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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: #0f1419;
  color: #e7e9ea;
  min-height: 100vh;
}

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 48px 24px;
}

.header h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.subtitle {
  color: #8b98a5;
  margin-bottom: 32px;
}

.start-form label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}

.input-row {
  display: flex;
  gap: 8px;
}

.input-row input {
  flex: 1;
  padding: 12px 16px;
  border: 1px solid #38444d;
  border-radius: 8px;
  background: #192734;
  color: #e7e9ea;
  font-size: 1rem;
}

.input-row input:focus {
  outline: none;
  border-color: #1d9bf0;
}

button {
  padding: 12px 20px;
  border: none;
  border-radius: 8px;
  background: #1d9bf0;
  color: #fff;
  font-size: 1rem;
  cursor: pointer;
  font-weight: 500;
}

button:hover {
  background: #1a8cd8;
}

button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.error {
  color: #f4212e;
  margin-top: 12px;
  font-size: 0.9rem;
}

.hidden {
  display: none !important;
}

.tips {
  margin-top: 48px;
  padding: 24px;
  background: #192734;
  border-radius: 12px;
  border: 1px solid #38444d;
}

.tips h2 {
  font-size: 1rem;
  margin-bottom: 12px;
}

.tips ul {
  padding-left: 20px;
  color: #8b98a5;
  line-height: 1.8;
}

/* Viewer */
.viewer-body {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

.toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: #192734;
  border-bottom: 1px solid #38444d;
  flex-shrink: 0;
}

.toolbar button {
  padding: 8px 12px;
  min-width: 36px;
}

.toolbar #address-bar {
  flex: 1;
  padding: 8px 12px;
  border: 1px solid #38444d;
  border-radius: 6px;
  background: #0f1419;
  color: #e7e9ea;
  font-size: 0.9rem;
}

.toolbar #address-bar:focus {
  outline: none;
  border-color: #1d9bf0;
}

.status {
  font-size: 0.8rem;
  color: #8b98a5;
  white-space: nowrap;
}

.btn-danger {
  background: #f4212e;
}

.btn-danger:hover {
  background: #dc1d28;
}

.viewport-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #000;
  position: relative;
  overflow: hidden;
}

#screen {
  max-width: 100%;
  max-height: 100%;
  cursor: default;
  outline: none;
}

.overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.overlay a {
  color: #1d9bf0;
  text-decoration: none;
}

.overlay a:hover {
  text-decoration: underline;
}

.panel {
  margin-bottom: 24px;
  padding: 24px;
  background: #192734;
  border-radius: 12px;
  border: 1px solid #38444d;
}

.panel h2 {
  font-size: 1.1rem;
  margin-bottom: 16px;
}

.stack-form label {
  display: block;
  margin: 12px 0 6px;
  font-weight: 500;
}

.stack-form input {
  width: 100%;
  padding: 10px 14px;
  border: 1px solid #38444d;
  border-radius: 8px;
  background: #0f1419;
  color: #e7e9ea;
  font-size: 1rem;
}

.stack-form input:focus {
  outline: none;
  border-color: #1d9bf0;
}

.stack-form button {
  margin-top: 16px;
}

.btn-row {
  display: flex;
  gap: 8px;
  margin-top: 16px;
}

.btn-secondary {
  background: #38444d;
}

.btn-secondary:hover {
  background: #4a5560;
}

.top-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
}

.welcome {
  flex: 1;
  color: #8b98a5;
  font-size: 0.9rem;
}

.hint {
  margin-top: 12px;
  color: #8b98a5;
  font-size: 0.85rem;
}

.success {
  color: #00ba7c;
  margin-top: 12px;
  font-size: 0.9rem;
}