/* ============================================================
   Excel Shortcuts — styles
   ============================================================ */

:root {
  --font: "Segoe UI", "Segoe UI Variable", system-ui, -apple-system, Arial, sans-serif;
  --mono: "Cascadia Code", Consolas, "Courier New", monospace;

  --accent: #107C41;
  --accent-dark: #0B5C30;
  --accent-soft: #E7F3EC;
  --accent-soft2: #CFE8DA;

  --bg: #F7F8F7;
  --bg-card: #FFFFFF;
  --bg-inset: #F0F2F0;
  --text: #1A1E1B;
  --text2: #5A6360;
  --border: #DDE3DE;
  --border2: #C8D2CB;
  --shadow: 0 1px 3px rgba(16, 40, 26, 0.08);
  --shadow-lg: 0 12px 40px rgba(16, 40, 26, 0.18);

  --key-bg: linear-gradient(180deg, #FFFFFF 0%, #EDF0ED 100%);
  --key-border: #C4CCC6;
  --key-edge: #B3BDB5;
  --key-text: #2A322C;

  --mx-bg: #FFFFFF;
  --mx-head: #F3F5F3;
  --mx-border: #E0E4E0;
  --mx-sel: rgba(16, 124, 65, 0.12);
  --mx-text: #333;

  --mark-bg: #FFE9A8;
  --ai: #7C3AED;
}

html[data-theme="dark"] {
  --accent: #2EA96A;
  --accent-dark: #1E7A4B;
  --accent-soft: #12281B;
  --accent-soft2: #1A3A27;

  --bg: #131715;
  --bg-card: #1B211D;
  --bg-inset: #161B18;
  --text: #E8ECE9;
  --text2: #93A099;
  --border: #2A322C;
  --border2: #3A453E;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.6);

  --key-bg: linear-gradient(180deg, #2A322C 0%, #1F2621 100%);
  --key-border: #3A453E;
  --key-edge: #10140f;
  --key-text: #DBE3DD;

  --mx-bg: #20262215;
  --mx-head: #232B26;
  --mx-border: #313B34;
  --mx-sel: rgba(46, 169, 106, 0.2);
  --mx-text: #CFD8D2;

  --mark-bg: #7A5E00;
  --ai: #A78BFA;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
}
button { font-family: var(--font); cursor: pointer; }
input, select { font-family: var(--font); }
mark { background: var(--mark-bg); color: inherit; border-radius: 3px; padding: 0 1px; }
[hidden] { display: none !important; }

/* ---------- Hero ---------- */
.hero { text-align: center; padding: 56px 20px 8px; transition: padding-top 220ms ease; }
.hero-inner { max-width: 760px; margin: 0 auto; }
.hero-title { font-size: 40px; font-weight: 700; margin: 0 0 10px; letter-spacing: -0.5px; }
.x-logo {
  width: 46px;
  height: 46px;
  vertical-align: -9px;
  margin-right: 8px;
  filter: drop-shadow(0 4px 10px rgba(16, 124, 65, 0.25));
}
.hero-sub { color: var(--text2); font-size: 16px; margin: 0 0 26px; }

body.scrolled .hero { padding-top: 28px; }

/* ---------- Sticky topbar (search + controls) ---------- */
.topbar {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  padding: 10px 20px 0;
  border-bottom: 1px solid transparent;
  transition: border-color .2s, box-shadow .2s, padding-top 220ms ease;
}
body.scrolled .topbar { border-bottom-color: var(--border); box-shadow: var(--shadow); padding-top: 5px; }

.search-wrap { max-width: 760px; margin: 0 auto; }
.search-box {
  display: flex; align-items: center; gap: 8px;
  background: var(--bg-card);
  border: 2px solid var(--border2);
  border-radius: 14px;
  padding: 6px 10px 6px 16px;
  box-shadow: var(--shadow);
  transition: border-color .15s, box-shadow .15s;
}
.search-box:focus-within { border-color: var(--accent); box-shadow: 0 0 0 4px rgba(16,124,65,.12), var(--shadow); }
.search-ico { color: var(--text2); flex: none; }
#searchInput {
  flex: 1; min-width: 0; border: 0; outline: 0; background: transparent;
  font-size: 17px; padding: 10px 0; color: var(--text);
  transition: padding 220ms ease, font-size 220ms ease;
}
body.scrolled #searchInput { padding: 6px 0; font-size: 15px; }
#searchInput::placeholder { color: var(--text2); opacity: .8; }

.icon-btn {
  border: 0; background: transparent; color: var(--text2);
  border-radius: 8px; padding: 7px 9px; font-size: 15px; line-height: 1;
  display: inline-flex; align-items: center; justify-content: center;
}
.icon-btn:hover { background: var(--bg-inset); color: var(--text); }
.clear-btn { display: none; }
.search-box.has-text .clear-btn { display: inline-flex; }
.capture-btn.on { background: var(--accent); color: #fff; }
.capture-btn.on:hover { background: var(--accent-dark); color: #fff; }

.ai-search-btn {
  flex: none;
  font-size: 13.5px; font-weight: 700; white-space: nowrap;
  color: #fff; background: var(--ai);
  padding: 8px 12px; border-radius: 9px;
}
.ai-search-btn:hover { background: var(--ai); color: #fff; filter: brightness(1.1); }
.ai-search-btn:disabled { opacity: .55; cursor: default; }

.capture-hint {
  display: none; margin: 8px auto 0; max-width: 760px;
  font-size: 13px; color: var(--text2);
  background: var(--accent-soft); border: 1px dashed var(--accent);
  border-radius: 10px; padding: 8px 12px; text-align: center;
}
body.capture .capture-hint { display: block; }

