:root{
  --bg:#0a1a2f; --bg2:#0d2038;
  --card:#122540; --card2:#0f1f37;
  --line:rgba(255,255,255,.08);
  --line2:rgba(255,255,255,.14);
  --txt:#e9eff7; --muted:#8ba0bb; --muted2:#5f7794;
  --accent:#34d399;
  --accent-dim:rgba(52,211,153,.14);
  --wrong:#f87171;
  --wrong-dim:rgba(248,113,113,.10);
  --gold:#e5b567;
  --chip:#16294a;
}
*{box-sizing:border-box;margin:0;padding:0}
body{
  background:radial-gradient(1200px 600px at 50% -10%, var(--bg2), var(--bg));
  color:var(--txt);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei",sans-serif;
  min-height:100vh; padding:32px 16px 80px;
  -webkit-font-smoothing:antialiased;
}
.mono{font-family:"SF Mono",ui-monospace,"Cascadia Code","Roboto Mono",Consolas,monospace}
.wrap{max-width:760px;margin:0 auto}

.topbar{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:18px}
.brand{font-size:15px;letter-spacing:.5px;color:var(--muted)}
.brand b{color:var(--txt);font-weight:600}
.progress{font-size:13px;color:var(--muted)}
.progress b{color:var(--accent);font-weight:600}

.tabs{display:flex;gap:6px;background:var(--card2);border:1px solid var(--line);
      border-radius:14px;padding:5px;margin-bottom:14px}
.tab{flex:1;text-align:center;padding:10px 8px;border-radius:10px;font-size:14px;
     color:var(--muted);cursor:pointer;transition:.18s;user-select:none;white-space:nowrap}
.tab:hover{color:var(--txt)}
.tab.active{background:#1b3358;color:var(--txt);
            box-shadow:0 1px 0 rgba(255,255,255,.05) inset}

.selector{display:flex;align-items:center;gap:12px;margin-bottom:18px;flex-wrap:wrap}
.selector label{font-size:13px;color:var(--muted)}
select{background:var(--chip);color:var(--txt);border:1px solid var(--line2);
  border-radius:10px;padding:9px 12px;font-size:14px;cursor:pointer;outline:none;font-family:inherit}
.pill-prim{font-size:12px;color:var(--gold);border:1px solid rgba(229,181,103,.3);
           border-radius:20px;padding:4px 11px;background:rgba(229,181,103,.06)}

.card{background:var(--card);border:1px solid var(--line);border-radius:18px;
      padding:24px;margin-bottom:16px;box-shadow:0 8px 30px rgba(0,0,0,.25)}
.kicker{font-size:12px;letter-spacing:1.5px;color:var(--muted2);text-transform:uppercase;
        display:flex;align-items:center;gap:8px;margin-bottom:14px;transition:.4s;flex-wrap:wrap}
.kicker .dot{width:6px;height:6px;border-radius:50%;background:var(--accent)}
.kicker .streak{margin-left:auto;color:var(--muted);letter-spacing:.5px;text-transform:none}
.kicker .streak b{color:var(--accent)}
.zt-badge{display:inline-block;font-size:10px;line-height:1;padding:2px 5px;border-radius:8px;
  background:var(--gold);color:var(--bg);font-weight:600;margin-left:6px;vertical-align:middle}

.prompt{font-size:24px;line-height:1.5;letter-spacing:.3px;margin-bottom:20px}
.blank{color:var(--gold);border-bottom:2px dashed rgba(229,181,103,.5);padding:0 22px}

.opts{display:grid;gap:10px;transition:opacity .45s ease, transform .45s ease, margin .45s ease}
.opts.collapsed{opacity:.3;transform:scale(.96);pointer-events:none;margin-top:-2px}
.opts.collapsed .opt{padding:9px 18px}
.opt{display:flex;align-items:center;gap:14px;padding:15px 18px;border-radius:12px;
     border:1.5px solid var(--line2);background:var(--card2);cursor:pointer;
     transition:.15s;font-size:17px}
.opt:hover{border-color:rgba(255,255,255,.3);transform:translateY(-1px)}
.opt .lab{width:26px;height:26px;flex:0 0 26px;border-radius:7px;background:var(--chip);
          display:grid;place-items:center;font-size:13px;font-weight:700;color:var(--muted);
          transition:.3s}
.opt.chosen{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-dim)}
.opt.chosen .lab{background:var(--accent);color:#06231a}
.opts.collapsed .opt.chosen{opacity:1}
.opt.pulse{animation:pulse .18s ease}
.opt.locked{cursor:default}
.opt.locked:hover{transform:none}

