:root {
  color-scheme: dark;
  --bg: #090f14;
  --panel: #101820;
  --panel-raised: #14202a;
  --field: #070c10;
  --line: #25333e;
  --line-strong: #3b5060;
  --text: #eff6f6;
  --muted: #71838d;
  --muted-strong: #a1b2ba;
  --accent: #72e6c1;
  --accent-soft: rgba(114, 230, 193, 0.12);
  --blue: #73b9ff;
  --blue-soft: rgba(115, 185, 255, 0.12);
  --amber: #ffc166;
  --red: #ff7580;
  --shadow: rgba(0, 0, 0, 0.26);
}

body.light {
  color-scheme: light;
  --bg: #edf2f1;
  --panel: #f9fbfa;
  --panel-raised: #fff;
  --field: #f1f5f4;
  --line: #ccd8d5;
  --line-strong: #96aaa5;
  --text: #172421;
  --muted: #6b7e79;
  --muted-strong: #50635e;
  --accent: #08795c;
  --accent-soft: rgba(8, 121, 92, 0.1);
  --blue: #236da8;
  --blue-soft: rgba(35, 109, 168, 0.1);
  --amber: #9d6410;
  --red: #bd3945;
  --shadow: rgba(25, 48, 42, 0.09);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  min-width: 320px;
  margin: 0;
  background:
    radial-gradient(circle at 8% -8%, rgba(114, 230, 193, 0.09), transparent 30rem),
    radial-gradient(circle at 95% 42%, rgba(115, 185, 255, 0.05), transparent 28rem),
    var(--bg);
  color: var(--text);
  font-family: "Space Grotesk", "Avenir Next", "Segoe UI", system-ui, sans-serif;
  transition: background-color 0.2s, color 0.2s;
}

button, textarea, input { font: inherit; }
button { color: inherit; cursor: pointer; }
button:focus-visible, textarea:focus-visible, input:focus-visible, pre:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.app { width: min(1220px, calc(100% - 48px)); margin: 0 auto; }

.topbar { height: 82px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 12px; color: var(--text); text-decoration: none; font-size: 13px; font-weight: 700; letter-spacing: 0.17em; }
.brand-mark { width: 42px; height: 30px; display: flex; align-items: center; justify-content: center; gap: 2px; border: 1px solid var(--line-strong); background: var(--panel); font: 600 10px "IBM Plex Mono", monospace; }
.brand-mark i { color: var(--muted); font-style: normal; }
.brand-mark b { color: var(--accent); font-size: 11px; }
.top-actions { display: flex; align-items: center; gap: 20px; }
.local-status { color: var(--muted); font: 500 10px "IBM Plex Mono", monospace; letter-spacing: 0.12em; }
.local-status i, #statusValue i { width: 6px; height: 6px; display: inline-block; margin-right: 7px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 9px var(--accent); }
.square-button { width: 36px; height: 36px; display: grid; place-items: center; border: 1px solid var(--line); background: transparent; }
.square-button:hover { border-color: var(--line-strong); background: var(--panel); }
.square-button svg { width: 17px; fill: none; stroke: currentColor; stroke-width: 1.6; }

.intro { min-height: 174px; display: flex; align-items: flex-end; justify-content: space-between; gap: 48px; padding: 40px 0 31px; }
.eyebrow { margin: 0; color: var(--muted); font: 500 9px "IBM Plex Mono", monospace; letter-spacing: 0.15em; }
.intro h1 { max-width: 760px; margin: 8px 0 0; font-size: clamp(33px, 4.4vw, 58px); font-weight: 500; line-height: 1; letter-spacing: -0.045em; }
.intro > p { width: min(360px, 36%); margin: 0 0 3px; color: var(--muted-strong); font-size: 13px; line-height: 1.65; }

