:root {
  --sb-w: 296px;
  --panel-w: 380px;
  --topbar-h: 56px;

  --bg: #f4f6fb;
  --bg-soft: #ffffff;
  --bg-elev: #ffffff;
  --border: #e6e8ec;
  --border-soft: #eef0f3;
  --text: #1f2328;
  --text-2: #57606a;
  --text-3: #8b949e;

  --primary: #2563eb;
  --primary-2: #4f8cff;
  --primary-soft: #e7f0ff;
  --accent: #06b6d4;
  --accent-2: #8b5cf6;

  --warn: #d97706;
  --green: #16a34a;
  --green-soft: #dcfce7;
  --yellow: #ca8a04;
  --yellow-soft: #fef9c3;
  --red: #dc2626;
  --red-soft: #fee2e2;

  --sb-bg: #0e1525;
  --sb-bg-2: #131c30;
  --sb-text: #d8e0f0;
  --sb-text-2: #94a3b8;
  --sb-text-3: #64748b;
  --sb-border: rgba(255,255,255,.06);
  --sb-hover: rgba(99,144,255,.10);
  --sb-active-bg: linear-gradient(135deg, rgba(79,140,255,.22), rgba(139,92,246,.18));
  --sb-active-text: #ffffff;
  --sb-active-border: rgba(99,144,255,.45);

  --shadow-sm: 0 1px 2px rgba(15,23,42,.06);
  --shadow:    0 4px 16px rgba(15,23,42,.06), 0 1px 2px rgba(15,23,42,.04);
  --shadow-lg: 0 10px 30px rgba(15,23,42,.12), 0 2px 6px rgba(15,23,42,.06);

  --radius: 8px;
  --radius-lg: 12px;

  --grad-hero: linear-gradient(135deg, #1e3a8a 0%, #2563eb 35%, #06b6d4 100%);
  --grad-brand: linear-gradient(135deg, #4f8cff 0%, #06b6d4 50%, #8b5cf6 100%);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei",
               "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  display: flex;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ================= sidebar (dark) ================= */
#sidebar {
  width: var(--sb-w);
  flex: 0 0 var(--sb-w);
  background:
    radial-gradient(ellipse 80% 240px at 0% 0%, rgba(79,140,255,.14), transparent 60%),
    radial-gradient(ellipse 80% 240px at 100% 100%, rgba(139,92,246,.10), transparent 60%),
    linear-gradient(180deg, var(--sb-bg) 0%, var(--sb-bg-2) 100%);
  color: var(--sb-text);
  border-right: 1px solid var(--sb-border);
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: sticky;
  top: 0;
  overflow: hidden;
}
#sidebar::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% -20%, rgba(99,144,255,.12), transparent 50%);
  pointer-events: none;
}
.sb-head {
  position: relative;
  padding: 18px 16px 12px;
  border-bottom: 1px solid var(--sb-border);
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}
.brand-mark {
  width: 36px; height: 36px;
  border-radius: 10px;
  background: var(--grad-brand);
  position: relative;
  box-shadow: 0 0 24px rgba(79,140,255,.35), 0 4px 14px rgba(15,23,42,.4);
  flex: 0 0 36px;
  animation: brandPulse 4s ease-in-out infinite;
}
.brand-mark::before, .brand-mark::after {
  content: "";
  position: absolute;
  border-radius: inherit;
}
.brand-mark::before {
  inset: 6px;
  background: rgba(14,21,37,.55);
  border-radius: 6px;
}
.brand-mark::after {
  inset: 11px;
  border: 1.5px solid rgba(255,255,255,.92);
  border-radius: 50%;
  border-right-color: transparent;
  border-bottom-color: transparent;
  transform: rotate(-30deg);
}
.brand-mark.big {
  width: 56px; height: 56px;
  border-radius: 14px;
  margin-bottom: 14px;
  flex: 0 0 56px;
}
.brand-mark.big::before { inset: 9px; border-radius: 8px; }
.brand-mark.big::after  { inset: 16px; border-width: 2px; }
@keyframes brandPulse {
  0%,100% { box-shadow: 0 0 18px rgba(79,140,255,.30), 0 4px 14px rgba(15,23,42,.4); }
  50%     { box-shadow: 0 0 28px rgba(99,144,255,.55), 0 4px 14px rgba(15,23,42,.4); }
}
.brand-text { min-width: 0; flex: 1; }
.brand-text h1 {
  margin: 0;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--sb-active-text);
  letter-spacing: .01em;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.brand-text p {
  margin: 2px 0 0;
  color: var(--sb-text-3);
  font-size: 11.5px;
}
.sb-search {
  position: relative;
}
.sb-search-ico {
  position: absolute;
  left: 10px; top: 50%;
  transform: translateY(-50%);
  font-size: 12px;
  color: var(--sb-text-3);
  pointer-events: none;
}
.sb-search input {
  width: 100%;
  padding: 7px 10px 7px 30px;
  border: 1px solid var(--sb-border);
  border-radius: 8px;
  font-size: 12.5px;
  outline: none;
  background: rgba(255,255,255,.04);
  color: var(--sb-text);
  transition: all .15s;
}
.sb-search input::placeholder { color: var(--sb-text-3); }
.sb-search input:focus {
  border-color: rgba(99,144,255,.55);
  background: rgba(99,144,255,.08);
  box-shadow: 0 0 0 3px rgba(99,144,255,.12);
}
.sb-foot {
  padding: 10px 16px;
  border-top: 1px solid var(--sb-border);
  color: var(--sb-text-3);
  font-size: 11px;
  position: relative;
}

