:root {
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --accent: #06b6d4;
  --bg-gradient-start: #0f172a;
  --bg-gradient-end: #1e293b;
  --card-bg: rgba(30, 41, 59, 0.7);
  --card-border: rgba(255, 255, 255, 0.1);
  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --input-bg: rgba(15, 23, 42, 0.6);
  --input-border: rgba(255, 255, 255, 0.1);
  --success: #10b981;
  --warning: #f59e0b;
}

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  margin: 0;
  padding: 0;
  min-height: 100vh;
  background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
  color: var(--text-main);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.container {
  width: 100%;
  max-width: 1000px;
  padding: 2rem;
  box-sizing: border-box;
}

h1 {
  font-size: 2.5rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 0.5rem;
  background: linear-gradient(to right, #60a5fa, #22d3ee);
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.02em;
}

.muted {
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 3rem;
  font-size: 1.1rem;
  line-height: 1.6;
  max-width: 700px;
  margin-left: auto;
  margin-right: auto;
}

.input-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.card {
  background: var(--card-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--card-border);
  border-radius: 1.5rem;
  padding: 1.5rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 30px 60px -12px rgba(0, 0, 0, 0.6);
  border-color: rgba(255, 255, 255, 0.2);
}

h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 0 0 1.5rem 0;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

label {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
  margin-top: 1rem;
}

label:first-of-type {
  margin-top: 0;
}

input {
  width: 100%;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: 0.75rem;
  padding: 0.75rem 1rem;
  color: var(--text-main);
  font-size: 1rem;
  transition: all 0.2s ease;
  box-sizing: border-box;
}

input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
  background: rgba(15, 23, 42, 0.8);
}

button {
  display: block;
  width: 100%;
  max-width: 400px;
  margin: 0 auto;
  padding: 1rem 2rem;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  border: none;
  border-radius: 1rem;
  font-size: 1.1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 10px 15px -3px rgba(59, 130, 246, 0.3);
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 20px 25px -5px rgba(59, 130, 246, 0.4);
  filter: brightness(1.1);
}

button:active {
  transform: translateY(0);
}

/* Output Section */
#out {
  margin-top: 2rem;
  animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
}

.result-column h4 {
  color: var(--accent);
  font-size: 1.1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.5rem;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-row:last-child {
  border-bottom: none;
}

.stat-label {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.stat-value {
  font-weight: 600;
  color: var(--text-main);
}

.highlight {
  color: var(--accent);
  font-weight: 700;
}

/* Table */
.table-container {
  margin-top: 2rem;
  overflow-x: auto;
  border-radius: 1rem;
  border: 1px solid var(--card-border);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

th {
  background: rgba(15, 23, 42, 0.8);
  color: var(--text-muted);
  font-weight: 600;
  text-align: left;
  padding: 1rem;
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.05em;
}

td {
  padding: 1rem;
  border-top: 1px solid var(--card-border);
  color: var(--text-main);
}

tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

/* Formulae Section */
#formulae {
  margin-top: 3rem;
  opacity: 0.7;
}

#formulae h3 {
  font-size: 1rem;
  color: var(--text-muted);
}

.formulae-block p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0.5rem 0;
}

.var {
  font-family: 'JetBrains Mono', monospace;
  color: var(--accent);
}