.expression-card { border: 1px solid var(--line); background: var(--panel); box-shadow: 0 18px 50px var(--shadow); }
.section-head, .card-head { min-height: 57px; display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 0 17px; border-bottom: 1px solid var(--line); }
.section-head > label { color: var(--muted); font: 500 9px "IBM Plex Mono", monospace; letter-spacing: 0.13em; }
.text-actions { display: flex; align-items: center; gap: 10px; }
.text-actions button, .copy-button { padding: 8px 0; border: 0; background: transparent; color: var(--muted); font: 500 8px "IBM Plex Mono", monospace; letter-spacing: 0.09em; }
.text-actions button:hover, .copy-button:hover { color: var(--text); }
.text-actions span { color: var(--line-strong); }
.expression-row { min-height: 92px; display: grid; grid-template-columns: auto minmax(0, 1fr) auto auto; align-items: center; gap: 10px; padding: 16px 22px; background: var(--field); border-bottom: 1px solid var(--line); }
.slash { color: var(--accent); font: 400 28px "IBM Plex Mono", monospace; }
.expression-row input { width: 100%; min-width: 0; border: 0; outline: 0; background: transparent; color: var(--text); font: 18px/1.5 "IBM Plex Mono", monospace; }
.expression-row output { min-width: 26px; color: var(--blue); font: 500 16px "IBM Plex Mono", monospace; }
.expression-footer { min-height: 68px; display: flex; align-items: center; justify-content: space-between; gap: 22px; padding: 10px 12px 10px 20px; }
.expression-footer > span { color: var(--muted); font: 400 8px "IBM Plex Mono", monospace; letter-spacing: 0.07em; }
.flag-list { display: flex; align-items: stretch; border: 1px solid var(--line); background: var(--field); }
.flag-list label { min-width: 68px; display: grid; grid-template-columns: 18px 1fr; align-items: center; gap: 0 4px; padding: 8px 10px; border-right: 1px solid var(--line); cursor: pointer; }
.flag-list label:last-child { border-right: 0; }
.flag-list label:hover { background: var(--panel-raised); }
.flag-list input { position: absolute; opacity: 0; pointer-events: none; }
.flag-list span { grid-row: 1 / span 2; width: 18px; height: 18px; display: grid; place-items: center; border: 1px solid var(--line-strong); color: var(--muted); font: 600 10px "IBM Plex Mono", monospace; }
.flag-list small { color: var(--muted); font: 500 6px "IBM Plex Mono", monospace; letter-spacing: 0.08em; }
.flag-list input:checked + span { border-color: var(--accent); background: var(--accent); color: #06140f; }
.flag-list input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.error-message { padding: 12px 20px; border-top: 1px solid rgba(255, 117, 128, 0.35); background: rgba(255, 117, 128, 0.08); color: var(--red); font: 500 11px/1.5 "IBM Plex Mono", monospace; }

.status-strip { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 16px; border: 1px solid var(--line); background: var(--panel); }
.status-strip > div { min-height: 66px; display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 13px 17px; border-right: 1px solid var(--line); }
.status-strip > div:last-child { border-right: 0; }
.status-strip span { color: var(--muted); font: 500 7px "IBM Plex Mono", monospace; letter-spacing: 0.1em; }
.status-strip strong { color: var(--muted-strong); font: 600 10px "IBM Plex Mono", monospace; letter-spacing: 0.05em; }
#statusValue { color: var(--accent); }
#statusValue.is-error { color: var(--red); }
#statusValue.is-error i { background: var(--red); box-shadow: none; }

.workspace { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 16px; margin-top: 16px; }
.panel, .matches-card, .replace-card { min-width: 0; border: 1px solid var(--line); background: var(--panel); }
.panel-head { min-height: 72px; display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 0 17px; border-bottom: 1px solid var(--line); }
.panel-head > div, .card-head > div { display: flex; align-items: center; gap: 14px; }
.panel-index { color: var(--accent); font: 600 11px "IBM Plex Mono", monospace; }
.result-panel .panel-index, .replace-card .panel-index { color: var(--blue); }
.panel-head p, .card-head p { margin: 0 0 5px; color: var(--muted); font: 500 8px "IBM Plex Mono", monospace; letter-spacing: 0.11em; }
.panel-head h2, .card-head h2 { margin: 0; font-size: 14px; font-weight: 500; }
.panel-stat, .card-head > span { color: var(--muted); font: 500 8px "IBM Plex Mono", monospace; letter-spacing: 0.07em; }
.source-panel textarea, .highlight-output { width: 100%; height: 328px; min-height: 260px; display: block; margin: 0; overflow: auto; resize: vertical; padding: 22px; border: 0; border-bottom: 1px solid var(--line); outline: 0; background: var(--field); color: var(--text); font: 13px/1.75 "IBM Plex Mono", monospace; white-space: pre-wrap; overflow-wrap: anywhere; tab-size: 2; }
.source-panel textarea:focus { box-shadow: inset 3px 0 0 var(--accent); }
.highlight-output { color: var(--muted-strong); }
.highlight-output mark { padding: 2px 0; border-bottom: 1px solid var(--accent); border-radius: 2px; background: var(--accent-soft); color: var(--text); box-shadow: inset 0 -1px 0 var(--accent); }
.highlight-output mark.is-selected { background: var(--accent); color: #06140f; box-shadow: 0 0 0 2px var(--accent); }
.highlight-output mark.is-empty::after { content: "∅"; display: inline-block; padding: 0 2px; color: #06140f; background: var(--accent); font-size: 9px; }
.panel-foot { min-height: 62px; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 9px 9px 9px 18px; }
.panel-foot > span { color: var(--muted); font: 400 8px "IBM Plex Mono", monospace; letter-spacing: 0.06em; }
.primary-button { width: 184px; height: 43px; display: flex; align-items: center; justify-content: space-between; padding: 0 15px; border: 0; background: var(--accent); color: #06140f; font-size: 9px; font-weight: 700; letter-spacing: 0.1em; }
.primary-button b { font-size: 17px; font-weight: 400; }
.primary-button:hover { filter: brightness(1.08); }
.result-foot { padding-right: 18px; }
.legend-swatch { width: 12px; height: 8px; display: inline-block; margin-right: 5px; background: var(--accent-soft); border-bottom: 1px solid var(--accent); }

