/* ============================================================
   TOPIC PAGE — header, notes column, side column
   ============================================================ */
.page.topic{max-width:1180px;padding-top:14px}

/* ---------- top strip ---------- */
.t-nav{display:flex;align-items:center;gap:14px;margin-bottom:12px;font-size:13px;min-height:36px}
.t-back{color:var(--ink-soft);text-decoration:none;font-weight:500;white-space:nowrap}
.t-back:hover{color:var(--ink)}
.t-pos{color:var(--ink-soft);font-size:12px;white-space:nowrap}
.t-steps{margin-left:auto;display:flex;gap:6px;min-width:0}
.t-step{
  display:flex;flex-direction:column;gap:2px;max-width:230px;min-width:0;
  padding:6px 11px;border:1px solid var(--rule);border-radius:6px;background:var(--panel);
  text-decoration:none;font-size:11px;color:var(--ink-soft);
}
.t-step.next{text-align:right}
.t-step b{font:500 13px/1.25 var(--serif);color:var(--ink);overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.t-step:hover{border-color:var(--ink-soft)}
.t-step:hover b{color:var(--dk)}
.t-step.off{opacity:.4}

/* ---------- header ---------- */
.t-head{
  background:var(--panel);border:1px solid var(--rule);border-left:4px solid var(--l0);border-radius:8px;
  padding:20px 24px 18px;box-shadow:var(--shadow);
}
.t-head.s1{border-left-color:var(--l1);background:linear-gradient(100deg,var(--l1-bg),var(--panel) 45%)}
.t-head.s2{border-left-color:var(--l2);background:linear-gradient(100deg,var(--l2-bg),var(--panel) 45%)}
.t-head.s3{border-left-color:var(--l3);background:linear-gradient(100deg,var(--l3-bg),var(--panel) 45%)}
.t-head.s4{border-left-color:var(--l4);background:linear-gradient(100deg,var(--l4-bg),var(--panel) 45%)}
.t-kicker{font-size:12px;color:var(--ink-soft);display:flex;flex-wrap:wrap;gap:4px 8px;align-items:center}
.t-kicker .src{margin:0}
.t-weight{margin-left:auto}
.t-weight b{color:var(--ink)}
.t-title{font:600 30px/1.2 var(--serif);letter-spacing:-.015em;margin:8px 0 0;max-width:34ch}
.t-dk{margin-top:8px}
.t-level{display:flex;flex-wrap:wrap;gap:10px 14px;align-items:center;margin-top:16px}
.t-remark{margin:12px 0 0;font-size:13.5px;color:var(--ink-soft);max-width:70ch}

/* ---------- two columns; editing gives the editor the full width ---------- */
.t-grid{display:grid;grid-template-columns:minmax(0,1fr) 340px;gap:22px;align-items:start;margin-top:22px}
.topic.editing .t-grid{grid-template-columns:minmax(0,1fr)}
.t-side{display:flex;flex-direction:column;gap:14px;min-width:0}

/* ---------- notes ---------- */
.notes-head{display:flex;align-items:center;gap:10px;margin-bottom:12px;flex-wrap:wrap}
.notes-head h2{font:600 20px/1.2 var(--serif)}
.notes-head .btn{margin-left:auto}
.sort-btn{
  appearance:none;cursor:pointer;background:none;border:0;padding:4px 2px;
  font:500 12px/1 var(--sans);color:var(--ink-soft);
}
.sort-btn:hover{color:var(--ink)}

.notes-empty{
  background:var(--panel);border:1px dashed var(--grid);border-radius:8px;padding:22px 24px;
  font-size:14px;color:var(--ink-soft);
}
.notes-empty p{margin:0 0 10px;max-width:60ch}
.notes-empty b{color:var(--ink)}

.note{
  background:var(--panel);border:1px solid var(--rule);border-radius:8px;
  padding:16px 22px 20px 14px;margin-bottom:14px;box-shadow:var(--shadow);
  scroll-margin-top:calc(var(--bar-h) + 16px);
}
.note-h{display:flex;gap:8px;align-items:flex-start}
.note-fold{
  appearance:none;border:0;background:none;cursor:pointer;color:var(--ink-soft);
  font-size:13px;line-height:1;padding:7px 5px;transition:transform .15s ease;
}
.note.collapsed .note-fold{transform:rotate(-90deg)}
.note-hd{flex:1;min-width:0}
.note-title{font:600 19px/1.3 var(--serif);letter-spacing:-.005em}
.note-date{font-size:12px;color:var(--ink-soft);margin-top:3px}
.note-date a{color:var(--dk)}
.note-acts{display:flex;gap:2px;flex:0 0 auto;opacity:.55;transition:opacity .15s ease}
.note:hover .note-acts, .note:focus-within .note-acts{opacity:1}
.note-acts button{
  appearance:none;cursor:pointer;background:none;border:1px solid transparent;border-radius:5px;
  font:500 12px/1 var(--sans);color:var(--ink-soft);padding:6px 8px;white-space:nowrap;
}
.note-acts button:hover{border-color:var(--rule);color:var(--ink)}
.note-acts button.danger:hover{color:var(--flag)}
.note-body{margin:12px 0 0 30px}
.note.collapsed .note-body{display:none}

