@import"https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500&display=swap";:root{--primary-color: #2196F3;--bg-color: #f5f5f5}body{font-family:Noto Sans SC,sans-serif;margin:0;padding-top:60px;background:var(--bg-color)}.nav-bar{position:fixed;top:0;left:0;right:0;background:#fff;box-shadow:0 2px 8px #0000001a;z-index:1000;padding:12px 2rem}.nav-container{display:flex;align-items:center;max-width:1200px;margin:0 auto}.nav-links{display:flex;gap:2rem;margin-left:2rem}.nav-link{color:#616161;text-decoration:none;font-weight:500;transition:color .2s}.nav-link:hover{color:var(--primary-color)}.nav-link.active{color:var(--primary-color);border-bottom:2px solid currentColor}.app-title{margin:0;font-size:1.5rem;color:var(--primary-color)}.container{display:flex;flex-direction:column;gap:2rem;max-width:1200px;margin:2rem auto 0;padding:2rem;position:relative}.upload-section{position:relative;background:#fff;border-radius:16px;padding:3rem 2rem;box-shadow:0 4px 20px #2196f31a;transition:all .3s cubic-bezier(.4,0,.2,1);overflow:hidden}.upload-section:before{content:"";font-family:"Font Awesome 5 Free";position:absolute;top:50%;left:50%;transform:translate(-50%,-50%);font-size:3rem;color:#2196f31a;z-index:0}.upload-section:hover{transform:translateY(-3px);box-shadow:0 8px 25px #2196f326}.upload-section:active{transform:translateY(0)}#upload{opacity:0;position:absolute;width:1px;height:1px}.upload-label{display:block;position:relative;z-index:1;background:linear-gradient(135deg,var(--primary-color),#42a5f5);color:#fff;padding:1rem 2rem;border-radius:8px;cursor:pointer;transition:all .3s ease;text-align:center;font-weight:500;box-shadow:0 4px 6px #2196f333}.upload-label:hover{background:linear-gradient(135deg,#1976d2,#1e88e5);box-shadow:0 6px 8px #2196f34d}.upload-label:active{transform:scale(.98)}.upload-loading{position:absolute;top:1rem;right:1rem;width:24px;height:24px;border:3px solid rgba(33,150,243,.2);border-top-color:var(--primary-color);border-radius:50%;animation:spin 1s linear infinite;opacity:0;transition:opacity .3s}@keyframes spin{to{transform:rotate(360deg)}}.uploading .upload-loading{opacity:1}@media (max-width: 768px){.upload-section{padding:2rem 1rem}.upload-label{padding:1rem;font-size:.9rem}#previewCanvas{max-height:60vh;aspect-ratio:auto 1/1}}#previewCanvas{border:2px solid #e0e0e0;border-radius:8px;transition:all .3s ease;aspect-ratio:auto 16/9;max-width:100%;max-height:70vh;object-fit:contain}#previewCanvas:hover{transform:scale(1.01);box-shadow:0 8px 15px #2196f333}.histogram-section{background:#f8f9fa;border-radius:12px;padding:2rem;box-shadow:0 4px 6px #0000000d}.range-slider input[type=range]{-webkit-appearance:none;width:100%;height:8px;background:linear-gradient(90deg,#2196f3,#e0e0e0 0%);border-radius:4px;margin:1rem 0}.range-slider input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:20px;height:20px;background:#2196f3;border-radius:50%;cursor:pointer;transition:background .2s}.range-slider input[type=range]:hover::-webkit-slider-thumb{background:#1976d2}.process-button{background:#4caf50;color:#fff;padding:12px 24px;border-radius:8px;border:none;cursor:pointer;margin-right:1rem;transition:opacity .2s}.export-button{background:var(--primary-color);color:#fff;padding:12px 24px;border-radius:8px;border:none;cursor:pointer;transition:opacity .2s}.export-button:hover{background:#1976d2;transform:translateY(-1px);box-shadow:0 4px 6px #2196f34d}.ad-container{background:#f5f5f5;border-radius:8px;padding:1.5rem;text-align:center;color:#616161;font-style:italic;animation:float 3s ease-in-out infinite}@keyframes float{0%{transform:translateY(0)}50%{transform:translateY(-4px)}to{transform:translateY(0)}}body{font-family:Segoe UI,system-ui;background:#f5f5f5;color:#212121}#histogramCanvas{height:150px;width:100%}.range-slider{display:flex;flex-direction:column;gap:1rem;margin-top:1rem}input[type=range]{width:100%;height:4px;background:#ddd;outline:none}.ad-container{height:90px;background:#fff;display:flex;justify-content:center;align-items:center;border-radius:4px}@media (max-width: 768px){.container{padding:10px}.upload-section,.histogram-section{padding:1rem}}#histogramCanvas{background:#f8f9fa;border-radius:8px;box-shadow:0 2px 4px #0000001a}canvas{image-rendering:crisp-edges}#histogramCanvas:after{content:"亮度值";position:absolute;top:10px;left:10px;font:12px/1.5 Arial,sans-serif;color:#666}.steg-type-toggle{display:flex;gap:1rem;margin-bottom:1.5rem}.type-btn{padding:.8rem 1.5rem;border-radius:8px;border:2px solid #2196F3;background:#fff;cursor:pointer;transition:all .3s}.type-btn.active{background:#2196f3;color:#fff}#secretText{width:100%;padding:1rem;border:2px solid #e0e0e0;border-radius:8px;resize:vertical}