; bottom: 8px;
  width: 3px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--flame), var(--steel) 55%, transparent);
  opacity: .55;
}

.job { position: relative; margin-bottom: 18px; }
/* weld-bead node on the run */
.job::before {
  content: "";
  position: absolute;
  left: -29px; top: 24px;
  width: 15px; height: 15px;
  border-radius: 50%;
  background: var(--bg);
  border: 3px solid var(--steel);
}
.job.now::before {
  border-color: var(--flame);
  box-shadow: 0 0 0 5px color-mix(in srgb, var(--flame) 16%, transparent);
}

.job-top {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  margin-bottom: 4px;
}
.job-top h3 { font-size: 1.05rem; font-weight: 700; letter-spacing: -0.01em; }
.job .when {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--fg-3);
  white-space: nowrap;
}
.job .co {
  font-size: 13px;
  color: var(--steel);
  font-weight: 500;
}
.job .proj {
  display: inline-block;
  margin-top: 9px;
  padding: 2px 9px;
  border: 1px dashed var(--line-2);
  border-radius: 6px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--fg-2);
}
.job ul { list-style: none; margin-top: 11px; }
.job li {
  position: relative;
  padding-left: 19px;
  margin-bottom: 7px;
  color: var(--fg-2);
  font-size: 14.2px;
}
/* flow-arrow bullet */
.job li::before {
  content: "";
  position: absolute;
  left: 2px; top: .62em;
  width: 7px; height: 7px;
  border-top: 1.6px solid var(--flame);
  border-right: 1.6px solid var(--flame);
  transform: rotate(45deg);
  opacity: .85;
}

.chips { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 13px; }
.chip {
  padding: 3px 9px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel-2);
  font-family: var(--mono);
  font-size: 11px;
  color: var(--fg-2);
}
.chip.hot { border-color: color-mix(in srgb, var(--flame) 45%, var(--line)); color: var(--flame); }

/* ---------- skills ---------- */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(255px, 1fr));
  gap: 14px;
}
.skill-card h3 {
  display: flex;
  align-items: center;
  gap: 9px;
  font-size: .96rem;
  font-weight: 700;
  margin-bottom: 12px;
}
.skill-card h3 svg { width: 19px; height: 19px; color: var(--flame); flex: none; }
.skill-card ul { list-style: none; }
.skill-card li {
  display: flex;
  gap: 9px;
  font-size: 13.8px;
  color: var(--fg-2);
  padding: 4px 0;
  border-bottom: 1px dashed var(--line);
}
.skill-card li:last-child { border-bottom: 0; }
.skill-card li::before {
  content: "—";
  color: var(--steel);
  font-family: var(--mono);
  flex: none;
}

/* toolchain */
.tools {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
  margin-top: 14px;
}
.tool {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 13px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  font-size: 13px;
  font-weight: 500;
  transition: border-color .18s, transform .18s;
}
.tool:hover { border-color: var(--flame); transform: translateY(-2px); }
.tool .sq {
  width: 9px; height: 9px;
  border-radius: 2px;
  flex: none;
  background: var(--steel);
}
.tool.core .sq { background: var(--flame); }
.tool small {
  display: block;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--fg-3);
  font-weight: 400;
}

/* ---------- standards ---------- */
.codes { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.code {
  padding: 7px 13px;
  border: 1px solid var(--line-2);
  border-radius: 8px;
  background: var(--panel);
  font-family: var(--mono);
  font-size: 12px;
  color: var(--fg);
}
.code span { color: var(--fg-3); }

/* ---------- education / award ---------- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 14px;
}
.edu .deg { font-size: 1.02rem; font-weight: 700; }
.edu .sch { color: var(--steel); font-size: 13.5px; margin-top: 2px; }
.edu .meta {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--fg-3);
  margin-top: 7px;
}
.edu hr { border: 0; border-top: 1px dashed var(--line); margin: 14px 0; }
.edu .sub-t {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--flame);
}

