* { box-sizing: border-box; }
body { margin: 0; font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans SC', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif; color: #222; background: #f6f8fa; }
.site-header { background: #2c3e50; color: #fff; }
.nav { max-width: 980px; margin: 0 auto; display: flex; justify-content: space-between; align-items: center; padding: 14px 16px; }
.nav-left { font-weight: 600; }
.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-links { list-style: none; margin: 0; padding: 0; display: flex; gap: 16px; }
.nav-links a { color: #dfe6ec; text-decoration: none; font-size: 14px; }
.btn-home { background: #409eff; color: #fff; text-decoration: none; padding: 8px 12px; border-radius: 4px; font-size: 14px; font-weight: 500; transition: background 0.3s; }
.btn-home:hover { background: #337ecc; }
.container { max-width: 980px; margin: 24px auto; padding: 0 16px; }
.breadcrumb { color: #667; font-size: 13px; margin-bottom: 12px; }
.page-title { font-size: 22px; font-weight: 600; color: #1f2d3d; text-align: center; margin: 16px 0 20px; }
.card { background: #fff; border-radius: 6px; box-shadow: 0 2px 10px rgba(0,0,0,.04); padding: 18px; margin-bottom: 20px; }
.card h2 { font-size: 18px; border-left: 3px solid #409eff; padding-left: 8px; color: #273444; }
.btn { background: #409eff; color: #fff; border: 0; padding: 10px 14px; border-radius: 4px; cursor: pointer; }
.btn:hover { background: #337ecc; }
.btn-plain { background: #fff; color: #409eff; border: 1px solid #409eff; }
.btn-plain:hover { background: #ecf5ff; }
.btn-copy { background: #f0f9ff; color: #0369a1; border: 1px solid #bae6fd; padding: 4px 8px; border-radius: 4px; font-size: 12px; cursor: pointer; }
.btn-copy:hover { background: #e0f2fe; }
.actions { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 12px; }
.world-clock { display: grid; grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(3, 1fr); gap: 16px; margin-top: 12px; }
.clock-item { background: #f8fafc; border: 1px solid #e2e8f0; border-radius: 8px; padding: 16px; text-align: center; min-height: 80px; display: flex; flex-direction: column; justify-content: center; }
.city { font-size: 14px; color: #64748b; margin-bottom: 8px; font-weight: 500; }
.time { font-size: 24px; font-weight: 700; color: #1e293b; margin-bottom: 4px; }
.date { font-size: 12px; color: #64748b; }
.conversion-section { margin-top: 12px; }
.input-group { display: flex; flex-direction: column; gap: 6px; margin-bottom: 16px; }
.input-group label { font-size: 13px; color: #555; }
.input-group input, .input-group select { padding: 8px 10px; border: 1px solid #dcdfe6; border-radius: 4px; font-size: 14px; }
.result-group { border: 1px solid #e4e7ed; border-radius: 6px; padding: 12px; background: #fbfcfe; margin-top: 16px; }
.result-item { display: flex; align-items: center; gap: 8px; padding: 6px 0; border-bottom: 1px dashed #eef2f7; }
.result-item:last-child { border-bottom: 0; }
.result-label { width: 120px; color: #5e6d82; font-size: 13px; flex: 0 0 auto; }
.result-item span:last-of-type { flex: 1; word-break: break-all; }
.help-content { margin-top: 12px; }
.help-content h3 { color: #2c3e50; font-size: 16px; margin: 16px 0 8px 0; border-left: 3px solid #409eff; padding-left: 8px; }
.help-content ul { margin: 8px 0; padding-left: 20px; }
.help-content li { margin: 6px 0; line-height: 1.5; }
.example { background: #f8fafc; border: 1px solid #e2e8f0; border-radius: 6px; padding: 12px; margin: 12px 0; }
.example p { margin: 6px 0; }
.example code { background: #e2e8f0; padding: 2px 6px; border-radius: 3px; font-family: 'Monaco', 'Menlo', 'Ubuntu Mono', monospace; }
.desc { color: #5e6d82; font-size: 14px; }

/* 版权信息样式 */
.site-footer { background: #2c3e50; color: #fff; text-align: center; padding: 20px 0; margin-top: 40px; }
.footer-content p { margin: 0; font-size: 14px; color: #dfe6ec; }

/* 移动端适配 */
@media (max-width: 768px) {
  .nav-right { flex-direction: column; gap: 8px; }
  .nav-links { display: none; }
  .btn-home { align-self: flex-end; }
  .page-title { font-size: 18px; }
  .card { padding: 16px; }
  .container { padding: 0 12px; }
  .world-clock { grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(3, 1fr); gap: 12px; }
  .clock-item { padding: 12px; min-height: 70px; }
  .time { font-size: 20px; }
  .actions { flex-direction: row; flex-wrap: wrap; gap: 6px; }
  .input-group { flex-direction: row; gap: 8px; }
  .input-group input, .input-group select { flex: 1; }
  .result-item { flex-direction: row; align-items: center; gap: 8px; }
  .result-label { width: 80px; flex: 0 0 auto; }
}

@media (max-width: 480px) {
  .page-title { font-size: 16px; }
  .card h2 { font-size: 16px; }
  .btn { padding: 8px 12px; font-size: 14px; }
  .time { font-size: 18px; }
  .world-clock { grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(3, 1fr); gap: 8px; }
  .clock-item { padding: 10px; min-height: 60px; }
  .actions { flex-direction: column; }
  .input-group { flex-direction: row; gap: 8px; }
  .input-group input, .input-group select { flex: 1; }
  .result-item { flex-direction: row; align-items: center; gap: 8px; }
  .result-label { width: 80px; flex: 0 0 auto; }
}

/* iPhone 13/14/15 优化 (390px-413px) */
@media (min-width: 390px) and (max-width: 413px) {
  .world-clock { grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(3, 1fr); gap: 10px; }
  .clock-item { padding: 10px; min-height: 65px; }
  .time { font-size: 18px; }
}

/* iPhone 6s Plus 优化 (414px-429px) */
@media (min-width: 414px) and (max-width: 429px) {
  .world-clock { grid-template-columns: repeat(2, 1fr); grid-template-rows: repeat(3, 1fr); gap: 12px; }
  .clock-item { padding: 12px; min-height: 70px; }
  .time { font-size: 20px; }
}