.tree {
  flex: 1;
  overflow-y: auto;
  padding: 10px 8px 16px;
  position: relative;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,.12) transparent;
}
.tree::-webkit-scrollbar { width: 6px; }
.tree::-webkit-scrollbar-thumb { background: rgba(255,255,255,.12); border-radius: 3px; }
.tree .group { margin: 10px 0; }
.tree .group-title {
  display: flex; align-items: center; gap: 6px;
  padding: 6px 12px;
  font-size: 10.5px; font-weight: 600;
  color: var(--sb-text-3);
  text-transform: uppercase;
  letter-spacing: .08em;
}
.tree .item, .tree .sub-item {
  display: flex; align-items: center; gap: 8px;
  padding: 7px 12px;
  margin: 1px 4px;
  border-radius: 8px;
  font-size: 13px;
  color: var(--sb-text);
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  border: 1px solid transparent;
  transition: background .12s, color .12s, border-color .12s;
  position: relative;
}
.tree .item:hover, .tree .sub-item:hover { background: var(--sb-hover); color: #fff; }
.tree .item.active, .tree .sub-item.active {
  background: var(--sb-active-bg);
  color: var(--sb-active-text);
  border-color: var(--sb-active-border);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,.04);
  font-weight: 600;
}
.tree .item.active::before, .tree .sub-item.active::before {
  content: "";
  position: absolute;
  left: -4px; top: 50%; transform: translateY(-50%);
  width: 3px; height: 60%;
  background: var(--grad-brand);
  border-radius: 3px;
}
.tree .item .ico, .tree .sub-item .ico {
  font-size: 13px; width: 18px; text-align: center;
  color: var(--sb-text-3); flex: 0 0 18px;
}
.tree .item.active .ico, .tree .sub-item.active .ico { color: #fff; }
.tree .sub { padding-left: 14px; }
.tree .sub-item { font-size: 12.5px; padding: 5px 12px; }
.tree .sub-group-title {
  padding: 8px 12px 4px;
  margin: 4px 4px 0;
  font-size: 10px; font-weight: 700;
  color: var(--sb-text-2);
  letter-spacing: .06em;
  border-top: 1px dashed var(--sb-border);
}
.tree .sub-group-title:first-child { border-top: 0; padding-top: 2px; }
.tree .ext { color: var(--sb-text-3); font-size: 10px; margin-left: auto; }

/* ================= main ================= */
#main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
}

#topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 18px;
  background: rgba(255,255,255,.78);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.tabs { display: flex; gap: 6px; flex-wrap: wrap; }
.tab {
  padding: 6px 14px;
  font-size: 12.5px;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  cursor: pointer;
  color: var(--text-2);
  transition: all .15s;
}
.tab:hover { color: var(--text); border-color: #cbd5e1; transform: translateY(-1px); }
.tab.active {
  background: var(--grad-brand);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 4px 12px rgba(79,140,255,.30);
}
.actions { display: flex; align-items: center; gap: 6px; }
.btn-icon {
  width: 30px; height: 30px;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  line-height: 1;
  color: var(--text-2);
  transition: all .15s;
}
.btn-icon:hover { color: var(--primary); border-color: var(--primary); }
#zoomLabel { font-size: 12px; color: var(--text-3); min-width: 38px; text-align: center; }
.btn-primary, .btn-ghost {
  padding: 7px 14px;
  font-size: 12.5px;
  border-radius: 8px;
  text-decoration: none;
  cursor: pointer;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text-2);
  transition: all .15s;
  display: inline-flex; align-items: center; gap: 4px;
}
.btn-primary {
  background: var(--grad-brand);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 4px 12px rgba(79,140,255,.32);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 6px 18px rgba(79,140,255,.40); }
.btn-ghost:hover { color: var(--primary); border-color: var(--primary); background: var(--primary-soft); }
.btn-ghost.active {
  background: var(--primary-soft);
  color: var(--primary);
  border-color: var(--primary);
}

#content { flex: 1; display: flex; min-height: 0; }
.viewer {
  flex: 1;
  overflow: auto;
  padding: 0;
  position: relative;
  min-width: 0;
  scroll-behavior: smooth;
}

/* ================= welcome ================= */
.welcome {
  max-width: 920px;
  margin: 0 auto;
  padding: 60px 28px 80px;
}
.welcome-hero {
  text-align: center;
  margin-bottom: 36px;
  padding: 50px 24px;
  background:
    radial-gradient(ellipse 80% 80% at 50% 0%, rgba(79,140,255,.12), transparent 70%),
    linear-gradient(180deg, #fff 0%, rgba(247,249,253,.6) 100%);
  border-radius: 20px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  animation: fadeUp .5s ease both;
}
.welcome-hero h2 {
  font-size: 28px;
  margin: 0 0 8px;
  background: var(--grad-hero);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 700;
  letter-spacing: -.01em;
}
.welcome-hero p {
  margin: 0;
  color: var(--text-2);
  font-size: 14px;
}
.welcome-hero .brand-mark.big { margin: 0 auto 18px; display: block; }

.welcome-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 10px;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
}
.welcome-list li {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 13px;
  color: var(--text-2);
  text-align: center;
}

.hints {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}
.hint-card {
  display: block;
  padding: 18px 18px 16px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: #fff;
  color: var(--text);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.55;
  transition: transform .18s, box-shadow .18s, border-color .18s;
  position: relative;
  overflow: hidden;
}
.hint-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 60%, rgba(79,140,255,.08) 100%);
  opacity: 0;
  transition: opacity .18s;
}
.hint-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--primary-2); }
.hint-card:hover::after { opacity: 1; }
.hint-card .hint-ico {
  display: inline-block;
  font-size: 20px;
  width: 40px; height: 40px;
  line-height: 40px;
  text-align: center;
  border-radius: 10px;
  background: var(--primary-soft);
  margin-bottom: 10px;
}
.hint-card.brief  .hint-ico { background: linear-gradient(135deg, #dbeafe, #c7d2fe); }
.hint-card.dev    .hint-ico { background: linear-gradient(135deg, #cffafe, #bae6fd); }
.hint-card strong { display: block; font-size: 14.5px; }
.hint-card small { display: block; margin-top: 4px; color: var(--text-3); font-weight: 400; font-size: 12px; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ================= md ================= */
.md-host {
  max-width: 1040px;
  margin: 0 auto;
  padding: 32px 28px 80px;
  animation: fadeUp .35s ease both;
}
.md-host .markdown-body { background: transparent; font-size: 15px; line-height: 1.75; }
.md-host .markdown-body img {
  max-width: 100%;
  border-radius: 8px;
  border: 1px solid var(--border-soft);
  box-shadow: var(--shadow-sm);
}
.md-host .markdown-body pre { background: #f6f8fa; border-radius: 8px; }
.md-host .markdown-body code { font-size: 90%; }
.md-host .markdown-body table { box-shadow: var(--shadow-sm); }
.md-host .markdown-body h1 {
  margin-top: 0;
  padding-bottom: 12px;
  border-bottom: 2px solid;
  border-image: var(--grad-brand) 1;
}
.md-host .markdown-body h2 {
  margin-top: 36px;
  padding: 8px 0 8px 14px;
  border-left: 4px solid var(--primary);
  border-bottom: 0;
  background: linear-gradient(90deg, rgba(99,144,255,.08), transparent 60%);
  border-radius: 0 6px 6px 0;
}
.md-host .markdown-body h3 {
  margin-top: 22px;
  color: var(--primary);
}
.md-host .markdown-body h3::before {
  content: "▸";
  margin-right: 6px;
  color: var(--accent);
}
.md-host .markdown-body blockquote {
  border-left-color: var(--accent);
  background: linear-gradient(90deg, rgba(6,182,212,.06), transparent);
  color: var(--text-2);
}