.opt.correct{
  border-color:var(--accent);
  background:linear-gradient(90deg, var(--accent-dim), rgba(52,211,153,.05));
  box-shadow:0 0 0 2px var(--accent-dim), 0 6px 22px rgba(52,211,153,.18);
  animation:correctIn .4s cubic-bezier(.2,.8,.25,1) both;
}
.opt.correct .lab{
  background:var(--accent);color:#06231a;
  transform:scale(1.18);
  box-shadow:0 0 14px rgba(52,211,153,.55);
}
.opt.wrongpick{border-color:var(--wrong);background:var(--wrong-dim)}
.opt.wrongpick .lab{background:var(--wrong);color:#2a0d0d}
.opt .tag{
  margin-left:auto;font-size:11px;color:var(--accent);opacity:0;
  display:flex;align-items:center;gap:5px;font-weight:600;letter-spacing:.5px;
}
.opt.correct .tag{
  opacity:1;
  animation:tagPop .42s cubic-bezier(.2,.9,.3,1.4) .12s both;
}
.opt .tag .check{
  display:inline-grid;place-items:center;
  width:24px;height:24px;border-radius:50%;
  background:var(--accent);color:#06231a;
  font-size:15px;font-weight:800;
}
@keyframes correctIn{
  0%{box-shadow:0 0 0 2px var(--accent-dim)}
  45%{box-shadow:0 0 0 5px rgba(52,211,153,.28), 0 8px 26px rgba(52,211,153,.28)}
  100%{box-shadow:0 0 0 2px var(--accent-dim), 0 6px 22px rgba(52,211,153,.18)}
}
@keyframes tagPop{
  0%{opacity:0;transform:scale(.4)}
  60%{opacity:1;transform:scale(1.15)}
  100%{opacity:1;transform:scale(1)}
}
@keyframes pulse{0%{transform:scale(1)}50%{transform:scale(1.035)}100%{transform:scale(1)}}

.hint-bet{font-size:13px;color:var(--gold);margin-top:14px;display:flex;align-items:center;gap:6px}
.locked-veil{margin-top:16px;padding:22px;border:1px dashed var(--line2);
  border-radius:14px;text-align:center;color:var(--muted2);font-size:14px;
  background:repeating-linear-gradient(45deg,transparent,transparent 8px,rgba(255,255,255,.015) 8px,rgba(255,255,255,.015) 16px)}

.painpoint{font-size:14px;color:var(--muted);line-height:1.7;margin:18px 0 16px}
.painpoint.enter{animation:softfade .4s ease .1s both}

.punch{font-size:22px;line-height:1.55;font-weight:600;color:var(--accent);
       padding:20px 22px;background:var(--accent-dim);border-left:3px solid var(--accent);
       border-radius:0 12px 12px 0;margin-bottom:18px}
.punch.enter{animation:rise .55s cubic-bezier(.2,.7,.2,1) .55s both}
.punch.small{font-size:18px;padding:15px 18px;margin-bottom:0}

.why-btn{background:var(--chip);color:var(--txt);border:1px solid var(--line2);
  border-radius:11px;padding:11px 18px;font-size:14px;cursor:pointer;font-family:inherit;transition:.15s}
.why-btn.enter{animation:softfade .45s ease 1.45s both}
.why-btn:hover{border-color:rgba(255,255,255,.35);background:#1b3358}

