.volume-tool {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  background: #fff;
  box-shadow: 0 12px 30px rgba(23, 33, 27, .08);
}

.volume-tool h2 { margin-bottom: 18px; font-size: 22px; }

.volume-toggle,
.shape-toggle {
  display: grid;
  gap: 8px;
}

.volume-toggle { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.shape-toggle { grid-template-columns: repeat(4, minmax(0, 1fr)); }

.volume-toggle button,
.shape-toggle button {
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 8px 10px;
  background: #fff;
  color: var(--muted);
  font-size: 13px;
  font-weight: 750;
}

.volume-toggle button:hover,
.shape-toggle button:hover,
.volume-toggle button[aria-pressed="true"],
.shape-toggle button[aria-pressed="true"] {
  border-color: var(--green);
  background: var(--green-pale);
  color: var(--green-dark);
}

.volume-fieldset {
  display: grid;
  gap: 14px;
  margin: 20px 0 0;
  padding: 0;
  border: 0;
}

.volume-fieldset legend,
.volume-field label {
  display: block;
  margin-bottom: 6px;
  color: #3e4b43;
  font-size: 13px;
  font-weight: 750;
}

.volume-field input,
.volume-field select {
  width: 100%;
  min-height: 44px;
  border: 1px solid #cbd5ce;
  border-radius: 6px;
  padding: 0 12px;
  background: #fff;
  color: var(--ink);
  outline: 0;
}

.volume-field input:focus,
.volume-field select:focus,
.volume-toggle button:focus-visible,
.shape-toggle button:focus-visible {
  border-color: var(--green);
  box-shadow: 0 0 0 3px rgba(22, 121, 74, .14);
  outline: 0;
}

.volume-fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.volume-fields .full { grid-column: 1 / -1; }
.volume-secondary-fields { margin-top: 14px; }

.volume-hint,
.volume-error {
  margin: 6px 0 0;
  font-size: 12px;
  line-height: 1.45;
}

.volume-hint { color: var(--muted); }
.volume-error { color: #a2382f; }

.volume-results {
  display: grid;
  gap: 12px;
  margin-top: 20px;
  padding: 18px;
  border-radius: var(--radius);
  background: #17211b;
  color: #fff;
}

.volume-primary {
  padding-bottom: 14px;
  border-bottom: 1px solid rgba(255, 255, 255, .16);
}

.volume-result-label { color: #aebdb3; font-size: 12px; }

.volume-result-value {
  margin-top: 2px;
  font-size: 32px;
  font-weight: 850;
  line-height: 1.1;
}

.volume-result-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.volume-result-grid strong {
  display: block;
  margin-top: 2px;
  font-size: 18px;
}

.volume-result-note {
  margin: 0;
  color: #d1ded5;
  font-size: 12px;
  line-height: 1.5;
}

.volume-section-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}

.volume-list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.volume-list li {
  padding: 14px 16px;
  border-left: 3px solid var(--green);
  background: var(--green-pale);
  line-height: 1.55;
}

.formula {
  margin: 0;
  padding: 16px;
  border-radius: var(--radius);
  background: #17211b;
  color: #e5f0e8;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
  line-height: 1.65;
  white-space: pre-wrap;
}

.related-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.related-link {
  display: block;
  border-top: 3px solid var(--green);
  padding-top: 14px;
  color: var(--ink);
  text-decoration: none;
}

.related-link:hover { color: var(--green-dark); }

.related-link span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

@media (max-width: 760px) {
  .shape-toggle { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .volume-section-grid,
  .related-links { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .volume-tool { padding: 16px; }
  .volume-fields { grid-template-columns: 1fr; }
  .volume-fields .full { grid-column: auto; }
}