:root {
  --primary-color: #0ea5e9;
  --primary-hover: #0284c7;
  --bg-color: #ecfdf5;
  --card-bg: #ffffff;
  --text-main: #0f172a;
  --text-muted: #64748b;
  --border-color: #e2e8f0;

  --color-green: #10b981;
  --color-green-bg: #d1fae5;
  --color-yellow: #f59e0b;
  --color-yellow-bg: #fef3c7;
  --color-orange: #f97316;
  --color-orange-bg: #ffedd5;
  --color-red: #ef4444;
  --color-red-bg: #fee2e2;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  --shadow-hover: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius-md: 12px;
  --radius-lg: 20px;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Base Gradient Background for premium feel */
body::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 400px;
  background: linear-gradient(to bottom, #bae6fd 0%, var(--bg-color) 100%);
  z-index: -1;
  pointer-events: none;
}

.dashboard-container {
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 3rem 1.5rem;
  flex-grow: 1;
}

.app-header {
  margin-bottom: 3rem;
  text-align: center;
}

.header-content {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.logo-area {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-area h1 {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.04em;
}

.subtitle {
  color: var(--text-muted);
  font-size: 1.125rem;
  font-weight: 500;
}

.calculator-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

@media (max-width: 800px) {
  .calculator-grid {
    grid-template-columns: 1fr;
  }
}

.card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-md);
  transition: box-shadow 0.3s ease;
}

.card:hover {
  box-shadow: var(--shadow-hover);
}

.input-section h2 {
  font-size: 1.25rem;
  margin-bottom: 1.75rem;
  color: var(--text-main);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

/* Toggle Buttons for Sexo */
.toggle-group {
  display: flex;
  gap: 0.5rem;
  background: #f1f5f9;
  padding: 0.35rem;
  border-radius: 12px;
}

.toggle-group input[type="radio"] {
  display: none;
}

.toggle-btn {
  flex: 1;
  text-align: center;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.875rem;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  color: var(--text-muted);
}

.toggle-group input[type="radio"]:checked+.toggle-btn {
  background: white;
  color: var(--primary-color);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.form-group-row {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.form-group-row .form-group {
  margin-bottom: 0;
}

.flex-1 {
  flex: 1;
}

/* Base Inputs */
input[type="number"],
input[type="text"].dynamic-input {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  font-size: 1.05rem;
  font-family: inherit;
  transition: all 0.2s;
  background-color: #f8fafc;
  color: var(--text-main);
}

input[type="number"]:focus,
input[type="text"].dynamic-input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(14, 165, 233, 0.15);
  background-color: #fff;
}

input[type="number"]::placeholder,
input[type="text"].dynamic-input::placeholder {
  color: #94a3b8;
}

.btn-calculate {
  width: 100%;
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 1.125rem;
  border-radius: 10px;
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  margin-top: 1.5rem;
  box-shadow: 0 4px 6px -1px rgba(14, 165, 233, 0.2), 0 2px 4px -1px rgba(14, 165, 233, 0.1);
}

.btn-calculate:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 10px 15px -3px rgba(14, 165, 233, 0.3), 0 4px 6px -2px rgba(14, 165, 233, 0.15);
}

.btn-calculate:active {
  transform: translateY(0);
}

/* Result Section */
.result-section {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  border: 4px solid transparent;
  transition: all 0.4s ease;
  min-height: 400px;
}

.result-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  color: var(--text-muted);
}

.result-placeholder p {
  font-size: 1.05rem;
  font-weight: 500;
}

.hidden {
  display: none !important;
}

.result-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  animation: scaleIn 0.5s cubic-bezier(0.16, 1, 0.3, 1);
  width: 100%;
}

@keyframes scaleIn {
  0% {
    opacity: 0;
    transform: scale(0.95) translateY(10px);
  }

  100% {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.result-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  font-weight: 700;
  margin-bottom: 1rem;
}

.gfr-value-container {
  margin-bottom: 2rem;
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 0.5rem;
}

.gfr-value {
  font-size: 4.5rem;
  font-weight: 800;
  line-height: 1;
  color: var(--text-main);
  letter-spacing: -0.04em;
  transition: color 0.4s ease;
}

.gfr-unit {
  font-size: 1.125rem;
  color: var(--text-muted);
  font-weight: 600;
}

.classification-box {
  background: var(--bg-color);
  padding: 1.25rem 2rem;
  border-radius: 16px;
  width: 100%;
  max-width: 320px;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  transition: all 0.4s ease;
}

.stage-label {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.stage-desc {
  font-size: 0.95rem;
  font-weight: 600;
}

.kdigo-info p {
  font-size: 0.8rem;
  color: #94a3b8;
  line-height: 1.5;
  max-width: 250px;
  margin: 0 auto;
}

/* Footers */
.app-footer {
  text-align: center;
  margin-top: 1rem;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.app-footer p {
  margin-bottom: 0.25rem;
}

.app-footer .warning {
  color: #b45309;
}

/* Copy Button */
.btn-copy {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 1.5rem;
  padding: 0.75rem 1.5rem;
  background-color: transparent;
  color: var(--primary-color);
  border: 1.5px solid var(--primary-color);
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-copy:hover {
  background-color: var(--primary-color);
  color: white;
  transform: translateY(-2px);
  box-shadow: 0 4px 6px -1px rgba(14, 165, 233, 0.2);
}

.btn-copy:active {
  transform: translateY(0);
}

/* Dynamic State Classes */
.state-green {
  border-color: var(--color-green);
  box-shadow: 0 10px 25px -5px rgba(16, 185, 129, 0.15);
}

.state-green .gfr-value {
  color: var(--color-green);
}

.state-green .classification-box {
  background-color: var(--color-green-bg);
  color: #047857;
}

.state-yellow {
  border-color: var(--color-yellow);
  box-shadow: 0 10px 25px -5px rgba(245, 158, 11, 0.15);
}

.state-yellow .gfr-value {
  color: var(--color-yellow);
}

.state-yellow .classification-box {
  background-color: var(--color-yellow-bg);
  color: #b45309;
}

.state-orange {
  border-color: var(--color-orange);
  box-shadow: 0 10px 25px -5px rgba(249, 115, 22, 0.15);
}

.state-orange .gfr-value {
  color: var(--color-orange);
}

.state-orange .classification-box {
  background-color: var(--color-orange-bg);
  color: #c2410c;
}

.state-red {
  border-color: var(--color-red);
  box-shadow: 0 10px 25px -5px rgba(239, 68, 68, 0.15);
}

.state-red .gfr-value {
  color: var(--color-red);
}

.state-red .classification-box {
  background-color: var(--color-red-bg);
  color: #b91c1c;
}