/* ================= ASCII architecture diagram ================= */
.md-host .markdown-body pre.ascii-diagram {
  background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
  color: #e2e8f0;
  padding: 20px 22px;
  border-radius: 12px;
  border: 1px solid #334155;
  box-shadow:
    0 8px 24px rgba(15,23,42,.18),
    inset 0 0 0 1px rgba(99,144,255,.08);
  position: relative;
  overflow-x: auto;
  font-family: "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  font-size: 12.5px;
  line-height: 1.55;
  margin: 18px 0;
}
.md-host .markdown-body pre.ascii-diagram::before {
  content: "ARCHITECTURE";
  position: absolute;
  top: 8px; right: 14px;
  font-size: 9px;
  letter-spacing: .15em;
  font-weight: 700;
  color: rgba(99,144,255,.7);
  font-family: -apple-system, sans-serif;
}
.md-host .markdown-body pre.ascii-diagram code {
  background: transparent;
  color: inherit;
  padding: 0;
  font-size: inherit;
  font-family: inherit;
  white-space: pre;
}

/* ================= drawio inline image ================= */
.md-host .markdown-body img.drawio-img {
  display: block;
  max-width: 100%;
  margin: 18px auto;
  border-radius: 10px;
  border: 1px solid var(--border-soft);
  background: #fff;
  box-shadow: var(--shadow-sm);
  cursor: zoom-in;
  transition: filter .15s, transform .15s, box-shadow .15s;
}
.md-host .markdown-body img.drawio-img:hover {
  filter: brightness(1.02);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}
.md-host .markdown-body img.drawio-img[data-loading] {
  min-height: 240px;
  background:
    linear-gradient(90deg, transparent 0%, rgba(99,144,255,.06) 50%, transparent 100%) 0 0/200% 100%,
    #fafbfd;
  animation: drawioShimmer 1.4s linear infinite;
  border-style: dashed;
  cursor: progress;
}
@keyframes drawioShimmer {
  from { background-position: -100% 0, 0 0; }
  to   { background-position:  100% 0, 0 0; }
}

/* ================= zoomable image ================= */
.md-host .markdown-body img.zoomable {
  cursor: zoom-in;
  transition: filter .15s, transform .15s;
}
.md-host .markdown-body img.zoomable:hover {
  filter: brightness(1.03);
  transform: translateY(-1px);
  box-shadow: var(--shadow);
}

/* ================= lightbox ================= */
body.lb-open { overflow: hidden; }
.lightbox-overlay {
  position: fixed;
  inset: 0;
  background: rgba(8,12,22,.86);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 999;
  display: flex;
  flex-direction: column;
  opacity: 0;
  transition: opacity .18s ease;
}
.lightbox-overlay.show { opacity: 1; }
.lightbox-overlay .lb-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 20px;
  color: #e2e8f0;
  background: linear-gradient(180deg, rgba(14,21,37,.7), transparent);
}
.lightbox-overlay .lb-title {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .01em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.lightbox-overlay .lb-close {
  width: 32px; height: 32px;
  border: 1px solid rgba(255,255,255,.18);
  background: rgba(255,255,255,.06);
  color: #fff;
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  transition: all .12s;
  flex: 0 0 32px;
}
.lightbox-overlay .lb-close:hover {
  background: rgba(255,255,255,.16);
  border-color: rgba(255,255,255,.30);
}
.lightbox-overlay .lb-body {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 32px 32px;
  min-height: 0;
}
.lightbox-overlay .lb-body img {
  max-width: 100%;
  max-height: 100%;
  border-radius: 10px;
  box-shadow: 0 24px 60px rgba(0,0,0,.4);
  animation: lbPop .25s ease both;
}
@keyframes lbPop {
  from { opacity: 0; transform: scale(.96); }
  to   { opacity: 1; transform: scale(1); }
}