.act-btn{background:var(--chip);color:var(--txt);border:1px solid var(--line2);
  border-radius:11px;padding:11px 18px;font-size:14px;cursor:pointer;font-family:inherit;transition:.15s}
.act-btn:hover{border-color:rgba(255,255,255,.35);background:#1b3358}
.act-btn:disabled{opacity:.4;cursor:not-allowed}
.act-btn:disabled:hover{border-color:var(--line2);background:var(--chip)}
.act-row{display:flex;gap:10px;flex-wrap:wrap;margin-top:20px}
.act-btn.primary{background:var(--accent);color:#06231a;border-color:transparent;font-weight:600}
.act-btn.primary:hover{filter:brightness(1.08)}
.act-btn.primary:disabled{background:var(--chip);color:var(--muted)}

.section-lbl{font-size:12px;letter-spacing:1px;color:var(--muted2);
             text-transform:uppercase;margin:22px 0 8px}
.bridge{font-size:15px;line-height:1.85;color:#d3deec}

.mp{margin-top:8px}
.mp-var{display:inline-block;font-size:12px;color:var(--gold);
        background:rgba(229,181,103,.08);border:1px solid rgba(229,181,103,.25);
        border-radius:20px;padding:3px 12px;margin-bottom:12px}
.mp-lines{background:var(--card2);border:1px solid var(--line);border-radius:12px;padding:16px 18px}
.mp-line{font-size:18px;line-height:1.6;letter-spacing:.3px;padding:6px 0}
.mp-line .rd{display:block;font-size:12.5px;color:var(--muted);letter-spacing:0;margin-top:3px;font-family:inherit}
.hl{color:var(--accent);font-weight:700;background:var(--accent-dim);border-radius:5px;padding:0 4px}
.mp-line.dim{color:var(--muted2)}
.takeaway{font-size:14px;line-height:1.75;color:#cdd8e8;margin-top:12px;
          padding-left:14px;border-left:2px solid var(--line2)}

.callback{font-size:15px;line-height:1.8;color:#d3deec;margin-top:6px;
          background:var(--card2);border:1px solid var(--line);border-radius:12px;padding:16px 18px}
.mnemonic{font-size:15px;line-height:1.85;color:#ffe8c2;margin-top:6px;white-space:pre-line;
          background:rgba(212,160,60,.10);border:1px solid rgba(212,160,60,.35);
          border-radius:12px;padding:16px 18px}

/* ==== Tab2 毫厘辨析 ==== */
.t2-context{font-size:16px;line-height:1.75;color:#e3eaf4;background:var(--card2);
  border:1px solid var(--line);border-radius:12px;padding:16px 18px;margin-bottom:16px}
.t2-context .lbl{font-size:11px;color:var(--muted2);letter-spacing:1.5px;
  text-transform:uppercase;display:block;margin-bottom:7px}
.t2-q{font-size:14px;color:var(--muted);margin-bottom:12px}
.t2-result{font-size:17px;font-weight:700;margin-bottom:16px;display:flex;
  align-items:center;gap:9px;animation:rise .3s ease both}
.t2-result.ok{color:var(--accent)}
.t2-result.no{color:var(--wrong)}
.t2-result .rmark{display:inline-grid;place-items:center;width:26px;height:26px;
  border-radius:50%;font-size:15px;font-weight:800}
.t2-result.ok .rmark{background:var(--accent);color:#06231a}
.t2-result.no .rmark{background:var(--wrong);color:#2a0d0d}
.t2-pair{display:grid;gap:10px;margin:6px 0 4px}
.t2-side{border:1.5px solid var(--line2);border-radius:12px;padding:14px 16px;
  position:relative;background:var(--card2);animation:softfade .35s ease both}
.t2-side.match{border-color:var(--accent);
  background:linear-gradient(90deg,var(--accent-dim),rgba(52,211,153,.04))}
.t2-side.wrong{border-color:var(--wrong);background:var(--wrong-dim)}
.t2-side .s{font-size:18px;line-height:1.55;letter-spacing:.3px}
.t2-side .rd{font-size:12.5px;color:var(--muted);margin-top:5px;line-height:1.6}
.t2-tag{position:absolute;top:13px;right:15px;font-size:11px;font-weight:700;letter-spacing:.5px}
.t2-side.match .t2-tag{color:var(--accent)}
.t2-side.wrong .t2-tag{color:var(--wrong)}