.chips {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center; justify-content: center;
  margin: 12px auto 0; max-width: 760px;
  overflow: hidden; max-height: 80px; transition: max-height .25s, margin .25s, opacity .2s;
}
.chips-label { color: var(--text2); font-size: 13px; }
.chip {
  border: 1px solid var(--border2); background: var(--bg-card); color: var(--text);
  border-radius: 999px; padding: 6px 13px; font-size: 13px;
  transition: border-color .12s, background .12s;
}
.chip:hover { border-color: var(--accent); background: var(--accent-soft); }
body.scrolled .chips, body.searching .chips { max-height: 0; margin-top: 0; opacity: 0; }

/* controls row inside topbar */
.controls { padding: 8px 0 0; }
.controls-inner { max-width: 1180px; margin: 0 auto; display: flex; align-items: center; }
.controls-spacer { flex: 1; }
.controls-right { flex: 1; display: flex; justify-content: flex-end; align-items: center; gap: 8px; }

/* Column wrapper — keeps both rows on the same center axis */
.controls-center {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 4px 0 10px;
  transition: padding-bottom 220ms ease;
}
body.scrolled .controls-center { padding-bottom: 5px; }

/* Main tabs: Shortcuts / Formulas */
.main-tabs {
  display: flex;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 4px;
  gap: 2px;
}
.main-tab {
  border: 0; background: transparent; color: var(--text2);
  padding: 8px 28px; border-radius: 9px; font-size: 14px; font-weight: 600;
  transition: background .15s, color .15s, box-shadow .15s;
}
.main-tab.active { background: var(--bg-card); color: var(--text); box-shadow: var(--shadow); }
.main-tab:hover:not(.active) { color: var(--text); }

/* Sub-controls: By key / By ribbon */
.sub-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  max-height: 60px;
  overflow: hidden;
  transition: max-height 220ms ease, opacity 220ms ease;
}
body.scrolled .sub-controls:not([hidden]) { max-height: 0; opacity: 0; }

/* Count caption — collapses with the sub-controls row */
.controls-center .count {
  max-height: 24px;
  overflow: hidden;
  transition: max-height 220ms ease, opacity 220ms ease;
}
body.scrolled .controls-center .count { max-height: 0; opacity: 0; }

/* In formulas mode the sub-controls are [hidden]; hide the count too */
#subControls[hidden] + .count { display: none; }

.seg { display: inline-flex; background: var(--bg-inset); border: 1px solid var(--border); border-radius: 10px; padding: 3px; }
.seg-btn {
  border: 0; background: transparent; color: var(--text2);
  padding: 6px 16px; border-radius: 8px; font-size: 13.5px; font-weight: 600;
}
.seg-btn.active { background: var(--bg-card); color: var(--text); box-shadow: var(--shadow); }
.count { color: var(--text2); font-size: 12px; opacity: .75; }

/* ---------- Main / sections ---------- */
.main { max-width: 1180px; margin: 0 auto; padding: 10px 20px 60px; }

.section { margin-top: 34px; }
.section-head { display: flex; align-items: baseline; gap: 10px; margin-bottom: 14px; }
.section-title { font-size: 20px; font-weight: 700; margin: 0; }
.section-count {
  font-size: 12px; font-weight: 600; color: var(--accent);
  background: var(--accent-soft); border-radius: 999px; padding: 3px 9px;
}

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 16px; }

/* ---------- Card ---------- */
.card {
  position: relative;
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 14px;
  padding: 16px 16px 14px; box-shadow: var(--shadow);
  display: flex; flex-direction: column; gap: 9px;
  transition: transform .15s, box-shadow .15s, border-color .15s;
  cursor: pointer;
}
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); border-color: var(--border2); }
.card-keys { display: flex; flex-wrap: wrap; align-items: center; row-gap: 6px; min-height: 28px; }
.card-name { font-size: 16px; font-weight: 700; margin: 0; }
.card-desc { font-size: 13.5px; color: var(--text2); margin: 0; line-height: 1.45; }
.card-foot { display: flex; gap: 6px; margin-top: auto; }
.tag {
  font-size: 11px; font-weight: 600; color: var(--text2);
  background: var(--bg-inset); border: 1px solid var(--border);
  border-radius: 6px; padding: 2.5px 8px;
}
.tag.tag-ribbon { color: var(--accent); background: var(--accent-soft); border-color: transparent; }

/* ---------- Favorite star ---------- */
.fav-btn {
  border: 0; background: transparent; cursor: pointer;
  font-size: 18px; line-height: 1; color: var(--text2);
  padding: 2px 4px; border-radius: 6px;
  transition: color .12s, transform .12s;
}
.fav-btn:hover { color: #f5b301; transform: scale(1.15); }
.fav-btn.on { color: #f5b301; }
.card > .fav-btn {
  position: absolute; top: 11px; right: 11px; z-index: 2;
  /* keep the tap target off the keycaps row */
  background: color-mix(in srgb, var(--bg-card) 82%, transparent);
}
.modal-fav { position: absolute; top: 12px; right: 46px; font-size: 21px; }
.fav-empty {
  color: var(--text2); font-size: 14px; text-align: center;
  padding: 30px 4px; margin: 0;
}

/* ---------- Windows / Mac toggle ---------- */
.platform-seg { display: inline-flex; background: var(--bg-inset); border: 1px solid var(--border); border-radius: 9px; padding: 2px; }
.platform-btn {
  border: 0; background: transparent; color: var(--text2); cursor: pointer;
  padding: 5px 11px; border-radius: 7px; font-size: 12.5px; font-weight: 600;
  transition: background .15s, color .15s;
}
.platform-btn.active { background: var(--bg-card); color: var(--text); box-shadow: var(--shadow); }
.platform-btn:hover:not(.active) { color: var(--text); }
.tag.tag-winonly { color: var(--text2); background: var(--bg-inset); border-color: var(--border); font-style: italic; }
.keys-dimmed { display: inline-flex; align-items: center; opacity: .5; margin-right: 8px; }