/* ================= missing image placeholder ================= */
.img-missing {
  margin: 14px 0;
  padding: 22px 18px;
  border: 1.5px dashed #cbd5e1;
  border-radius: 12px;
  background:
    repeating-linear-gradient(135deg, transparent 0 12px, rgba(99,144,255,.04) 12px 13px),
    #fafbfd;
  text-align: center;
}
.im-icon { font-size: 28px; margin-bottom: 6px; opacity: .6; }
.im-title { font-weight: 600; color: var(--text-2); font-size: 13.5px; margin-bottom: 2px; }
.im-path { font-family: ui-monospace, monospace; font-size: 11px; color: var(--text-3); margin-bottom: 8px; }
.im-hint { font-size: 12px; color: var(--text-3); max-width: 460px; margin: 0 auto; line-height: 1.55; }

/* ================= pen ================= */
.pen-host {
  display: flex;
  justify-content: center;
  padding: 28px;
  min-height: 100%;
  background:
    radial-gradient(circle at 30% 20%, rgba(79,140,255,.06), transparent 40%),
    radial-gradient(circle at 70% 80%, rgba(139,92,246,.06), transparent 40%),
    linear-gradient(45deg, #eef1f6 25%, transparent 25%),
    linear-gradient(-45deg, #eef1f6 25%, transparent 25%),
    linear-gradient(45deg, transparent 75%, #eef1f6 75%),
    linear-gradient(-45deg, transparent 75%, #eef1f6 75%);
  background-size: auto, auto, 24px 24px, 24px 24px, 24px 24px, 24px 24px;
  background-position: 0 0, 0 0, 0 0, 0 12px, 12px -12px, -12px 0;
  background-color: #f9fafd;
}
.pen-frame {
  background: #fff;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
  border-radius: 12px;
  overflow: hidden;
  transform-origin: top center;
  display: inline-block;
  animation: fadeUp .4s ease both;
}
.pen-frame img { display: block; max-width: 1440px; height: auto; }
.pen-meta {
  position: sticky;
  top: 0;
  background: rgba(255,255,255,.86);
  backdrop-filter: blur(10px);
  padding: 10px 18px;
  font-size: 12px;
  color: var(--text-2);
  border-bottom: 1px solid var(--border-soft);
  z-index: 1;
}
.pen-meta strong { color: var(--text); margin-right: 4px; }

.diagram-host { width: 100%; height: 100%; }
.diagram-host iframe { width: 100%; height: calc(100vh - var(--topbar-h)); border: 0; background: #fff; }

.empty {
  margin: 60px auto;
  max-width: 520px;
  text-align: center;
  color: var(--text-3);
  font-size: 13px;
}
.empty .icon { font-size: 32px; margin-bottom: 6px; }

/* ================= A: panel ================= */
.panel {
  width: var(--panel-w);
  flex: 0 0 var(--panel-w);
  border-left: 1px solid var(--border);
  background: #fff;
  display: flex;
  flex-direction: column;
  height: calc(100vh - var(--topbar-h));
  position: sticky;
  top: var(--topbar-h);
  animation: slideInRight .25s ease both;
}
@keyframes slideInRight { from { transform: translateX(20px); opacity: 0; } to { transform: none; opacity: 1; } }
.panel-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 14px; border-bottom: 1px solid var(--border-soft);
  background: linear-gradient(180deg, #fafbfd 0%, #fff 100%);
}
.panel-title { font-size: 13px; font-weight: 700; }
.panel-close { background: transparent; border: 0; cursor: pointer; color: var(--text-3); font-size: 14px; }
.panel-close:hover { color: var(--text); }
.panel-tabs { display: flex; gap: 2px; padding: 8px 8px 0; border-bottom: 1px solid var(--border-soft); }
.panel-tabs .ptab {
  padding: 7px 11px; font-size: 12px; border: 0; background: transparent;
  cursor: pointer; color: var(--text-2); border-bottom: 2px solid transparent;
  transition: all .15s;
}
.panel-tabs .ptab:hover { color: var(--text); }
.panel-tabs .ptab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
  font-weight: 600;
}
.panel-body { flex: 1; overflow: auto; padding: 12px; font-size: 12.5px; line-height: 1.55; }

