:root{--primary:#4361ee;--primary-dark:#3a56d4;--secondary:#7209b7;--success:#06d6a0;--danger:#ef476f;--warning:#ffd166;--info:#118ab2;--light:#f8f9fa;--dark:#212529;--gray:#6c757d;--light-gray:#e9ecef;--border-radius:12px;--box-shadow:0 8px 25px rgba(0, 0, 0, 0.1);--transition:all 0.3s ease}*{margin:0;padding:0;box-sizing:border-box}body{font-family:'Segoe UI',Tahoma,Geneva,Verdana,sans-serif;display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;background:linear-gradient(135deg,#f5f7fa 0,#e4edf5 100%);color:var(--dark);margin:0;padding:20px;box-sizing:border-box}.container{background-color:#fff;padding:30px 40px;border-radius:var(--border-radius);box-shadow:var(--box-shadow);text-align:center;width:100%;max-width:900px;box-sizing:border-box;margin-bottom:20px;position:relative;overflow:hidden}.container::before{content:'';position:absolute;top:0;left:0;right:0;height:5px;background:linear-gradient(90deg,var(--primary),var(--secondary))}h1{color:var(--primary);margin-bottom:15px;font-size:2.2em;display:flex;align-items:center;justify-content:center;gap:12px}.app-info-container{width:100%;border:1px solid var(--light-gray);border-radius:var(--border-radius);margin-bottom:25px;overflow:hidden}.app-info-header{background-color:var(--light);padding:12px 15px;cursor:pointer;display:flex;justify-content:space-between;align-items:center;font-weight:600;color:var(--info)}.app-info-header .toggle-icon{transition:transform .3s}.app-info-header.collapsed .toggle-icon{transform:rotate(-90deg)}.app-info-content{padding:15px;background-color:#fff;border-top:1px solid var(--light-gray);display:block;text-align:left;font-size:.95em;line-height:1.6}.app-info-container.collapsed .app-info-content{display:none}.app-info-content p{margin-bottom:10px}.status{padding:12px 20px;border-radius:8px;margin:20px 0;font-weight:600;font-size:.95em;display:flex;align-items:center;gap:10px}.status.info{background-color:rgba(17,138,178,.1);color:var(--info);border-left:4px solid var(--info)}.status.success{background-color:rgba(6,214,160,.1);color:var(--success);border-left:4px solid var(--success)}.status.error{background-color:rgba(239,71,111,.1);color:var(--danger);border-left:4px solid var(--danger)}.main-content{position:relative;width:100%;display:flex;flex-direction:column;align-items:center}.input-mode-selector{display:flex;gap:10px;margin-bottom:20px;width:100%;justify-content:center}.mode-btn{padding:10px 20px;border:2px solid var(--primary);border-radius:8px;background-color:#fff;color:var(--primary);cursor:pointer;font-weight:600;transition:var(--transition)}.mode-btn.active,.mode-btn:hover{background-color:var(--primary);color:#fff}.input-container{width:100%;margin-bottom:20px;text-align:left}.input-container h3{margin-bottom:10px;color:var(--primary)}textarea{width:100%;min-height:150px;padding:15px;border:1px solid var(--light-gray);border-radius:8px;font-family:monospace;font-size:14px;resize:vertical;box-sizing:border-box}.upload-area{border:3px dashed #b8d6ff;border-radius:10px;padding:40px 30px;margin-top:25px;cursor:pointer;transition:var(--transition);color:var(--gray);font-size:1.1em;width:100%;box-sizing:border-box;background-color:#f8fbff;position:relative;text-align:center;display:flex;flex-direction:column;align-items:center}.upload-area.active,.upload-area:hover{background-color:#eaf8ff;border-color:var(--primary);transform:translateY(-3px)}.upload-area .icon{font-size:3.5rem;margin-bottom:15px;color:#b8d6ff;transition:var(--transition)}.upload-area:hover .icon{color:var(--primary)}.upload-area p{margin:0;padding:5px 0}.upload-area button{background:linear-gradient(to right,var(--primary),var(--secondary));color:#fff;border:none;padding:12px 30px;border-radius:8px;cursor:pointer;font-size:1.05em;transition:var(--transition);margin-top:20px;font-weight:600;box-shadow:0 4px 15px rgba(67,97,238,.3)}.upload-area button:hover{background:linear-gradient(to right,var(--primary-dark),#65199e);box-shadow:0 6px 20px rgba(67,97,238,.4);transform:translateY(-2px)}.action-buttons{display:flex;gap:15px;margin:20px 0;justify-content:center;width:100%}.action-btn{background:linear-gradient(to right,var(--primary),var(--secondary));color:#fff;border:none;padding:12px 25px;border-radius:8px;cursor:pointer;font-size:1.05em;transition:var(--transition);font-weight:600;display:flex;align-items:center;gap:10px;box-shadow:0 4px 15px rgba(67,97,238,.3)}.action-btn:hover{background:linear-gradient(to right,var(--primary-dark),#65199e);box-shadow:0 