:root{--color-primary:#2563eb;--color-primary-hover:#1d4ed8;--color-primary-light:#dbeafe;--color-success:#16a34a;--color-warning:#d97706;--color-danger:#dc2626;--color-text:#1f2937;--color-text-secondary:#6b7280;--color-bg:#f9fafb;--color-bg-white:#fff;--color-border:#e5e7eb;--color-focus:#3b82f6;--color-focus-ring:#3b82f680;--radius-sm:4px;--radius-md:8px;--radius-lg:12px;--shadow-sm:0 1px 2px #0000000d;--shadow-md:0 4px 6px -1px #0000001a;--shadow-lg:0 10px 15px -3px #0000001a;--font-size-sm:14px;--font-size-base:16px;--font-size-lg:18px;--font-size-xl:20px;--font-size-2xl:22px;--spacing-xs:4px;--spacing-sm:8px;--spacing-md:16px;--spacing-lg:24px;--spacing-xl:32px;--transition-fast:.15s ease;--transition-normal:.25s ease}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{height:100%;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,sans-serif;font-size:var(--font-size-base);color:var(--color-text);background:var(--color-bg);line-height:1.6}:focus-visible{outline:3px solid var(--color-focus);outline-offset:2px;border-radius:var(--radius-sm)}.sr-only{clip:rect(0, 0, 0, 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.skip-link{background:var(--color-primary);color:#fff;padding:var(--spacing-sm) var(--spacing-md);border-radius:var(--radius-md);z-index:1000;font-weight:600;text-decoration:none;position:absolute;top:-100%;left:50%;transform:translate(-50%)}.skip-link:focus{top:var(--spacing-md)}.app-layout{flex-direction:column;height:100%;display:flex}.app-header{background:var(--color-bg-white);border-bottom:2px solid var(--color-border);padding:var(--spacing-sm) var(--spacing-md);align-items:center;gap:var(--spacing-md);flex-shrink:0;display:flex}.app-header h1{color:var(--color-primary);white-space:nowrap;font-size:22pt;font-weight:700}.header-subtitle{color:var(--color-text-secondary);text-align:center;flex:1;font-size:20pt}.lang-toggle{flex-shrink:0;margin-left:auto}.app-main{flex:1;display:flex;overflow:hidden}.tab-nav{background:var(--color-bg-white);border-bottom:2px solid var(--color-border);flex-shrink:0;display:flex}.tab-nav-item{padding:var(--spacing-sm) var(--spacing-lg);color:var(--color-text-secondary);cursor:pointer;transition:all var(--transition-fast);white-space:nowrap;background:0 0;border:none;border-bottom:3px solid #0000;font-size:18pt;font-weight:500}.tab-nav-item:hover{color:var(--color-primary);background:var(--color-primary-light)}.tab-nav-item[aria-selected=true]{color:var(--color-primary);border-bottom-color:var(--color-primary);font-weight:600}.btn{align-items:center;gap:var(--spacing-xs);padding:var(--spacing-sm) var(--spacing-md);border:1px solid var(--color-border);border-radius:var(--radius-md);font-size:var(--font-size-base);cursor:pointer;transition:all var(--transition-fast);background:var(--color-bg-white);color:var(--color-text);font-weight:500;text-decoration:none;display:inline-flex}.btn:hover{background:var(--color-bg)}.btn-primary{background:var(--color-primary);color:#fff;border-color:var(--color-primary)}.btn-primary:hover{background:var(--color-primary-hover)}.btn-danger{color:var(--color-danger);border-color:var(--color-danger)}.btn-danger:hover{background:#fef2f2}.btn-sm{padding:var(--spacing-xs) var(--spacing-sm);font-size:var(--font-size-sm)}.btn:disabled{opacity:.5;cursor:not-allowed}.form-group{margin-bottom:var(--spacing-md)}.form-label{margin-bottom:var(--spacing-xs);font-weight:600;font-size:var(--font-size-base);display:block}.form-input,.form-select,.form-textarea{width:100%;padding:var(--spacing-sm) var(--spacing-md);border:2px solid var(--color-border);border-radius:var(--radius-md);font-size:var(--font-size-base);transition:border-color var(--transition-fast);background:var(--color-bg-white);font-family:inherit}.form-input:focus,.form-select:focus,.form-textarea:focus{border-color:var(--color-focus);box-shadow:0 0 0 3px var(--color-focus-ring);outline:none}.form-textarea{resize:vertical;min-height:80px}.card{background:var(--color-bg-white);border:1px solid