/* ---------- Practice / quiz mode ---------- */
.practice-bar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-top: 8px; }
.quiz-score { margin-left: auto; color: var(--text2); font-size: 13px; }
.quiz-score b { color: var(--text); }
.quiz-card {
  max-width: 620px; margin: 28px auto 0; text-align: center;
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 16px;
  padding: 34px 28px 26px; box-shadow: var(--shadow);
}
.quiz-label { color: var(--text2); font-size: 13px; text-transform: uppercase; letter-spacing: .06em; }
.quiz-name { font-size: 26px; margin: 8px 0 6px; }
.quiz-desc { color: var(--text2); font-size: 14.5px; line-height: 1.5; margin: 0 auto; max-width: 440px; }
.quiz-input {
  min-height: 56px; margin: 22px auto 6px; display: flex; align-items: center; justify-content: center;
  border: 1px dashed var(--border2); border-radius: 12px; padding: 10px 16px; background: var(--bg-inset);
}
.quiz-hint { color: var(--text2); font-size: 14px; }
.quiz-pressed { display: inline-flex; flex-wrap: wrap; align-items: center; justify-content: center; row-gap: 6px; }
.quiz-feedback { min-height: 22px; font-size: 14.5px; font-weight: 600; margin: 4px 0; }
.quiz-feedback.ok { color: var(--accent); }
.quiz-feedback.err { color: #d1453b; }
.quiz-demo { height: 200px; margin: 12px 0 4px; }
.quiz-actions { display: flex; gap: 10px; justify-content: center; margin-top: 14px; }
.quiz-touch-note { display: none; color: var(--text2); font-size: 12.5px; margin: 12px 0 0; }
@media (pointer: coarse) { .quiz-touch-note { display: block; } }
@keyframes quizShake {
  10%, 90% { transform: translateX(-2px); }
  20%, 80% { transform: translateX(4px); }
  30%, 50%, 70% { transform: translateX(-7px); }
  40%, 60% { transform: translateX(7px); }
}
.quiz-card.shake { animation: quizShake .5s; }

/* ---------- Keycaps ---------- */
.key {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 28px; height: 28px; padding: 0 8px;
  border-radius: 7px; font-size: 12.5px; font-weight: 600; line-height: 1;
  color: var(--key-text); background: var(--key-bg);
  border: 1px solid var(--key-border);
  box-shadow: inset 0 -2px 0 var(--key-edge), 0 1px 2px rgba(0,0,0,.12);
  white-space: nowrap;
}
.key-s { min-width: 22px; height: 22px; font-size: 11px; padding: 0 6px; border-radius: 5px; }
.key-lg { min-width: 38px; height: 38px; font-size: 16px; padding: 0 12px; border-radius: 9px; }
.plus { margin: 0 5px; color: var(--text2); font-weight: 600; font-size: 13px; }
.then { margin: 0 6px; color: var(--accent); font-weight: 700; font-size: 13px; }
.or-sep { margin: 0 5px; color: var(--text2); font-size: 12px; font-style: italic; }
.key.pressed { transform: translateY(2px); box-shadow: inset 0 -1px 0 var(--key-edge); background: var(--accent-soft2); border-color: var(--accent); }

/* ---------- Demo strip / mini Excel ---------- */
.demo {
  position: relative; height: 158px; border-radius: 10px; overflow: hidden;
  border: 1px solid var(--border);
  background:
    linear-gradient(color-mix(in srgb, var(--bg-inset) 50%, transparent), color-mix(in srgb, var(--bg-inset) 50%, transparent)),
    repeating-linear-gradient(0deg, transparent 0 25px, var(--border) 25px 26px),
    repeating-linear-gradient(90deg, transparent 0 62px, var(--border) 62px 63px);
  background-color: var(--mx-bg);
}
.demo.static::after {
  content: "▶";
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 600; color: var(--text2);
  background: color-mix(in srgb, var(--bg-card) 42%, transparent);
  opacity: 0; transition: opacity .2s;
  pointer-events: none;
}
.card:hover .demo.static::after {
  opacity: 0;
}
.modal-demo { height: 240px; margin-top: 16px; }

.mx { position: absolute; inset: 0; display: flex; flex-direction: column; background: var(--mx-bg); font-size: 11px; color: var(--mx-text); }
.mx-fbar {
  display: flex; align-items: center; gap: 6px; padding: 4px 6px;
  background: var(--mx-head); border-bottom: 1px solid var(--mx-border);
  font-size: 10.5px; flex: none;
}
.mx-name { min-width: 34px; padding: 2px 5px; background: var(--mx-bg); border: 1px solid var(--mx-border); border-radius: 3px; text-align: center; }
.mx-fx { color: var(--text2); font-style: italic; font-family: var(--mono); }
.mx-input { flex: 1; padding: 2px 6px; background: var(--mx-bg); border: 1px solid var(--mx-border); border-radius: 3px; min-height: 17px; font-family: var(--mono); white-space: nowrap; overflow: hidden; }
.mx-caret::after { content: "|"; animation: mx-blink .8s steps(1) infinite; color: var(--accent); }
@keyframes mx-blink { 50% { opacity: 0; } }

.mx-ribbon { display: flex; gap: 2px; padding: 3px 6px 0; background: var(--mx-head); font-size: 10px; flex: none; }
.mx-rtab { padding: 3px 8px; border-radius: 4px 4px 0 0; color: var(--text2); position: relative; }
.mx-rtab.hot { background: var(--mx-bg); color: var(--accent); font-weight: 700; box-shadow: 0 -1px 0 var(--accent) inset; }