6px 20px rgba(67,97,238,.4);transform:translateY(-2px)}.action-btn:disabled{background:#b0bec5;cursor:not-allowed;transform:none;box-shadow:none}.action-btn.encode{background:linear-gradient(to right,var(--info),var(--primary))}.action-btn.encode:hover{background:linear-gradient(to right,#0f7ca1,var(--primary-dark))}.action-btn.decode{background:linear-gradient(to right,var(--success),#05b992)}.action-btn.decode:hover{background:linear-gradient(to right,#05b992,#049e7e)}#outputContainer{margin-top:30px;width:100%;text-align:left;background-color:#fff;border-radius:var(--border-radius);box-shadow:var(--box-shadow);padding:25px;box-sizing:border-box;display:none;border-top:3px solid var(--success)}#outputContainer.show{display:block;animation:.5s fadeIn}@keyframes fadeIn{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}#outputContainer h2{color:var(--success);font-size:1.5em;margin-bottom:20px;display:flex;align-items:center;gap:10px}#outputText{width:100%;min-height:150px;padding:15px;border:1px solid var(--light-gray);border-radius:8px;font-family:monospace;font-size:14px;background-color:#f9f9f9;resize:vertical;box-sizing:border-box}.output-actions{display:flex;gap:10px;margin-top:15px;justify-content:flex-end}.output-btn{background:linear-gradient(to right,var(--success),#05b992);color:#fff;border:none;border-radius:6px;padding:8px 15px;cursor:pointer;font-size:.9em;transition:var(--transition);text-decoration:none;display:flex;align-items:center;gap:5px;box-shadow:0 3px 10px rgba(6,214,160,.3)}.output-btn:hover{background:linear-gradient(to right,#05b992,#049e7e);box-shadow:0 5px 15px rgba(6,214,160,.4);transform:translateY(-2px)}.output-btn.copy{background:linear-gradient(to right,var(--info),var(--primary))}.output-btn.copy:hover{background:linear-gradient(to right,#0f7ca1,var(--primary-dark))}#historyContainer{margin-top:30px;width:100%;text-align:left;background-color:#fff;border-radius:var(--border-radius);box-shadow:var(--box-shadow);padding:25px;box-sizing:border-box;display:none;border-top:3px solid var(--info)}#historyContainer.show{display:block;animation:.5s fadeIn}#historyContainer h2{color:var(--info);font-size:1.5em;margin-bottom:20px;display:flex;align-items:center;gap:10px}.history-controls{display:flex;justify-content:space-between;align-items:center;margin-bottom:15px;flex-wrap:wrap;gap:10px}.history-limit{display:flex;align-items:center;gap:10px}.history-limit input{width:80px;padding:5px 10px;border:1px solid var(--light-gray);border-radius:4px}#historyList{list-style:none;padding:0;max-height:300px;overflow-y:auto;border:1px solid var(--light-gray);border-radius:8px;background-color:#fbfdff}#historyList li{display:flex;justify-content:space-between;align-items:center;padding:12px 15px;border-bottom:1px solid #eee;font-size:.95em;color:var(--dark);transition:var(--transition)}#historyList li:hover{background-color:rgba(17,138,178,.05)}#historyList li:last-child{border-bottom:none}#historyList li .history-info{display:flex;align-items:center;gap:10px;flex-grow:1}#historyList li .history-info i{color:var(--info)}#historyList li .history-content{flex-grow:1;word-break:break-all;font-family:monospace;font-size:.85em}#historyList li .history-actions{display:flex;gap:5px}.history-btn{background-color:transparent;color:var(--info);border:none;border-radius:5px;padding:5px;cursor:pointer;font-size:.85em;transition:var(--transition);display:flex;align-items:center;justify-content:center;width:30px;height:30px}.history-btn:hover{background-color:var(--info);color:#fff}.hidden{display:none!important}.current-file{margin-top:15px;padding:10px 15px;background-color:#f8f9fa;border-radius:8px;display:flex;justify-content:space-between;align-items:center}.current-file-info{display:flex;align-items:center;gap:10px}.current-file-info i{color:var(--primary)}.current-file-name{font-weight:500}.remove-file-btn{background-color:transparent;color:var(--danger);border:none;border-radius:5px;padding:5px 10px;cursor:pointer;font-size:.85em;transition:var(--transition)}.remove-file-btn:hover{background-color:var(--danger);color:#fff}@media (max-width:768px){.container{padding:20px}h1{font-size:1.8em}.upload-area{padding:30px 20px}.action-buttons{flex-direction:column}.mode-btn{padding:8px 15px;font-size:.9em}.history-controls{flex-direction:column;align-items:flex-start}}footer{margin-top:20px;color:var(--gray);font-size:.9em;text-align:center;padding:15px}.title-icon{height:1em;vertical-align:middle;margin-right:12px}