:root{--bg:#fff;--bg-secondary:#f5f5f7;--bg-tertiary:#e8e8ed;--text:#1d1d1f;--text-secondary:#86868b;--border:#d2d2d7;--primary:#007aff;--primary-hover:#0060cc;--primary-text:#fff;--danger:#ff3b30;--drop-bg:#f5f5f7;--drop-border:#c7c7cc;--drop-border-hover:#007aff;--shadow:#00000014;--radius:12px;--radius-sm:8px;--transition:.2s ease}[data-theme=dark]{--bg:#1c1c1e;--bg-secondary:#2c2c2e;--bg-tertiary:#3a3a3c;--text:#f5f5f7;--text-secondary:#98989d;--border:#38383a;--primary:#0a84ff;--primary-hover:#409cff;--primary-text:#fff;--danger:#ff453a;--drop-bg:#2c2c2e;--drop-border:#48484a;--drop-border-hover:#0a84ff;--shadow:#0000004d}*,:before,:after{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg);color:var(--text);min-height:100vh;transition:background var(--transition), color var(--transition);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,sans-serif;line-height:1.5}#app{flex-direction:column;max-width:900px;height:100vh;margin:0 auto;padding:0 20px;display:flex}button{cursor:pointer;font-family:inherit;font-size:inherit;color:inherit;background:0 0;border:none}select{color:var(--text);background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;padding:6px 10px;font-family:inherit;font-size:13px}select:focus{outline:2px solid var(--primary);outline-offset:1px}input[type=number]{color:var(--text);background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);text-align:center;width:64px;padding:6px 8px;font-family:inherit;font-size:13px}input[type=number]:focus{outline:2px solid var(--primary);outline-offset:1px}.hidden{display:none!important}.material-symbols-outlined{font-variation-settings:"FILL" 0, "wght" 400, "GRAD" 0, "opsz" 24}.top-bar{border-bottom:1px solid var(--border);-webkit-user-select:none;user-select:none;justify-content:space-between;align-items:center;height:52px;padding:0 4px;display:flex}.top-bar .logo{align-items:center;gap:8px;font-size:16px;font-weight:600;display:flex}.top-bar .logo .circles{gap:4px;display:flex}.top-bar .logo .circle{border:1.5px solid #0000;border-radius:50%;width:10px;height:10px}.top-bar .actions{gap:2px;display:flex}.top-bar .icon-btn{width:36px;height:36px;color:var(--text-secondary);transition:background var(--transition), color var(--transition);border-radius:50%;justify-content:center;align-items:center;text-decoration:none;display:flex}.top-bar .icon-btn:hover{background:var(--bg-secondary);color:var(--text)}.back-btn{color:var(--primary);border-radius:var(--radius-sm);transition:background var(--transition);align-items:center;gap:4px;padding:6px 10px;font-size:14px;font-weight:500;display:flex}.back-btn:hover{background:var(--bg-secondary)}.drop-zone{border:2px dashed var(--drop-border);border-radius:var(--radius);background:var(--drop-bg);min-height:200px;transition:border-color var(--transition), background var(--transition);cursor:pointer;flex-direction:column;justify-content:center;align-items:center;gap:12px;margin-top:16px;display:flex}.drop-zone.dragover{border-color:var(--drop-border-hover);background:color-mix(in srgb, var(--drop-bg) 80%, var(--primary) 20%)}.drop-zone .icon{width:40px;height:40px;color:var(--text-secondary)}.drop-zone .hint{color:var(--text-secondary);text-align:center;font-size:14px;line-height:1.6}.drop-zone .hint-mobile{display:none}.drop-zone .hint small{opacity:.7;font-size:12px}.add-image-btn{border:1px dashed var(--drop-border);border-radius:var(--radius-sm);color:var(--text-secondary);transition:border-color var(--transition), color var(--transition);align-items:center;gap:4px;margin-top:12px;padding:8px 