/* ============================================================
   Options Handbook — shared styles
   Palette: cool paper + dark instrument panels; P/L green & red
   Type: IBM Plex Serif (display) / Plex Sans (body) / Plex Mono (data)
   ============================================================ */

:root{
  --paper:#F4F6F5;
  --card:#FFFFFF;
  --ink:#14212B;
  --muted:#5B6B76;
  --line:#DDE4E2;
  --panel:#0C1820;
  --panel-2:#122230;
  --panel-edge:#24394A;
  --panel-text:#C8D6DE;
  --gain:#1E9E71;
  --gain-bright:#3CDFA3;
  --loss:#CE4A37;
  --loss-bright:#FF6A55;
  --amber:#D99A3D;
  --amber-soft:#F6E8CF;
  --serif:"IBM Plex Serif","Songti SC","Noto Serif SC",serif;
  --sans:"IBM Plex Sans",-apple-system,"PingFang SC","Noto Sans SC","Microsoft YaHei",sans-serif;
  --mono:"IBM Plex Mono","SFMono-Regular",Menlo,Consolas,monospace;
  --w-text:46rem;
  --w-wide:60rem;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

body{
  margin:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:1.0625rem;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}

/* ---------- bilingual switching ---------- */
html[data-lang="zh"] .en{display:none !important}
html[data-lang="en"] .zh{display:none !important}
html[data-lang="en"] body{line-height:1.65}

/* ---------- header / nav ---------- */
.topbar{
  position:sticky;top:0;z-index:50;
  display:flex;align-items:center;gap:1rem;
  padding:.65rem 1.25rem;
  background:rgba(244,246,245,.92);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.topbar .brand{
  font-family:var(--mono);font-size:.8rem;letter-spacing:.08em;
  color:var(--muted);text-decoration:none;white-space:nowrap;
}
.topbar .brand b{color:var(--ink)}
.topbar .spacer{flex:1}
.topbar nav{display:flex;gap:1rem;font-size:.85rem}
.topbar nav a{color:var(--muted);text-decoration:none}
.topbar nav a:hover{color:var(--ink)}
.lang-switch{
  display:flex;border:1px solid var(--line);border-radius:999px;overflow:hidden;
  font-family:var(--mono);font-size:.75rem;
}
.lang-switch button{
  border:0;background:transparent;color:var(--muted);
  padding:.3rem .7rem;cursor:pointer;font:inherit;
}
.lang-switch button[aria-pressed="true"]{background:var(--ink);color:var(--paper)}
@media (max-width:32rem){
  .topbar{flex-wrap:wrap;padding:.55rem .9rem;gap:.4rem .75rem}
  .topbar nav{gap:.75rem;font-size:.8rem}
}
.lang-switch button:focus-visible,
a:focus-visible,button:focus-visible,input:focus-visible{
  outline:2px solid var(--amber);outline-offset:2px;
}

/* ---------- layout ---------- */
.page{max-width:var(--w-text);margin:0 auto;padding:2.5rem 1.25rem 6rem}
.wide{max-width:var(--w-wide);margin-left:calc(50% - min(50vw - 1.25rem, var(--w-wide)/2));width:min(calc(100vw - 2.5rem),var(--w-wide))}
@media (max-width:64rem){.wide{margin-left:0;width:100%}}

h1,h2,h3{font-family:var(--serif);line-height:1.25;letter-spacing:-.01em}
h1{font-size:2.3rem;font-weight:600;margin:.5rem 0 1rem}
h2{font-size:1.55rem;font-weight:600;margin:3.5rem 0 1rem}
h3{font-size:1.15rem;font-weight:600;margin:2rem 0 .6rem}
p{margin:.9rem 0}
a{color:inherit;text-decoration-color:var(--amber);text-underline-offset:3px}
a:hover{color:var(--amber)}
strong{font-weight:600}

.eyebrow{
  font-family:var(--mono);font-size:.75rem;letter-spacing:.14em;
  text-transform:uppercase;color:var(--amber);margin:0;
}
.lede{font-size:1.15rem;color:var(--muted)}

hr{border:0;border-top:1px solid var(--line);margin:3rem 0}

.term{border-bottom:1px dashed var(--amber);text-decoration:none}
.term:hover{background:var(--amber-soft)}

