:root{--bg:#f5f5f7;--bg-card:#fff;--text-primary:#1d1d1f;--text-secondary:#86868b;--text-tertiary:#aeaeb2;--border:#e5e5ea;--border-light:#f0f0f2;--accent:#007aff;--accent-hover:#0066d6;--danger:#ff3b30;--success:#34c759;--warning:#ff9500;--shadow-sm:0 1px 3px #0000000a;--shadow-md:0 2px 8px #0000000f;--radius-sm:8px;--radius-md:12px;--radius-lg:16px;--radius-xl:20px;--tab-height:56px;--header-height:48px;--max-width:480px;--font:-apple-system, "PingFang SC", "Helvetica Neue", system-ui, sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{font-family:var(--font);background:var(--bg);color:var(--text-primary);-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale;line-height:1.5}a{color:var(--accent);text-decoration:none}button{font-family:var(--font);cursor:pointer;font-size:inherit;background:0 0;border:none;outline:none}input,textarea{font-family:var(--font);font-size:inherit;border:none;outline:none}img{max-width:100%;display:block}.app-container{max-width:var(--max-width);background:var(--bg);min-height:100vh;padding-bottom:calc(var(--tab-height) + 16px);margin:0 auto;position:relative}.header{z-index:100;-webkit-backdrop-filter:blur(12px);border-bottom:1px solid var(--border-light);height:var(--header-height);background:#ffffffd9;justify-content:space-between;align-items:center;padding:0 16px;display:flex;position:sticky;top:0}.header-title{letter-spacing:-.02em;text-align:center;flex:1;font-size:17px;font-weight:600}.header-action{color:var(--accent);font-size:15px;font-weight:500}.tab-bar{width:100%;max-width:var(--max-width);height:var(--tab-height);-webkit-backdrop-filter:blur(12px);border-top:1px solid var(--border-light);z-index:100;background:#ffffffeb;justify-content:space-around;align-items:center;display:flex;position:fixed;bottom:0;left:50%;transform:translate(-50%)}.tab-item{color:var(--text-tertiary);-webkit-tap-highlight-color:transparent;flex-direction:column;align-items:center;gap:2px;padding:4px 12px;font-size:10px;transition:color .15s;display:flex}.tab-item.active{color:var(--accent)}.tab-item.disabled{color:var(--border)}.tab-item svg{width:24px;height:24px}.tab-fab{background:var(--accent);color:#fff;-webkit-tap-highlight-color:transparent;border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:48px;height:48px;margin-bottom:8px;transition:transform .15s,box-shadow .15s;display:flex;box-shadow:0 3px 14px #007aff59}.tab-fab:active{transform:scale(.92);box-shadow:0 2px 8px #007aff33}.tab-fab svg{width:22px;height:22px}.card{background:var(--bg-card);border-radius:var(--radius-md);box-shadow:var(--shadow-sm);margin-bottom:8px;padding:16px}.post-card{background:var(--bg-card);border-bottom:1px solid var(--border-light);cursor:pointer;padding:16px;transition:background .15s}.post-card:active{background:#f8f8fa}.post-header{align-items:center;gap:10px;margin-bottom:8px;display:flex}.post-avatar{background:var(--border);width:36px;height:36px;color:var(--text-secondary);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-size:14px;display:flex;overflow:hidden}.post-avatar img{object-fit:cover;width:100%;height:100%}.post-author{flex:1;min-width:0}.post-author-name{color:var(--text-primary);font-size:14px;font-weight:600}.post-meta{color:var(--text-tertiary);align-items:center;gap:6px;font-size:12px;display:flex}.studio-badge{color:var(--accent);background:#007aff14;border-radius:10px;padding:1px 8px;font-size:11px}.post-content{color:var(--text-primary);word-break:break-word;margin-bottom:10px;font-size:15px;line-height:1.6}.post-images{border-radius:var(--radius-sm);gap:4px;margin-bottom:10px;display:grid;overflow:hidden}.post-images.single