:root {
  --primary: #f7931a;
  --primary-dark: #d47f15;
  --secondary: #4a5568;
  --background: #f7fafc;
  --surface: #ffffff;
  --border: #e2e8f0;
  --text: #1a202c;
  --text-light: #718096;
  --success: #48bb78;
  --error: #f56565;
  --warning: #ed8936;
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell',
    'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  background: var(--background);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

/* Header */
header {
  text-align: center;
  margin-bottom: 2rem;
}

header h1 {
  font-size: 2.5rem;
  color: var(--text);
  margin-bottom: 0.5rem;
}

.subtitle {
  color: var(--text-light);
  font-size: 1.1rem;
}

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

.tab-button {
  padding: 0.75rem 1.5rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-light);
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.2s;
  margin-bottom: -2px;
}

.tab-button:hover {
  color: var(--primary);
}

.tab-button.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* Tab Content */
.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* Card */
.card {
  background: var(--surface);
  border-radius: 0.5rem;
  padding: 2rem;
  box-shadow: var(--shadow);
}

.card h2 {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
  color: var(--text);
}

.description {
  color: var(--text-light);
  margin-bottom: 2rem;
}

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

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

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

input[type='text'],
input[type='number'],
textarea {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  font-size: 0.875rem;
  transition: all 0.2s;
}

input[type='text']:focus,
input[type='number']:focus,
textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(247, 147, 26, 0.1);
}

textarea {
  resize: vertical;
  font-family: 'Courier New', monospace;
}

small {
  display: block;
  margin-top: 0.25rem;
  color: var(--text-light);
  font-size: 0.75rem;
}

.checkbox-group {
  display: flex;
  align-items: center;
}

.checkbox-group label {
  display: flex;
  align-items: center;
  font-weight: 400;
  margin-bottom: 0;
  cursor: pointer;
}

.checkbox-group input[type='checkbox'] {
  width: auto;
  margin-right: 0.5rem;
  cursor: pointer;
}

/* Advanced Options */
.advanced-options {
  margin: 1.5rem 0;
  padding: 1rem;
  background: var(--background);
  border-radius: 0.375rem;
}

.advanced-options summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text);
  user-select: none;
}

.advanced-options[open] summary {
  margin-bottom: 1rem;
}

/* Button */
.btn {
  padding: 0.75rem 1.5rem;
  border: none;
  border-radius: 0.375rem;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-primary {
  background: var(--primary);
  color: white;
}

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

.btn-primary:active {
  transform: translateY(0);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none !important;
}

/* Results */
.results {
  margin-top: 2rem;
}

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.result-count {
  font-size: 0.875rem;
  color: var(--text-light);
}

.utxo-list,
.tx-list {
  display: grid;
  gap: 1rem;
}

.utxo-item,
.tx-item {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: var(--background);
}

.utxo-header,
.tx-header {
  display: flex;
  justify-content: space-between;
  align-items: start;
  margin-bottom: 0.75rem;
}

.amount {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--success);
}

.confirmations {
  display: inline-block;
  padding: 0.25rem 0.5rem;
  background: var(--success);
  color: white;
  border-radius: 0.25rem;
  font-size: 0.75rem;
  font-weight: 600;
}

.confirmations.unsafe {
  background: var(--warning);
}

.detail-row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
  font-size: 0.875rem;
}

.detail-label {
  font-weight: 600;
  color: var(--text-light);
}

.detail-value {
  font-family: 'Courier New', monospace;
  word-break: break-all;
  color: var(--text);
}

.balance-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.balance-card {
  padding: 1.5rem;
  background: var(--background);
  border: 1px solid var(--border);
  border-radius: 0.375rem;
}

.balance-label {
  font-size: 0.875rem;
  color: var(--text-light);
  margin-bottom: 0.5rem;
}

.balance-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
}

.balance-value.positive {
  color: var(--success);
}

/* Error/Success Messages */
.message {
  padding: 1rem;
  border-radius: 0.375rem;
  margin-bottom: 1rem;
}

.message.error {
  background: #fed7d7;
  color: #c53030;
  border: 1px solid #fc8181;
}

.message.success {
  background: #c6f6d5;
  color: #276749;
  border: 1px solid #9ae6b4;
}

/* Footer */
footer {
  margin-top: 3rem;
  text-align: center;
  color: var(--text-light);
  font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  header h1 {
    font-size: 2rem;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .tabs {
    flex-direction: column;
  }

  .tab-button {
    text-align: left;
  }
}