.mx-table-wrap { flex: 1; overflow: hidden; position: relative; }
.mx-grid { border-collapse: collapse; width: 100%; table-layout: fixed; }
.mx-grid th {
  background: var(--mx-head); color: var(--text2); font-weight: 600; font-size: 9.5px;
  border: 1px solid var(--mx-border); padding: 2px 0; text-align: center;
  transition: background .2s, color .2s;
}
.mx-grid th.rowh { width: 22px; }
.mx-grid td {
  border: 1px solid var(--mx-border); padding: 2.5px 5px; height: 21px;
  white-space: nowrap; overflow: hidden; background: var(--mx-bg);
  transition: background .25s, color .2s, font-weight .1s, transform .3s;
  font-variant-numeric: tabular-nums;
}
.mx-grid td.num { text-align: right; }

.mx-grid td.sel { background: var(--mx-sel); }
.mx-grid td.active { outline: 2px solid var(--accent); outline-offset: -2px; background: var(--mx-bg); }
.mx-grid td.sel.active { background: var(--mx-bg); }
.mx-grid th.hot { background: var(--accent-soft2); color: var(--accent-dark); }
.mx-grid td.ants { outline: 2px dashed var(--accent); outline-offset: -2px; animation: mx-ants .5s steps(2) infinite; }
@keyframes mx-ants { 50% { outline-color: transparent; } }

.mx-grid td.fx-bold { font-weight: 700; }
.mx-grid td.fx-italic { font-style: italic; }
.mx-grid td.fx-under { text-decoration: underline; }
.mx-grid td.fx-strike { text-decoration: line-through; }
.mx-grid td.fx-fill { background: #FFF2CC; color: #333; }
.mx-grid td.fx-red { color: #C0392B; }
.mx-grid td.fx-border { outline: 2px solid var(--mx-text); outline-offset: -2px; }
.mx-grid td.fx-center { text-align: center; }
.mx-grid td.fx-left { text-align: left; }
.mx-grid td.fx-right { text-align: right; }
.mx-grid td.fx-indent { padding-left: 14px; }
.mx-grid td.fx-big { font-size: 13px; }
.mx-grid td.fx-small { font-size: 9px; }
.mx-grid td.fx-wrap { white-space: normal; line-height: 1.15; font-size: 9.5px; }
.mx-grid td.fx-style { background: var(--accent); color: #fff; font-weight: 700; }
.mx-grid td.fx-cond { background: #F8D7DA; color: #B02A37; font-weight: 600; }
.mx-grid td.fx-good { background: #D1E7DD; color: #0F5132; font-weight: 600; }
.mx-grid tr.gone td { transform: scaleY(0); height: 0; padding: 0; border-width: 0; }
.mx-grid td.hidden-col { color: transparent; }

.mx-tabs { display: flex; gap: 1px; background: var(--mx-head); border-top: 1px solid var(--mx-border); padding: 2px 6px 3px; font-size: 9.5px; flex: none; }
.mx-tab { padding: 2px 9px; border-radius: 0 0 4px 4px; color: var(--text2); background: transparent; transition: all .2s; }
.mx-tab.on { background: var(--mx-bg); color: var(--accent); font-weight: 700; box-shadow: 0 1px 0 var(--accent) inset; }

/* floating popups inside demo */
.mx-pop {
  position: absolute; left: 50%; top: 46%; transform: translate(-50%, -50%) scale(.85);
  min-width: 45%; max-width: 88%;
  background: var(--bg-card); border: 1px solid var(--border2); border-radius: 8px;
  box-shadow: var(--shadow-lg); opacity: 0; transition: opacity .2s, transform .2s;
  z-index: 5; overflow: hidden;
}
.mx-pop.show { opacity: 1; transform: translate(-50%, -50%) scale(1); }
.mx-pop-title {
  background: var(--accent); color: #fff; font-size: 10.5px; font-weight: 700;
  padding: 4px 8px; display: flex; justify-content: space-between; align-items: center;
}
.mx-pop-x { opacity: .8; font-weight: 400; }
.mx-pop-body { padding: 8px; display: flex; flex-direction: column; gap: 5px; }
.mx-pop-line { height: 8px; border-radius: 3px; background: var(--bg-inset); border: 1px solid var(--border); }
.mx-pop-line.w60 { width: 60%; } .mx-pop-line.w80 { width: 80%; } .mx-pop-line.w40 { width: 40%; }
.mx-pop-btns { display: flex; gap: 5px; justify-content: flex-end; padding: 0 8px 8px; }
.mx-pop-btn { font-size: 9px; padding: 2px 10px; border-radius: 3px; border: 1px solid var(--border2); background: var(--bg-inset); }
.mx-pop-btn.pri { background: var(--accent); color: #fff; border-color: var(--accent); }

.mx-menu {
  position: absolute; z-index: 6;
  background: var(--bg-card); border: 1px solid var(--border2); border-radius: 6px;
  box-shadow: var(--shadow-lg); font-size: 10px; padding: 3px;
  opacity: 0; transform: translateY(-4px); transition: opacity .18s, transform .18s;
}
.mx-menu.show { opacity: 1; transform: translateY(0); }
.mx-menu-item { padding: 3px 10px; border-radius: 4px; white-space: nowrap; color: var(--text); }
.mx-menu-item.hot { background: var(--accent); color: #fff; }

