/* Calculator Navigation */
.calculator-nav { background: var(--header-bg); padding: 1rem 0; border-bottom: 2px solid var(--primary); }
.calculator-nav-container { max-width: 1200px; margin: 0 auto; padding: 0 1rem; display: flex; flex-wrap: wrap; gap: 0.5rem; justify-content: center; }
.calc-nav-btn { background: none; color: #fff; border: 1px solid var(--primary); padding: 0.5rem 1rem; border-radius: 6px; font-size: 0.9rem; font-weight: 500; cursor: pointer; text-decoration: none; transition: all 0.2s; white-space: nowrap; }
.calc-nav-btn:hover { background: var(--primary); color: #fff; }
.calc-nav-btn.active { background: var(--primary); color: #fff; border-color: var(--primary); }

/* Calculator Main */
.calculator-main { padding: 2rem 1rem 6rem 1rem; min-height: 70vh; background: var(--bg); }
.calculator-container { max-width: 800px; margin: 0 auto; background: var(--card-bg); border-radius: 14px; box-shadow: 0 2px 12px var(--border); padding: 2rem; }
.calculator-container h1 { font-size: 2.2rem; color: var(--text); margin-bottom: 0.5rem; text-align: center; }
.calculator-description { color: var(--muted-text); font-size: 1.1rem; margin-bottom: 2rem; text-align: center; }

/* Calculator Form */
.calculator-form { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 1.5rem; margin-bottom: 2rem; }
.form-group { display: flex; flex-direction: column; }
.form-group label { font-weight: 600; color: var(--text); margin-bottom: 0.5rem; font-size: 1rem; }
.form-group input, .form-group select { padding: 0.8rem; border: 2px solid var(--input-border); border-radius: 6px; font-size: 1rem; transition: border-color 0.2s; background: var(--input-bg); color: var(--text); }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--primary); }

.calculate-btn { background: linear-gradient(90deg, var(--header-bg) 0%, var(--primary) 100%); color: #fff; border: none; padding: 1rem 2rem; border-radius: 6px; font-size: 1.1rem; font-weight: 600; cursor: pointer; transition: all 0.2s; grid-column: 1 / -1; margin-top: 1rem; }
.calculate-btn:hover { background: linear-gradient(90deg, var(--primary) 0%, var(--header-bg) 100%); transform: translateY(-2px); }

/* Results */
.results-container { background: var(--input-bg); border-radius: 8px; padding: 1.5rem; border-left: 4px solid var(--primary); }
.results-container h2 { color: var(--text); margin-bottom: 1rem; font-size: 1.5rem; }
.result-item { display: flex; justify-content: space-between; align-items: center; padding: 0.8rem 0; border-bottom: 1px solid var(--input-border); }
.result-item:last-child { border-bottom: none; }
.result-label { font-weight: 600; color: var(--text); }
.result-value { font-weight: 700; color: var(--primary); font-size: 1.1rem; }

/* Responsive Design */
@media (max-width: 768px) {
  .calculator-nav-container { justify-content: flex-start; overflow-x: auto; padding: 0 0.5rem; }
  .calc-nav-btn { font-size: 0.8rem; padding: 0.4rem 0.8rem; }
  .calculator-container { padding: 1.5rem; margin: 0 0.5rem; }
  .calculator-form { grid-template-columns: 1fr; gap: 1rem; }
  .result-item { flex-direction: column; align-items: flex-start; gap: 0.3rem; }
}