/* ---------- strategy spec strip (options-chain style) ---------- */
.spec{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(9rem,1fr));
  border:1px solid var(--line);border-radius:10px;overflow:hidden;
  background:var(--card);margin:1.25rem 0;
}
.spec div{padding:.7rem .9rem;border-left:1px solid var(--line)}
.spec div:first-child{border-left:0}
.spec dt{
  font-family:var(--mono);font-size:.68rem;letter-spacing:.1em;
  text-transform:uppercase;color:var(--muted);margin:0 0 .2rem;
}
.spec dd{margin:0;font-size:.9rem;font-weight:500}
.spec .pos{color:var(--gain)}
.spec .neg{color:var(--loss)}

/* ---------- dark instrument panel (signature element) ---------- */
.panel{
  background:linear-gradient(180deg,var(--panel-2),var(--panel));
  border:1px solid var(--panel-edge);
  border-radius:14px;
  color:var(--panel-text);
  padding:1.1rem 1.2rem 1.2rem;
  margin:1.5rem 0;
  box-shadow:0 12px 30px -18px rgba(12,24,32,.55);
}
.panel .panel-title{
  display:flex;align-items:baseline;gap:.75rem;flex-wrap:wrap;
  font-family:var(--mono);font-size:.78rem;letter-spacing:.1em;
  text-transform:uppercase;color:#8FA6B4;margin:0 0 .6rem;
}
.panel .panel-title .dot{
  width:.5rem;height:.5rem;border-radius:50%;
  background:var(--amber);display:inline-block;align-self:center;
}
.panel svg{display:block;width:100%;height:auto}
.panel .readout{
  display:flex;gap:1.5rem;flex-wrap:wrap;
  font-family:var(--mono);font-size:.8rem;color:#8FA6B4;margin-top:.6rem;
}
.panel .readout b{color:var(--panel-text);font-weight:500}
.panel .readout .g{color:var(--gain-bright)}
.panel .readout .r{color:var(--loss-bright)}
/* static figure cards: for published single values that are not a time series */
.panel .figs{display:grid;grid-template-columns:repeat(auto-fit,minmax(11rem,1fr));gap:1rem;margin:.2rem 0 .2rem}
.panel .fig{border:1px solid var(--panel-edge);border-radius:10px;padding:.8rem 1rem}
.panel .fig .v{display:block;font-family:var(--mono);font-size:2rem;line-height:1.15;color:var(--loss-bright)}
.panel .fig .k{display:block;font-family:var(--mono);font-size:.78rem;letter-spacing:.04em;color:#8FA6B4;margin-top:.2rem}

.controls{display:grid;grid-template-columns:repeat(auto-fit,minmax(14rem,1fr));gap:.8rem 1.5rem;margin-top:1rem}
.ctrl label{
  display:flex;justify-content:space-between;
  font-family:var(--mono);font-size:.75rem;color:#8FA6B4;margin-bottom:.25rem;
}
.ctrl label output{color:var(--amber)}
.ctrl input[type=range]{width:100%;accent-color:var(--amber)}

/* ---------- case file card ---------- */
.case{
  border:1px solid var(--line);border-left:4px solid var(--amber);
  border-radius:10px;background:var(--card);
  padding:1.25rem 1.4rem;margin:1.75rem 0;
}
.case .case-tag{
  font-family:var(--mono);font-size:.7rem;letter-spacing:.12em;
  text-transform:uppercase;color:var(--amber);margin:0 0 .3rem;
}
.case h3{margin-top:.1rem}
.case .verdict{
  font-family:var(--mono);font-size:.8rem;border-radius:6px;
  padding:.55rem .8rem;margin-top:1rem;display:inline-block;
}
.case .verdict.gain{background:#E4F5EE;color:var(--gain)}
.case .verdict.loss{background:#FBE9E5;color:var(--loss)}

/* ---------- callouts ---------- */
.note,.warn{
  border-radius:10px;padding:1rem 1.2rem;margin:1.4rem 0;font-size:.97rem;
}
.note{background:#EAF1EF;border:1px solid #D3E2DD}
.warn{background:#FBEFE0;border:1px solid #F0D9B8}
.note p:first-child,.warn p:first-child{margin-top:0}
.note p:last-child,.warn p:last-child{margin-bottom:0}
.warn .warn-tag,.note .note-tag{
  font-family:var(--mono);font-size:.7rem;letter-spacing:.12em;
  text-transform:uppercase;display:block;margin-bottom:.3rem;
}
.warn .warn-tag{color:var(--loss)}
.note .note-tag{color:var(--gain)}

