:root {
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #20221f;
  background: #ecece8;
  font-synthesis: none;
}

* { box-sizing: border-box; }

html, body { margin: 0; min-height: 100%; }

body {
  min-height: 100svh;
  background:
    radial-gradient(circle at top, rgba(255,255,255,.95), transparent 40%),
    #ecece8;
}

button, input { font: inherit; }

.app-shell {
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: max(14px, env(safe-area-inset-top)) 14px max(14px, env(safe-area-inset-bottom));
}

.calculator {
  width: min(100%, 430px);
  background: rgba(250,250,248,.96);
  border: 1px solid rgba(32,34,31,.08);
  border-radius: 24px;
  box-shadow: 0 16px 42px rgba(32,34,31,.10);
  padding: 18px;
}

.app-header { margin-bottom: 14px; }
.eyebrow {
  margin: 0 0 3px;
  color: #777b73;
  font-size: .78rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: clamp(1.55rem, 7vw, 2rem);
  line-height: 1.05;
  letter-spacing: -.04em;
}

.control-group { margin-top: 12px; }
.group-label {
  display: block;
  margin-bottom: 7px;
  color: #5f635c;
  font-size: .86rem;
  font-weight: 700;
}

.segmented {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  padding: 5px;
  border-radius: 14px;
  background: #e9eae5;
}
.segmented.two { grid-template-columns: repeat(2, 1fr); }
.segment {
  border: 0;
  border-radius: 10px;
  padding: 10px 8px;
  color: #53574f;
  background: transparent;
  font-weight: 750;
  cursor: pointer;
}
.segment.active {
  color: #1f211e;
  background: #fff;
  box-shadow: 0 2px 9px rgba(32,34,31,.10);
}

.input-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 14px;
}

.field {
  display: grid;
  gap: 6px;
}
.field span {
  color: #5f635c;
  font-size: .86rem;
  font-weight: 700;
}
.field small { font-size: .72rem; color: #8b8f87; }
.field input {
  width: 100%;
  min-height: 49px;
  border: 1px solid #d8dad4;
  border-radius: 12px;
  padding: 0 12px;
  color: #20221f;
  background: #fff;
  font-size: 1.15rem;
  font-weight: 750;
  outline: none;
  transition: border-color .15s ease, box-shadow .15s ease;
}
.field input:focus {
  border-color: #7b8176;
  box-shadow: 0 0 0 3px rgba(83,87,79,.10);
}
.field input.invalid { border-color: #9f4b47; }

.result-card {
  margin-top: 15px;
  min-height: 142px;
  border-radius: 18px;
  background: #20221f;
  color: #fff;
  padding: 16px;
  display: grid;
  align-content: center;
  text-align: center;
}
.result-label {
  color: #bfc3ba;
  font-size: .82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .07em;
}
#resultado {
  margin-top: 3px;
  font-size: clamp(2.6rem, 13vw, 4.2rem);
  line-height: .98;
  letter-spacing: -.05em;
}
.coefficient {
  margin-top: 8px;
  color: #d7dbd2;
  font-size: .88rem;
}
.message {
  margin-top: 5px;
  color: #9fa49a;
  font-size: .78rem;
}

@media (max-height: 690px) {
  .app-shell { place-items: start center; padding-top: 8px; padding-bottom: 8px; }
  .calculator { padding: 14px; border-radius: 20px; }
  .app-header { margin-bottom: 8px; }
  .control-group { margin-top: 8px; }
  .segment { padding: 8px 6px; }
  .input-grid { margin-top: 10px; gap: 8px; }
  .field input { min-height: 44px; }
  .result-card { min-height: 118px; margin-top: 10px; padding: 12px; }
}

@media (min-width: 760px) {
  .calculator { width: min(92vw, 720px); padding: 26px; }
  .input-grid { grid-template-columns: repeat(4, 1fr); }
  .result-card { min-height: 160px; }
}

.app-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.icon-button,
.text-button,
.primary-button,
.secondary-button {
  border: 0;
  cursor: pointer;
  font-weight: 750;
}

.icon-button {
  width: 40px;
  height: 40px;
  flex: 0 0 40px;
  border-radius: 12px;
  color: #53574f;
  background: #e9eae5;
  font-size: 1.15rem;
}

.settings-view[hidden],
#calculator-view[hidden] { display: none; }

.settings-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
}

.settings-heading h2 {
  margin: 0;
  font-size: 1.65rem;
  line-height: 1.05;
  letter-spacing: -.04em;
}

.text-button {
  border-radius: 10px;
  padding: 9px 12px;
  color: #353833;
  background: #e9eae5;
}

.settings-intro {
  margin: 14px 0 12px;
  color: #666a62;
  font-size: .86rem;
  line-height: 1.4;
}

.density-list {
  display: grid;
  gap: 9px;
}

.density-card {
  border: 1px solid #dedfd9;
  border-radius: 15px;
  background: #fff;
  padding: 12px;
}

.density-topline {
  display: grid;
  grid-template-columns: 70px 1fr;
  align-items: end;
  gap: 10px;
}

.density-topline > strong {
  padding-bottom: 12px;
  font-size: 1rem;
}

.density-field {
  display: grid;
  gap: 5px;
}

.density-field span {
  color: #5f635c;
  font-size: .8rem;
  font-weight: 700;
}

.density-field small { color: #8b8f87; }

.density-field input {
  min-height: 43px;
  width: 100%;
  border: 1px solid #d8dad4;
  border-radius: 11px;
  padding: 0 11px;
  background: #fff;
  color: #20221f;
  font-size: 1rem;
  font-weight: 750;
  outline: none;
}

.density-field input:focus {
  border-color: #7b8176;
  box-shadow: 0 0 0 3px rgba(83,87,79,.10);
}

.density-field input.invalid { border-color: #9f4b47; }

.coefficient-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-top: 9px;
}

.coefficient-grid span {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  border-radius: 9px;
  padding: 8px 9px;
  color: #6d7169;
  background: #f1f2ee;
  font-size: .75rem;
}

.coefficient-grid strong {
  color: #30332e;
  font-variant-numeric: tabular-nums;
}

.settings-message {
  min-height: 20px;
  margin-top: 9px;
  font-size: .78rem;
  text-align: center;
}

.settings-message.success { color: #3f684b; }
.settings-message.error { color: #9f4b47; }

.settings-actions {
  display: grid;
  grid-template-columns: 1fr 1.4fr;
  gap: 9px;
  margin-top: 5px;
}

.primary-button,
.secondary-button {
  min-height: 46px;
  border-radius: 12px;
}

.primary-button {
  color: #fff;
  background: #20221f;
}

.secondary-button {
  color: #353833;
  background: #e9eae5;
}

@media (max-height: 720px) {
  .settings-intro { margin: 9px 0; }
  .density-list { gap: 7px; }
  .density-card { padding: 9px; }
  .density-field input { min-height: 39px; }
  .coefficient-grid { margin-top: 6px; }
  .coefficient-grid span { padding: 6px 8px; }
  .settings-actions { margin-top: 2px; }
}

.coefficient-card-title {
  margin-bottom: 9px;
  font-size: 1rem;
}

.coefficient-edit-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 9px;
}