/* ---------- contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 12px;
}
.cc {
  display: flex;
  align-items: center;
  gap: 13px;
  padding: 15px 17px;
  border: 1px solid var(--line);
  border-radius: var(--r);
  background: var(--panel);
  transition: border-color .18s, transform .18s;
}
.cc:hover { border-color: var(--flame); transform: translateY(-2px); }
.cc svg { width: 19px; height: 19px; color: var(--flame); flex: none; }
.cc .k {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--fg-3);
}
.cc .v { font-size: 13.8px; font-weight: 500; word-break: break-word; }

/* ---------- footer ---------- */
footer {
  border-top: 1px solid var(--line);
  padding: 30px 0 40px;
  margin-top: 30px;
}
.foot {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}
.foot .n { font-weight: 700; }
.foot .s {
  font-family: var(--mono);
  font-size: 11.5px;
  color: var(--fg-3);
  margin-top: 2px;
}
.foot-links { display: flex; gap: 8px; }

/* ---------- reveal ----------
   Gated on .js so that with scripting off (or site.js failing to load) the
   whole page still renders instead of everything below the hero going blank. */
.js .rv {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .6s cubic-bezier(.2,.7,.3,1), transform .6s cubic-bezier(.2,.7,.3,1);
}
.js .rv.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .rv { opacity: 1; transform: none; transition: none; }
  .flow, .tag-term .dot { animation: none; }
}

/* ---------- responsive ---------- */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .portrait { order: -1; width: 180px; justify-self: start; }
  .stats { grid-template-columns: repeat(2, 1fr); }
}

/* Nav tieng Viet co 8 muc can ~1019px; duoi nguong nay chuyen sang menu mobile. */
@media (max-width: 1070px) {
  .nav-links {
    position: fixed;
    inset: var(--nav-h) 0 auto 0;
    flex-direction: column;
    gap: 0;
    padding: 10px 20px 18px;
    border-bottom: 1px solid var(--line);
    background: var(--bg);
    box-shadow: var(--shadow);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { white-space: normal; padding: 11px 6px; font-size: 15px; border-bottom: 1px solid var(--line); border-radius: 0; }
  .burger { display: grid; }
  .nav-tools { margin-left: auto; }
  .hero { padding: 40px 0 34px; }
  section { padding: 42px 0; }
  .tl { padding-left: 24px; }
  .job::before { left: -23px; width: 13px; height: 13px; }
  .job .when { margin-left: 0; width: 100%; }
}

@media (max-width: 400px) {
  body { font-size: 15px; }
  .wrap { padding-inline: 16px; }
  .stats { grid-template-columns: 1fr; }
}

/* ---------- print ---------- */
@media print {
  .nav, .bg, .bg-glow, .cta, .spool, footer { display: none; }
  body { background: #fff; color: #000; font-size: 11pt; }
  .card, .cc { border-color: #ccc; break-inside: avoid; }
}

/* ---------- thẻ công cụ (tránh trùng .tool của mục Stack) ---------- */
.tool-top { display: flex; align-items: flex-start; gap: 12px; margin-bottom: 11px; }
.tool-ico { width: 34px; height: 34px; flex: none; color: var(--flame); }
.toolcard h3 { font-size: 1.05rem; font-weight: 700; letter-spacing: -0.01em; }
.tool-sub {
  font-family: var(--mono); font-size: 11.5px; color: var(--steel); margin-top: 2px;
}
.toolcard ul { list-style: none; margin-bottom: 12px; }
.toolcard li {
  position: relative; padding-left: 19px; margin-bottom: 7px;
  color: var(--fg-2); font-size: 14px;
}
.toolcard li::before {
  content: ""; position: absolute; left: 2px; top: .62em;
  width: 7px; height: 7px;
  border-top: 1.6px solid var(--flame); border-right: 1.6px solid var(--flame);
  transform: rotate(45deg); opacity: .85;
}
.tool-act { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.tool-act .btn { padding: 8px 14px; font-size: 13px; }
.tool-note {
  margin-top: 14px; font-size: 13px; color: var(--fg-3); text-align: center;
}

/* ---------- dòng thông tin việc làm ---------- */
.job-meta {
  display: flex; flex-wrap: wrap; align-items: center;
  gap: 4px 0; margin-top: 5px;
  font-size: 12.5px; color: var(--fg-3);
}
.job-meta .jm { display: inline-flex; align-items: center; }
.job-meta .jm + .jm::before {
  content: ""; width: 3px; height: 3px; border-radius: 50%;
  background: currentColor; opacity: .6; margin: 0 9px;
}
.when .dur { font-weight: 400; color: var(--fg-3); }
.when .dur::before { content: " · "; }