/* ---------- quiz ---------- */
.quiz-set{counter-reset:q}
.quiz{
  border:1px solid var(--line);border-radius:10px;background:var(--card);
  padding:1.2rem 1.4rem;margin:1.2rem 0;
}
.quiz .q{font-weight:600;margin:0 0 .8rem}
.quiz .q::before{
  counter-increment:q;content:"Q" counter(q);
  font-family:var(--mono);font-weight:500;color:var(--amber);
  margin-right:.6rem;font-size:.85rem;
}
.quiz .opts{display:grid;gap:.5rem}
.quiz .opts button{
  text-align:left;font:inherit;font-size:.95rem;line-height:1.5;
  border:1px solid var(--line);border-radius:8px;background:var(--paper);
  padding:.6rem .9rem;cursor:pointer;color:var(--ink);
}
.quiz .opts button:hover{border-color:var(--amber)}
.quiz .opts button .key{
  font-family:var(--mono);font-size:.8rem;color:var(--muted);margin-right:.55rem;
}
.quiz.answered .opts button{cursor:default}
.quiz .opts button.correct{border-color:var(--gain);background:#E4F5EE}
.quiz .opts button.wrong{border-color:var(--loss);background:#FBE9E5}
.quiz .expl{
  display:none;margin:1rem 0 0;padding-top:.9rem;
  border-top:1px dashed var(--line);font-size:.95rem;color:var(--muted);
}
.quiz.answered .expl{display:block}
.quiz .expl b{color:var(--ink)}

/* ---------- think prompt ---------- */
.think{
  border-left:3px solid var(--ink);padding:.2rem 0 .2rem 1.1rem;
  margin:1.6rem 0;color:var(--ink);font-size:.98rem;
}
.think .think-tag{
  font-family:var(--mono);font-size:.7rem;letter-spacing:.12em;
  text-transform:uppercase;color:var(--muted);display:block;margin-bottom:.2rem;
}

/* ---------- TOC (index) ---------- */
.toc{list-style:none;padding:0;margin:2rem 0}
.toc li{
  display:flex;align-items:baseline;gap:1rem;
  padding:.85rem .25rem;border-bottom:1px solid var(--line);
}
.toc .num{font-family:var(--mono);font-size:.8rem;color:var(--amber);min-width:2.2rem}
.toc a{text-decoration:none;font-weight:500}
.toc a:hover{color:var(--amber)}
.toc .soon{color:var(--muted)}

/* ---------- glossary ---------- */
.gloss-search{
  width:100%;font:inherit;font-size:1rem;
  border:1px solid var(--line);border-radius:10px;
  padding:.7rem 1rem;background:var(--card);margin:1.5rem 0 .5rem;
}
.gloss{width:100%;border-collapse:collapse;font-size:.95rem}
.gloss th{
  text-align:left;font-family:var(--mono);font-size:.7rem;
  letter-spacing:.12em;text-transform:uppercase;color:var(--muted);
  border-bottom:2px solid var(--ink);padding:.6rem .5rem;
}
.gloss td{border-bottom:1px solid var(--line);padding:.7rem .5rem;vertical-align:top}
.gloss td.t{font-family:var(--mono);font-size:.85rem;white-space:nowrap;font-weight:500}
.gloss td.c{white-space:nowrap;color:var(--muted)}
.gloss tr.hide{display:none}

/* ---------- chapter footer nav ---------- */
.chap-nav{
  display:flex;justify-content:space-between;gap:1rem;
  margin-top:4rem;padding-top:1.5rem;border-top:1px solid var(--line);
  font-size:.9rem;
}
.chap-nav a{text-decoration:none;color:var(--muted)}
.chap-nav a:hover{color:var(--amber)}

/* ---------- cover ---------- */
.cover{padding:4.5rem 0 2rem}
.cover h1{font-size:clamp(2.4rem,6vw,3.6rem);margin:.75rem 0}
.cover .payoff-mark{margin:2rem 0 0}

/* ---------- print ---------- */
@media print{
  .topbar,.controls,.chap-nav{display:none !important}
  body{background:#fff;font-size:10.5pt}
  .page{max-width:100%;padding:0}
  .panel{box-shadow:none;break-inside:avoid;-webkit-print-color-adjust:exact;print-color-adjust:exact}
  .quiz,.spec{break-inside:avoid}
  /* Case cards routinely exceed one page (the tallest carries two panels). A box taller than
     the page box makes the browser ignore break-inside:avoid and split it anywhere, so keep
     the parts that do fit intact instead of asking for the whole card. */
  .case h3{break-after:avoid}
  .case .verdict{break-inside:avoid;break-before:avoid}
  p{orphans:3;widows:3}
  .quiz .expl{display:block}
  a{text-decoration:none;color:inherit}
}