/* Options Lens: a ledger-paper look. Warm stock, ink rules, one vermilion accent. */
:root {
  --bg: #f3efe6;
  --card: #fffdf8;
  --ink: #17202b;
  --muted: #566170;
  --rule: #d8d1c1;
  --rule-strong: #17202b;
  --accent: #b3361f;
  --accent-ink: #ffffff;
  --pos: #0b7a5c;
  --neg: #b3361f;
  --today: #2956c0;
  --pos-fill: rgba(11, 122, 92, 0.16);
  --neg-fill: rgba(179, 54, 31, 0.14);
  --focus: #2956c0;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f141b;
    --card: #161d27;
    --ink: #ece8df;
    --muted: #9ba6b5;
    --rule: #2b3543;
    --rule-strong: #ece8df;
    --accent: #ff7a5c;
    --accent-ink: #0f141b;
    --pos: #3fd0a0;
    --neg: #ff7a5c;
    --today: #84a7ff;
    --pos-fill: rgba(63, 208, 160, 0.17);
    --neg-fill: rgba(255, 122, 92, 0.16);
    --focus: #84a7ff;
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 16px/1.5 var(--sans);
  background-image: linear-gradient(var(--rule) 1px, transparent 1px);
  background-size: 100% 32px;
  background-attachment: local;
}
.wrap { max-width: 1180px; margin: 0 auto; padding-inline: 16px; }
.skip { position: absolute; left: 16px; top: -48px; background: var(--ink); color: var(--bg); padding: 8px 12px; z-index: 10; }
.skip:focus { top: 8px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
.nojs { padding-block: 16px; }

/* Masthead */
.masthead { background: var(--ink); color: var(--bg); border-bottom: 4px double var(--accent); }
@media (prefers-color-scheme: dark) { .masthead { background: #0a0e13; color: var(--ink); } }
.masthead .wrap { padding-block: 22px 18px; }
.brand { display: flex; align-items: center; gap: 12px; margin: 0; font: 600 clamp(1.7rem, 4vw, 2.3rem)/1.1 var(--serif); letter-spacing: -0.01em; }
.logo { flex: none; color: currentColor; }
.masthead .logo path { stroke: #ff7a5c; }
.tagline { margin: 6px 0 0; color: inherit; opacity: 0.8; font-size: 1rem; max-width: 60ch; }

/* Layout */
.layout { display: grid; gap: 20px; padding-block: 24px 36px; }
@media (min-width: 940px) {
  .layout { grid-template-columns: 300px minmax(0, 1fr); gap: 28px; align-items: start; }
  .rail { position: sticky; top: 16px; }
}
main { display: grid; gap: 24px; min-width: 0; }

.card { background: var(--card); border: 1px solid var(--rule); border-top: 3px solid var(--rule-strong); padding: 20px 16px 22px; min-width: 0; }
@media (min-width: 560px) { .card { padding: 24px 24px 26px; } }
h2 { margin: 0 0 16px; font: 600 1.45rem/1.2 var(--serif); display: flex; align-items: baseline; gap: 10px; }
h3 { margin: 28px 0 10px; font: 600 1.05rem/1.2 var(--serif); }
.no { font: 500 0.72rem/1 var(--mono); color: var(--accent); letter-spacing: 0.08em; border: 1px solid currentColor; padding: 3px 5px; transform: translateY(-3px); }
.lede { margin: 0 0 16px; color: var(--muted); max-width: 70ch; }
.fine { margin: 10px 0 0; font-size: 0.82rem; color: var(--muted); }
.eyebrow { margin: 0; font: 500 0.72rem/1.2 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }

/* Fields */
.field { margin: 0 0 16px; }
.field-head { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 6px; }
.field label { font-weight: 600; font-size: 0.92rem; }
.num { display: inline-flex; align-items: center; gap: 4px; font-family: var(--mono); color: var(--muted); }
.num input, .leg input[type="number"], .leg select, #iv-price {
  font: 500 0.95rem/1.2 var(--mono); color: var(--ink); background: transparent;
  border: 1px solid var(--rule-strong); border-radius: 0; padding: 7px 8px; width: 7.2em; text-align: right;
  min-height: 38px;
}
.leg select { text-align: left; width: auto; font-family: var(--sans); }
input[type="range"] { width: 100%; height: 28px; margin: 0; background: transparent; accent-color: var(--accent); cursor: pointer; }

