/* ===============================
   Blue Whale — Core Stylesheet
   =============================== */

/* --- Base Layout --- */
body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: linear-gradient(to bottom, #d4f0ff 0%, #0a0f1c 60%);
  color: #e0f7ff;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header.hero {
  text-align: center;
  padding: 3rem 1rem 2rem;
}

.hero h1 {
  font-size: 2.5rem;
  color: #4fc3f7;
  margin-bottom: 0.5rem;
}

.hero p {
  font-size: 1.1rem;
  opacity: 0.85;
}

/* --- Navigation Grid --- */
.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 1rem;
  padding: 1rem;
  width: 90%;
  max-width: 800px;
}

.nav-item {
  background: rgba(0, 168, 232, 0.1);
  border: 1px solid rgba(0, 168, 232, 0.3);
  border-radius: 1rem;
  padding: 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
  font-weight: 500;
}

.nav-item:hover {
  background: rgba(0, 168, 232, 0.3);
  transform: scale(1.05);
}

/* --- Page Sections --- */
.page {
  display: none;
  padding: 2rem;
  width: 90%;
  max-width: 800px;
  animation: fadeIn 0.5s ease;
}

.page.active {
  display: block;
}

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

/* --- Buttons --- */
.btn-secondary {
  background: #4fc3f7;
  border: none;
  color: #000;
  padding: 0.8rem 1.2rem;
  border-radius: 0.5rem;
  cursor: pointer;
  font-weight: 600;
  transition: background 0.3s;
}

.btn-secondary:hover {
  background: #81d4fa;
}

/* --- Vault Link (Gemini's Suggestion) --- */
.vault-link {
  display: inline-block;
  background: rgba(79, 195, 247, 0.2);
  border: 1px solid #4fc3f7;
  color: #4fc3f7;
  padding: 0.8rem 1.5rem;
  border-radius: 0.5rem;
  text-decoration: none;
  margin-top: 1rem;
  transition: all 0.3s ease;
  cursor: pointer;
}

.vault-link:hover {
  background: rgba(79, 195, 247, 0.4);
  transform: translateY(-2px);
}

/* --- Probe Result --- */
.probe-result {
  background: rgba(79, 255, 176, 0.1);
  padding: 1rem;
  border-radius: 0.5rem;
  margin: 1rem 0;
  border-left: 4px solid #4fffb0;
}

/* --- Vault Modal --- */
.vault-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000;
}

.modal-content {
  background: #1d2d50;
  padding: 2rem;
  border-radius: 1rem;
  max-width: 400px;
  text-align: center;
  border: 2px solid #4fc3f7;
}

.modal-content h3 {
  margin-top: 0;
  color: #4fc3f7;
}

.modal-content ul {
  list-style: none;
  padding: 0;
  text-align: left;
  margin: 1.5rem 0;
}

.modal-content li {
  padding: 0.5rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.modal-content li:last-child {
  border-bottom: none;
}

.modal-content button {
  background: #4fc3f7;
  border: none;
  margin-top: 1rem;
  padding: 0.6rem 1.2rem;
  border-radius: 0.5rem;
  cursor: pointer;
  color: #000;
  font-weight: 600;
}

/* --- Footer --- */
footer {
  margin-top: auto;
  padding: 1rem;
  font-size: 0.8rem;
  opacity: 0.6;
  text-align: center;
}

/* --- Responsive Design --- */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }
  
  .nav-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .page {
    padding: 1rem;
  }
}

@media (max-width: 480px) {
  .nav-grid {
    grid-template-columns: 1fr;
  }
  
  .hero h1 {
    font-size: 1.75rem;
  }
}