var(--color-border);border-radius:var(--radius-lg);padding:var(--spacing-md);box-shadow:var(--shadow-sm)}.card-hover:hover{box-shadow:var(--shadow-md);border-color:var(--color-primary)}.list-item{padding:var(--spacing-md);border-bottom:1px solid var(--color-border);cursor:pointer;transition:background var(--transition-fast);align-items:center;gap:var(--spacing-md);display:flex}.list-item:hover{background:var(--color-primary-light)}.list-item:last-child{border-bottom:none}.chat-container{flex-direction:column;height:100%;display:flex}.chat-messages{padding:var(--spacing-md);gap:var(--spacing-md);flex-direction:column;flex:1;display:flex;overflow-y:auto}.chat-message{max-width:85%;padding:var(--spacing-md);border-radius:var(--radius-lg);word-break:break-word;line-height:1.7}.chat-message-user{background:var(--color-primary);color:#fff;border-bottom-right-radius:var(--radius-sm);align-self:flex-end}.chat-message-assistant{background:var(--color-bg-white);border:1px solid var(--color-border);border-bottom-left-radius:var(--radius-sm);align-self:flex-start}.chat-message-system{background:var(--color-primary-light);color:var(--color-text-secondary);font-size:var(--font-size-sm);border-radius:var(--radius-md);align-self:center}.chat-input-area{gap:var(--spacing-sm);padding:var(--spacing-md);border-top:2px solid var(--color-border);background:var(--color-bg-white);align-items:flex-end;display:flex;position:relative}.chat-input{resize:none;min-height:48px;max-height:120px;padding:var(--spacing-sm) var(--spacing-md);border:2px solid var(--color-border);border-radius:var(--radius-md);font-size:var(--font-size-base);flex:1;font-family:inherit}.chat-input:focus{border-color:var(--color-focus);box-shadow:0 0 0 3px var(--color-focus-ring);outline:none}.modal-overlay{z-index:100;background:#00000080;justify-content:center;align-items:center;display:flex;position:fixed;inset:0}.modal-content{background:var(--color-bg-white);border-radius:var(--radius-lg);padding:var(--spacing-lg);width:90%;max-width:500px;max-height:90vh;box-shadow:var(--shadow-lg);overflow-y:auto}.modal-title{margin-bottom:var(--spacing-md);font-size:18pt;font-weight:700}.empty-state{height:100%;color:var(--color-text-secondary);justify-content:center;align-items:center;gap:var(--spacing-md);padding:var(--spacing-xl);text-align:center;flex-direction:column;display:flex}.loading-spinner{border:3px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;width:20px;height:20px;animation:.6s linear infinite spin;display:inline-block}@keyframes spin{to{transform:rotate(360deg)}}.typing-indicator{padding:var(--spacing-sm) var(--spacing-md);gap:4px;display:inline-flex}.typing-indicator span{background:var(--color-text-secondary);border-radius:50%;width:8px;height:8px;animation:1.4s ease-in-out infinite typing}.typing-indicator span:nth-child(2){animation-delay:.2s}.typing-indicator span:nth-child(3){animation-delay:.4s}@keyframes typing{0%,80%,to{opacity:.3;transform:scale(.8)}40%{opacity:1;transform:scale(1)}}.sidebar{border-right:2px solid var(--color-border);background:var(--color-bg-white);flex-direction:column;flex-shrink:0;width:300px;display:flex}.sidebar-header{padding:var(--spacing-md);border-bottom:1px solid var(--color-border);justify-content:space-between;align-items:center;display:flex}.sidebar-list{flex:1;overflow-y:auto}.badge{font-size:var(--font-size-sm);border-radius:12px;padding:2px 8px;font-weight:600;display:inline-block}.badge-active{color:var(--color-success);background:#dcfce7}.badge-closed{color:var(--color-text-secondary);background:#f3f4f6}.message-image{border-radius:var(--radius-md);max-width:200px;max-height:200px;margin-top:var(--spacing-xs);cursor:pointer}.upload-btn{border:2px solid var(--color-border);border-radius:var(--radius-md);background:var(--color-bg-white);cursor:pointer;width:48px;height:48px;transition:all var(--transition-fast);flex-shrink:0;justify-content:center;align-items:center;display:inline-flex}.upload-btn:hover{border-color:var(--color-primary);background:var(--color-primary-light)}@media (width<=768px){.sidebar{border-right:none;border-bottom:2px solid var(--color-border);width:100%}.app-main{flex-direction:column}.tab-nav{overflow-x:auto}}