.note.editing{padding:16px 18px 16px;border-color:var(--dk)}
.note-title-in{
  width:100%;font:600 21px/1.3 var(--serif);color:var(--ink);background:transparent;
  border:0;border-bottom:1px solid var(--rule);padding:4px 2px 10px;margin-bottom:12px;
}
.note-title-in:focus{outline:none;border-bottom-color:var(--dk)}
.note-edit-foot{display:flex;align-items:center;gap:8px;margin-top:12px}
.note-edit-foot .saved{margin-right:auto;font-size:12px;color:var(--l4)}
.note-edit-foot .saved.busy{color:var(--ink-soft)}

/* ---------- side column ---------- */
.t-desc p{margin:0;font-size:14px;line-height:1.55}
.t-desc .ex{margin-top:10px;padding:9px 11px;background:var(--dk-bg);border-radius:5px;font-size:13.5px}
.t-desc .ex b{display:block;font:600 11px/1.3 var(--sans);color:var(--dk);margin-bottom:3px;letter-spacing:.02em}

.rel + .rel{margin-top:12px}
.rel h3{font:600 12px/1.3 var(--sans);margin:0 0 6px}
.rel-hint{font-size:12px;color:var(--flag);margin:-2px 0 6px}

.qlog textarea{
  width:100%;resize:vertical;min-height:66px;font:14px/1.45 var(--sans);color:var(--ink);
  border:1px solid var(--rule);border-radius:5px;padding:8px 10px;background:var(--input);
}
.qlog-foot{display:flex;gap:8px;align-items:center;justify-content:space-between;margin-top:8px;flex-wrap:wrap}
.side-log{list-style:none;margin:14px 0 0;padding:0}
.side-log a{display:block;text-decoration:none;padding:8px 0;border-top:1px solid var(--rule)}
.side-log a:hover .sl-text{color:var(--dk)}
.sl-date{display:block;font:600 11.5px/1.3 var(--sans);color:var(--dk)}
.sl-text{display:block;font-size:13.5px;margin-top:2px}
.sl-notes{display:block;font-size:12px;color:var(--ink-soft);margin-top:2px}
.t-log .more{display:inline-block;margin-top:8px;font-size:12.5px;color:var(--dk)}

@media (max-width:980px){
  .t-grid{grid-template-columns:minmax(0,1fr)}
}
@media (max-width:640px){
  .t-nav{flex-wrap:wrap;gap:6px 12px}
  .t-steps{flex:1 1 100%;margin:0}
  .t-step{flex:1;max-width:none}
  .t-head{padding:16px 16px 14px}
  .t-title{font-size:23px}
  .t-weight{margin-left:0}
  .t-level .seg{flex:1 1 100%}
  .t-level .seg button{flex:1;padding:11px 2px;font-size:11.5px}
  .note{padding:14px 14px 16px 8px}
  .note-h{flex-wrap:wrap}
  .note-acts{opacity:1;flex:1 1 100%;justify-content:flex-end}
  .note-body{margin-left:6px}
  .note.editing{padding:12px}
}

/* ---------- computed level in the header ---------- */
.t-level .submeter i{width:13px;height:13px;border-radius:3px}
.t-pct{font-size:13px;color:var(--ink-soft)}
.t-pct b{color:var(--ink)}

