:root {
  --bg: #f4f4f1;
  --panel: #ffffff;
  --text: #111111;
  --muted: #6d6d68;
  --line: #ddddda;
  --accent: #d7ff64;
  --dark: #111111;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Avenir Next", Avenir, "Helvetica Neue", Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

button,
select,
input {
  font: inherit;
}

.tool-header {
  min-height: 64px;
  gap: 18px;
  padding: 0 28px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  justify-content: space-between;
  background: var(--dark);
  color: white;
}

.logo {
  color: white;
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.05em;
}


.calculator {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 56px 0 80px;
}

.intro {
  max-width: 760px;
  margin-bottom: 46px;
}

.eyebrow {
  margin: 0 0 10px;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.intro h1 {
  margin: 0;
  font-size: clamp(2.5rem, 6vw, 5.2rem);
  line-height: 0.95;
  letter-spacing: -0.055em;
}

.intro-text {
  max-width: 650px;
  margin: 24px 0 0;
  font-size: 1.08rem;
  line-height: 1.6;
  color: var(--muted);
}

.calculator-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(320px, 0.9fr);
  gap: 24px;
  align-items: start;
}

.components-panel,
.build-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: 26px;
}

.build-panel {
  position: sticky;
  top: 24px;
}

.section-heading,
.build-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.section-heading > div,
.build-header > div {
  display: flex;
  align-items: center;
  gap: 14px;
}

.section-heading h2,
.build-header h2 {
  margin: 0;
  font-size: 1.35rem;
}

.step {
  display: inline-flex;
  min-width: 38px;
  height: 38px;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: var(--dark);
  color: white;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.section-spacing {
  margin-top: 38px;
}

.selector-group {
  display: grid;
  grid-template-columns: minmax(190px, 0.78fr) minmax(0, 1.22fr);
  gap: 8px 14px;
  margin-top: 22px;
}

.select-all-row {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-top: 18px;
  color: var(--text);
  font-weight: 600;
}

.select-all-row input {
  width: 18px;
  height: 18px;
  accent-color: var(--dark);
}

.selector-group label {
  grid-column: span 1;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 66px;
  padding: 10px 0;
  font-size: 1rem;
  line-height: 1.2;
  font-weight: 600;
  color: var(--muted);
}

.component-label-icon {
  display: inline-flex;
  flex: 0 0 44px;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  border: 0;
  border-radius: 0;
  background-color: transparent;
  box-shadow: none;
  background-image: url("assets/component-sprite.png");
  background-repeat: no-repeat;
  background-size: 400% 300%;
  background-position: 0 0;
}

.component-image-rear-derailleur { background-position: 33.333% 0; }
.component-image-front-derailleur { background-position: 66.667% 0; }
.component-image-crankset { background-position: 100% 0; }
.component-image-chainrings { background-position: 0 50%; }
.component-image-cassette { background-position: 33.333% 50%; }
.component-image-chain { background-position: 66.667% 50%; }
.component-image-bottom-bracket { background-position: 100% 50%; }
.component-image-brakes { background-position: 0 100%; }
.component-image-disc-rotors { background-position: 33.333% 100%; }
.component-image-batteries { background-position: 66.667% 100%; }
.component-image-electronic-connections { background-position: 100% 100%; }

.selector-group select {
  width: 100%;
  min-height: 66px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: white;
  color: var(--text);
  outline: none;
}

.selector-group select:focus,
.custom-component input:focus {
  border-color: #999;
}

.selector-group select:disabled {
  background: #f2f2ef;
  color: #999;
}

.component-info {
  margin-top: 16px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: #fafaf8;
}

.hidden {
  display: none;
}

.build-check {
  margin-top: 18px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: #fafaf8;
  color: var(--muted);
  font-size: 0.86rem;
}

.build-check-header,
.build-check-complete {
  display: flex;
  justify-content: space-between;
  gap: 12px;
}

.build-check-header strong,
.build-check-complete strong {
  color: var(--text);
}

.build-check-message {
  margin: 8px 0 6px;
  line-height: 1.4;
}

.build-check-list {
  display: grid;
  gap: 4px;
  margin: 0;
  padding-left: 18px;
}

.build-check-list a {
  color: var(--text);
  text-decoration: underline;
  text-decoration-color: #bdbdb5;
  text-underline-offset: 3px;
}

