@charset "UTF-8";

:root {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
  color: #172747;
  color-scheme: light;
  background: #f0f6fb;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  touch-action: manipulation;
}

body {
  margin: 0;
}

button,
input {
  font: inherit;
}

button,
label,
summary {
  -webkit-tap-highlight-color: transparent;
}

button,
summary {
  cursor: pointer;
}

input {
  accent-color: #364eb4;
}

a {
  color: #354eae;
  text-underline-offset: 3px;
}

button:focus-visible,
input:focus-visible,
summary:focus-visible,
a:focus-visible {
  outline: 3px solid #087d91;
  outline-offset: 3px;
}

#contents {
  max-width: 850px;
  padding: 32px 24px 24px;
  margin: auto;
}

.title-row,
.toolbar,
.toggle-options,
.selection-panel,
.table-heading,
footer {
  display: flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
}

h1 {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 14px;
  align-items: baseline;
  margin: 0;
  font-size: 32px;
  letter-spacing: -1px;
}

.subtitle {
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0;
}

#version-info {
  flex-shrink: 0;
  font-size: 12px;
  color: #617089;
}

.intro {
  margin: 12px 0 24px;
  font-size: 14px;
  line-height: 1.7;
  color: #55647c;
}

#table-app {
  padding: 20px;
  background: #ffffff;
  border: 1px solid #d8e2ee;
  border-radius: 16px;
  box-shadow: 0 8px 24px #223a6510;
}

.toolbar {
  flex-wrap: wrap;
  gap: 8px 16px;
}

.base-options {
  display: flex;
  padding: 3px;
  margin: 0;
  background: #edf1f8;
  border: 0;
  border-radius: 9px;
}

.base-options label {
  position: relative;
  cursor: pointer;
}

.base-options input,
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.base-options span {
  display: block;
  padding: 10px 16px;
  font-size: 14px;
  font-weight: 600;
  border-radius: 7px;
}

.base-options input:checked + span {
  color: #ffffff;
  background: #364eb4;
}

.base-options input:focus-visible + span {
  outline: 3px solid #087d91;
  outline-offset: 2px;
}

.toggle-options {
  flex-wrap: wrap;
  gap: 0 16px;
}

.toggle-options label {
  display: flex;
  gap: 7px;
  align-items: center;
  min-height: 44px;
  font-size: 13px;
  cursor: pointer;
}

.toggle-options input {
  width: 17px;
  height: 17px;
  margin: 0;
}

.selection-panel {
  min-height: 130px;
  padding: 18px 20px;
  margin: 16px 0 20px;
  background: #f1f4ff;
  border: 1px solid #e0e6fa;
  border-radius: 10px;
}

.eyebrow {
  margin: 0 0 7px;
  font-size: 12px;
  font-weight: 600;
  color: #50638d;
}

.equation,
.cell-button,
th {
  font-family: SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-variant-numeric: tabular-nums;
}

.equation {
  margin: 0;
  font-size: clamp(22px, 4.8vw, 32px);
  font-weight: 700;
  color: #263c8c;
  white-space: nowrap;
}

.comparison {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: #55647c;
}

.answer-button {
  flex-shrink: 0;
  min-height: 44px;
  padding: 10px 16px;
  font-size: 14px;
  font-weight: 600;
  color: #ffffff;
  background: #364eb4;
  border: 1px solid #364eb4;
  border-radius: 8px;
}

