/* §04 atlas index */
.explorer {
  position: relative;
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  gap: var(--s6);
  max-width: min(1360px, 100%);
  margin: var(--s6) auto 0;
  padding-inline: clamp(12px, 2.5vw, 40px);
  align-items: start;
}
.explorer__noscript { padding-block: var(--s6); color: var(--ink-muted); }
.explorer__filtersbtn { display: none; }

/* ---- rail ---- */
.explorer__rail {
  position: sticky;
  top: calc(var(--nav-h) + 16px);
  display: grid;
  gap: var(--s5);
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  background: var(--paper-elev);
  box-shadow: var(--shadow-soft);
  padding: calc(var(--s5) + 4px);
  max-height: calc(100dvh - var(--nav-h) - 32px);
  overflow-y: auto;
}
.rail__mode {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border: 1px solid var(--line);
  border-radius: var(--r-full);
  overflow: hidden;
}
.rail__modebtn {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 8px 4px;
  color: var(--ink-muted);
}
.rail__modebtn.is-active { background: var(--ink); color: var(--paper); }

.rail__search { position: relative; display: block; }
.rail__search input {
  width: 100%;
  font-size: var(--fs-small);
  padding: 12px 34px 12px 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  background: var(--paper);
  transition: border-color var(--d-fast) var(--ease), box-shadow var(--d-fast) var(--ease);
}
.rail__search input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--moss-soft);
}
.rail__search kbd { position: absolute; right: 9px; top: 50%; transform: translateY(-50%); color: var(--ink-faint); }

.rail__group { display: grid; gap: var(--s2); }
.rail__label {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: var(--track-wide);
  text-transform: uppercase;
  color: var(--ink-muted);
}
.rail__years { display: flex; align-items: center; gap: var(--s2); }
.rail__years select {
  flex: 1;
  font-family: var(--font-mono);
  font-size: var(--fs-mono);
  padding: 6px 8px;
  border: 1px solid var(--line);
  border-radius: var(--r-xs);
  background: var(--paper);
}
.rail__chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.05em;
  color: var(--ink-soft);
  border: 1px solid var(--hairline);
  border-radius: var(--r-full);
  padding: 4px 11px;
  transition: all var(--d-fast) var(--ease);
}
.chip:hover { border-color: var(--line); transform: translateY(-1px); }
.chip.is-on { background: var(--ink); border-color: var(--ink); color: var(--paper); }
.rail__clear {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.06em;
  color: var(--ink-muted);
  text-align: left;
}
.rail__clear:hover { color: var(--ink); }
.rail__status { font-family: var(--font-mono); font-size: var(--fs-micro); color: var(--ink-muted); letter-spacing: 0.06em; }

/* ---- main: tree + list ---- */
.explorer__main { display: grid; gap: var(--s6); min-width: 0; }

.explorer__tree {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--s5);
  align-items: start;
}
/* each role is a plate: gradient crown, numeral badge, count pill */
.tree__role {
  position: relative;
  min-width: 0;
  background: var(--paper-elev);
  border: 1px solid var(--hairline);
  border-radius: var(--r-md);
  box-shadow: var(--shadow-soft);
  padding: var(--s5) var(--s4) var(--s4);
  overflow: hidden;
}
.tree__role::before {
  content: "";
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--role-fill), color-mix(in srgb, var(--role-fill) 30%, transparent));
}
.tree__rolehead {
  display: flex;
  align-items: center;
  gap: var(--s3);
  width: 100%;
  text-align: left;
  padding: 4px;
  border-radius: var(--r-sm);
}
.tree__rolehead:hover, .tree__rolehead.is-on { background: var(--role-soft); }
.tree__numeral {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--role);
  width: 26px;
  height: 26px;
  flex: none;
  display: grid;
  place-items: center;
  border: 1px solid var(--role-line);
  border-radius: 50%;
  background: var(--role-soft);
}
.tree__rolename { font-family: var(--font-display); font-weight: 600; font-size: 17.5px; flex: 1; }
.tree__rolehead .tree__count {
  background: var(--role-soft);
  border-radius: var(--r-full);
  padding: 2px 10px;
}
.tree__question { font-size: 14px; color: var(--ink-muted); margin: var(--s2) 0 var(--s4) 4px; }
.tree__family { margin-bottom: var(--s4); }
.tree__family:last-child { margin-bottom: 0; }
.tree__familyname {
  display: flex;
  align-items: center;
  gap: var(--s3);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin: 0 0 6px 4px;
}
.tree__familyname::after { content: ""; flex: 1; height: 1px; background: var(--hairline); }
.tree__leaves { list-style: none; padding: 0; display: grid; gap: 2px; }
/* each leaf carries a count bar on a shared scale — the tree doubles as a bar chart */
.tree__leaf {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--s2);
  width: 100%;
  text-align: left;
  font-size: 14px;
  color: var(--ink-soft);
  padding: 5px 6px 7px;
  border-radius: var(--r-xs);
  border-left: 2px solid transparent;
}
.tree__leaf::after {
  content: "";
  position: absolute;
  left: 6px;
  bottom: 3px;
  height: 2px;
  width: calc((100% - 12px) * var(--bar, 0));
  border-radius: 1px;
  background: var(--role-fill);
  opacity: 0.5;
  transition: opacity var(--d-fast) var(--ease);
}
.tree__leaf:hover { background: var(--role-soft); color: var(--ink); }
.tree__leaf:hover::after { opacity: 0.85; }
.tree__leaf.is-on { background: var(--role-soft); border-left-color: var(--role); color: var(--ink); font-weight: 500; }
.tree__leaf .tree__count { margin-left: auto; }
.tree__count {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--role);
}

