:root {
  --bg-color: #0f172a;
  --panel-bg: rgba(30, 41, 59, 0.7);
  --panel-border: rgba(255, 255, 255, 0.1);
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --success: #10b981;
  --error: #ef4444;
  --input-bg: rgba(15, 23, 42, 0.6);
  --input-border: rgba(255, 255, 255, 0.2);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg-color);
  background-image: radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15), transparent 25%),
                    radial-gradient(circle at 85% 30%, rgba(16, 185, 129, 0.15), transparent 25%);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem;
}

.container {
  width: 100%;
  max-width: 500px;
}

.glass-panel {
  background: var(--panel-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--panel-border);
  border-radius: 24px;
  padding: 2.5rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
  animation: slideUp 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.header {
  text-align: center;
  margin-bottom: 2rem;
}

.header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  background: linear-gradient(135deg, #fff, #94a3b8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

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

.form-group {
  margin-bottom: 1.5rem;
}

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

.form-control {
  width: 100%;
  padding: 0.875rem 1rem;
  background: var(--input-bg);
  border: 1px solid var(--input-border);
  border-radius: 12px;
  color: var(--text-main);
  font-size: 1rem;
  transition: all 0.2s ease;
  outline: none;
}

.form-control:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25);
}

.btn {
  width: 100%;
  padding: 1rem;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.5rem;
}

.btn:hover {
  background: var(--primary-hover);
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(1px);
}

.btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

/* Spinner */
.spinner {
  display: none;
  width: 20px;
  height: 20px;
  border: 3px solid rgba(255,255,255,0.3);
  border-radius: 50%;
  border-top-color: white;
  animation: spin 1s ease-in-out infinite;
}

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

.btn.loading .spinner {
  display: block;
}
.btn.loading .btn-text {
  display: none;
}

/* Alert Messages */
.alert {
  padding: 1rem;
  border-radius: 12px;
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
  display: none;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.alert.error {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
  color: #fca5a5;
  display: block;
}

.alert.success {
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
  color: #6ee7b7;
  display: block;
}

/* Result Card */
.result-card {
  margin-top: 1.5rem;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 16px;
  padding: 1.5rem;
  display: none;
}

.result-card.active {
  display: block;
  animation: slideUp 0.4s ease;
}

.result-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.result-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.result-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.result-value {
  font-size: 0.95rem;
  font-weight: 500;
  word-break: break-all;
}

.status-badge {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
}

.status-valid {
  background: rgba(16, 185, 129, 0.2);
  color: #6ee7b7;
}

.status-invalid {
  background: rgba(239, 68, 68, 0.2);
  color: #fca5a5;
}

.license-key-box {
  background: var(--input-bg);
  padding: 1rem;
  border-radius: 8px;
  border: 1px solid var(--input-border);
  font-family: monospace;
  font-size: 0.85rem;
  word-break: break-all;
  margin-bottom: 1rem;
  color: #93c5fd;
}

/* Sections */
#login-section { display: block; }
#generator-section { display: none; }