/* Calculon's website. Colours come from theme.css (the app's Glacier theme). */

@font-face {
  font-family: "Fira Code";
  src: url("fonts/FiraCode-Regular.ttf") format("truetype");
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: "Fira Code";
  src: url("fonts/FiraCode-Bold.ttf") format("truetype");
  font-weight: 700;
  font-display: swap;
}

:root {
  --mono: "Fira Code", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --radius: 12px;
  --shadow: 0 24px 48px -16px rgb(15 23 42 / 0.25);
  --page: 1120px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --shadow: 0 24px 48px -12px rgb(0 0 0 / 0.5);
  }
}

* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.6 var(--sans);
  -webkit-font-smoothing: antialiased;
}
a {
  color: var(--accent);
}
h1,
h2,
h3 {
  color: var(--heading);
  line-height: 1.2;
  margin: 0 0 0.5em;
}
h1 {
  font-size: clamp(2.2rem, 6vw, 3.6rem);
  letter-spacing: -0.02em;
}
h2 {
  font-size: clamp(1.6rem, 4vw, 2.3rem);
  letter-spacing: -0.01em;
}
h3 {
  font-size: 1.1rem;
}
p {
  margin: 0 0 1em;
}
.wrap {
  max-width: var(--page);
  margin: 0 auto;
  padding: 0 16px;
}
.muted {
  color: var(--muted);
}

/* Icons: Phosphor SVGs used as a mask, so they take any colour */
.icon {
  display: inline-block;
  flex: none;
  width: 20px;
  height: 20px;
  background: var(--icon-neutral);
  -webkit-mask: center / contain no-repeat;
  mask: center / contain no-repeat;
}

/* Top bar */
.top {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.top .wrap {
  display: flex;
  align-items: center;
  gap: 24px;
  height: 60px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--heading);
  font-size: 19px;
  font-weight: 700;
  text-decoration: none;
  margin-right: auto;
}
.brand img {
  width: 32px;
  height: 32px;
}
.top nav {
  display: flex;
  gap: 24px;
  font-size: 17px;
}
.top nav a {
  color: var(--muted);
  text-decoration: none;
}
.top nav a:hover {
  color: var(--text);
}
@media (max-width: 640px) {
  .top nav .optional {
    display: none;
  }
}

/* Hero */
.hero {
  padding: 72px 0 40px;
  text-align: center;
}
.hero .lead {
  max-width: 640px;
  margin: 0 auto 28px;
  font-size: 1.2rem;
  color: var(--label);
}
.hero .window {
  margin-top: 48px;
  text-align: left;
}

/* Download buttons */
.downloads {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}
.button {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-weight: 600;
  text-decoration: none;
}
.button.primary {
  background: var(--focus);
  border-color: var(--focus);
  color: #fff;
}
.button:hover {
  filter: brightness(1.08);
}
.download-note {
  margin-top: 12px;
  font-size: 14px;
  color: var(--muted);
}

/* The app window */
.window {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.titlebar {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  background: var(--sidebar);
  border-bottom: 1px solid var(--border);
  font-size: 13px;
  color: var(--muted);
}
/* window buttons on the right, as on most Linux desktops: minimise, maximise, close */
.titlebar .dots {
  position: absolute;
  right: 12px;
  display: flex;
  gap: 8px;
}
.titlebar .dots i {
  position: relative;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--surface);
}
.titlebar .dots i::before,
.titlebar .dots i::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  border-color: var(--muted);
}
.titlebar .dots i:nth-child(1)::before {
  width: 8px;
  border-top: 1.5px solid var(--muted);
  transform: translate(-50%, 2px);
}
.titlebar .dots i:nth-child(2)::before {
  width: 7px;
  height: 7px;
  border: 1.5px solid var(--muted);
  transform: translate(-50%, -50%);
}
.titlebar .dots i:nth-child(3)::before,
.titlebar .dots i:nth-child(3)::after {
  width: 9px;
  border-top: 1.5px solid var(--muted);
  transform: translate(-50%, -50%) rotate(45deg);
}
.titlebar .dots i:nth-child(3)::after {
  transform: translate(-50%, -50%) rotate(-45deg);
}
.menubar {
  display: flex;
  gap: 18px;
  padding: 4px 14px;
  background: var(--sidebar);
  font-size: 14px;
  color: var(--label);
}
.window-body {
  display: grid;
  grid-template-columns: 220px 1fr;
  min-height: 330px;
}
.side {
  background: var(--sidebar);
  border-right: 1px solid var(--border);
  padding: 10px 8px;
  font-size: 14px;
}
.side .row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 8px;
  border-radius: 6px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--label);
}
.side .row.child {
  padding-left: 26px;
}
/* sheets open on a click; folders, Help and Trash are plain labels */
.side button.row {
  width: 100%;
  border: 0;
  background: none;
  font: inherit;
  text-align: left;
  cursor: pointer;
}
.side button.row:hover {
  background: var(--surface);
}
.side button.row:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: -2px;
}
.side .row.current,
.side button.row.current:hover {
  background: var(--selection);
  color: var(--heading);
}
.side .gap {
  height: 10px;
}
.statusbar {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 5px 14px;
  background: var(--sidebar);
  border-top: 1px solid var(--border);
  font-size: 14px;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
}
.statusbar .rates {
  overflow: hidden;
  text-overflow: ellipsis;
}
@media (max-width: 760px) {
  .window-body {
    grid-template-columns: 1fr;
  }
  .side,
  .menubar,
  .statusbar .rates {
    display: none;
  }
}