.lower-grid { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(360px, 0.92fr); gap: 16px; margin-top: 16px; }
.matches-card, .replace-card { min-height: 408px; }
.card-head { min-height: 66px; }
.copy-button { padding: 8px 10px; border: 1px solid var(--line); }
.match-list { max-height: 340px; overflow: auto; }
.empty-state { min-height: 250px; display: grid; place-items: center; padding: 32px; text-align: center; }
.empty-state strong { display: block; margin-bottom: 8px; font-size: 14px; font-weight: 500; }
.empty-state span { color: var(--muted); font: 10px/1.6 "IBM Plex Mono", monospace; }
.match-item { border-bottom: 1px solid var(--line); }
.match-item:last-child { border-bottom: 0; }
.match-summary { width: 100%; min-height: 58px; display: grid; grid-template-columns: 38px minmax(0, 1fr) auto auto; align-items: center; gap: 12px; padding: 10px 16px; border: 0; background: transparent; text-align: left; }
.match-summary:hover, .match-item.is-selected .match-summary { background: var(--accent-soft); }
.match-number { width: 28px; height: 28px; display: grid; place-items: center; border: 1px solid var(--line); color: var(--accent); font: 600 9px "IBM Plex Mono", monospace; }
.match-value { min-width: 0; overflow: hidden; color: var(--text); font: 11px "IBM Plex Mono", monospace; text-overflow: ellipsis; white-space: nowrap; }
.match-range, .match-groups-count { color: var(--muted); font: 500 7px "IBM Plex Mono", monospace; letter-spacing: 0.06em; white-space: nowrap; }
.capture-list { display: grid; gap: 1px; padding: 0 16px 14px 66px; }
.capture-row { min-width: 0; display: grid; grid-template-columns: minmax(76px, auto) minmax(0, 1fr); gap: 12px; padding: 8px 10px; background: var(--field); }
.capture-row dt { color: var(--blue); font: 500 8px "IBM Plex Mono", monospace; }
.capture-row dd { min-width: 0; margin: 0; overflow: hidden; color: var(--muted-strong); font: 10px "IBM Plex Mono", monospace; text-overflow: ellipsis; white-space: nowrap; }
.capture-row dd.is-unset { color: var(--muted); font-style: italic; }

.replace-card { display: flex; flex-direction: column; }
.replace-label { margin: 17px 17px 8px; color: var(--muted); font: 500 8px "IBM Plex Mono", monospace; letter-spacing: 0.09em; }
.replace-card > input { margin: 0 17px; padding: 13px 14px; border: 1px solid var(--line); outline: 0; background: var(--field); color: var(--text); font: 12px "IBM Plex Mono", monospace; }
.replace-card > input:focus { border-color: var(--blue); }
.template-hints { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin: 10px 17px 14px; }
.template-hints code { padding: 3px 5px; background: var(--blue-soft); color: var(--blue); font: 8px "IBM Plex Mono", monospace; }
.template-hints span { margin-right: 5px; color: var(--muted); font: 7px "IBM Plex Mono", monospace; }
.replacement-output { min-height: 178px; max-height: 250px; flex: 1; margin: 0; overflow: auto; padding: 17px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: var(--field); color: var(--muted-strong); font: 11px/1.7 "IBM Plex Mono", monospace; white-space: pre-wrap; overflow-wrap: anywhere; }
.replace-foot { min-height: 42px; display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 0 17px; color: var(--muted); font: 400 7px "IBM Plex Mono", monospace; letter-spacing: 0.05em; }