/* Buttons and segmented controls */
.btn { font: 600 0.92rem/1 var(--sans); min-height: 40px; padding: 0 16px; border: 1px solid var(--rule-strong); background: var(--ink); color: var(--bg); cursor: pointer; border-radius: 0; }
.btn:hover { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.ghost { background: transparent; color: var(--ink); }
.btn.ghost:hover { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
fieldset { border: 0; padding: 0; margin: 0; min-width: 0; }
legend { padding: 0; font: 500 0.72rem/1.2 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); margin-bottom: 6px; }
.seg { display: flex; flex-wrap: wrap; }
.seg label { position: relative; }
.seg input { position: absolute; opacity: 0; inset: 0; width: 100%; height: 100%; margin: 0; cursor: pointer; }
.seg span { display: block; padding: 9px 18px; min-height: 40px; border: 1px solid var(--rule-strong); margin: 0 -1px -1px 0; font-weight: 600; background: transparent; cursor: pointer; }
.seg input:checked + span { background: var(--ink); color: var(--bg); }
.seg input:focus-visible + span { outline: 3px solid var(--focus); outline-offset: 2px; position: relative; z-index: 1; }
.seg.small span { padding: 6px 12px; min-height: 34px; font-size: 0.88rem; }
.controls { display: grid; gap: 16px; margin-bottom: 20px; }
@media (min-width: 640px) { .controls { grid-template-columns: auto 1fr; align-items: end; gap: 28px; } .controls .field { margin: 0; } }

/* Price hero */
.hero { display: grid; gap: 16px; padding: 16px 0; border-block: 1px dashed var(--rule-strong); margin-bottom: 20px; }
@media (min-width: 640px) { .hero { grid-template-columns: auto 1fr; align-items: end; gap: 32px; } }
.price { margin: 2px 0 0; font: 600 clamp(2.6rem, 8vw, 3.8rem)/1 var(--serif); font-variant-numeric: tabular-nums; letter-spacing: -0.02em; }
.split { margin: 0; display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px 20px; }
@media (min-width: 640px) { .split { grid-template-columns: repeat(4, 1fr); } }
.split dt { font: 500 0.7rem/1.2 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }
.split dd { margin: 2px 0 0; font: 600 1.15rem/1.2 var(--mono); }

/* Greeks */
.greeks { display: grid; grid-template-columns: repeat(auto-fit, minmax(210px, 1fr)); gap: 12px; margin: 0; }
.greek { border: 1px solid var(--rule); padding: 12px 14px 14px; background: color-mix(in srgb, var(--card) 70%, var(--bg)); }
.greek dt { display: flex; justify-content: space-between; align-items: baseline; font-family: var(--serif); font-weight: 600; font-size: 1.05rem; }
.greek dt small { font: 500 0.7rem/1 var(--mono); color: var(--muted); letter-spacing: 0.06em; text-transform: uppercase; }
.greek .v { display: block; margin: 4px 0 6px; font: 600 1.55rem/1.1 var(--mono); font-variant-numeric: tabular-nums; }
.greek dd { margin: 0; font-size: 0.86rem; color: var(--muted); }

/* Charts */
.chart { position: relative; width: 100%; border: 1px solid var(--rule); background: var(--card); touch-action: pan-y; }
.chart svg { display: block; }
.chart text { font: 11px var(--mono); fill: var(--muted); }
.chart .grid { stroke: var(--rule); stroke-width: 1; }
.chart .axis { stroke: var(--rule-strong); stroke-width: 1; }
.chart .zero { stroke: var(--ink); stroke-width: 1.25; }
.chart .s-expiry { fill: none; stroke: var(--ink); stroke-width: 2.4; stroke-linejoin: round; }
.chart .s-today { fill: none; stroke: var(--today); stroke-width: 2.2; stroke-dasharray: 7 4; }
.chart .s-greek { fill: none; stroke: var(--accent); stroke-width: 2.4; stroke-linejoin: round; }
.chart .m-spot { stroke: var(--accent); stroke-width: 1.5; }
.chart .m-strike { stroke: var(--muted); stroke-width: 1; stroke-dasharray: 3 4; }
.chart .m-label { fill: var(--accent); font-weight: 600; }
.chart .be { fill: var(--card); stroke: var(--ink); stroke-width: 2; }
.chart .fill-pos { fill: var(--pos-fill); }
.chart .fill-neg { fill: var(--neg-fill); }
.chart .xh { stroke: var(--ink); stroke-width: 1; }
.chart .dot-expiry { fill: var(--ink); }
.chart .dot-today { fill: var(--today); }
.chart .dot-greek { fill: var(--accent); }
.chart:focus-visible { outline: 3px solid var(--focus); outline-offset: 2px; }
.readout { margin: 8px 0 0; min-height: 1.5em; font: 500 0.88rem/1.5 var(--mono); }
.legend { list-style: none; display: flex; flex-wrap: wrap; gap: 6px 20px; margin: 8px 0 0; padding: 0; font-size: 0.85rem; color: var(--muted); }
.legend li { display: flex; align-items: center; gap: 8px; }
.k-expiry { stroke: var(--ink); stroke-width: 2.4; }
.k-today { stroke: var(--today); stroke-width: 2.2; stroke-dasharray: 7 4; }
.k-spot { stroke: var(--accent); stroke-width: 1.5; }
.k-be { fill: var(--card); stroke: var(--ink); stroke-width: 2; }

