@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;700&family=Inter:wght@400;500;600&family=JetBrains+Mono:wght@400;500;700&display=swap');

:root {
  --sidebar-width: 260px;
  --color-bg: #0A1F33;
  --color-bg-deep: #071726;
  --color-surface: #0F2A44;
  --color-border: #1E4976;
  --color-grid: rgba(94, 169, 214, 0.10);
  --color-text: #E6EDF3;
  --color-muted: #7C96B3;
  --color-accent: #5EEAD4;
  --color-server: #FBBF24;
  --color-pink: #FB7185;
  --color-blue: #93C5FD;
  --color-purple: #C4B5FD;
  --color-green: #86EFAC;
  --color-orange: #FB923C;
  --group-c1: var(--color-accent);
  --group-c2: var(--color-server);
  --group-c3: var(--color-blue);
  --group-c4: var(--color-pink);
  --group-c5: var(--color-purple);
  --group-c6: var(--color-green);
  --group-c7: var(--color-orange);
  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font-body);
  background:
    linear-gradient(var(--color-grid) 1px, transparent 1px) 0 0/40px 40px,
    linear-gradient(90deg, var(--color-grid) 1px, transparent 1px) 0 0/40px 40px,
    radial-gradient(ellipse at 50% -10%, #123252 0%, var(--color-bg) 55%, var(--color-bg-deep) 100%);
  color: var(--color-text);
  display: flex;
  min-height: 100vh;
}

#sidebar-placeholder {
  width: var(--sidebar-width);
  flex-shrink: 0;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
}

.sidebar-inner { position: sticky; top: 0; padding: 24px 16px; }

.sidebar-home, .sidebar-link {
  display: block;
  color: var(--color-muted);
  text-decoration: none;
  padding: 10px 12px;
  border-radius: 8px;
  margin-bottom: 4px;
  font-size: 14px;
}

.sidebar-home.active, .sidebar-link.active {
  background: rgba(94, 234, 212, 0.12);
  color: var(--color-accent);
}

.sidebar-list { list-style: none; padding: 0; margin: 6px 0 0; }
.sidebar-link { display: flex; gap: 8px; align-items: flex-start; }
.check { color: var(--color-server); width: 14px; flex-shrink: 0; }

.sidebar-group-block {
  --gc: var(--group-c1);
  border-left: 2px solid color-mix(in srgb, var(--gc) 35%, transparent);
  padding-left: 10px;
  margin: 18px 0 0;
}
.sidebar-group-block.group-c1 { --gc: var(--group-c1); }
.sidebar-group-block.group-c2 { --gc: var(--group-c2); }
.sidebar-group-block.group-c3 { --gc: var(--group-c3); }
.sidebar-group-block.group-c4 { --gc: var(--group-c4); }
.sidebar-group-block.group-c5 { --gc: var(--group-c5); }
.sidebar-group-block.group-c6 { --gc: var(--group-c6); }

.sidebar-group {
  display: flex;
  align-items: center;
  gap: 6px;
  width: 100%;
  border: none;
  background: none;
  margin: 0;
  padding: 4px 2px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .07em;
  text-transform: uppercase;
  color: var(--gc);
  border-radius: 6px;
  transition: background .15s;
}
.sidebar-group:hover { background: color-mix(in srgb, var(--gc) 10%, transparent); }
.sidebar-group-icon { font-size: 13px; filter: grayscale(0); }
.sidebar-group-label { flex: 1; text-align: left; }
.sidebar-group-chevron {
  font-size: 10px;
  transition: transform .15s;
  flex-shrink: 0;
}
.sidebar-group[aria-expanded="false"] .sidebar-group-chevron { transform: rotate(-90deg); }
.sidebar-list.collapsed { display: none; }
.sidebar-group-block .sidebar-link.active {
  background: color-mix(in srgb, var(--gc) 16%, transparent);
  color: var(--gc);
}
.sidebar-group-block .check { color: var(--gc); }

main {
  flex: 1;
  padding: 40px 48px;
  max-width: 960px;
}

main h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 28px;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
}
.intro { color: var(--color-muted); margin-bottom: 32px; line-height: 1.6; }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--color-accent);
  text-transform: uppercase;
  border: 1px solid var(--color-border);
  display: inline-block;
  padding: 5px 12px;
  border-radius: 999px;
  background: rgba(94, 234, 212, 0.06);
  margin-bottom: 16px;
}

