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

:root {
  --bg: #f5f5f5;
  --card-bg: #ffffff;
  --text: #1a1a1a;
  --text-secondary: #666666;
  --border: #e5e5e5;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #dc2626;
  --danger-hover: #b91c1c;
  --success: #16a34a;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

.app {
  max-width: 480px;
  margin: 0 auto;
  padding: 20px;
  min-height: 100vh;
}

/* 头部 */
header {
  padding: 16px 0;
  margin-bottom: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
}

.logo svg {
  color: var(--primary);
}

/* 卡片 */
.card {
  background: var(--card-bg);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  overflow: hidden;
}

.card-header {
  padding: 20px 20px 0;
}

.card-header h2 {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.card-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 4px;
}

.card-body {
  padding: 20px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
  width: 100%;
}

.btn:active {
  transform: scale(0.98);
}

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

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

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

.btn-danger:hover {
  background: var(--danger-hover);
}

/* 分隔线 */
.divider {
  display: flex;
  align-items: center;
  gap: 16px;
  margin: 24px 0;
  color: var(--text-secondary);
  font-size: 14px;
}

.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* 输入框组 */
.input-group {
  display: flex;
  gap: 8px;
}

.input-group input {
  flex: 1;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  letter-spacing: 4px;
  text-align: center;
  text-transform: uppercase;
  transition: border-color 0.15s ease;
  outline: none;
}

.input-group input:focus {
  border-color: var(--primary);
}

.input-group input::placeholder {
  letter-spacing: 0;
  text-transform: none;
  font-weight: 400;
  color: #999;
}

.input-group .btn {
  width: auto;
  min-width: 48px;
  padding: 12px 16px;
}

/* 共享码显示 */
.share-code-box {
  background: var(--bg);
  border-radius: 8px;
  padding: 16px;
  text-align: center;
  margin: 16px 0;
}

.share-code-box .label {
  display: block;
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.code {
  display: block;
  font-size: 32px;
  font-weight: 700;
  letter-spacing: 8px;
  color: var(--text);
  font-family: "SF Mono", "Monaco", "Menlo", monospace;
}

.hint {
  font-size: 13px;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 16px;
}

/* 状态信息 */
.status {
  margin-top: 16px;
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 13px;
  display: none;
}

.status:not(:empty) {
  display: block;
}

.status.success {
  background: #f0fdf4;
  color: var(--success);
  border: 1px solid #bbf7d0;
}

.status.error {
  background: #fef2f2;
  color: var(--danger);
  border: 1px solid #fecaca;
}

.status.info {
  background: #eff6ff;
  color: var(--primary);
  border: 1px solid #bfdbfe;
}

.hidden {
  display: none !important;
}

/* 视频区域 */
#video-container {
  margin-top: 24px;
}

.video-wrapper {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: #000;
  box-shadow: var(--shadow);
}

#remote-video {
  width: 100%;
  aspect-ratio: 16 / 9;
  background: #000;
  display: block;
  cursor: pointer;
  object-fit: contain;
}

#video-controls {
  position: absolute;
  bottom: 12px;
  right: 12px;
  display: flex;
  gap: 6px;
  opacity: 0;
  transition: opacity 0.2s ease;
}

.video-wrapper:hover #video-controls {
  opacity: 1;
}

.btn-control {
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 8px;
  background: rgba(0, 0, 0, 0.6);
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s ease;
  backdrop-filter: blur(4px);
}

.btn-control:hover {
  background: rgba(0, 0, 0, 0.8);
}

#video-status {
  text-align: center;
  margin-top: 12px;
  font-size: 13px;
  color: var(--text-secondary);
}

.viewer-count {
  display: inline-block;
  background: var(--success);
  color: white;
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 12px;
  margin-top: 12px;
}

/* 放大遮罩 */
.video-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  cursor: pointer;
}

.video-overlay video {
  max-width: 90%;
  max-height: 90%;
  border-radius: 8px;
}

.video-overlay .close-btn {
  position: absolute;
  top: 20px;
  right: 20px;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.15);
  color: white;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s ease;
}

.video-overlay .close-btn:hover {
  background: rgba(255, 255, 255, 0.25);
}

/* 诊断按钮 */
.btn-secondary {
  background: var(--text-secondary);
  color: white;
}

.btn-secondary:hover {
  background: #555;
}

/* 诊断结果 */
.diagnosis-result {
  margin-top: 12px;
  padding: 12px;
  background: var(--bg);
  border-radius: 8px;
  font-size: 13px;
  line-height: 1.8;
  word-break: break-all;
}

.diagnosis-result strong {
  color: var(--text);
}

.diagnosis-result p {
  margin: 0;
  color: var(--text-secondary);
}

/* 页脚 */
footer {
  text-align: center;
  padding: 20px 0;
  margin-top: 20px;
}

.version {
  font-size: 11px;
  color: var(--text-secondary);
  opacity: 0.6;
}

/* 响应式 */
@media (max-width: 480px) {
  .app {
    padding: 16px;
  }
  
  .code {
    font-size: 28px;
    letter-spacing: 6px;
  }
}