.mx-flash {
  position: absolute; left: 50%; top: 46%; transform: translate(-50%, -50%) scale(.8);
  background: color-mix(in srgb, var(--bg-card) 94%, transparent);
  border: 1px solid var(--border2);
  border-radius: 12px; padding: 12px 20px; font-size: 14px; font-weight: 700;
  box-shadow: var(--shadow-lg); opacity: 0; transition: opacity .25s, transform .25s;
  z-index: 5; display: flex; align-items: center; gap: 8px; white-space: nowrap;
}
.mx-flash.show { opacity: 1; transform: translate(-50%, -50%) scale(1); }

.mx-keys {
  position: absolute; left: 50%; bottom: 8px; transform: translateX(-50%) translateY(6px);
  display: flex; align-items: center; z-index: 7;
  background: color-mix(in srgb, var(--bg-card) 88%, transparent);
  border: 1px solid var(--border); border-radius: 10px; padding: 5px 9px;
  box-shadow: var(--shadow-lg); opacity: 0; transition: opacity .2s, transform .2s;
}
.mx-keys.show { opacity: 1; transform: translateX(-50%) translateY(0); }

.mx-chart {
  position: absolute; right: 6%; top: 12%; width: 46%; height: 64%;
  background: var(--bg-card); border: 1px solid var(--border2); border-radius: 6px;
  box-shadow: var(--shadow-lg); z-index: 5; padding: 8px 8px 4px;
  display: flex; align-items: flex-end; gap: 6px;
  opacity: 0; transform: scale(.8); transition: opacity .25s, transform .25s;
}
.mx-chart.show { opacity: 1; transform: scale(1); }
.mx-chart.full { left: 8%; right: 8%; width: auto; top: 10%; height: 70%; }
.mx-bar { flex: 1; background: var(--accent); border-radius: 2px 2px 0 0; height: 0; transition: height .5s cubic-bezier(.2,.8,.3,1); }
.mx-bar:nth-child(2) { background: #6FBF92; }
.mx-bar:nth-child(3) { background: #3E9E6C; }
.mx-bar:nth-child(4) { background: #9AD4B4; }

.mx-freeze-h { position: absolute; left: 0; right: 0; height: 2px; background: var(--accent-dark); z-index: 4; box-shadow: 0 1px 3px rgba(0,0,0,.3); }
.mx-freeze-v { position: absolute; top: 0; bottom: 0; width: 2px; background: var(--accent-dark); z-index: 4; box-shadow: 1px 0 3px rgba(0,0,0,.3); }

/* filter buttons in header cells */
.mx-fbtn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 11px; height: 11px; margin-left: 3px; border-radius: 2px;
  background: var(--bg-card); border: 1px solid var(--border2);
  font-size: 7px; color: var(--text2); vertical-align: 1px;
}

/* table stripes */
.mx-grid tr.stripe td { background: var(--accent-soft); }
.mx-grid tr.thead td { background: var(--accent); color: #fff; font-weight: 700; }

/* ---------- Results / AI zone ---------- */
.results-zone { margin-top: 26px; animation: table-in .15s ease-out; }
.results-head { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-bottom: 14px; }
.results-head h2 { margin: 0; font-size: 20px; }
.ai-zone { display: flex; align-items: center; gap: 10px; }
.ai-msg { color: var(--text2); font-size: 13.5px; }
.btn {
  border: 1px solid var(--border2); background: var(--bg-card); color: var(--text);
  border-radius: 10px; padding: 8px 16px; font-size: 13.5px; font-weight: 600;
  transition: all .12s;
}
.btn:hover { border-color: var(--accent); }
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.btn-ghost { border-color: transparent; background: transparent; color: var(--text2); }
.btn-ai { background: var(--ai); border-color: var(--ai); color: #fff; }
.btn-ai:hover { filter: brightness(1.1); border-color: var(--ai); }
.btn:disabled { opacity: .55; cursor: default; }

.ai-status {
  margin: 0 0 14px; font-size: 13.5px; padding: 10px 14px; border-radius: 10px;
  background: color-mix(in srgb, var(--ai) 8%, var(--bg-card));
  border: 1px solid color-mix(in srgb, var(--ai) 30%, var(--border));
}
.ai-status.err { background: #FBECEC; border-color: #E5B8B8; color: #8A2323; }
html[data-theme="dark"] .ai-status.err { background: #3A1D1D; border-color: #6E3030; color: #F1B8B8; }
.ai-spin { display: inline-block; width: 12px; height: 12px; border: 2px solid var(--ai); border-top-color: transparent; border-radius: 50%; animation: spin .7s linear infinite; vertical-align: -1px; margin-right: 6px; }
@keyframes spin { to { transform: rotate(360deg); } }

.no-results { color: var(--text2); text-align: center; padding: 40px 0; }

/* ---------- Modal ---------- */
.overlay {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(10, 20, 14, 0.45);
  backdrop-filter: blur(3px);
  display: flex; align-items: center; justify-content: center; padding: 24px;
}
.modal {
  position: relative; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 18px; box-shadow: var(--shadow-lg);
  width: 640px; max-width: 100%; max-height: 90vh; overflow-y: auto;
  padding: 26px 28px 24px;
  animation: modal-in .18s ease-out;
}
@keyframes modal-in { from { opacity: 0; transform: translateY(10px) scale(.98); } }
.modal-sm {
  width: 470px;
  /* fit the whole settings form on screen — no inner scrollbar */
  max-height: calc(100vh - 24px);
  padding: 20px 24px 18px;
}
.modal-sm .modal-title { font-size: 20px; margin-bottom: 6px; }
.modal-sm .modal-desc { font-size: 13px; line-height: 1.5; }
.field-hint { font-weight: 400; color: var(--text2); opacity: .8; text-transform: none; }
.modal-close { position: absolute; top: 14px; right: 14px; font-size: 14px; }
.modal-keys { display: flex; flex-wrap: wrap; align-items: center; row-gap: 8px; margin-bottom: 12px; }
.modal-title { margin: 0 0 8px; font-size: 24px; }
.modal-desc { margin: 0; color: var(--text2); font-size: 14.5px; line-height: 1.55; }
.modal-tags { display: flex; gap: 6px; margin-top: 12px; }
.related { margin-top: 20px; }
.related h3 { font-size: 13px; text-transform: uppercase; letter-spacing: .06em; color: var(--text2); margin: 0 0 8px; }
.related-chips { display: flex; flex-wrap: wrap; gap: 7px; }
.related-chip {
  display: inline-flex; align-items: center; gap: 7px;
  border: 1px solid var(--border2); background: var(--bg-inset);
  border-radius: 9px; padding: 5px 10px; font-size: 12.5px; color: var(--text);
}
.related-chip:hover { border-color: var(--accent); background: var(--accent-soft); }