.stage {
  position: relative;
  background: linear-gradient(180deg, rgba(15, 42, 68, 0.7), rgba(10, 31, 51, 0.5));
  border: 1px solid var(--color-border);
  border-radius: 16px;
  min-height: 320px;
  padding: 24px;
  overflow-x: auto;
  overflow-y: hidden;
  margin-bottom: 24px;
}

.diagram {
  position: relative;
  width: 100%;
  min-width: 640px;
  height: 280px;
}

.btn {
  font-family: var(--font-mono);
  letter-spacing: .04em;
  background: var(--color-accent);
  color: #04241f;
  border: none;
  padding: 10px 20px;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  font-size: 14px;
  transition: transform .15s, box-shadow .15s;
}
.btn:hover:not(:disabled) { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(94, 234, 212, .25); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none; }

.prevnext { display: flex; justify-content: space-between; margin-top: 32px; }
.prevnext-link { color: var(--color-accent); text-decoration: none; font-size: 14px; }
.prevnext-link.disabled { color: var(--color-muted); }

.fullscreen-toggle {
  position: fixed;
  top: 16px;
  right: 16px;
  z-index: 50;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-muted);
  cursor: pointer;
  transition: color .15s, border-color .15s;
}
.fullscreen-toggle:hover { color: var(--color-accent); border-color: var(--color-accent); }
.fullscreen-toggle svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 1.8; }
.fullscreen-toggle .icon-exit { display: none; }
:fullscreen .fullscreen-toggle .icon-enter { display: none; }
:fullscreen .fullscreen-toggle .icon-exit { display: block; }
@media (max-width: 720px){ .fullscreen-toggle { top: 10px; right: 10px; width: 36px; height: 36px; } }

.packet {
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent);
  box-shadow: 0 0 14px rgba(94, 234, 212, 0.7);
  transition: left 2.2s ease, top 2.2s ease, opacity 0.3s ease;
  opacity: 0;
}
.packet.visible { opacity: 1; }
.packet.request { background: var(--color-server); box-shadow: 0 0 14px rgba(251, 191, 36, 0.7); }
.packet.response { background: var(--color-accent); box-shadow: 0 0 14px rgba(94, 234, 212, 0.7); }

.packet-label {
  position: absolute;
  transform: translate(-50%, -140%);
  background: var(--color-bg-deep);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  white-space: nowrap;
  opacity: 0;
  transition: left 2.2s ease, top 2.2s ease, opacity 0.3s ease;
  pointer-events: none;
  z-index: 3;
}
.packet-label.visible { opacity: 1; }
.packet-label.request { color: var(--color-server); border-color: rgba(251, 191, 36, 0.4); }
.packet-label.response { color: var(--color-accent); border-color: rgba(94, 234, 212, 0.4); }

.node {
  position: absolute;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100px;
  text-align: center;
}
.node-icon {
  position: relative;
  width: 56px;
  height: 56px;
  border-radius: 12px;
  border: 1.5px solid var(--color-border);
  background: var(--color-surface);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color .3s, box-shadow .3s, transform .3s;
}
.node-icon svg {
  width: 26px;
  height: 26px;
  stroke: var(--color-muted);
  fill: none;
  stroke-width: 1.6;
  transition: stroke .3s;
}
.node-label {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted);
  transition: color .3s;
  line-height: 1.4;
}
.node-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-accent);
}
.node-desc {
  margin-top: 4px;
  font-size: 11px;
  color: var(--color-muted);
  line-height: 1.35;
}

.node.active .node-icon {
  border-color: var(--ping, var(--color-accent));
  transform: translateY(-2px);
  box-shadow:
    0 0 0 4px color-mix(in srgb, var(--ping, var(--color-accent)) 18%, transparent),
    0 0 22px color-mix(in srgb, var(--ping, var(--color-accent)) 45%, transparent);
}
.node.active .node-icon svg { stroke: var(--ping, var(--color-accent)); }
.node.active .node-label { color: var(--ping, var(--color-accent)); }
.node.active .node-icon::after {
  content: "";
  position: absolute;
  inset: -6px;
  border-radius: 14px;
  border: 1.5px solid var(--ping, var(--color-accent));
  animation: nodePing 1.15s ease-out infinite;
  pointer-events: none;
}
@keyframes nodePing {
  0% { transform: scale(.88); opacity: .9; }
  100% { transform: scale(1.35); opacity: 0; }
}