16px;font-size:13px;display:inline-flex}.add-image-btn:hover{border-color:var(--primary);color:var(--primary)}.params-card{background:var(--bg-secondary);border-radius:var(--radius);flex-direction:column;gap:12px;margin-top:12px;padding:16px;display:flex}.param-row{flex-wrap:wrap;align-items:center;gap:10px;display:flex}.param-label{color:var(--text-secondary);white-space:nowrap;min-width:fit-content;font-size:13px}.num-input{width:64px}.fmt-select{width:80px}.segmented-control{background:var(--bg-tertiary);border-radius:8px;gap:2px;padding:2px;display:flex}.segmented-btn{color:var(--text-secondary);transition:background var(--transition), color var(--transition);white-space:nowrap;border-radius:6px;padding:5px 14px;font-size:13px;font-weight:500}.segmented-btn.active{background:var(--bg);color:var(--text);box-shadow:0 1px 3px var(--shadow)}.segmented-btn:not(.active):hover{color:var(--text)}.segmented-btn.disabled{opacity:.3;cursor:not-allowed;pointer-events:none}.color-picker-wrapper input[type=color]{border:2px solid var(--border);cursor:pointer;background:0 0;border-radius:50%;width:16px;height:16px;padding:0}.color-picker-wrapper input[type=color]::-webkit-color-swatch-wrapper{padding:0}.color-picker-wrapper input[type=color]::-webkit-color-swatch{border:none;border-radius:50%}.image-strip-container{margin-top:12px}.image-strip{flex-wrap:wrap;gap:8px;padding:4px 0 8px;display:flex}.image-strip .thumb{aspect-ratio:4/3;border-radius:var(--radius-sm);cursor:pointer;transition:border-color var(--transition);border:2px solid #0000;flex:0 0 calc(20% - 7px);position:relative;overflow:hidden}.image-strip .thumb.active{border-color:var(--primary)}.image-strip .thumb img{object-fit:cover;pointer-events:none;width:100%;height:100%}.image-strip .thumb .thumb-number{color:#fff;pointer-events:none;background:#00000073;border-radius:50%;justify-content:center;align-items:center;width:18px;height:18px;font-size:11px;font-weight:600;line-height:1;display:flex;position:absolute;top:2px;left:2px}.image-strip .thumb .remove-btn{background:var(--danger);color:#fff;opacity:0;width:20px;height:20px;transition:opacity var(--transition);border-radius:50%;justify-content:center;align-items:center;font-size:12px;display:flex;position:absolute;top:2px;right:2px}.image-strip .thumb:hover .remove-btn{opacity:1}.image-strip .thumb.dragging{opacity:.4}.image-strip .thumb.drag-over{border-color:var(--primary);background:color-mix(in srgb, var(--bg) 80%, var(--primary) 20%)}.action-bar .action-btn{background:var(--primary);color:var(--primary-text);border-radius:var(--radius);text-align:center;transition:background var(--transition);flex:1;padding:14px;font-size:16px;font-weight:600}.action-bar .action-btn:hover{background:var(--primary-hover)}.action-bar .action-btn:disabled,.action-bar .action-btn.disabled{background:var(--bg-tertiary);color:var(--text-secondary);cursor:not-allowed}.action-bar .action-btn:disabled:hover,.action-bar .action-btn.disabled:hover{background:var(--bg-tertiary)}.clear-btn{border:1px solid var(--border);border-radius:var(--radius);color:var(--text-secondary);white-space:nowrap;transition:border-color var(--transition), color var(--transition);padding:14px 20px;font-size:14px;font-weight:500}.clear-btn:hover{border-color:var(--danger);color:var(--danger)}.result-container{flex-direction:column;align-items:center;padding:24px 0;display:flex}.result-container .preview-area{border:1px solid var(--border);border-radius:var(--radius);background:var(--bg-secondary);width:100%;max-height:70vh;overflow:auto}.result-container .preview-area