/* ==== Tab3 实战淬火 ==== */
.t3-source{font-size:12px;color:var(--muted2);letter-spacing:.5px;margin-bottom:12px}
.t3-result{font-size:17px;font-weight:700;margin:2px 0 16px;display:flex;
  align-items:center;gap:9px;animation:rise .3s ease both}
.t3-result.ok{color:var(--accent)} .t3-result.no{color:var(--wrong)}
.t3-result .rmark{display:inline-grid;place-items:center;width:26px;height:26px;
  border-radius:50%;font-size:15px;font-weight:800}
.t3-result.ok .rmark{background:var(--accent);color:#06231a}
.t3-result.no .rmark{background:var(--wrong);color:#2a0d0d}
.t3-diag{border:1.5px solid var(--wrong);background:var(--wrong-dim);
  border-radius:12px;padding:15px 17px;margin-top:6px;animation:softfade .35s ease both}
.t3-diag .dlbl{font-size:11px;color:var(--wrong);letter-spacing:1px;
  text-transform:uppercase;margin-bottom:7px;font-weight:700}
.t3-diag .dtext{font-size:14.5px;line-height:1.7;color:#f0dede}
.t3-diag .bounce{margin-top:11px;display:inline-flex;align-items:center;gap:6px;
  font-size:13px;color:var(--gold);cursor:pointer;border:1px solid rgba(229,181,103,.35);
  border-radius:9px;padding:7px 12px;background:rgba(229,181,103,.06);transition:.15s}
.t3-diag .bounce:hover{background:rgba(229,181,103,.12)}
.t3-recall{margin-top:12px;border:1px solid var(--accent);border-radius:12px;
  padding:16px 18px;background:linear-gradient(180deg,var(--accent-dim),transparent);
  animation:softfade .35s ease both}
.t3-recall .rlbl{font-size:11px;color:var(--accent);letter-spacing:1px;
  text-transform:uppercase;margin-bottom:10px;font-weight:700}
.t3-recall .r-note{font-size:13px;color:var(--muted);margin-top:10px;line-height:1.6}
.t3-selfq{font-size:14.5px;color:#d3deec;line-height:1.7;margin:4px 0 2px}
.t3-selfq b{color:var(--txt)}
/* 选对后先亮出的“本质精华语”（28字级），压在自问句之前 */
.t3-essence{position:relative;font-size:16px;line-height:1.75;color:var(--txt);
  font-weight:600;letter-spacing:.2px;margin:10px 0 14px;padding:14px 16px 14px 44px;
  border:1px solid rgba(229,181,103,.35);border-radius:12px;
  background:linear-gradient(135deg,rgba(229,181,103,.10),rgba(229,181,103,.02));
  animation:essIn .5s ease both}
.t3-essence .ess-tag{position:absolute;left:14px;top:15px;font-size:10px;font-weight:700;
  letter-spacing:1px;color:var(--bg);background:var(--gold);border-radius:6px;
  padding:2px 6px;line-height:1.2}
@keyframes essIn{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}
.welded-note{font-size:13px;color:var(--gold);line-height:1.7;margin-top:12px;
  border-left:2px solid rgba(229,181,103,.4);padding-left:12px}