.flow-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  padding: 3px 10px;
  border-radius: 999px;
  margin-bottom: 8px;
  text-transform: uppercase;
}
.flow-tag.request { background: rgba(251, 191, 36, 0.12); color: var(--color-server); border: 1px solid rgba(251, 191, 36, 0.35); }
.flow-tag.response { background: rgba(94, 234, 212, 0.12); color: var(--color-accent); border: 1px solid rgba(94, 234, 212, 0.35); }
.flow-tag.idle { background: rgba(124, 150, 179, 0.12); color: var(--color-muted); border: 1px solid var(--color-border); }

.console {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 8px;
}
@media (max-width: 720px) { .console { grid-template-columns: 1fr; } }
.pane {
  background: var(--color-bg-deep);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 16px 18px;
  min-height: 96px;
}
.pane .tag {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .1em;
  color: var(--color-muted);
  text-transform: uppercase;
}
.pane .step-text { margin-top: 8px; font-size: 14.5px; color: var(--color-text); line-height: 1.5; }
.pane pre {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--color-accent);
  white-space: pre-wrap;
  word-break: break-word;
  min-height: 18px;
}
.pane pre.request-data { color: var(--color-server); }

.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 16px;
}
.info-card {
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: 12px;
  padding: 16px 18px;
}
.info-card .info-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: rgba(94, 234, 212, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 10px;
}
.info-card .info-icon svg { width: 20px; height: 20px; stroke: var(--color-accent); fill: none; stroke-width: 1.7; }
.info-card h3 {
  font-family: var(--font-display);
  font-size: 15px;
  margin: 0 0 6px;
  color: var(--color-text);
}
.info-card p { margin: 0; font-size: 13px; color: var(--color-muted); line-height: 1.55; }
.info-card code {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-server);
  background: rgba(251, 191, 36, 0.1);
  padding: 1px 5px;
  border-radius: 4px;
}

.stepper { font-family: var(--font-mono); font-size: 12px; color: var(--color-muted); text-align: center; margin-top: 14px; }
.stepper b { color: var(--color-server); }

.mini-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(420px, 1fr));
  gap: 20px;
  margin-top: 16px;
}
.mini-block {
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: 14px;
  padding: 18px;
}
.mini-block h3 {
  font-family: var(--font-display);
  font-size: 16px;
  margin: 0 0 12px;
  color: var(--color-text);
}
.mini-stage {
  position: relative;
  background: linear-gradient(180deg, rgba(15, 42, 68, 0.7), rgba(10, 31, 51, 0.5));
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 16px;
  overflow-x: auto;
  margin-bottom: 12px;
}
.mini-diagram { position: relative; width: 100%; min-width: 340px; height: 150px; }

.roadmap-group-block {
  --gc: var(--group-c1);
  border: 1px solid color-mix(in srgb, var(--gc) 30%, var(--color-border));
  border-radius: 14px;
  padding: 4px 20px 8px;
  margin: 24px 0 0;
  background: color-mix(in srgb, var(--gc) 5%, transparent);
}
.roadmap-group-block:first-child { margin-top: 4px; }
.roadmap-group-block.group-c1 { --gc: var(--group-c1); }
.roadmap-group-block.group-c2 { --gc: var(--group-c2); }
.roadmap-group-block.group-c3 { --gc: var(--group-c3); }
.roadmap-group-block.group-c4 { --gc: var(--group-c4); }
.roadmap-group-block.group-c5 { --gc: var(--group-c5); }
.roadmap-group-block.group-c6 { --gc: var(--group-c6); }

.roadmap-group {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--gc);
  padding: 14px 4px 6px;
}
.roadmap-group-icon { font-size: 16px; }

.roadmap-link {
  display: block;
  color: var(--color-text);
  text-decoration: none;
  padding: 14px 4px;
  border-bottom: 1px solid var(--color-border);
  transition: color .2s, padding-left .2s;
}
.roadmap-group-block .roadmap-link:last-child { border-bottom: none; }
.roadmap-link:hover { color: var(--color-accent); padding-left: 10px; }
.roadmap-group-block .roadmap-link:hover { color: var(--gc); }

.url-part { cursor: pointer; padding: 2px 4px; border-radius: 4px; }
.url-part:hover, .url-part.active { background: rgba(94, 234, 212, 0.15); color: var(--color-accent); }