.build-check-complete {
  color: #4f6c55;
}

.component-main {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  align-items: flex-start;
}

.component-name {
  display: block;
  font-weight: 700;
  margin-bottom: 4px;
}

.component-config {
  display: block;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.4;
}

.component-main strong {
  white-space: nowrap;
  font-size: 1.2rem;
}

.weight-block {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 2px;
  text-align: right;
}

.weight-includes {
  color: var(--muted);
  font-size: 0.75rem;
  line-height: 1.25;
  max-width: 220px;
}

.source-row {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  gap: 14px;
  font-size: 0.8rem;
  color: var(--muted);
}

.source-row a {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
}

.source-row a:hover {
  text-decoration: underline;
}

.add-button {
  width: 100%;
  margin-top: 16px;
  min-height: 48px;
  border: 0;
  border-radius: 12px;
  background: var(--dark);
  color: white;
  cursor: pointer;
  font-weight: 700;
}

.add-button:hover {
  opacity: 0.88;
}

.add-button.secondary {
  background: var(--accent);
  color: var(--dark);
}

.custom-component {
  margin-top: 22px;
  display: grid;
  gap: 12px;
}

.custom-component input {
  width: 100%;
  min-height: 50px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: white;
  outline: none;
}

.custom-weight-row {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 10px;
}

.custom-weight-row span {
  color: var(--muted);
}

.text-button {
  border: 0;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}

.text-button:hover {
  color: var(--text);
}

.build-list {
  margin-top: 22px;
  display: grid;
  gap: 10px;
}

.empty-build {
  padding: 24px 0;
  color: var(--muted);
  text-align: center;
  font-size: 0.92rem;
}

.build-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.build-item:last-child {
  border-bottom: 0;
}

.build-item-main {
  min-width: 0;
}

.build-item-name {
  display: block;
  font-weight: 700;
  margin-bottom: 3px;
}

.build-item-meta {
  display: block;
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.35;
}

.build-item-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.build-item-weight {
  white-space: nowrap;
  font-weight: 700;
}

.remove-item {
  width: 28px;
  height: 28px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: white;
  cursor: pointer;
}

.total-block {
  margin-top: 26px;
  padding: 22px;
  border-radius: 16px;
  background: var(--dark);
  color: white;
}

.total-block span,
.total-block small {
  display: block;
  color: #bdbdb8;
}

.total-block strong {
  display: block;
  margin: 6px 0;
  font-size: clamp(2.2rem, 5vw, 3.8rem);
  letter-spacing: -0.05em;
}

@media (max-width: 860px) {
  .calculator {
    width: min(100% - 20px, 760px);
    padding-top: 34px;
  }

  .tool-header {
    padding: 0 16px;
  }


  .calculator-layout {
    grid-template-columns: 1fr;
  }

  .build-panel {
    position: static;
  }

  .selector-group {
    grid-template-columns: 1fr;
  }

  .selector-group label {
    min-height: 48px;
    margin-top: 4px;
    padding: 4px 0;
  }

  .component-label-icon {
    flex-basis: 34px;
    width: 34px;
    height: 34px;
    font-size: 1.2rem;
  }

  .intro {
    margin-bottom: 30px;
  }

  .components-panel,
  .build-panel {
    padding: 18px;
    border-radius: 16px;
  }
}

/* Balanced columns keep the page title centered in the viewport. */
.tool-header .logo { justify-self: start; white-space: nowrap; }
.tool-title {
  color: #bdbdb8;
  font-size: 0.82rem;
  letter-spacing: 0.08em;
  text-align: center;
}
.tool-nav {
  display: flex;
  justify-self: end;
}
.tool-nav a {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  color: #ffffff;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  white-space: nowrap;
}
.tool-nav svg { flex: none; }
.tool-header a:hover { opacity: 0.7; }
.tool-header a:focus-visible {
  outline: 2px solid currentColor;
  outline-offset: 5px;
  border-radius: 2px;
}
@media (max-width: 600px) {
  .tool-header {
    grid-template-columns: 1fr 1fr;
    padding-top: 16px;
    padding-bottom: 16px;
    gap: 16px;
  }
  .tool-title {
    grid-column: 1 / -1;
    grid-row: 2;
  }
  .tool-nav { grid-column: 2; grid-row: 1; }
}