.api-group { margin-bottom: 16px; }
.api-group h4 {
  margin: 0 0 8px; font-size: 11px; font-weight: 700;
  color: var(--text-3); text-transform: uppercase; letter-spacing: .06em;
}
.api-row {
  display: flex; gap: 8px; align-items: baseline;
  padding: 6px 8px;
  margin: 2px 0;
  border-radius: 6px;
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  font-size: 11.5px;
  transition: background .12s;
}
.api-row:hover { background: #f6f8fb; }
.api-row .m {
  font-weight: 700; padding: 2px 6px; border-radius: 4px; font-size: 10px; flex: 0 0 auto;
}
.api-row .m.GET     { background: #dbeafe; color: #1e40af; }
.api-row .m.POST    { background: #dcfce7; color: #166534; }
.api-row .m.PUT     { background: #fef9c3; color: #854d0e; }
.api-row .m.DELETE  { background: #fee2e2; color: #991b1b; }
.api-row .m.WS, .api-row .m.SSE { background: #f3e8ff; color: #6b21a8; }
.api-row .p { flex: 1; word-break: break-all; color: var(--text); }

.map-row {
  display: grid; grid-template-columns: 1fr 1fr; gap: 8px;
  padding: 8px 0; border-bottom: 1px dashed var(--border-soft);
}
.map-row .lhs { color: var(--text); font-weight: 500; font-size: 12.5px; }
.map-row .rhs { color: var(--text-2); font-size: 11.5px; }
.map-row .rhs code { background: #f1f3f5; padding: 1px 5px; border-radius: 4px; font-size: 11px; }

.constraint {
  padding: 10px 12px; margin-bottom: 8px;
  background: linear-gradient(135deg, #fff8e7 0%, #fff 100%);
  border-left: 3px solid var(--warn); border-radius: 6px;
  font-size: 12.5px;
  box-shadow: var(--shadow-sm);
}
.constraint .c-num { font-weight: 700; color: var(--warn); margin-right: 6px; }

.checklist .ck { display: flex; gap: 8px; padding: 6px 0; align-items: flex-start; }
.checklist input { margin-top: 3px; }

/* ================= B: brief ================= */
.brief-host {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px 28px 60px;
  animation: fadeUp .4s ease both;
}
.brief-head {
  background:
    radial-gradient(ellipse 60% 100% at 0% 0%,   rgba(255,255,255,.18), transparent 70%),
    radial-gradient(ellipse 60% 100% at 100% 100%, rgba(6,182,212,.30), transparent 60%),
    var(--grad-hero);
  color: #fff;
  border-radius: 18px;
  padding: 28px 32px 32px;
  margin-bottom: 18px;
  box-shadow: 0 10px 40px rgba(37,99,235,.25);
  position: relative;
  overflow: hidden;
}
.brief-head::before {
  content: "";
  position: absolute;
  width: 280px; height: 280px;
  right: -80px; top: -80px;
  background: radial-gradient(circle, rgba(255,255,255,.18), transparent 70%);
  border-radius: 50%;
}
.brief-head h1 { margin: 0 0 8px; font-size: 26px; font-weight: 700; letter-spacing: -.01em; }
.brief-head .sub { font-size: 14px; opacity: .92; }
.brief-head .meta {
  display: flex; gap: 8px; flex-wrap: wrap; margin-top: 16px;
  font-size: 12.5px;
}
.brief-head .meta span {
  background: rgba(255,255,255,.16);
  backdrop-filter: blur(8px);
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.20);
}

.kpi-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
  margin-bottom: 18px;
}
.kpi {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px 20px;
  box-shadow: var(--shadow);
  position: relative;
  overflow: hidden;
}
.kpi::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: var(--grad-brand);
}
.kpi .k-label { font-size: 12px; color: var(--text-3); margin-bottom: 4px; }
.kpi .k-value {
  font-size: 28px; font-weight: 700; color: var(--text);
  background: var(--grad-hero);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.1;
}
.kpi .k-unit { font-size: 13px; color: var(--text-3); margin-left: 4px; -webkit-text-fill-color: var(--text-3); }