@media (max-width: 768px) {
  body { flex-direction: column; }
  #sidebar-placeholder {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--color-border);
  }
  .sidebar-inner { position: static; padding: 12px; }
  .sidebar-list { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 8px; }
  .sidebar-list li { flex: 1 1 auto; }
  main { padding: 24px; }
}

.callout {
  border-left: 3px solid var(--color-server);
  padding: 10px 16px;
  background: rgba(251, 191, 36, 0.06);
  border-radius: 0 8px 8px 0;
  font-size: 14px;
  color: var(--color-text);
  margin: 16px 0;
  line-height: 1.6;
}
.callout b { color: var(--color-server); }
.callout.tip { border-left-color: var(--color-accent); background: rgba(94, 234, 212, 0.06); }
.callout.tip b { color: var(--color-accent); }

.code-block {
  background: var(--color-bg-deep);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  overflow: hidden;
  margin: 16px 0;
}
.code-block .head {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-bottom: 1px solid var(--color-border);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-muted);
}
.code-block .head .dot { width: 7px; height: 7px; border-radius: 50%; background: var(--color-accent); }
.code-block pre {
  margin: 0;
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.65;
  color: var(--color-text);
  overflow-x: auto;
}
.code-block .php-tag { color: var(--color-server); }
.code-block .php-fn { color: var(--color-pink); }
.code-block .php-str { color: var(--color-accent); }
.code-block .cmt { color: var(--color-muted); }
.code-block .html-tag { color: #93C5FD; }

.steps-list {
  counter-reset: step;
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.steps-list li {
  counter-increment: step;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 12px 16px;
  background: var(--color-bg-deep);
}
.steps-list li::before {
  content: counter(step);
  flex-shrink: 0;
  width: 24px; height: 24px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-accent);
  font-family: var(--font-mono);
  font-size: 12px;
  display: flex; align-items: center; justify-content: center;
  margin-top: 1px;
}
.steps-list .s-main { font-size: 14.5px; color: var(--color-text); line-height: 1.5; }
.steps-list .s-detail { font-family: var(--font-mono); font-size: 12px; color: var(--color-muted); margin-top: 4px; }

.exercise {
  border: 1px solid var(--color-border);
  border-radius: 14px;
  padding: 22px 24px;
  background: linear-gradient(180deg, rgba(15, 42, 68, 0.5), rgba(10, 31, 51, 0.35));
  margin: 20px 0 32px;
}
.exercise h3 {
  font-family: var(--font-display);
  font-size: 17px;
  margin: 0 0 10px;
  color: var(--color-accent);
}
.exercise details {
  margin-top: 16px;
  border: 1px solid var(--color-border);
  border-radius: 10px;
  background: var(--color-bg-deep);
  padding: 4px 16px;
}
.exercise summary {
  cursor: pointer;
  padding: 10px 0;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--color-accent);
  user-select: none;
}
.exercise details[open] summary { border-bottom: 1px solid var(--color-border); margin-bottom: 12px; }
.exercise details .code-block { margin: 0 0 16px; }

.form-demo-input {
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-deep);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 13.5px;
}
.form-demo-input:focus { outline: none; border-color: var(--color-accent); }

.get-results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 10px;
  margin-top: 16px;
}
.get-result-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  background: var(--color-bg-deep);
  border: 1px solid var(--color-border);
  border-radius: 8px;
  padding: 10px 14px;
  font-size: 13.5px;
}
.get-result-card b { color: var(--color-accent); white-space: nowrap; }

.exercise.mini {
  padding: 16px 20px;
  margin: 0 0 32px;
}
.exercise.mini h4 {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin: 0 0 8px;
}
.exercise.mini p.intro { margin-bottom: 12px; }

.answer-lock { margin-top: 14px; }
.lock-row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; }
.lock-input {
  flex: 1;
  min-width: 160px;
  padding: 9px 12px;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: var(--color-bg-deep);
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: 13px;
}
.lock-input:focus { outline: none; border-color: var(--color-accent); }
.lock-btn-sm {
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 9px 16px;
}
.lock-msg { font-family: var(--font-mono); font-size: 12px; margin: 8px 0 0; min-height: 16px; }
.lock-msg.err { color: var(--color-pink); }
.lock-msg.ok { color: var(--color-accent); }
.lock-content { margin-top: 12px; }
.lock-content .code-block { margin: 0; }

main h2 {
  font-family: var(--font-display);
  font-size: 20px;
  margin: 36px 0 4px;
}
main h2 + .intro { margin-top: 0; }

