/* ═══════════════════════════════════════════════════════
   NeoCalculator.net — Half-Life Calculator CSS
   ═══════════════════════════════════════════════════════ */

.half-life-container {
  padding-top: 30px;
  padding-bottom: 50px;
}

.hero-section {
  text-align: center;
  margin-bottom: 25px;
}

.hero-section h1 {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--text-light);
  margin-bottom: 8px;
}

.hero-section p {
  color: var(--text-muted);
  font-size: 1rem;
}

/* Tabs Switcher Nav */
.hl-tab-nav {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.hl-tab-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 10px 20px;
  border-radius: var(--radius);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.hl-tab-btn.active, .hl-tab-btn:hover {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

/* Card Panel Container */
.hl-card-panel {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 30px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  margin-bottom: 40px;
}

.hl-card-panel h2 {
  font-size: 1.4rem;
  margin-bottom: 8px;
  color: var(--text-light);
}

.panel-desc {
  color: var(--text-muted);
  margin-bottom: 24px;
  font-size: 0.92rem;
}

/* Form Layout */
.hl-form-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-light);
}

.form-group input {
  width: 100%;
  padding: 12px 16px;
  font-size: 1rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background-color: var(--bg-card);
  color: var(--text-light);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.25);
}

.hl-action-btns {
  display: flex;
  gap: 12px;
}

/* Result Box Styling */
.hl-result-box {
  background: var(--formula-bg);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  border-radius: 10px;
  padding: 20px;
  margin-top: 25px;
  color: var(--text-light);
  animation: fadeIn 0.3s ease-in-out;
}

.hl-result-box h3 {
  font-size: 1.1rem;
  margin-bottom: 12px;
  color: var(--accent);
}

.hl-res-main {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-light);
  margin-bottom: 15px;
}

.steps-list {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.7;
  border-top: 1px dashed var(--border);
  padding-top: 12px;
  margin-top: 12px;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to { opacity: 1; transform: translateY(0); }
}