/* A sheet: line numbers, the text, and the answers column */
.sheet {
  position: relative;
  padding: 12px 0;
  font: 15px/1.75 var(--mono);
  font-variant-ligatures: contextual;
  background: var(--bg);
}
.line {
  display: grid;
  grid-template-columns: 2.6em minmax(0, 1fr) minmax(7.5em, 36%);
  min-height: 1.75em;
}
.line .n {
  text-align: right;
  padding-right: 0.9em;
  color: var(--comment);
  user-select: none;
}
.line .src {
  white-space: pre;
  overflow: hidden;
  text-overflow: ellipsis;
  padding-right: 0.8em;
}
.line .ans {
  text-align: right;
  padding: 0 14px 0 10px;
  border-left: 1px solid var(--border);
  color: var(--result);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 0;
  transition: opacity 0.35s;
}
.line .ans.shown {
  opacity: 1;
}
.line .ans.total {
  font-weight: 700;
}
.line.current {
  background: var(--current-line);
}
.caret {
  display: inline-block;
  width: 2px;
  height: 1.2em;
  margin-right: -2px;
  vertical-align: -0.2em;
  background: var(--text);
  animation: blink 1s steps(1) infinite;
}
@keyframes blink {
  50% {
    opacity: 0;
  }
}
.number {
  color: var(--number);
}
.unit {
  color: var(--unit);
}
.variable {
  color: var(--variable);
}
.keyword {
  color: var(--keyword);
}
.operator {
  color: var(--operator);
}
.comment {
  color: var(--comment);
  font-style: italic;
}
.heading {
  color: var(--heading);
  font-weight: 700;
}
.label {
  color: var(--label);
  font-weight: 700;
}
.tag {
  color: var(--tag);
}
.miss {
  text-decoration: underline wavy var(--misspelled);
  text-decoration-thickness: 1px;
  text-underline-offset: 4px;
}
@media (max-width: 520px) {
  .sheet {
    font-size: 13px;
  }
  .line {
    grid-template-columns: 2.1em minmax(0, 1fr) minmax(6.5em, 40%);
  }
}

/* The right-click menu over the misspelled word in the kitchen sheet */
.ctxmenu {
  position: absolute;
  z-index: 2;
  min-width: 250px;
  padding: 4px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: var(--shadow);
  font: 13.5px/1.4 var(--sans);
  color: var(--text);
  opacity: 0;
  transform: translateY(-4px);
  transition:
    opacity 0.2s,
    transform 0.2s;
  pointer-events: none;
}
.ctxmenu.shown {
  opacity: 1;
  transform: none;
}
.ctxmenu .item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 4px 10px;
  border-radius: 5px;
}
.ctxmenu .item.hl {
  background: var(--selection);
}
.ctxmenu .item.suggestion {
  font-weight: 700;
  padding-left: 40px;
}
.ctxmenu .keys {
  margin-left: auto;
  padding-left: 24px;
  color: var(--muted);
}
.ctxmenu hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 4px 6px;
}
@media (max-width: 520px) {
  .ctxmenu {
    min-width: 0;
    font-size: 12.5px;
  }
  .ctxmenu .keys {
    display: none;
  }
}

/* Sections */
section {
  padding: 72px 0;
}
section.alt {
  background: var(--sidebar);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.section-head {
  max-width: 680px;
  margin-bottom: 36px;
}

/* Examples: tabs on the left, the sheet on the right */
.examples {
  display: grid;
  grid-template-columns: minmax(240px, 340px) 1fr;
  gap: 32px;
  align-items: start;
}
.tabs {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.tab {
  display: block;
  width: 100%;
  padding: 14px 16px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: none;
  color: var(--text);
  font: inherit;
  text-align: left;
  cursor: pointer;
}
.tab strong {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--heading);
}
.tab span.text {
  display: block;
  margin-top: 4px;
  font-size: 15px;
  color: var(--muted);
}
.tab:hover {
  background: var(--surface);
}
.tab[aria-selected="true"] {
  background: var(--surface);
  border-color: var(--border);
}
.tab:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}
.example .window-body {
  grid-template-columns: 1fr;
  min-height: 0;
}
.example .sheet {
  min-height: 300px;
}
.rates-note {
  margin-top: 12px;
  font-size: 14px;
  color: var(--muted);
}
@media (max-width: 860px) {
  .examples {
    grid-template-columns: 1fr;
  }
  .tabs {
    flex-direction: row;
    overflow-x: auto;
    padding-bottom: 4px;
  }
  .tab {
    flex: none;
    width: auto;
    padding: 10px 14px;
  }
  .tab span.text {
    display: none;
  }
}

/* Feature cards */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}
.card {
  padding: 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
}
.card .icon {
  width: 28px;
  height: 28px;
  margin-bottom: 12px;
}
.card p {
  margin: 0;
  color: var(--label);
  font-size: 15.5px;
}

/* FAQ */
.faq {
  max-width: 760px;
}
.faq details {
  border-bottom: 1px solid var(--border);
  padding: 16px 0;
}
.faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--heading);
  font-size: 1.1rem;
}
.faq details > div {
  margin-top: 12px;
  color: var(--label);
}
code,
pre {
  font-family: var(--mono);
  font-size: 0.88em;
}
pre {
  overflow-x: auto;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
}

/* Footer */
.cta {
  text-align: center;
}
.cta img {
  width: 72px;
  height: 72px;
  margin-bottom: 12px;
}
footer {
  padding: 32px 0 48px;
  border-top: 1px solid var(--border);
  font-size: 16px;
  color: var(--muted);
}
footer .links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-bottom: 10px;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .line .ans,
  .ctxmenu {
    transition: none;
  }
  .caret {
    animation: none;
  }
}