/* ==== Tab4 非此不可 ==== */
.t4-steps{display:flex;gap:8px;margin-bottom:18px}
.t4-step{flex:1;text-align:center;font-size:12px;color:var(--muted2);
  padding:8px 6px;border-radius:9px;border:1px solid var(--line);background:var(--card2);
  letter-spacing:.5px}
.t4-step.on{color:var(--accent);border-color:var(--accent);background:var(--accent-dim)}
.t4-step.done{color:var(--muted);border-color:var(--line2)}
.t4-softnote{font-size:13px;color:var(--gold);line-height:1.7;margin-bottom:16px;
  border:1px solid rgba(229,181,103,.3);border-radius:11px;padding:11px 14px;
  background:rgba(229,181,103,.06)}
.t4-setup{font-size:16px;line-height:1.8;color:#e6edf6;background:var(--card2);
  border:1px solid var(--line);border-radius:12px;padding:17px 19px;margin-bottom:8px}
.t4-setup .lbl{font-size:11px;color:var(--muted2);letter-spacing:1.5px;
  text-transform:uppercase;display:flex;align-items:center;gap:8px;margin-bottom:9px}
.t4-diff{font-size:10px;color:var(--muted);border:1px solid var(--line2);
  border-radius:20px;padding:2px 9px;letter-spacing:.5px}
.t4-hintstruct{font-size:13px;color:var(--muted);margin:12px 0 8px}
.t4-hintstruct b{color:var(--gold)}
textarea{width:100%;min-height:96px;resize:vertical;background:var(--card2);
  color:var(--txt);border:1.5px solid var(--line2);border-radius:12px;
  padding:14px 16px;font-size:16px;line-height:1.6;font-family:inherit;outline:none;
  transition:.15s}
textarea:focus{border-color:rgba(255,255,255,.35)}
.t4-yours{background:var(--card2);border:1px solid var(--line);border-radius:12px;
  padding:15px 17px;font-size:16px;line-height:1.7;color:#e6edf6;
  white-space:pre-wrap;word-break:break-word}
.t4-yours.empty{color:var(--muted2);font-style:italic}
.t4-followhint{color:#ff6b6b;font-weight:600;font-size:14px;margin-left:8px}
.t4-editcompare{margin-top:6px}
.t4-gate{display:grid;gap:10px;margin-top:6px}
.t4-check{display:flex;align-items:flex-start;gap:12px;padding:13px 16px;
  border:1.5px solid var(--line2);border-radius:12px;background:var(--card2);
  cursor:pointer;transition:.15s;font-size:14.5px;line-height:1.6;color:#d3deec}
.t4-check:hover{border-color:rgba(255,255,255,.3)}
.t4-check.checked{border-color:var(--accent);background:var(--accent-dim);color:#e9f7f2}
.t4-box{flex:0 0 22px;width:22px;height:22px;border-radius:6px;border:1.5px solid var(--line2);
  display:grid;place-items:center;font-size:14px;color:transparent;margin-top:1px;transition:.15s}
.t4-check.checked .t4-box{background:var(--accent);border-color:var(--accent);color:#06231a;font-weight:800}
.t4-sample{border:1px solid var(--accent);border-radius:12px;padding:16px 18px;
  background:linear-gradient(180deg,var(--accent-dim),transparent);animation:softfade .4s ease both}
.t4-sample .lbl{font-size:11px;color:var(--accent);letter-spacing:1.5px;
  text-transform:uppercase;margin-bottom:9px;font-weight:700}
.t4-sample .txt{font-size:17px;line-height:1.6;color:#eafaf5}
.t4-compare-note{font-size:14px;color:#cdd8e8;line-height:1.75;margin-top:14px}
.t4-close{margin-top:16px;font-size:14px;color:var(--gold);line-height:1.7;
  border-left:2px solid rgba(229,181,103,.4);padding-left:13px;font-style:italic}
.t4-earned{margin-top:16px;border:1px solid var(--accent);border-radius:12px;
  padding:14px 17px;background:var(--accent-dim);animation:tagPop .5s cubic-bezier(.2,.9,.3,1.4) both}
.t4-earned .e-title{font-size:15px;font-weight:700;color:var(--accent);
  display:flex;align-items:center;gap:8px}
.t4-earned .e-note{font-size:12.5px;color:var(--muted);margin-top:7px;line-height:1.6}
.t4-badges{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:6px}
.t4-badge{font-size:11px;letter-spacing:.5px;border-radius:20px;padding:3px 11px;
  border:1px solid var(--line2);color:var(--muted)}
.t4-badge.on{border-color:var(--accent);color:var(--accent);background:var(--accent-dim)}