img{border-radius:var(--radius-sm);object-fit:cover;background:var(--border);width:100%;max-height:300px}.post-images.multi{grid-template-columns:1fr 1fr 1fr}.post-images.multi img{aspect-ratio:1;object-fit:cover;background:var(--border)}.post-footer{color:var(--text-tertiary);align-items:center;gap:20px;font-size:13px;display:flex}.post-action{cursor:pointer;-webkit-tap-highlight-color:transparent;align-items:center;gap:4px;padding:4px 0;display:flex}.post-action.active{color:var(--accent)}.post-studio-name{color:var(--text-secondary);margin-bottom:8px;font-size:13px}.tag{background:var(--border-light);color:var(--text-secondary);border-radius:10px;padding:2px 8px;font-size:11px;display:inline-block}.tag.study{color:var(--accent);background:#007aff14}.tag.anonymous{color:var(--danger);background:#ff3b3014}.tag.artwork{color:var(--success);background:#34c75914}.tag.secondhand{color:var(--warning);background:#ff950014}.tag.fan{color:#af52de;background:#af52de14}.tag.notice{color:var(--text-secondary);background:#0000000a}.btn{border-radius:var(--radius-sm);-webkit-tap-highlight-color:transparent;justify-content:center;align-items:center;gap:6px;padding:10px 20px;font-size:15px;font-weight:500;transition:all .15s;display:inline-flex}.btn-primary{background:var(--accent);color:#fff}.btn-primary:active{background:var(--accent-hover);transform:scale(.98)}.btn-secondary{background:var(--border-light);color:var(--text-primary)}.btn-secondary:active{background:#e5e5ea}.btn-block{width:100%}.btn-danger{background:var(--danger);color:#fff}.form-group{margin-bottom:16px}.form-label{color:var(--text-secondary);margin-bottom:6px;font-size:13px;font-weight:500;display:block}.form-input{background:var(--bg);border-radius:var(--radius-sm);width:100%;color:var(--text-primary);padding:12px 14px;font-size:16px;transition:background .15s}.form-input:focus{background:#eaeaee}.form-textarea{background:var(--bg);border-radius:var(--radius-sm);width:100%;color:var(--text-primary);resize:vertical;min-height:120px;padding:12px 14px;font-size:16px}.form-textarea:focus{background:#eaeaee}.page{padding:0}.page-header{padding:20px 16px 12px}.page-title{letter-spacing:-.03em;margin-bottom:4px;font-size:28px;font-weight:700}.page-subtitle{color:var(--text-secondary);font-size:15px}.feed{padding:0}.feed-tabs{-webkit-overflow-scrolling:touch;scrollbar-width:none;gap:0;margin-bottom:4px;padding:0 16px;display:flex;overflow-x:auto}.feed-tabs::-webkit-scrollbar{display:none}.feed-tab{color:var(--text-tertiary);-webkit-tap-highlight-color:transparent;border-bottom:2px solid #0000;flex-shrink:0;padding:8px 16px;font-size:14px;font-weight:500;transition:all .15s}.feed-tab.active{color:var(--text-primary);border-bottom-color:var(--accent)}.empty-state{text-align:center;padding:60px 20px}.empty-state svg{width:48px;height:48px;color:var(--border);margin-bottom:12px}.empty-state h3{color:var(--text-primary);margin-bottom:4px;font-size:17px;font-weight:600}.empty-state p{color:var(--text-tertiary);font-size:14px}.loading-spinner{justify-content:center;padding:40px 0;display:flex}.loading-spinner:after{content:"";border:2px solid var(--border);border-top-color:var(--accent);border-radius:50%;width:24px;height:24px;animation:.6s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}.sheet-overlay{z-index:200;background:#0000004d;position:fixed;inset:0}.sheet{width:100%;max-width:var(--max-width);background:var(--bg-card);border-radius:var(--radius-lg) var(--radius-lg) 0 0;z-index:201;max-height:80vh;padding:20px 16px;padding-bottom:calc(var(--tab-height) + 