.pipe-step {
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: 12px;
  padding: 16px 20px;
  font-size: 14px;
  transition: background 0.3s, border-color 0.3s, color 0.3s;
}
.pipe-step.active { background: rgba(94, 234, 212, 0.15); border-color: var(--color-accent); color: var(--color-accent); }

/* ===== Nhóm màu thứ 7 — dùng cho nhóm "Quy trình làm đồ án" (bài 19-26) ===== */
.sidebar-group-block.group-c7 { --gc: var(--group-c7); }
.roadmap-group-block.group-c7 { --gc: var(--group-c7); }

/* ===== Bảng tài liệu — đặc tả, use case, test case... ===== */
.doc-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 13.5px;
  background: var(--color-bg-deep);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  overflow: hidden;
}
.doc-table th {
  text-align: left;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--color-muted);
  background: var(--color-surface);
  padding: 10px 14px;
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}
.doc-table td {
  padding: 11px 14px;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
  vertical-align: top;
  line-height: 1.55;
}
.doc-table tr:last-child td { border-bottom: none; }
.doc-table td code, .doc-table th code { font-family: var(--font-mono); font-size: 12.5px; color: var(--color-accent); }
.doc-table .col-id { font-family: var(--font-mono); color: var(--color-server); white-space: nowrap; }
.doc-table .muted { color: var(--color-muted); }
.doc-table-wrap { overflow-x: auto; }

/* ===== Khối "Đầu vào → Đầu ra" ở đầu mỗi bài ===== */
.deliverable {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 20px 0 28px;
}
@media (max-width: 720px) { .deliverable { grid-template-columns: 1fr; } }
.deliverable .box {
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 14px 18px;
  background: var(--color-bg-deep);
}
.deliverable .box.out { border-color: color-mix(in srgb, var(--color-orange) 45%, var(--color-border)); }
.deliverable .box h4 {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--color-muted);
}
.deliverable .box.out h4 { color: var(--color-orange); }
.deliverable .box ul { margin: 0; padding-left: 18px; color: var(--color-text); font-size: 13.5px; line-height: 1.7; }

/* ===== Checklist nghiệm thu cuối mỗi bài ===== */
.checklist {
  border: 1px solid color-mix(in srgb, var(--color-green) 35%, var(--color-border));
  border-radius: 14px;
  padding: 18px 22px;
  background: rgba(134, 239, 172, 0.05);
  margin: 24px 0 32px;
}
.checklist h3 {
  font-family: var(--font-display);
  font-size: 16px;
  margin: 0 0 12px;
  color: var(--color-green);
}
.checklist ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 9px; }
.checklist li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 14px;
  color: var(--color-text);
  line-height: 1.55;
}
.checklist li::before {
  content: "☐";
  color: var(--color-green);
  font-size: 15px;
  flex-shrink: 0;
  line-height: 1.4;
}

/* ===== Sơ đồ quy trình làm đồ án (doan-flow.js) ===== */
.dflow {
  border: 1px solid var(--color-border);
  border-radius: 16px;
  background:
    radial-gradient(ellipse at 15% 0%, rgba(94,234,212,.08), transparent 60%),
    radial-gradient(ellipse at 85% 100%, rgba(251,146,60,.08), transparent 60%),
    var(--color-bg-deep);
  padding: 20px 22px 18px;
  margin: 24px 0 32px;
}
.dflow-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 12px; margin-bottom: 16px; }
.dflow-title {
  font-family: var(--font-display); font-size: 16px; color: var(--color-text);
}
.dflow-sub { font-family: var(--font-mono); font-size: 11px; color: var(--color-muted); }

.dflow-grid {
  position: relative;
  padding-top: 16px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
}
@media (max-width: 860px) { .dflow-grid { grid-template-columns: repeat(2, 1fr); } }