/* settings */
.field-label { display: block; font-size: 12.5px; font-weight: 600; color: var(--text2); margin: 13px 0 5px; }
.key-row { display: flex; gap: 6px; }
#apiKeyInput {
  flex: 1; border: 1px solid var(--border2); background: var(--bg-inset); color: var(--text);
  border-radius: 9px; padding: 9px 12px; font-size: 13.5px; outline: none;
}
#apiKeyInput:focus, #apiUrlInput:focus { border-color: var(--accent); }
#modelSelect, #apiUrlInput {
  width: 100%; border: 1px solid var(--border2); background: var(--bg-inset); color: var(--text);
  border-radius: 9px; padding: 9px 10px; font-size: 13.5px; outline: none;
}
#apiUrlInput {
  padding: 9px 12px;
}
.settings-actions { display: flex; gap: 8px; margin-top: 14px; }
.settings-status { margin-top: 10px; font-size: 13px; min-height: 18px; }
.settings-status.ok { color: var(--accent); }
.settings-status.err { color: #C0392B; }

/* ---------- Ribbon Bar (Excel style) ---------- */
.ribbon-bar {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  margin: 0 -20px; /* span edge-to-edge in topbar */
  padding: 0 20px;
}
.ribbon-bar-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}
.ribbon-bar-inner::-webkit-scrollbar {
  display: none;
}
.ribbon-tab {
  background: transparent;
  border: 0;
  color: var(--text2);
  padding: 10px 16px 8px;
  font-size: 13.5px;
  font-weight: 600;
  position: relative;
  transition: color 0.15s, background-color 0.15s;
  white-space: nowrap;
}
.ribbon-tab:hover {
  background-color: var(--bg-inset);
  color: var(--text);
}
.ribbon-tab.active {
  color: var(--accent);
  font-weight: 700;
}
.ribbon-tab.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 16px;
  right: 16px;
  height: 3px;
  background-color: var(--accent);
  border-radius: 99px 99px 0 0;
}

/* ---------- Shortcut Table ---------- */
.table-wrap {
  width: 100%;
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg-card);
  box-shadow: var(--shadow);
  margin-top: 16px;
  animation: table-in .15s ease-out;
}
@keyframes table-in { from { opacity: 0; transform: translateY(4px); } }
.shortcut-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 14px;
}
.shortcut-table th {
  background: var(--bg-inset);
  color: var(--text2);
  font-weight: 600;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
.shortcut-table td {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
  color: var(--text);
}
.shortcut-table tbody tr {
  cursor: pointer;
  transition: background-color 0.1s;
}
.shortcut-table tbody tr:hover {
  background-color: color-mix(in srgb, var(--accent-soft) 40%, var(--bg-card));
}
.shortcut-table tbody tr:last-child td {
  border-bottom: 0;
}
.shortcut-table .keys-cell {
  vertical-align: middle;
}
.shortcut-table .cat-cell {
  font-size: 12px;
}

/* ---------- Formula Maker (Excel style) ---------- */
.formula-zone {
  margin-top: 16px;
  animation: table-in .15s ease-out;
}
/* AI hint strip (browse mode) */
.fn-ai-hint {
  margin: 18px 0 0;
  font-size: 13px;
  color: var(--text2);
  background: color-mix(in srgb, var(--ai) 6%, var(--bg-card));
  border: 1px dashed color-mix(in srgb, var(--ai) 45%, var(--border));
  border-radius: 10px;
  padding: 9px 14px;
  cursor: pointer;
  transition: color .15s, border-color .15s;
}
.fn-ai-hint:hover { color: var(--text); border-color: var(--ai); }
.fn-ai-hint .ai-spark { font-weight: 700; }
.ai-spark { color: var(--ai); }

/* Excel version filter bar */
.fn-ver-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 14px 0 0;
}
.fn-ver-label { font-size: 13px; font-weight: 600; color: var(--text2); }
.fn-ver-select {
  border: 1px solid var(--border2);
  background: var(--bg-card);
  color: var(--text);
  border-radius: 999px;
  padding: 6px 12px;
  font-size: 13px;
  cursor: pointer;
  transition: border-color .12s;
}
.fn-ver-select:hover, .fn-ver-select:focus { border-color: var(--accent); outline: none; }
.fn-ver-note { font-size: 12.5px; color: var(--text2); }
.tag.tag-ver {
  color: var(--ai);
  background: color-mix(in srgb, var(--ai) 10%, var(--bg-card));
  border-color: transparent;
  white-space: nowrap;
}

