@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:opsz,wght@8..60,400&display=swap');

@font-face{
  font-family: 'Modamode Local';
  src: url('fonts/modamode.regular.ttf') format('truetype');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

:root{
  --bf-page: #fbf9f4;
  --bf-panel: #dde6ed;
  --bf-input: #ffffff;
  --bf-teal: #40798C;
  --bf-ink: #0B2027;

  --bf-series-green: #456c30;
  --bf-series-sandy: #F49E4C;
  --bf-series-brick: #AB3428;

  --bf-title-font: 'Modamode Local', Arial, Helvetica, sans-serif;
  --bf-ui-font: 'Source Serif 4', 'Times New Roman', Times, serif;
  --bf-explain-font: 'Source Serif 4', 'Times New Roman', Times, serif;

  --bf-font-title: 42px;
  --bf-font-regular: 20px;
  --bf-font-small: 17px;
}

*{ box-sizing: border-box; }

html,
body{
  margin: 0;
  background: var(--bf-page);
  color: var(--bf-ink);
  font-family: var(--bf-ui-font);
  font-size: var(--bf-font-regular);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.bf-page{
  max-width: 1320px;
  margin: 0 auto;
  padding: 36px 36px 24px;
}

.bf-frame{
  background: var(--bf-page);
  border: 3px solid var(--bf-teal);
  padding: 28px 32px 26px;
}

.bf-title{
  margin: 0 0 24px;
  color: var(--bf-teal);
  font-family: var(--bf-title-font);
  font-size: var(--bf-font-title);
  font-weight: 400;
  line-height: 1.15;
}

.bf-page h2,
.bf-page h3,
.bf-page h4,
.bf-page h5,
.bf-page h6,
.bf-heading{
  color: var(--bf-teal);
  font-family: var(--bf-title-font);
  font-weight: 400;
}

.bf-panel{
  background: var(--bf-panel);
  border-left: 3px solid var(--bf-teal);
  margin-bottom: 22px;
  padding: 14px 16px;
}

.bf-panel-white{
  background: var(--bf-input);
}

.bf-params{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.bf-param-group{
  display: grid;
  grid-template-rows: repeat(2, auto);
  gap: 12px;
  min-width: 0;
}

.bf-param{
  display: grid;
  grid-template-rows: 36px 42px auto;
  gap: 4px;
  min-width: 0;
}

.bf-param-label{
  color: var(--bf-ink);
  font-size: var(--bf-font-small);
  line-height: 1.3;
}

.bf-input{
  width: 100%;
  height: 42px;
  border: 1px solid var(--bf-input);
  border-radius: 0;
  background: var(--bf-input);
  color: var(--bf-ink);
  font: 400 var(--bf-font-regular) var(--bf-ui-font);
  outline: none;
  padding: 7px 9px;
}

.bf-input:focus{
  border-color: var(--bf-teal);
}

.bf-param-unit,
.bf-minor{
  color: var(--bf-ink);
  font-size: var(--bf-font-small);
}

.bf-stats{
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.bf-stat{
  min-width: 0;
}

.bf-stat-label{
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--bf-ink);
  font-size: var(--bf-font-small);
  margin-bottom: 6px;
}

.bf-swatch{
  display: inline-block;
  width: 10px;
  height: 10px;
}

.bf-swatch.green{ background: var(--bf-series-green); }
.bf-swatch.sandy{ background: var(--bf-series-sandy); }
.bf-swatch.brick{ background: var(--bf-series-brick); }
.bf-swatch.ink{ background: var(--bf-ink); }

.bf-stat-value{
  color: var(--bf-ink);
  font-size: var(--bf-font-regular);
  line-height: 1;
}

.bf-chart-panel{
  height: 410px;
  position: relative;
}

.bf-controls{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  background: var(--bf-input);
}

.bf-control{
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
}

.bf-control-head{
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.bf-control-label{
  color: var(--bf-ink);
  font-size: var(--bf-font-small);
}

.bf-control-value{
  color: var(--bf-ink);
  font-size: var(--bf-font-regular);
}

.bf-range{
  width: 100%;
  height: 26px;
  appearance: none;
  -webkit-appearance: none;
  background: var(--bf-input);
  cursor: pointer;
}

.bf-range::-webkit-slider-runnable-track{
  height: 2px;
  background: var(--bf-teal);
  border: none;
}

.bf-range::-moz-range-track{
  height: 2px;
  background: var(--bf-teal);
  border: none;
}

.bf-range::-webkit-slider-thumb{
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  margin-top: -8px;
  border: 1.5px solid var(--bf-teal);
  border-radius: 0;
  background: var(--bf-panel);
}

.bf-range::-moz-range-thumb{
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--bf-teal);
  border-radius: 0;
  background: var(--bf-panel);
  cursor: pointer;
}

.bf-ticks{
  display: flex;
  justify-content: space-between;
  color: var(--bf-ink);
  font-size: var(--bf-font-small);
}

.bf-actions{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 24px;
  padding-top: 18px;
}

.bf-button-row{
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.bf-button{
  border: none;
  border-left: 3px solid var(--bf-teal);
  border-radius: 0;
  background: var(--bf-panel);
  color: var(--bf-ink);
  cursor: pointer;
  font: 400 var(--bf-font-small) var(--bf-ui-font);
  padding: 10px 18px;
}

.bf-speed-row{
  display: grid;
  grid-template-columns: minmax(220px, 0.7fr) minmax(220px, 1.4fr) minmax(80px, 0.2fr);
  align-items: center;
  gap: 18px;
  background: var(--bf-input);
}

.bf-modal-backdrop{
  position: fixed;
  inset: 0;
  z-index: 20;
  display: none;
  align-items: center;
  justify-content: center;
  background: rgba(11,32,39,0.36);
  padding: 24px;
}

.bf-modal-backdrop.open{
  display: flex;
}

.bf-modal{
  width: min(900px, 100%);
  max-height: min(760px, calc(100vh - 48px));
  overflow: auto;
  background: var(--bf-input);
  border-left: 3px solid var(--bf-teal);
  padding: 22px 26px;
}

.bf-modal-head{
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 10px;
}

.bf-modal h2,
.bf-modal h3,
.bf-modal h4{
  color: var(--bf-teal);
  font-family: var(--bf-title-font);
  font-weight: 400;
}

.bf-modal p,
.bf-modal li{
  font-family: var(--bf-explain-font);
}

.bf-math-block{
  overflow-x: auto;
  margin: 12px 0;
  padding: 12px 16px;
  background: var(--bf-input);
  border-left: 3px solid var(--bf-teal);
}

.bf-attribution{
  margin-top: 18px;
  color: var(--bf-ink);
  font-size: var(--bf-font-small);
  text-align: center;
}

.bf-attribution a{
  color: var(--bf-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--bf-teal);
}

@media (max-width: 980px){
  .bf-params{ grid-template-columns: repeat(3, 1fr); }
  .bf-controls{ grid-template-columns: 1fr; }
}

@media (max-width: 560px){
  :root{ --bf-font-title: 28px; }
  .bf-page{ padding: 18px 12px; }
  .bf-frame{ padding: 22px 14px 18px; }
  .bf-params,
  .bf-stats,
  .bf-controls,
  .bf-speed-row{
    grid-template-columns: 1fr;
  }
  .bf-chart-panel{ height: 340px; }
  .bf-control-head{ flex-wrap: wrap; gap: 4px 10px; }
  .bf-button-row,
  .bf-button{ width: 100%; }
}