/* ---------- Claude skills ---------- */
.skills-list { display: grid; gap: 10px; }

.skillrow { padding: 15px 17px; }
.skillrow-head {
  display: flex; flex-wrap: wrap; align-items: flex-start;
  gap: 10px 14px; justify-content: space-between;
}
.skillrow h3 {
  font-family: var(--mono); font-size: 1rem; font-weight: 700;
  letter-spacing: -0.01em; word-break: break-word;
}
.skillrow-meta {
  font-family: var(--mono); font-size: 11.5px; color: var(--fg-3); margin-top: 3px;
}
.skillrow-act { display: flex; flex-wrap: wrap; gap: 7px; }
.skillrow-act .btn { padding: 7px 13px; font-size: 12.5px; }
.skillrow-desc {
  margin-top: 10px; color: var(--fg-2); font-size: 14px; max-width: 78ch;
}

.skillmsg {
  border: 1px dashed var(--line-2); border-radius: var(--r);
  padding: 20px; text-align: center;
}
.skillmsg .t { font-weight: 600; font-size: 14px; }
.skillmsg .b {
  color: var(--fg-2); font-size: 13px; margin-top: 5px;
  max-width: 62ch; margin-inline: auto;
}
.skillmsg .btn { margin-top: 12px; }
.skillmsg.warn { border-color: color-mix(in srgb, var(--flame) 45%, var(--line)); }
.skillmsg.warn .t { color: var(--flame); }
.skillmsg.load .t { color: var(--fg-3); font-weight: 400; }

.skills-how {
  margin-top: 14px; border: 1px solid var(--line); border-radius: var(--r);
  background: var(--panel); padding: 12px 16px;
}
.skills-how summary {
  cursor: pointer; font-size: 13.5px; font-weight: 600; color: var(--fg-2);
}
.skills-how summary:hover { color: var(--flame); }
.skills-how p { margin-top: 9px; font-size: 13.5px; color: var(--fg-2); }
.skills-how pre {
  margin-top: 8px; padding: 11px 13px; overflow-x: auto;
  background: var(--bg-2); border: 1px solid var(--line); border-radius: 8px;
}
.skills-how code {
  font-family: var(--mono); font-size: 12.5px; color: var(--fg); white-space: pre;
}
.skills-how code span { color: var(--fg-3); }

/* Muc Hoc van gap lai thanh mot nut bam. Summary phai giu display:list-item,
   vi dat display:flex la Chrome bo luon tam giac mo/dong. */
.edufold {
  border: 1px solid var(--line); border-radius: var(--r);
  background: var(--panel); padding: 16px 20px;
  transition: border-color .18s;
}
.edufold:hover { border-color: var(--line-2); }
.edufold summary {
  cursor: pointer; margin-left: 2px;
  font-family: var(--sans); font-size: clamp(1.15rem, 2.6vw, 1.5rem);
  font-weight: 700; letter-spacing: -0.02em; color: var(--fg);
  list-style-position: outside;
}
.edufold summary::marker { color: var(--flame); font-size: .75em; }
.edufold summary svg {
  /* trang nay co rule chung svg{display:block}, de nguyen thi icon xuong
     dong rieng va vertical-align khong con tac dung */
  display: inline-block;
  width: 1.05em; height: 1.05em; color: var(--flame);
  vertical-align: -0.16em; margin-right: 10px;
}
.edufold summary:hover { color: var(--flame); }
.edufold[open] summary {
  padding-bottom: 13px; margin-bottom: 15px;
  border-bottom: 1px solid var(--line);
}
/* the ben trong phai sang hon nen khoi gap moi con phan biet duoc */
.edufold .card { background: var(--panel-2); }

.skills-refresh {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px;
  justify-content: center; margin-top: 4px;
}
.skills-refresh .btn { padding: 6px 13px; font-size: 12.5px; }
.skills-hint { font-size: 12px; color: var(--fg-3); }