:root {
  --green-dark: #2d5016;
  --green-mid: #4a7c2e;
  --green-light: #6ba33e;
  --green-bg: #f0f7e8;
  --brown: #8b6914;
  --brown-light: #d4a84b;
  --gray-100: #f5f5f5;
  --gray-200: #e8e8e8;
  --gray-300: #d0d0d0;
  --gray-600: #666;
  --gray-800: #333;
  --white: #fff;
  --red: #c0392b;
  --blue: #2980b9;
  --orange: #e67e22;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--gray-100);
  color: var(--gray-800);
  line-height: 1.5;
}

/* === Header === */
.header {
  background: linear-gradient(135deg, var(--green-dark), var(--green-mid));
  color: var(--white);
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.header h1 {
  font-size: 1.4rem;
  font-weight: 700;
}

.header .subtitle {
  font-size: 0.8rem;
  opacity: 0.8;
}

/* === Tabs === */
.tabs {
  display: flex;
  background: var(--white);
  border-bottom: 2px solid var(--green-mid);
  overflow-x: auto;
}

.tab-btn {
  padding: 0.75rem 1.25rem;
  border: none;
  background: none;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-600);
  white-space: nowrap;
  border-bottom: 3px solid transparent;
  transition: all 0.2s;
}

.tab-btn:hover {
  color: var(--green-mid);
  background: var(--green-bg);
}

.tab-btn.active {
  color: var(--green-dark);
  border-bottom-color: var(--green-light);
  background: var(--green-bg);
}

.tab-content {
  display: none;
  padding: 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

.tab-content.active {
  display: block;
}

/* === Forms / Params === */
.params-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.param-group {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.param-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-600);
}

.param-group input,
.param-group select {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--gray-300);
  border-radius: 6px;
  font-size: 1rem;
  transition: border-color 0.2s;
}

.param-group input:focus,
.param-group select:focus {
  outline: none;
  border-color: var(--green-mid);
  box-shadow: 0 0 0 3px rgba(74, 124, 46, 0.15);
}

.radio-group {
  display: flex;
  gap: 1rem;
  padding: 0.5rem 0;
}

.radio-group label {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-weight: 400;
  cursor: pointer;
}

/* === Buttons === */
.btn {
  padding: 0.6rem 1.5rem;
  border: none;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--green-mid);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--green-dark);
}

.btn-secondary {
  background: var(--gray-200);
  color: var(--gray-800);
}

.btn-secondary:hover {
  background: var(--gray-300);
}

.btn-warning {
  background: var(--orange);
  color: var(--white);
}

.btn-warning:hover {
  background: #d35400;
}

.btn-report {
  background: var(--white);
  color: var(--green-dark);
  border: 2px solid rgba(255,255,255,0.4);
  font-weight: 700;
}

.btn-report:hover {
  background: var(--green-bg);
}

.btn-group {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

/* === Data Table === */
.table-wrapper {
  overflow-x: auto;
  margin-top: 1rem;
  border-radius: 8px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
  font-size: 0.85rem;
}

thead th {
  background: var(--green-dark);
  color: var(--white);
  padding: 0.6rem 0.5rem;
  text-align: center;
  font-weight: 600;
  position: sticky;
  top: 0;
  z-index: 1;
}

tbody td {
  padding: 0.35rem 0.4rem;
  text-align: center;
  border-bottom: 1px solid var(--gray-200);
}

tbody tr:nth-child(even) {
  background: var(--gray-100);
}

tbody tr:hover {
  background: var(--green-bg);
}

tbody td.col-label {
  font-weight: 600;
  background: var(--green-bg);
  text-align: left;
  padding-left: 0.75rem;
  white-space: nowrap;
}

tbody td.col-central {
  background: #fff3cd;
}

tbody td.col-total,
tbody td.col-media {
  font-weight: 600;
  background: #e8f5e9;
}

table input[type="number"] {
  width: 70px;
  padding: 0.25rem 0.3rem;
  border: 1px solid var(--gray-300);
  border-radius: 4px;
  text-align: center;
  font-size: 0.85rem;
}

table input[type="number"]:focus {
  outline: none;
  border-color: var(--green-mid);
}

/* === Results Table === */
.results-table td {
  font-variant-numeric: tabular-nums;
}

.row-interp td {
  color: #999;
  font-style: italic;
}

.row-real td {
  font-weight: 600;
}

/* === Charts === */
.chart-container {
  background: var(--white);
  border-radius: 8px;
  padding: 1rem;
  margin-top: 1.5rem;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
}

.chart-container canvas {
  max-height: 400px;
}

/* === Optimal Widths === */
.optimal-widths {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 1.5rem;
}

.optimal-card {
  background: var(--white);
  border-radius: 8px;
  padding: 1rem;
  box-shadow: 0 1px 4px rgba(0,0,0,0.08);
  border-left: 4px solid var(--green-mid);
}

.optimal-card h3 {
  font-size: 0.85rem;
  color: var(--gray-600);
  margin-bottom: 0.5rem;
}

.optimal-card .values {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.optimal-card .value-tag {
  background: var(--green-bg);
  padding: 0.25rem 0.6rem;
  border-radius: 12px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--green-dark);
}

.optimal-card.alt-dir {
  border-left-color: var(--red);
}
.optimal-card.alt-dir .value-tag {
  background: #fde8e8;
  color: var(--red);
}

.optimal-card.alt-esq {
  border-left-color: var(--blue);
}
.optimal-card.alt-esq .value-tag {
  background: #e8f0fd;
  color: var(--blue);
}

.optimal-card.continuo {
  border-left-color: var(--orange);
}
.optimal-card.continuo .value-tag {
  background: #fef3e8;
  color: var(--orange);
}

/* === Status / Messages === */
.msg-info {
  padding: 0.75rem 1rem;
  background: #e3f2fd;
  border-radius: 6px;
  color: #1565c0;
  margin-bottom: 1rem;
}

.msg-empty {
  text-align: center;
  padding: 3rem;
  color: var(--gray-600);
}

/* === Responsive === */
@media (max-width: 600px) {
  .header h1 { font-size: 1.1rem; }
  .tab-btn { padding: 0.6rem 0.75rem; font-size: 0.8rem; }
  .tab-content { padding: 1rem; }
  .params-grid { grid-template-columns: 1fr; }
  table input[type="number"] { width: 55px; }
}