.brief-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 14px;
  margin-bottom: 18px;
}
.brief-card {
  background: #fff; border: 1px solid var(--border); border-radius: 14px;
  padding: 18px 22px;
  box-shadow: var(--shadow);
  transition: transform .15s, box-shadow .15s;
}
.brief-card:hover { transform: translateY(-1px); box-shadow: var(--shadow-lg); }
.brief-card h3 {
  margin: 0 0 10px; font-size: 11.5px; color: var(--text-3);
  font-weight: 700; text-transform: uppercase; letter-spacing: .08em;
  display: flex; align-items: center; gap: 6px;
}
.brief-card h3::before {
  content: ""; width: 4px; height: 14px;
  background: var(--grad-brand);
  border-radius: 2px;
}
.brief-card p  { margin: 0 0 8px; font-size: 14px; line-height: 1.75; color: var(--text); }
.brief-card ul { margin: 0; padding-left: 20px; line-height: 1.8; font-size: 13.5px; }

.shots {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 14px; margin-bottom: 18px;
}
.shot {
  display: block; background: #fff; border: 1px solid var(--border); border-radius: 12px;
  overflow: hidden; text-decoration: none; color: inherit;
  box-shadow: var(--shadow);
  transition: transform .18s, box-shadow .18s, border-color .18s;
}
.shot:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--primary-2); }
.shot img {
  width: 100%; height: 200px; object-fit: cover; object-position: top;
  display: block; background: #f3f4f6;
  transition: transform .3s;
}
.shot:hover img { transform: scale(1.02); }
.shot .cap {
  padding: 10px 14px; font-size: 13px;
  border-top: 1px solid var(--border-soft);
  font-weight: 500;
}

.timeline {
  background: #fff; border: 1px solid var(--border); border-radius: 14px;
  padding: 18px 22px;
  box-shadow: var(--shadow);
}
.timeline h3 {
  margin: 0 0 14px; font-size: 11.5px; color: var(--text-3);
  font-weight: 700; text-transform: uppercase; letter-spacing: .08em;
  display: flex; align-items: center; gap: 6px;
}
.timeline h3::before {
  content: ""; width: 4px; height: 14px;
  background: var(--grad-brand);
  border-radius: 2px;
}
.tl-row {
  display: grid; grid-template-columns: 32px 1fr; gap: 12px;
  padding: 10px 0; align-items: flex-start;
  border-bottom: 1px dashed var(--border-soft);
  position: relative;
}
.tl-row:last-child { border-bottom: 0; }
.tl-row::after {
  content: "";
  position: absolute;
  left: 15px; top: 32px; bottom: -10px;
  width: 2px;
  background: var(--border-soft);
}
.tl-row:last-child::after { display: none; }
.tl-row .dot {
  width: 26px; height: 26px; border-radius: 50%;
  line-height: 24px; font-size: 13px; font-weight: 700;
  text-align: center;
  background: #e5e7eb; color: var(--text-3);
  border: 2px solid #fff;
  box-shadow: 0 0 0 1px var(--border);
  z-index: 1;
}
.tl-row.done   .dot { background: var(--green);   color: #fff; box-shadow: 0 0 0 1px var(--green),  0 0 12px rgba(22,163,74,.30); }
.tl-row.doing  .dot { background: var(--primary); color: #fff; box-shadow: 0 0 0 1px var(--primary), 0 0 12px rgba(37,99,235,.30); animation: doingPulse 2s ease-in-out infinite; }
.tl-row.todo   .dot { background: #fff; color: var(--text-3); }
.tl-row.block  .dot { background: var(--red);     color: #fff; box-shadow: 0 0 0 1px var(--red),    0 0 12px rgba(220,38,38,.30); }
@keyframes doingPulse { 0%,100% { box-shadow: 0 0 0 1px var(--primary), 0 0 8px rgba(37,99,235,.30); } 50% { box-shadow: 0 0 0 1px var(--primary), 0 0 18px rgba(37,99,235,.55); } }
.tl-row .name  { font-weight: 600; font-size: 14.5px; }
.tl-row .desc  { font-size: 12.5px; color: var(--text-2); margin-top: 3px; line-height: 1.6; }

@media (max-width: 1280px) {
  .panel { display: none; }
}
@media (max-width: 760px) {
  :root { --sb-w: 240px; }
  .md-host { padding: 16px; }
  .brief-grid { grid-template-columns: 1fr; }
  .welcome-hero h2 { font-size: 22px; }
}