img{width:100%;height:auto;display:block}.result-actions{gap:12px;margin-top:20px;display:flex}.download-btn{background:var(--primary);color:var(--primary-text);border-radius:var(--radius-sm);transition:background var(--transition);padding:10px 24px;font-size:14px;font-weight:500}.download-btn:hover{background:var(--primary-hover)}.split-grid{gap:8px;margin-top:20px;display:grid}.split-grid-3{grid-template-columns:repeat(3,1fr)}.split-grid-2{grid-template-columns:repeat(2,1fr)}.split-grid .cell img{border:1px solid var(--border);cursor:pointer;border-radius:4px;width:100%;height:auto}.loading-overlay{z-index:100;background:#0006;justify-content:center;align-items:center;display:flex;position:fixed;inset:0}.loading-overlay .spinner{border:3px solid var(--bg);border-top-color:var(--primary);border-radius:50%;width:36px;height:36px;animation:.7s linear infinite spin}@keyframes spin{to{transform:rotate(360deg)}}.main-content{flex:1;grid-template-columns:55% 1fr;align-content:start;gap:16px;min-height:0;padding-top:16px;display:grid}.left-panel{flex-direction:column;grid-column:1;gap:12px;min-height:0;display:flex}.right-panel{flex-direction:column;grid-area:1/2;gap:12px;min-height:0;display:flex}.action-bar{grid-area:2/2;gap:12px;margin-top:4px;display:flex}.drop-area{flex-direction:column;flex:1;min-height:0;display:flex}.drop-area .drop-zone{flex:1;min-height:140px;margin-top:0}.strip-wrapper{flex-shrink:0}.params-scroll{flex-direction:column;flex:1;gap:12px;min-height:0;display:flex;overflow-y:auto}@media (width<=768px){#app{height:auto;min-height:100vh;padding:0 12px;overflow-x:hidden}.main-content{grid-template-columns:1fr;gap:0}.left-panel{grid-area:2/1;gap:8px}.right-panel{grid-area:1/1;gap:8px}.action-bar{grid-area:3/1;margin-top:8px;padding-bottom:16px}.drop-zone,.drop-area .drop-zone{border:1px solid var(--primary);border-radius:var(--radius);background:var(--primary);min-height:0;color:var(--primary-text);flex-direction:row;flex:none;gap:6px;margin-top:8px;padding:12px 16px;font-size:14px;font-weight:600}.drop-zone .icon{width:18px;height:18px;color:var(--primary-text)}.drop-zone .hint{display:none}.drop-zone .hint-mobile{color:var(--primary-text);font-size:14px;font-weight:600;display:block}.image-strip .thumb{flex:0 0 calc(33.33% - 6px)}.strip-wrapper{max-height:240px;overflow-y:auto}.params-scroll{overflow-y:visible}.param-row{flex-wrap:wrap;gap:8px;min-width:0}.segmented-control{flex-shrink:1;min-width:0;overflow:hidden}.top-bar .logo{font-size:14px}.top-bar .icon-btn{width:32px;height:32px}.mode-section{margin-top:8px}.params-card{gap:8px;padding:10px}.segmented-btn{padding:4px 10px;font-size:12px}}@media (width<=600px){#app{padding:0 8px}.param-row{gap:6px}}.theme-container{position:relative}.theme-popover{background:var(--bg);border:1px solid var(--border);border-radius:var(--radius-sm);box-shadow:0 4px 16px var(--shadow);z-index:50;opacity:0;transform-origin:100% 0;pointer-events:none;gap:2px;padding:4px;transition:opacity .15s,transform .15s;display:flex;position:absolute;top:calc(100% + 4px);right:0;transform:scale(.92)}.theme-popover:not(.hidden){opacity:1;pointer-events:auto;transform:scale(1)}.theme-popover .theme-option{width:36px;height:36px;color:var(--text-secondary);transition:background var(--transition), color var(--transition);cursor:pointer;background:0 0;border:none;border-radius:6px;justify-content:center;align-items:center;padding:0;display:flex}.theme-popover .theme-option:hover{background:var(--bg-secondary);color:var(--text)}.theme-popover .theme-option.active{background:var(--bg-tertiary);color:var(--primary)}