details{margin-top:14px;border-top:1px solid var(--line);padding-top:12px}
summary{cursor:pointer;font-size:13px;color:var(--muted);list-style:none;
        display:flex;align-items:center;gap:7px;user-select:none}
summary::-webkit-details-marker{display:none}
summary::before{content:"⌄";color:var(--muted2);transition:.2s}
details[open] summary::before{transform:rotate(180deg)}
.fold-body{font-size:14px;line-height:1.8;color:var(--muted);padding:12px 0 4px}
.fold-body .fo{padding:5px 0;border-bottom:1px solid var(--line)}
.fold-body .fo:last-child{border-bottom:none}
.fold-body .fo b{color:var(--txt)}
/* 蓝框提示：加深理解，看看 X 选项为什么不对 */
.t3-hint{display:inline-block;margin:12px 0 6px;padding:9px 16px;font-size:14px;
  color:var(--gold);border:1px solid rgba(229,181,103,.5);border-radius:10px;
  background:rgba(229,181,103,.05);letter-spacing:.3px}
.t3-hint b{color:var(--gold);font-weight:700}
/* 选中后直接摊开的完整解析：三栏对齐（选项+英文 | ✓/✗ | 解释） */
.t3-fullopen{margin-top:10px}
.fo-grid{display:grid;grid-template-columns:auto auto 1fr;
  column-gap:14px;row-gap:0;align-items:baseline;font-size:14.5px;line-height:1.85}
.fo-grid .fo{display:contents}
.fo-opt{color:#c7d3e3;white-space:nowrap;padding:8px 0;
  border-bottom:1px solid var(--line)}
.fo-opt b{color:var(--txt);font-weight:700;margin-right:2px}
.fo-mark{padding:8px 0;border-bottom:1px solid var(--line);text-align:center;font-weight:700}
.fo-exp{color:#c7d3e3;padding:8px 0;border-bottom:1px solid var(--line)}
.fo-ok{color:#4ade80}
.fo-no{color:#f0776b}
.fo-correct .fo-opt b,.fo-correct .fo-opt{color:#7ee6a6}
/* 最后一行去掉分隔线 */
.fo-grid .fo:last-child .fo-opt,
.fo-grid .fo:last-child .fo-mark,
.fo-grid .fo:last-child .fo-exp{border-bottom:none}
.badge-pending{font-size:11px;color:var(--gold);border:1px solid rgba(229,181,103,.3);
               border-radius:6px;padding:1px 7px;margin-left:6px}
.ref{font-size:13px;color:var(--muted);padding:4px 0;line-height:1.6}

.expand-wrap.enter{animation:softfade .4s ease both}

@keyframes rise{from{opacity:0;transform:translateY(14px) scale(.98)}
                to{opacity:1;transform:none}}
@keyframes softfade{from{opacity:0;transform:translateY(6px)}to{opacity:1;transform:none}}

.placeholder{text-align:center;padding:50px 20px;color:var(--muted)}
.placeholder .big{font-size:16px;color:var(--txt);margin-bottom:8px}
.fade{animation:softfade .35s ease}

footer{max-width:760px;margin:26px auto 0;font-size:12px;color:var(--muted2);
       line-height:1.7;text-align:center}

