:root {
  color-scheme: light;
  --bg: #f6f7f9;
  --panel: #ffffff;
  --ink: #20242a;
  --muted: #68717d;
  --line: #d9dee5;
  --accent: #0f766e;
  --accent-dark: #115e59;
  --warn: #a16207;
  --error: #b42318;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
}

main {
  width: min(920px, calc(100% - 32px));
  margin: 0 auto;
  padding: 48px 0;
}

.header h1 {
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.1;
  letter-spacing: 0;
}

.header p {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 18px;
  align-items: start;
}

.panel,
.side {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 12px 30px rgba(32, 36, 42, 0.06);
}

.panel {
  padding: 24px;
}

.side {
  padding: 20px;
}

.tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 22px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f9fafb;
}

.tab {
  min-height: 42px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--muted);
  font-size: 15px;
  cursor: pointer;
}

.tab.active {
  background: var(--accent);
  color: white;
  font-weight: 700;
}

label {
  display: block;
  margin-bottom: 8px;
  color: #39414d;
  font-size: 14px;
  font-weight: 700;
}

.field {
  margin-bottom: 18px;
}

.input-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 8px;
  align-items: center;
}

input {
  width: 100%;
  min-height: 46px;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  color: var(--ink);
  font-size: 16px;
  outline: none;
}

input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(15, 118, 110, 0.12);
}

.unit {
  min-width: 92px;
  color: var(--muted);
  font-size: 14px;
  text-align: left;
}

.mini {
  margin-top: 8px;
  color: var(--muted);
  font-size: 13px;
}

.actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 4px;
}

button.primary,
button.secondary {
  min-height: 44px;
  border-radius: 6px;
  padding: 0 16px;
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
}

button.primary {
  background: var(--accent);
  color: white;
}

button.primary:hover {
  background: var(--accent-dark);
}

button.secondary {
  background: white;
  color: var(--ink);
  border-color: var(--line);
}

.result {
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.result-value {
  font-size: clamp(28px, 6vw, 46px);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: 0;
}

.result-unit {
  margin-top: 6px;
  color: var(--muted);
  font-size: 15px;
}

.status {
  min-height: 22px;
  margin-top: 12px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.status.error {
  color: var(--error);
}

.status.warn {
  color: var(--warn);
}

.side h2 {
  margin: 0 0 14px;
  font-size: 18px;
  letter-spacing: 0;
}

.fact {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.fact:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.fact span {
  color: var(--muted);
  font-size: 13px;
}

.fact strong {
  font-size: 16px;
}

@media (max-width: 760px) {
  main {
    padding: 28px 0;
  }

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

  .panel {
    padding: 18px;
  }

  .input-row {
    grid-template-columns: 1fr;
  }

  .unit {
    min-width: 0;
  }
}