/* ---------- subtopics ---------- */
.t-main{display:flex;flex-direction:column;gap:22px;min-width:0}
.t-subs{padding:14px 16px 12px}
.subs-head{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin-bottom:6px}
.subs-head h2{font:600 20px/1.2 var(--serif);color:var(--ink);margin:0}
.subs-hint{font-size:11.5px;color:var(--ink-soft)}
.subs-hint kbd{padding:2px 4px;font-size:10px}
.subs-all{margin-left:auto;font-size:12px;color:var(--ink-soft);display:flex;align-items:center;gap:6px}
.subs-all select, .note-sub-in select{
  font:13px var(--sans);color:var(--ink);background:var(--panel);border:1px solid var(--rule);border-radius:5px;padding:5px 6px;
}
.sub-row{
  display:flex;align-items:center;gap:8px 14px;flex-wrap:wrap;justify-content:space-between;
  padding:9px 8px 9px 11px;border-left:3px solid transparent;border-bottom:1px solid var(--rule);
  border-radius:3px;cursor:default;
}
.sub-row:last-child{border-bottom:0}
.sub-row.s1{border-left-color:var(--l1);background:linear-gradient(90deg,var(--l1-bg),transparent 60%)}
.sub-row.s2{border-left-color:var(--l2);background:linear-gradient(90deg,var(--l2-bg),transparent 60%)}
.sub-row.s3{border-left-color:var(--l3);background:linear-gradient(90deg,var(--l3-bg),transparent 60%)}
.sub-row.s4{border-left-color:var(--l4);background:linear-gradient(90deg,var(--l4-bg),transparent 60%)}
.sub-row.sel{box-shadow:inset 0 0 0 1.5px var(--dk)}
.sub-main{flex:1 1 220px;min-width:0;display:flex;align-items:baseline;gap:6px 10px;flex-wrap:wrap}
.sub-name{font:15px/1.35 var(--serif)}
.sub-own{font:italic 11px/1 var(--sans);color:var(--ink-soft)}
.sub-tools{display:inline-flex;gap:4px;align-items:center}
.sub-tools button{
  appearance:none;cursor:pointer;background:none;border:1px solid transparent;border-radius:4px;
  font:500 11.5px/1 var(--sans);color:var(--ink-soft);padding:4px 6px;
}
.sub-tools button:hover{border-color:var(--rule);color:var(--ink)}
.sub-new{opacity:0;transition:opacity .15s ease}
.sub-row:hover .sub-new, .sub-row.sel .sub-new, .sub-new:focus-visible{opacity:1}
.sub-notes{background:var(--note-bg)!important;border-color:var(--note-rule)!important;color:var(--ink)!important}
.sub-notes.on{background:var(--ink)!important;border-color:var(--ink)!important;color:var(--on-ink)!important}
.sub-del:hover{color:var(--flag)!important}
.sub-row .seg button{padding:7px 7px;font-size:11px}
.sub-add{margin-top:8px}
.sub-add input{
  width:100%;font:13.5px var(--sans);color:var(--ink);background:transparent;
  border:1px dashed var(--rule);border-radius:5px;padding:7px 10px;
}
.sub-add input:focus{outline:none;border-style:solid;border-color:var(--dk);background:var(--panel)}

/* ---------- how well you understand a note ---------- */
.note.nl1{border-left:4px solid var(--l1)} .note.nl2{border-left:4px solid var(--l2)}
.note.nl3{border-left:4px solid var(--l3)} .note.nl4{border-left:4px solid var(--l4)}
.nlv{display:flex;align-items:center;gap:3px;margin-top:7px;flex-wrap:wrap}
.nlv-label{font-size:11.5px;color:var(--ink-soft);margin-right:3px}
.nlv button{
  appearance:none;cursor:pointer;font:500 11px/1 var(--sans);color:var(--ink-soft);
  background:var(--panel);border:1px solid var(--rule);border-radius:999px;padding:4px 8px;
}
.nlv button:hover{border-color:var(--ink-soft);color:var(--ink)}
.nlv button[aria-pressed="true"]{color:var(--on-level);font-weight:600;border-color:transparent}
.nlv .nb1[aria-pressed="true"]{background:var(--l1)} .nlv .nb2[aria-pressed="true"]{background:var(--l2)}
.nlv .nb3[aria-pressed="true"]{background:var(--l3)} .nlv .nb4[aria-pressed="true"]{background:var(--l4)}
/* unrated notes keep the control quiet until you point at the note */
.note.nl0:not(.editing) .nlv{opacity:.55}
.note.nl0:hover .nlv{opacity:1}
.note-sub{
  appearance:none;cursor:pointer;font:600 11px/1.3 var(--sans);color:var(--dk);background:var(--dk-bg);
  border:0;border-radius:3px;padding:1px 6px;margin-right:6px;
}
.note-sub:hover{text-decoration:underline}
.note-meta-in{display:flex;align-items:center;gap:8px 18px;flex-wrap:wrap;margin:-4px 0 12px}
.note-meta-in .nlv{margin-top:0}
.note-sub-in{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--ink-soft)}
.note-sub-in select{max-width:280px}
.notes-filter{margin:-4px 0 12px}
.chip-n{color:var(--ink-soft);font-weight:400;margin-left:2px}
.chip.active .chip-n{color:inherit;opacity:.8}

@media (max-width:640px){
  .subs-hint{display:none}
  .subs-all{margin-left:0}
  .sub-row{padding:10px 6px 10px 9px}
  .sub-row .seg{flex:1 1 100%}
  .sub-row .seg button{flex:1;padding:9px 2px;font-size:10.5px}
  .sub-new{opacity:1}
}

.t-rel{margin-top:12px;font-size:13px;display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.rel-link{color:var(--ink-soft);text-decoration:none;font-size:12.5px}
.rel-link:hover{color:var(--flag);text-decoration:underline}
.t-rel-note{color:var(--ink-soft)}
.t-weight.off{color:var(--flag);font-weight:600}