.samples { margin-top: 16px; border: 1px solid var(--line); background: var(--panel); }
.samples-head { min-height: 104px; display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; padding: 24px 20px 20px; border-bottom: 1px solid var(--line); }
.samples-head h2 { margin: 7px 0 0; font-size: 22px; font-weight: 500; letter-spacing: -0.025em; }
.samples-head > p { width: 230px; margin: 0; color: var(--muted); font-size: 11px; line-height: 1.5; }
.sample-grid { display: grid; grid-template-columns: repeat(5, 1fr); }
.sample-grid button { min-width: 0; min-height: 126px; display: grid; align-content: center; gap: 7px; padding: 16px; border: 0; border-right: 1px solid var(--line); background: transparent; text-align: left; }
.sample-grid button:last-child { border-right: 0; }
.sample-grid button:hover { background: var(--accent-soft); }
.sample-grid span { color: var(--accent); font: 600 8px "IBM Plex Mono", monospace; }
.sample-grid strong { font: 600 9px "IBM Plex Mono", monospace; letter-spacing: 0.07em; }
.sample-grid code { min-width: 0; overflow: hidden; color: var(--muted-strong); font: 9px "IBM Plex Mono", monospace; text-overflow: ellipsis; white-space: nowrap; }
.sample-grid small { color: var(--muted); font: 500 7px "IBM Plex Mono", monospace; letter-spacing: 0.07em; }

footer { min-height: 112px; display: flex; align-items: center; justify-content: space-between; gap: 20px; color: var(--muted); font: 500 7px "IBM Plex Mono", monospace; letter-spacing: 0.1em; }
.toast { position: fixed; z-index: 20; right: 24px; bottom: 24px; max-width: min(360px, calc(100% - 48px)); padding: 12px 16px; border: 1px solid var(--line-strong); background: var(--panel-raised); color: var(--text); box-shadow: 0 14px 40px var(--shadow); font: 500 10px "IBM Plex Mono", monospace; opacity: 0; transform: translateY(10px); pointer-events: none; transition: 0.2s; }
.toast.show { opacity: 1; transform: translateY(0); }

@media (max-width: 980px) {
  .expression-footer { align-items: flex-start; flex-direction: column; }
  .flag-list { width: 100%; }
  .flag-list label { flex: 1; }
  .status-strip { grid-template-columns: repeat(2, 1fr); }
  .status-strip > div:nth-child(2) { border-right: 0; }
  .status-strip > div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .workspace, .lower-grid { grid-template-columns: 1fr; }
  .sample-grid { grid-template-columns: repeat(3, 1fr); }
  .sample-grid button:nth-child(3) { border-right: 0; }
  .sample-grid button:nth-child(-n+3) { border-bottom: 1px solid var(--line); }
}

@media (max-width: 680px) {
  .app { width: min(100% - 24px, 1220px); }
  .topbar { height: 68px; }
  .local-status { display: none; }
  .intro { min-height: 200px; display: block; padding: 40px 0 27px; }
  .intro > p { width: 100%; margin-top: 20px; }
  .section-head { align-items: flex-start; flex-direction: column; padding: 14px; }
  .expression-row { grid-template-columns: auto minmax(0, 1fr) auto; padding: 14px; }
  .expression-row output { grid-column: 2; }
  .flag-list { display: grid; grid-template-columns: repeat(3, 1fr); }
  .flag-list label:nth-child(3) { border-right: 0; }
  .flag-list label:nth-child(-n+3) { border-bottom: 1px solid var(--line); }
  .status-strip { grid-template-columns: 1fr; }
  .status-strip > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .status-strip > div:nth-child(3) { border-bottom: 1px solid var(--line); }
  .status-strip > div:last-child { border-bottom: 0; }
  .panel-head { align-items: flex-start; flex-direction: column; padding: 15px; }
  .source-panel textarea, .highlight-output { height: 280px; padding: 16px; }
  .lower-grid { grid-template-columns: minmax(0, 1fr); }
  .match-summary { grid-template-columns: 34px minmax(0, 1fr) auto; }
  .match-groups-count { display: none; }
  .capture-list { padding-left: 16px; }
  .samples-head { align-items: flex-start; flex-direction: column; }
  .samples-head > p { width: 100%; }
  .sample-grid { grid-template-columns: 1fr; }
  .sample-grid button { border-right: 0; border-bottom: 1px solid var(--line); }
  .sample-grid button:nth-child(3) { border-right: 0; }
  .sample-grid button:last-child { border-bottom: 0; }
  footer { align-items: flex-start; flex-direction: column; justify-content: center; }
}

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