:root{--bg: #f5f5f7;--card: #ffffff;--text: #1d1d1f;--text2: #6e6e73;--text3: #a1a1a6;--blue: #007aff;--blue-bg: #eaf4ff;--green: #34c759;--green-bg: #e8f8ed;--red: #ff3b30;--red-bg: #ffeceb;--orange: #ff9500;--orange-bg: #fff5e5;--radius: 16px;--radius-sm: 10px;--shadow: 0 1px 3px rgba(0, 0, 0, .06), 0 8px 24px rgba(0, 0, 0, .05);--nav-h: 56px}*{margin:0;padding:0;box-sizing:border-box;-webkit-tap-highlight-color:transparent}html,body{height:100%}body{font-family:-apple-system,BlinkMacSystemFont,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif;background:var(--bg);color:var(--text);font-size:15px;line-height:1.6;-webkit-font-smoothing:antialiased}#app{min-height:100%}a{color:var(--blue);text-decoration:none}button{font-family:inherit;cursor:pointer;border:none;background:none;font-size:15px}input,textarea,select{font-family:inherit;font-size:15px}.page{max-width:680px;margin:0 auto;padding:calc(2px + env(safe-area-inset-top)) 16px calc(var(--nav-h) + 24px)}.page-hero{padding:4px 16px 6px}.card{background:var(--card);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px;margin-bottom:14px;transition:transform .15s ease}.card:active{transform:scale(.99)}.page-title{font-size:20px;font-weight:700}.page-sub{color:var(--text2);font-size:13px;margin-top:2px}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:11px 18px;border-radius:12px;font-weight:600;transition:all .15s ease;min-height:40px}.btn-primary{background:var(--blue);color:#fff}.btn-primary:active{transform:scale(.97);opacity:.85}.btn-primary:disabled{background:#a9cdf5}.btn-plain{background:#e8e8ed;color:var(--text)}.btn-plain:disabled{opacity:.45}.btn-danger{background:var(--red);color:#fff}.btn-danger:disabled{opacity:.6}.btn-block{width:100%}.btn-sm{padding:7px 12px;font-size:13px;border-radius:9px;min-height:34px}.tag{display:inline-flex;align-items:center;padding:2px 8px;border-radius:6px;font-size:11px;font-weight:600;line-height:1.5}.tag-type{background:var(--blue-bg);color:var(--blue)}.tag-lv1{background:var(--green-bg);color:#248a3d}.tag-lv2{background:var(--orange-bg);color:#c93400}.tag-lv3{background:var(--red-bg);color:#d70015}.field{margin-bottom:14px}.field label{display:block;font-size:13px;color:var(--text2);margin-bottom:6px}.input{width:100%;padding:12px 14px;border:1.5px solid #d9d9de;border-radius:12px;background:#fff;outline:none;transition:border .15s;font-size:16px}.input:focus{border-color:var(--blue)}textarea.input{min-height:90px;resize:vertical}select.input{-moz-appearance:none;appearance:none;-webkit-appearance:none;background-image:url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23a1a1a6' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 12px center;padding-right:32px}.bottom-nav{position:fixed;left:0;right:0;bottom:0;height:calc(var(--nav-h) + env(safe-area-inset-bottom));padding-bottom:env(safe-area-inset-bottom);background:#ffffffeb;backdrop-filter:blur(20px) saturate(180%);-webkit-backdrop-filter:blur(20px) saturate(180%);border-top:.5px solid rgba(0,0,0,.1);display:flex;z-index:100}.bottom-nav a{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;color:var(--text3);font-size:10px;text-decoration:none}.bottom-nav a .nav-ico{font-size:20px;line-height:1}.bottom-nav a.router-link-active{color:var(--blue)}.spinner{width:22px;height:22px;border:2.5px solid #d9d9de;border-top-color:var(--blue);border-radius:50%;animation:spin .8s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.center-loading{display:flex;flex-direction:column;align-items:center;gap:10px;padding:48px 0;color:var(--text2);font-size:13px}.toast{position:fixed;top:16px;left:50%;transform:translate(-50%);background:#1d1d1feb;color:#fff;padding:10px 20px;border-radius:20px;font-size:13px;z-index:999;animation:fadein .2s ease}@keyframes fadein{0%{opacity:0;transform:translate(-50%,-6px)}}.opt{display:flex;align-items:flex-start;gap:10px;padding:12px 14px;border:1.5px solid #e3e3e8;border-radius:13px;margin-bottom:10px;cursor:pointer;transition:all .15s ease;background:#fff}.opt:active{transform:scale(.985)}.opt .opt-key{flex-shrink:0;width:24px;height:24px;border-radius:50%;border:1.5px solid #c7c7cc;display:flex;align-items:center;justify-content:center;font-size:13px;font-weight:600;color:var(--text2);transition:all .15s}.opt.selected{border-color:var(--blue);background:var(--blue-bg)}.opt.selected .opt-key{background:var(--blue);border-color:var(--blue);color:#fff}.opt.correct{border-color:var(--green);background:var(--green-bg)}.opt.correct .opt-key{background:var(--green);border-color:var(--green);color:#fff}.opt.wrong{border-color:var(--red);background:var(--red-bg)}.opt.wrong .opt-key{background:var(--red);border-color:var(--red);color:#fff}.opt.dim{opacity:.45}.opt-text,.q-body,.q-card .q-body,.w-body{overflow-wrap:break-word;word-break:break-word}.analysis-box{background:#fbfbfd;border-radius:13px;padding:14px;margin-top:12px;border:1px solid #eeeeF2}.analysis-box h4{font-size:14px;margin-bottom:6px;display:flex;align-items:center;gap:6px}.ai-tip{color:var(--text3);font-size:11px;margin-top:8px}@media(min-width:768px){.bottom-nav{left:50%;transform:translate(-50%);max-width:680px;border-radius:20px 20px 0 0}}