16px);position:fixed;bottom:0;left:50%;overflow-y:auto;transform:translate(-50%)}.sheet-handle{background:var(--border);border-radius:2px;width:36px;height:4px;margin:0 auto 16px}.studio-list{flex-direction:column;gap:6px;display:flex}.studio-item{background:var(--bg);border-radius:var(--radius-sm);cursor:pointer;-webkit-tap-highlight-color:transparent;padding:14px 16px;transition:background .15s}.studio-item:active{background:#eaeaee}.studio-item.selected{background:#007aff14;border:1px solid #007aff33}.studio-item h4{margin-bottom:2px;font-size:15px;font-weight:600}.studio-item p{color:var(--text-secondary);font-size:13px}.back-btn{color:var(--accent);align-items:center;gap:4px;padding:4px 0;font-size:15px;font-weight:500;display:flex}.divider{background:var(--border-light);height:1px;margin:12px 0}.toast{color:#fff;border-radius:var(--radius-sm);z-index:300;background:#000c;padding:10px 20px;font-size:14px;animation:.3s toastIn;position:fixed;top:60px;left:50%;transform:translate(-50%)}@keyframes toastIn{0%{opacity:0;transform:translate(-50%)translateY(-10px)}to{opacity:1;transform:translate(-50%)translateY(0)}}@media (width>=768px){.app-container{border-left:1px solid var(--border-light);border-right:1px solid var(--border-light)}}.image-preview{flex-wrap:wrap;gap:8px;margin-top:8px;display:flex}.image-preview-item{border-radius:var(--radius-sm);background:var(--border);width:80px;height:80px;position:relative;overflow:hidden}.image-preview-item img{object-fit:cover;width:100%;height:100%}.image-preview-item .remove-btn{color:#fff;background:#00000080;border-radius:50%;justify-content:center;align-items:center;width:20px;height:20px;font-size:12px;display:flex;position:absolute;top:2px;right:2px}.upload-btn{border-radius:var(--radius-sm);border:1px dashed var(--border);width:80px;height:80px;color:var(--text-tertiary);cursor:pointer;background:0 0;flex-direction:column;justify-content:center;align-items:center;font-size:12px;display:flex}.comment-item{border-bottom:1px solid var(--border-light);gap:10px;padding:12px 0;display:flex}.comment-item:last-child{border-bottom:none}.comment-content{flex:1;min-width:0}.comment-name{margin-bottom:2px;font-size:13px;font-weight:600}.comment-text{color:var(--text-primary);font-size:14px;line-height:1.5}.comment-time{color:var(--text-tertiary);margin-top:4px;font-size:11px}.create-post{padding:16px}.create-post textarea{resize:none;background:0 0;width:100%;min-height:200px;padding:12px 0;font-size:16px;line-height:1.6}.create-post textarea::placeholder{color:var(--text-tertiary)}.post-type-selector{flex-wrap:wrap;gap:8px;margin-bottom:16px;display:flex}.post-type-btn{background:var(--bg);color:var(--text-secondary);border:1px solid #0000;border-radius:16px;padding:6px 14px;font-size:13px;transition:all .15s}.post-type-btn.active{color:var(--accent);background:#007aff14;border-color:#007aff33}.login-page{flex-direction:column;min-height:100vh;padding:60px 24px 40px;display:flex}.login-logo{text-align:center;margin-bottom:40px}.login-logo h1{letter-spacing:-.03em;margin-bottom:6px;font-size:32px;font-weight:700}.login-logo p{color:var(--text-secondary);font-size:15px}.toggle-row{justify-content:space-between;align-items:center;padding:12px 0;display:flex}.toggle-label{font-size:15px}.toggle{background:var(--border);cursor:pointer;border-radius:15px;width:48px;height:30px;transition:background .2s;position:relative}.toggle.active{background:var(--accent)}.toggle:after{content:"";background:#fff;border-radius:50%;width:26px;height:26px;transition:transform .2s;position:absolute;top:2px;left:2px;box-shadow:0 1px 3px #0003}.toggle.active:after{transform:translate(18px)}