/* ============================================================
   common.css — 7 个计算器页面共享的基础样式
   各页面仍保留自身特有样式（内嵌 <style>，加载顺序在本文件之后）
   ============================================================ */

/* 基础重置 */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

/* 布局容器 */
.wrap{max-width:680px;margin:0 auto}

/* 卡片 */
.card{background:#fff;border-radius:10px;padding:20px;box-shadow:0 2px 8px rgba(0,0,0,0.06);margin-bottom:16px}

/* 面板（Tab 切换） */
.panel{display:none}
.panel.on{display:block}

/* 按钮悬停 */
button:hover{background:#096dd9}

/* FSC 提示点 */
.fsc-dot{display:inline-block;width:8px;height:8px;background:#78BE20;border-radius:50%;flex-shrink:0}

/* 弹窗 */
.modal-bg{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.4);display:flex;align-items:center;justify-content:center;z-index:9999}
.modal-box{background:#fff;border-radius:8px;box-shadow:0 4px 20px rgba(0,0,0,.15);overflow:hidden}
.modal-h{display:flex;justify-content:space-between;align-items:center;padding:12px 16px;border-bottom:1px solid #f0f0f0;font-weight:600;font-size:15px}
.modal-body{padding:16px}
.modal-f{display:flex;gap:8px;justify-content:center;padding:12px 16px;border-top:1px solid #f0f0f0}

/* 顶部导航 */
.topnav{background:#fff;border-bottom:1px solid #e8e8e8;box-shadow:0 1px 4px rgba(0,0,0,0.04)}
.topnav-inner{max-width:680px;margin:0 auto;display:flex;gap:2px;overflow-x:auto;-webkit-overflow-scrolling:touch;padding:8px 12px}
.topnav a{display:inline-block;padding:6px 12px;font-size:13px;color:#666;text-decoration:none;border-radius:6px;white-space:nowrap;flex-shrink:0;transition:all .2s}
.topnav a:hover{background:#e6f7ff;color:#1890ff}
.topnav a.active{background:#1890ff;color:#fff;font-weight:bold}