.answer-button:hover {
  background: #253b97;
}

.table-heading {
  margin: 0 0 10px;
  font-size: 13px;
}

.table-heading p {
  margin: 0;
  font-weight: 600;
}

.table-hint {
  color: #617089;
}

.table-scroll {
  max-height: 70vh;
  overflow: auto;
  overscroll-behavior-x: contain;
  scroll-padding: 48px;
  border: 1px solid #9aaacd;
  border-radius: 8px;
}

table {
  width: 100%;
  min-width: 608px;
  table-layout: fixed;
  border-spacing: 0;
}

th,
td {
  height: 40px;
  padding: 0;
  text-align: center;
  border-right: 1px solid #dce3f0;
  border-bottom: 1px solid #dce3f0;
}

th {
  font-size: 15px;
  color: #2b407b;
  background: #e0e7ff;
}

thead th {
  position: sticky;
  top: 0;
  z-index: 2;
  border-bottom-color: #9aaacd;
}

th[scope="row"] {
  position: sticky;
  left: 0;
  z-index: 1;
  border-right-color: #9aaacd;
}

thead .corner {
  left: 0;
  z-index: 3;
}

tr > :last-child {
  border-right: 0;
}

tbody tr:last-child > * {
  border-bottom: 0;
}

.group-end-column {
  border-right-color: #9aaacd;
}

.group-end-row {
  border-bottom-color: #9aaacd;
}

td {
  background: #ffffff;
}

td.is-square {
  background: #f4f6fb;
}

td.is-crosshair {
  background: #e8eeff;
}

td.is-current,
th.is-highlighted {
  color: #ffffff;
  background: #364eb4;
}

.cell-button {
  display: block;
  width: 100%;
  min-height: 39px;
  padding: 0;
  font-size: 15px;
  line-height: 39px;
  color: inherit;
  touch-action: manipulation;
  background: transparent;
  border: 0;
  border-radius: 0;
}

.cell-button:focus-visible {
  position: relative;
  z-index: 1;
  outline: 3px solid #087d91;
  outline-offset: -3px;
}

td.is-selected .cell-button {
  box-shadow: inset 0 0 0 2px #364eb4;
}

.practice-mode td:not(.is-current) .cell-button {
  color: #6c7890;
}

.help {
  margin: 12px 0 0;
  font-size: 12px;
  line-height: 1.8;
  color: #617089;
}

.keyboard-help {
  margin-top: 2px;
}

.guide {
  padding: 18px 4px;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.9;
  border-bottom: 1px solid #d8e2ee;
}

.guide summary {
  min-height: 28px;
  font-weight: 600;
}

.guide p {
  max-width: 66ch;
  color: #55647c;
}

footer {
  flex-wrap: wrap;
  gap: 8px;
  padding: 20px 4px 0;
  font-size: 12px;
  line-height: 1.8;
  color: #617089;
}

.notice {
  padding: 16px;
  background: #ffffff;
  border: 1px solid #d8e2ee;
  border-radius: 8px;
}

@media (width <= 600px) {
  #contents {
    padding: 20px 12px;
  }

  h1 {
    display: block;
    font-size: 28px;
  }

  .subtitle {
    display: block;
    margin-top: 3px;
    font-size: 13px;
  }

  .intro {
    margin: 12px 0 18px;
    font-size: 13px;
  }

  #table-app {
    padding: 14px 12px;
    border-radius: 12px;
  }

  .toolbar {
    gap: 4px;
  }

  .toggle-options {
    justify-content: flex-start;
    width: 100%;
  }

  .selection-panel {
    flex-wrap: wrap;
    gap: 12px;
    padding: 16px;
    margin-top: 10px;
  }

  .table-scroll {
    max-height: 64vh;
  }
}

@media print {
  :root {
    color: #000000;
    background: #ffffff;
  }

  #contents {
    max-width: none;
    padding: 0;
  }

  #table-app {
    padding: 0;
    border: 0;
    box-shadow: none;
  }

  .toolbar,
  .selection-panel,
  .help,
  .guide,
  #version-info {
    display: none;
  }

  .table-scroll {
    max-height: none;
    overflow: visible;
  }

  table {
    min-width: 0;
  }

  th,
  td.is-current,
  th.is-highlighted {
    color: #000000;
    background: #ffffff;
  }

  td.is-selected .cell-button {
    box-shadow: none;
  }

  thead th,
  th[scope="row"] {
    position: static;
  }
}