.dflow-card {
  position: relative;
  display: flex; flex-direction: column; gap: 4px;
  padding: 12px 12px 11px;
  border: 1px solid var(--color-border);
  border-radius: 12px;
  background: var(--color-surface);
  text-decoration: none;
  transition: transform .25s, border-color .25s, box-shadow .25s, background .25s;
}
.dflow-card::after {
  content: "›";
  position: absolute; right: -11px; top: 50%; transform: translateY(-50%);
  color: var(--color-border); font-size: 20px; line-height: 1; z-index: 2;
  transition: color .25s;
}
.dflow-card:nth-child(4n)::after,
.dflow-card:nth-child(8)::after { content: none; }
@media (max-width: 860px) {
  .dflow-card:nth-child(4n)::after { content: "›"; }
  .dflow-card:nth-child(2n)::after { content: none; }
}
.dflow-num {
  font-family: var(--font-mono); font-size: 10px; letter-spacing: .08em;
  text-transform: uppercase; color: var(--color-muted);
}
.dflow-icon { font-size: 22px; line-height: 1.1; }
.dflow-name { font-family: var(--font-display); font-size: 13.5px; color: var(--color-text); }
.dflow-out {
  font-family: var(--font-mono); font-size: 10.5px; color: var(--color-muted);
  border-top: 1px dashed var(--color-border); padding-top: 6px; margin-top: 2px;
}
.dflow-card:hover { transform: translateY(-2px); border-color: var(--c); }
.dflow-card:hover .dflow-name { color: var(--c); }

.dflow-card.done {
  border-color: color-mix(in srgb, var(--c) 55%, var(--color-border));
  background: color-mix(in srgb, var(--c) 9%, var(--color-surface));
}
.dflow-card.done .dflow-num { color: var(--c); }
.dflow-card.done::after { color: var(--c); }
.dflow-card.active {
  border-color: var(--c);
  background: color-mix(in srgb, var(--c) 16%, var(--color-surface));
  box-shadow: 0 0 0 1px var(--c), 0 0 26px -6px var(--c);
  transform: translateY(-3px);
  animation: dflowPing 1.1s ease-out;
}
.dflow-card.active .dflow-name,
.dflow-card.active .dflow-num { color: var(--c); }
.dflow-card.here { border-color: var(--c); }
.dflow-card.here .dflow-num::after {
  content: " · bài này"; color: var(--c);
}
@keyframes dflowPing {
  0%   { box-shadow: 0 0 0 0 color-mix(in srgb, var(--c) 60%, transparent), 0 0 26px -6px var(--c); }
  70%  { box-shadow: 0 0 0 14px transparent, 0 0 26px -6px var(--c); }
  100% { box-shadow: 0 0 0 1px var(--c), 0 0 26px -6px var(--c); }
}

.dflow-packet {
  position: absolute; left: 0; top: 0; z-index: 5;
  display: flex; align-items: center; gap: 7px;
  padding: 5px 11px;
  border-radius: 999px;
  background: var(--color-bg-deep);
  border: 1px solid var(--pc, var(--color-accent));
  box-shadow: 0 0 22px -4px var(--pc, var(--color-accent));
  opacity: 0; pointer-events: none;
  transform: translate(-50%, -50%);
  transition: transform .78s cubic-bezier(.45,.05,.25,1), opacity .3s, border-color .4s, box-shadow .4s;
}
.dflow-packet::before {
  content: ""; width: 8px; height: 8px; border-radius: 50%;
  background: var(--pc, var(--color-accent));
  box-shadow: 0 0 10px var(--pc, var(--color-accent));
  animation: dflowBlink 1s infinite;
}
@keyframes dflowBlink { 50% { opacity: .35; } }
.dflow-packet.show { opacity: 1; }
.dflow-packet-label {
  font-family: var(--font-mono); font-size: 11px; white-space: nowrap;
  color: var(--pc, var(--color-accent));
}

.dflow-bar {
  height: 4px; border-radius: 999px; background: var(--color-border);
  margin: 18px 0 14px; overflow: hidden;
}
.dflow-bar i {
  display: block; height: 100%; width: 0;
  border-radius: 999px; background: var(--color-border);
  transition: width .78s cubic-bezier(.45,.05,.25,1), background .4s;
}

.dflow-detail {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
  min-height: 30px; opacity: 0; transition: opacity .3s;
}
.dflow-detail.show { opacity: 1; }
.dflow-chip {
  font-family: var(--font-mono); font-size: 11px;
  padding: 5px 10px; border-radius: 999px;
  border: 1px solid var(--color-border); color: var(--color-muted);
}
.dflow-step { font-family: var(--font-display); font-size: 13px; }
.dflow-arrow { font-size: 14px; }
.dflow-done-tag {
  font-family: var(--font-mono); font-size: 11px; padding: 5px 10px;
  border-radius: 999px; color: var(--color-green);
  border: 1px solid var(--color-green);
  background: rgba(134,239,172,.08);
}

.dflow-controls { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.dflow-controls .btn { font-size: 13px; padding: 8px 16px; }