/* ============ 真题精讲精练(unitMode) ============ */
.u-dash{ margin-bottom:18px; }
.u-dash-top{ display:flex; align-items:baseline; gap:12px; flex-wrap:wrap; font-size:16px; }
.u-cover{ margin-left:auto; color:var(--muted); font-size:14px; }
.u-cover b{ color:var(--accent); font-size:17px; }
.u-bar{ height:8px; background:var(--chip); border-radius:5px; margin:10px 0; overflow:hidden; }
.u-bar-fill{ height:100%; background:linear-gradient(90deg,var(--accent),var(--gold)); transition:width .4s; }
.u-subs{ display:flex; gap:8px; flex-wrap:wrap; }
.u-subpill{ font-size:12.5px; padding:4px 10px; border-radius:14px; background:var(--chip);
  color:var(--muted); cursor:pointer; border:1px solid var(--line); user-select:none; }
.u-subpill:hover{ border-color:var(--line2); color:var(--txt); }
.u-subpill.active{ background:var(--accent-dim); color:var(--accent); border-color:var(--accent); }
.u-nav{ display:flex; align-items:center; gap:14px; margin-bottom:16px; }
.u-navbtn{ padding:6px 14px; border-radius:8px; background:var(--chip); color:var(--txt);
  border:1px solid var(--line); cursor:pointer; font-size:14px; }
.u-navbtn:disabled{ opacity:.35; cursor:default; }
.u-navpos{ color:var(--muted); font-size:14px; margin:0 auto; }
.u-sec{ margin:14px 0; padding:14px 16px; border-radius:10px; background:var(--card2); border:1px solid var(--line); }
.u-sectag{ font-size:12.5px; color:var(--gold); margin-bottom:8px; }
.u-donebadge{ color:var(--accent); margin-left:8px; }
.u-problem{ font-size:16px; line-height:1.7; color:var(--txt); }
.u-fig{ margin-top:10px; text-align:center; }
.u-fig img{ max-width:100%; border-radius:8px; background:#fff; padding:6px; }
.u-self{ border-left:3px solid var(--gold); }
.u-selfprompt{ color:var(--txt); margin-bottom:10px; }
.u-hint{ margin:8px 0; padding:10px 12px; background:var(--accent-dim); border-radius:8px; color:var(--txt); }
.u-warn{ margin:8px 0; color:var(--wrong); font-size:14px; }
.u-solution{ border-left:3px solid var(--accent); }
.u-steps{ margin:8px 0 8px 20px; line-height:1.8; }
.u-steps li{ margin-bottom:6px; }
.u-answer{ margin-top:10px; font-size:15.5px; }
.u-answer b{ color:var(--accent); }
.u-verify{ margin-top:6px; color:var(--muted); font-size:13.5px; }
.u-method{ border-left:3px solid var(--gold); }
.u-whentouse{ margin-top:8px; color:var(--gold); font-size:14px; }
.u-variant{ margin:10px 0; padding:10px 12px; background:var(--chip); border-radius:8px; }
.u-vprompt{ font-size:14.5px; line-height:1.6; }
.u-vreveal{ margin-top:8px; color:var(--txt); font-size:14px; }
.u-vreveal b{ color:var(--accent); }
.u-redo{ border-left:3px solid var(--accent); }
.u-redoprompt{ font-size:15px; line-height:1.6; }
.u-mastery{ margin-top:8px; color:var(--muted); font-size:13.5px; }
.u-mastered{ margin-top:10px; color:var(--accent); }
.act-btn.primary{ background:var(--accent); color:#04121f; font-weight:600; border:none; }
.act-btn.u-vshow{ margin-top:6px; font-size:13px; padding:5px 12px; }

/* ============ 基础地基卡 ============ */
.u-basics{ margin:14px 0; }
.u-basics-toggle{ width:100%; text-align:left; padding:11px 16px; border-radius:10px;
  background:linear-gradient(90deg,var(--accent-dim),transparent); color:var(--accent);
  border:1px solid var(--accent); cursor:pointer; font-size:15px; font-weight:600; }
.u-basics-toggle:hover{ background:var(--accent-dim); }
.u-basics-body{ margin-top:10px; padding:16px; border-radius:10px; background:var(--card2); border:1px solid var(--line); }
.u-basics-intro{ color:var(--txt); line-height:1.8; margin-bottom:14px; padding-bottom:12px; border-bottom:1px solid var(--line); }
.u-concept{ margin:12px 0; padding:12px 14px; border-radius:8px; background:var(--chip); border-left:3px solid var(--gold); }
.u-concept-name{ font-size:15px; font-weight:600; color:var(--gold); margin-bottom:6px; }
.u-concept-plain{ color:var(--txt); line-height:1.7; }
.u-concept-why{ margin-top:7px; color:var(--accent); font-size:13.5px; }
.u-concept-eg{ margin-top:6px; color:var(--muted); font-size:13.5px; font-family:var(--mono,monospace); }
.u-concept-leads{ margin-top:6px; color:var(--muted2); font-size:12.5px; }
.u-basics-closing{ margin-top:14px; padding-top:12px; border-top:1px solid var(--line); color:var(--txt); line-height:1.8; font-style:italic; }