/* ---- list (accordion: leaf groups collapsed by default) ---- */
.list__tools {
  display: flex;
  align-items: baseline;
  gap: var(--s4);
  margin-bottom: var(--s4);
}
.list__toolsum {
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.06em;
  color: var(--ink-muted);
}
.list__toolbtn {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--hairline);
  padding-bottom: 1px;
}
.list__toolbtn:hover { color: var(--ink); border-bottom-color: var(--ink); }

.list__leafgroup { margin-bottom: var(--s3); }
.list__leafgroup.is-open { margin-bottom: var(--s6); }
.list__leafhead {
  display: flex;
  align-items: baseline;
  gap: var(--s3);
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 560;
  border-bottom: 1px solid var(--role-line);
  padding-bottom: 6px;
  margin-bottom: var(--s2);
}
.leaf__toggle {
  flex: 1;
  display: flex;
  align-items: baseline;
  gap: var(--s2);
  min-width: 0;
  font: inherit;
  color: inherit;
  text-align: left;
  padding: 4px 6px;
  border-radius: var(--r-xs);
  transition: background var(--d-fast) var(--ease);
}
.leaf__toggle:hover { background: var(--role-soft); }
.leaf__chev {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--role);
  display: inline-block;
  transition: transform var(--d-fast) var(--ease);
  transform-origin: 45% 55%;
}
.list__leafgroup.is-open .leaf__chev { transform: rotate(90deg); }
.leaf__focus {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.06em;
  color: var(--ink-muted);
  white-space: nowrap;
  opacity: 0;
  transition: opacity var(--d-fast) var(--ease), color var(--d-fast) var(--ease);
}
.list__leafhead:hover .leaf__focus, .leaf__focus:focus-visible { opacity: 1; }
.leaf__focus:hover { color: var(--role); }
.list__leafcount { font-family: var(--font-mono); font-size: var(--fs-micro); color: var(--role); }
.list__flat { list-style: none; padding: 0; display: grid; }
.list__empty { color: var(--ink-muted); padding: var(--s6) 0; }

.paper { border-bottom: 1px solid var(--hairline-soft); }
.paper__row {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr) auto;
  grid-template-areas: "year title venue" ". chips chips";
  align-items: baseline;
  column-gap: var(--s3);
  width: 100%;
  text-align: left;
  padding: 9px 6px;
  border-radius: var(--r-xs);
  transition: background var(--d-fast) var(--ease);
}
.paper__row:hover { background: var(--role-soft); }
.paper.is-open .paper__row { background: var(--role-soft); }
.paper__year { grid-area: year; font-family: var(--font-mono); font-size: var(--fs-micro); color: var(--ink-muted); }
.paper__title { grid-area: title; font-size: 15px; line-height: 1.45; }
.paper.is-open .paper__title { font-weight: 500; }
.paper__venue {
  grid-area: venue;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.05em;
  color: var(--role);
  white-space: nowrap;
}
.paper__chips { grid-area: chips; display: flex; flex-wrap: wrap; gap: 4px; margin-top: 2px; }
.pchip {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--ink-muted);
  border: 1px solid var(--hairline);
  border-radius: var(--r-full);
  padding: 1px 7px;
}
.paper__detail {
  padding: 4px 6px 14px calc(62px + var(--s3) + 6px);
  display: grid;
  gap: var(--s3);
}
.pd__insight { font-size: 15px; color: var(--ink-soft); max-width: 74ch; }
.pd__zh summary {
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.08em;
  color: var(--ink-muted);
}
.pd__zh p { font-size: 13.5px; color: var(--ink-muted); margin-top: 6px; max-width: 74ch; }
.pd__actions { display: flex; gap: var(--s4); }
.pd__link {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--role);
  text-decoration: none;
  border-bottom: 1px solid var(--role-line);
  padding-bottom: 1px;
}
.pd__link:hover { border-bottom-color: var(--role); }

/* ---- responsive ---- */
@media (max-width: 1020px) {
  .explorer { grid-template-columns: 1fr; }
  .explorer__filtersbtn {
    display: block;
    position: sticky;
    top: calc(var(--nav-h) + 8px);
    z-index: 20;
    justify-self: start;
    font-family: var(--font-mono);
    font-size: var(--fs-mono);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    background: var(--ink);
    color: var(--paper);
    border-radius: var(--r-full);
    padding: 9px 18px;
    box-shadow: var(--shadow-lift);
  }
  .explorer__rail { display: none; }
  .rail-open .explorer__rail {
    display: grid;
    position: sticky;
    top: calc(var(--nav-h) + 52px);
    z-index: 19;
    max-height: 60dvh;
  }
  .explorer__tree { grid-template-columns: 1fr; gap: var(--s4); }
  .paper__row { grid-template-columns: 54px minmax(0, 1fr); grid-template-areas: "year title" "year venue" ". chips"; }
  .paper__venue { justify-self: start; }
  .paper__detail { padding-left: 6px; }
}