/* category chips (filter by task) */
.fn-cats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 4px;
}
.fn-cats .chip.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* syntax-breakdown animation (function detail) */
.syn {
  margin: 16px 0 4px;
  padding: 14px 16px;
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 10px;
}
.syn-line {
  font-family: var(--mono);
  font-size: 14px;
  line-height: 1.9;
  word-break: break-word;
}
.syn-fn { color: var(--accent-dark); font-weight: 700; }
html[data-theme="dark"] .syn-fn { color: var(--accent); }
.syn-paren, .syn-comma { color: var(--text2); }
.syn-arg {
  padding: 2px 5px;
  border-radius: 5px;
  transition: background .2s, color .2s;
}
.syn-arg.opt { color: var(--text2); font-style: italic; }
.syn-arg.hot {
  background: var(--accent-soft2);
  color: var(--accent-dark);
  font-weight: 700;
}
html[data-theme="dark"] .syn-arg.hot { color: var(--accent); }
.syn-arg.opt.hot {
  background: var(--accent-soft);
  outline: 1px dashed var(--accent);
}
.syn-cap {
  margin-top: 9px;
  font-size: 12.5px;
  color: var(--text2);
  min-height: 17px;
  line-height: 1.45;
}
.syn-cap b { color: var(--text); font-family: var(--mono); }
.formula-result-box {
  margin: 0 0 16px;
  background: color-mix(in srgb, var(--ai) 4%, var(--bg-card));
  border: 1px solid color-mix(in srgb, var(--ai) 25%, var(--border));
  border-radius: 14px;
  padding: 16px;
  box-shadow: var(--shadow);
  animation: table-in 0.2s ease-out;
}
.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}
.result-header h3 {
  font-size: 14px;
  font-weight: 700;
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text2);
}
.btn-sm {
  padding: 4px 10px;
  font-size: 12px;
  border-radius: 6px;
}
.formula-output {
  font-family: var(--mono);
  font-size: 16px;
  padding: 12px 16px;
  background: var(--accent-soft);
  border-radius: 8px;
  border: 1px solid var(--border2);
  overflow-x: auto;
  color: var(--accent-dark);
  font-weight: 700;
  margin-bottom: 16px;
}
html[data-theme="dark"] .formula-output {
  color: var(--accent);
}
.explanation-header {
  font-size: 13px;
  font-weight: 700;
  color: var(--text2);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}
.formula-explanation {
  font-size: 14px;
  line-height: 1.5;
  color: var(--text);
  margin: 0;
}

/* Formula cards (same language as shortcut cards) */
.card-formula {
  font-family: var(--mono);
  font-size: 12.5px;
  font-weight: 600;
  color: var(--accent-dark);
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft2);
  border-radius: 8px;
  padding: 6px 10px;
  white-space: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}
.card-formula::-webkit-scrollbar { display: none; }
html[data-theme="dark"] .card-formula { color: var(--accent); }
.modal-formula {
  font-size: 14.5px;
  width: 100%;
  padding: 10px 14px;
  margin-bottom: 4px;
}
.modal-syntax {
  display: inline-block;
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 12px;
  color: var(--text2);
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 9px;
}
button.tag { cursor: pointer; }
.copy-tag { margin-left: auto; }
.copy-tag:hover { border-color: var(--accent); color: var(--accent); background: var(--accent-soft); }

/* ---------- AI Chat Mode — search box transforms into chat input ---------- */

/* The chat spark icon (hidden normally, shown in chat mode) */
.chat-ico {
  display: none;
  color: var(--ai);
  font-size: 17px;
  flex: none;
  line-height: 1;
}
body.ai-chat .chat-ico { display: block; }
body.ai-chat .search-ico { display: none; }

/* Hide capture button and show attach button in chat mode */
.chat-attach {
  display: none;
  cursor: pointer;
  color: var(--text2);
}
.chat-attach:hover { background: var(--bg-inset); color: var(--text); }
body.ai-chat .chat-attach { display: inline-flex; align-items: center; justify-content: center; }
body.ai-chat #captureBtn { display: none; }

/* Search box border gets AI color in chat mode */
body.ai-chat .search-box {
  border-color: var(--ai);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--ai) 12%, transparent), var(--shadow);
}
body.ai-chat .search-box:focus-within {
  box-shadow: 0 0 0 5px color-mix(in srgb, var(--ai) 18%, transparent), var(--shadow);
}

/* AI button becomes send button in chat mode */
body.ai-chat .ai-search-btn {
  background: var(--ai);
  color: #fff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 10px;
}

/* Hide suggestion chips in chat mode */
body.ai-chat .chips { max-height: 0; margin-top: 0; opacity: 0; pointer-events: none; }

/* Image preview strip (inside searchWrap, below search-box) */
.chat-image-preview {
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 760px;
  margin: 8px auto 0;
  background: var(--bg-card);
  border: 1px solid var(--border2);
  border-radius: 10px;
  padding: 7px 10px;
}
.chat-image-preview img {
  max-height: 56px;
  max-width: 90px;
  border-radius: 6px;
  object-fit: contain;
  display: block;
  flex: none;
}
.chat-img-remove {
  font-size: 12px;
  padding: 4px 6px;
  flex: none;
}
.chat-img-label {
  font-size: 12.5px;
  color: var(--text2);
  flex: 1;
  min-width: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* ---------- AI Chat messages area ---------- */
.chat-section {
  animation: table-in .15s ease-out;
}
.chat-messages {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-top: 16px;
}
.chat-welcome {
  text-align: center;
  padding: 36px 20px 20px;
  color: var(--text2);
}
.chat-spark {
  font-size: 34px;
  color: var(--ai);
  margin-bottom: 12px;
  line-height: 1;
}
.chat-welcome p { margin: 0 0 8px; font-size: 15px; line-height: 1.55; max-width: 520px; margin-left: auto; margin-right: auto; }
.chat-welcome-hint { font-size: 13px; opacity: .75; }

