:root {
  --bg-color: #0f172a;
  --surface-color: #1e293b;
  --surface-hover: #334155;
  --border-color: #334155;
  --primary-color: #38bdf8;
  --primary-hover: #0284c7;
  --secondary-color: #818cf8;
  --accent-color: #10b981;
  --danger-color: #ef4444;
  --warning-color: #f59e0b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  --font-mono: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, Courier, monospace;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

header {
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

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

.brand-icon {
  font-size: 1.8rem;
}

.brand-title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary-color);
  letter-spacing: -0.5px;
}

.brand-subtitle {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.nav-links {
  display: flex;
  gap: 1rem;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 0.8rem;
  border-radius: 6px;
  transition: all 0.2s;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary-color);
  background-color: var(--surface-hover);
}

main {
  flex: 1;
  max-width: 1200px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* Tabs Navigation */
.tabs {
  display: flex;
  gap: 0.5rem;
  border-bottom: 2px solid var(--border-color);
  margin-bottom: 2rem;
  overflow-x: auto;
  padding-bottom: 2px;
}

.tab-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.75rem 1.25rem;
  cursor: pointer;
  border-radius: 8px 8px 0 0;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--text-main);
  background-color: var(--surface-hover);
}

.tab-btn.active {
  color: var(--primary-color);
  background-color: var(--surface-color);
  border-bottom: 3px solid var(--primary-color);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.3s ease-in-out;
}

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

/* Cards & Layout */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

@media (max-width: 860px) {
  .grid-2 {
    grid-template-columns: 1fr;
  }
}

.card {
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.75rem;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.2);
}

.card-title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.card-desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.5rem;
}

/* Form Controls */
.form-group {
  margin-bottom: 1.25rem;
}

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

.hint {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.35rem;
}

input[type="text"],
input[type="password"],
input[type="number"],
textarea,
select {
  width: 100%;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.95rem;
  padding: 0.75rem 1rem;
  transition: border-color 0.2s;
}

input[type="text"]:focus,
input[type="password"]:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--primary-color);
}

textarea {
  min-height: 110px;
  resize: vertical;
}

/* File Upload Area */
.file-dropzone {
  border: 2px dashed var(--border-color);
  border-radius: 10px;
  padding: 1.5rem 1rem;
  text-align: center;
  cursor: pointer;
  background-color: rgba(15, 23, 42, 0.5);
  transition: all 0.2s;
  position: relative;
}

.file-dropzone:hover, .file-dropzone.dragover {
  border-color: var(--primary-color);
  background-color: rgba(56, 189, 248, 0.05);
}

.file-dropzone input[type="file"] {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.file-dropzone-icon {
  font-size: 2rem;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
}

.file-dropzone-text {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.file-info {
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--accent-color);
  font-weight: 500;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background-color: var(--primary-color);
  color: #0f172a;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s;
  width: 100%;
}

.btn:hover {
  background-color: var(--primary-hover);
  color: #ffffff;
}

.btn-secondary {
  background-color: var(--surface-hover);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--border-color);
  color: var(--primary-color);
}

.btn-success {
  background-color: var(--accent-color);
  color: #0f172a;
}

.btn-success:hover {
  background-color: #059669;
  color: #ffffff;
}

/* Badges & Stats */
.badge {
  display: inline-block;
  padding: 0.25rem 0.6rem;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 9999px;
  text-transform: uppercase;
}

.badge-info {
  background-color: rgba(56, 189, 248, 0.2);
  color: var(--primary-color);
}

.badge-success {
  background-color: rgba(16, 185, 129, 0.2);
  color: var(--accent-color);
}

.badge-warning {
  background-color: rgba(245, 158, 11, 0.2);
  color: var(--warning-color);
}

.badge-danger {
  background-color: rgba(239, 68, 68, 0.2);
  color: var(--danger-color);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 1rem;
  margin: 1.25rem 0;
}

.stat-item {
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  padding: 0.85rem;
  border-radius: 8px;
  text-align: center;
}

.stat-val {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--primary-color);
}

.stat-lbl {
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-top: 0.25rem;
}

/* Hexdump Box */
.hexdump-box {
  background-color: #0a0e17;
  color: #38bdf8;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
  white-space: pre;
  border: 1px solid var(--border-color);
  max-height: 250px;
  line-height: 1.4;
}

/* Findings Alert Box */
.findings-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin: 1rem 0;
}

.finding-item {
  border-left: 4px solid;
  padding: 0.75rem 1rem;
  background-color: var(--bg-color);
  border-radius: 0 8px 8px 0;
}

.finding-item.danger {
  border-color: var(--danger-color);
}

.finding-item.warning {
  border-color: var(--warning-color);
}

.finding-item.success {
  border-color: var(--accent-color);
}

.finding-title {
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.2rem;
}

.finding-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Sample Downloads Table */
.sample-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.sample-card {
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.sample-title {
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.sample-desc {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

/* Alert Notification */
.alert {
  padding: 1rem;
  border-radius: 8px;
  margin-bottom: 1.25rem;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.alert-danger {
  background-color: rgba(239, 68, 68, 0.15);
  border: 1px solid var(--danger-color);
  color: #fca5a5;
}

.alert-info {
  background-color: rgba(56, 189, 248, 0.15);
  border: 1px solid var(--primary-color);
  color: #bae6fd;
}

/* Spinner */
.spinner {
  display: inline-block;
  width: 1.2rem;
  height: 1.2rem;
  border: 3px solid rgba(255, 255, 255, 0.3);
  border-radius: 50%;
  border-top-color: #ffffff;
  animation: spin 0.8s ease-in-out infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

footer {
  background-color: var(--surface-color);
  border-top: 1px solid var(--border-color);
  text-align: center;
  padding: 1.5rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 3rem;
}