/* Parity */
.parity { display: grid; gap: 8px 24px; font-family: var(--mono); }
@media (min-width: 640px) { .parity { grid-template-columns: 1fr 1fr; } }
.parity .side { border: 1px solid var(--rule); padding: 10px 12px; }
.parity .side b { display: block; font-size: 1.2rem; }
.parity .side span { font-size: 0.78rem; color: var(--muted); }
.parity .verdict { grid-column: 1 / -1; font-family: var(--sans); font-size: 0.92rem; }
.parity .ok { color: var(--pos); font-weight: 700; }

/* IV */
.iv-grid { display: grid; gap: 16px; margin-bottom: 16px; }
@media (min-width: 640px) { .iv-grid { grid-template-columns: minmax(200px, 1fr) 1.4fr; gap: 32px; align-items: end; } }
.iv-grid .field { margin: 0; }
.iv-out .price { font-size: clamp(2.2rem, 7vw, 3rem); }

/* Strategy */
.presets { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.preset { font: 600 0.88rem/1 var(--sans); min-height: 40px; padding: 0 14px; border: 1px solid var(--rule-strong); background: transparent; color: var(--ink); cursor: pointer; border-radius: 0; }
.preset:hover { background: color-mix(in srgb, var(--ink) 10%, transparent); }
.preset[aria-pressed="true"] { background: var(--ink); color: var(--bg); }
.legs { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.leg { border: 1px solid var(--rule); padding: 12px 14px 0; display: grid; gap: 4px 14px; grid-template-columns: repeat(auto-fit, minmax(120px, auto)); align-items: end; }
.leg .cell { display: grid; gap: 4px; margin-bottom: 12px; font-size: 0.78rem; color: var(--muted); }
.leg .cell > label { font: 500 0.7rem/1.2 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; }
.leg input[type="number"] { width: 5.5em; }
.leg .wide { grid-column: 1 / -1; }
.leg .wide .field { margin: 0 0 8px; }
.leg .badge { font: 700 0.95rem/1.2 var(--serif); color: var(--ink); }
.leg .badge.short { color: var(--neg); }
.leg .badge.long { color: var(--pos); }
.leg .entry { font: 600 0.95rem var(--mono); color: var(--ink); }
.leg .rm { justify-self: start; min-height: 38px; }

.stats { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0; margin: 20px 0; border: 1px solid var(--rule); }
@media (min-width: 720px) { .stats { grid-template-columns: repeat(4, 1fr); } }
.stats > div { padding: 10px 12px; border-right: 1px solid var(--rule); border-bottom: 1px solid var(--rule); margin: 0 -1px -1px 0; }
.stats dt { font: 500 0.7rem/1.2 var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }
.stats dd { margin: 4px 0 0; font: 600 1.15rem/1.25 var(--mono); font-variant-numeric: tabular-nums; overflow-wrap: anywhere; }
.stats dd.pos { color: var(--pos); }
.stats dd.neg { color: var(--neg); }
.stats dd small { display: block; font: 500 0.78rem/1.4 var(--mono); color: var(--muted); }

/* Footer */
.foot { border-top: 4px double var(--rule-strong); background: var(--card); color: var(--muted); font-size: 0.88rem; }
.foot .wrap { padding-block: 18px 28px; }
.foot p { margin: 0 0 6px; max-width: 80ch; }
.foot a { color: var(--ink); }

@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; transition: none !important; } }