.chat-msg {
  display: flex;
  flex-direction: column;
  max-width: 78%;
  animation: chat-in .18s ease-out;
}
@keyframes chat-in { from { opacity: 0; transform: translateY(6px); } }
.chat-msg-user { align-self: flex-end; align-items: flex-end; }
.chat-msg-ai { align-self: flex-start; align-items: flex-start; }

.chat-bubble {
  padding: 11px 15px;
  border-radius: 16px;
  font-size: 14px;
  line-height: 1.55;
  word-break: break-word;
  white-space: pre-wrap;
}
.chat-msg-user .chat-bubble {
  background: var(--ai);
  color: #fff;
  border-bottom-right-radius: 4px;
}
.chat-msg-ai .chat-bubble {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text);
  border-bottom-left-radius: 4px;
  box-shadow: var(--shadow);
}
.chat-msg-ai .chat-bubble.thinking {
  color: var(--text2);
  font-style: italic;
}
.chat-bubble img.chat-msg-image {
  display: block;
  max-width: 100%;
  max-height: 240px;
  border-radius: 10px;
  margin-bottom: 8px;
  object-fit: contain;
}
.chat-bubble strong { font-weight: 700; }
.chat-bubble code {
  font-family: var(--mono);
  background: var(--bg-inset);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1px 5px;
  font-size: 12.5px;
  color: var(--accent-dark);
}
html[data-theme="dark"] .chat-bubble code { color: var(--accent); }
.chat-msg-user .chat-bubble code { background: rgba(255,255,255,.2); border-color: rgba(255,255,255,.3); color: #fff; }
.chat-bubble ul, .chat-bubble ol { margin: 6px 0 6px 16px; padding: 0; }
.chat-bubble li { margin-bottom: 3px; }
.chat-bubble p { margin: 0 0 6px; }
.chat-bubble p:last-child { margin-bottom: 0; }

/* hint bar below the search box in chat mode */
.chat-hint-bar {
  display: none;
  max-width: 760px;
  margin: 6px auto 0;
  font-size: 11.5px;
  color: var(--text2);
  text-align: center;
}
body.ai-chat .chat-hint-bar { display: block; }
.chat-hint-bar kbd {
  font-family: var(--mono);
  font-size: 10px;
  background: var(--bg-inset);
  border: 1px solid var(--border2);
  border-radius: 4px;
  padding: 1px 4px;
}
.chat-exit-btn {
  border: 0; background: transparent; color: var(--ai);
  font-size: 11.5px; cursor: pointer; padding: 0; font-family: var(--font);
  font-weight: 600;
}
.chat-exit-btn:hover { text-decoration: underline; }

/* ---------- Footer ---------- */
.footer { border-top: 1px solid var(--border); margin-top: 30px; padding: 22px 20px 34px; }
.footer-inner {
  max-width: 1180px; margin: 0 auto; display: flex; flex-wrap: wrap; gap: 14px 26px;
  align-items: center; color: var(--text2); font-size: 13px;
}
.legend { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; }
.legend-item { display: inline-flex; align-items: center; gap: 5px; }
.footer-note { margin-left: auto; }

/* ---------- Responsive ---------- */

/* Avoid the grey tap-flash and 300ms delay on touch */
button, .card, .chip, .ribbon-tab, .related-chip, .platform-btn, .main-tab, .seg-btn {
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

@media (max-width: 700px) {
  .hero { padding: 38px 16px 6px; }
  body.scrolled .hero { padding-top: 22px; }
  .hero-title { font-size: 29px; }
  .hero-sub { font-size: 15px; margin-bottom: 18px; }

  .topbar { padding-left: 16px; padding-right: 16px; }
  .main { padding: 10px 16px 56px; }
  .ribbon-bar { margin: 0 -16px; padding: 0 16px; }

  /* Controls: stack the Win/Mac + theme + settings group below the tabs
     so the row never overflows on narrow screens */
  .controls-spacer { display: none; }
  .controls-inner { flex-wrap: wrap; justify-content: center; row-gap: 8px; }
  .controls-center { flex: 1 1 100%; order: 1; }
  .controls-right { flex: 1 1 100%; order: 2; justify-content: center; }

  .main-tab { padding: 8px 18px; font-size: 13px; }
  .sub-controls { gap: 8px; }

  .search-box { padding: 5px 8px 5px 14px; gap: 6px; }
  #searchInput { font-size: 16px; } /* 16px avoids iOS zoom-on-focus */
  .ai-search-btn { padding: 8px 10px; }

  .overlay { padding: 14px; align-items: flex-start; padding-top: max(14px, env(safe-area-inset-top)); }
  .modal { padding: 20px; border-radius: 16px; max-height: calc(100vh - 28px); }
  .modal-title { font-size: 21px; }
  .modal-demo { height: 200px; }
  .modal-fav { right: 44px; }

  .quiz-card { padding: 24px 16px 20px; margin-top: 20px; }
  .quiz-name { font-size: 22px; }
  .practice-bar { row-gap: 8px; }
  .quiz-score { margin-left: 0; flex-basis: 100%; }

  .footer { padding: 22px 16px 34px; }
  .footer-note { margin-left: 0; }
}

@media (max-width: 430px) {
  .hero-title { font-size: 25px; }
  .x-logo { width: 38px; height: 38px; vertical-align: -7px; }
  /* the physical-key capture button is not useful on touch keyboards */
  .capture-btn { display: none; }
  .chips { gap: 6px; }
  .chip { padding: 6px 11px; font-size: 12.5px; }
  .card { padding: 14px 14px 12px; }
  .main-tab { padding: 7px 14px; }
}