:root{--color-text:#6b6375;--color-text-heading:#08060d;--color-bg:#fff;--color-border:#d1d5db;--color-primary:#2563eb;--color-primary-hover:#1d4ed8;--color-primary-foreground:#fff;--color-accent-bg:#aa3bff1a;--font-sans:"Intel", system-ui, "Segoe UI", Roboto, sans-serif}*,:before,:after{box-sizing:border-box}@font-face{font-family:Intel;src:url(/fonts/intel-regular.woff2)format("woff2"),url(/fonts/intel-regular.woff)format("woff");font-weight:400;font-style:normal;font-display:swap}body{font-family:var(--font-sans);background:var(--color-bg);color:var(--color-text);margin:0}.chat-container{align-items:stretch;gap:10px;width:100%;margin-bottom:20px;display:flex}.input-wrapper{flex:auto;min-width:0;position:relative}.search-icon{width:18px;height:18px;color:var(--color-text);position:absolute;top:50%;left:10px;transform:translateY(-50%)}.chat-input{border:1px solid var(--color-border);resize:none;box-sizing:border-box;border-radius:8px;width:100%;height:40px;max-height:190px;padding:10px 12px 10px 36px;font-family:inherit;font-size:14px;line-height:20px;overflow-y:auto}.mic-btn{border:1px solid var(--color-border);background:var(--color-bg);cursor:pointer;border-radius:8px;flex:none;height:40px;padding:0 12px}.mic-btn:hover{background:#f3f4f6}.send-btn{background-color:var(--color-primary);height:40px;color:var(--color-primary-foreground);cursor:pointer;white-space:nowrap;font-family:"Intel", var(--font-sans);border:none;border-radius:8px;flex:none;padding:0 16px}.send-btn:hover{background-color:var(--color-primary-hover)}.send-btn:disabled{opacity:.6;cursor:not-allowed}@media (width<=600px){.chat-container{flex-direction:column}.send-btn,.mic-btn{width:100%}}.letter-toolbar{justify-content:flex-end;width:100%;max-width:900px;margin:10px auto 0;padding:0 12px;display:flex}.icon-btn{border:1px solid var(--color-border);background:var(--color-primary);width:34px;height:34px;color:var(--color-primary-foreground);cursor:pointer;border-radius:8px;justify-content:center;align-items:center;transition:all .2s;display:flex}.icon-btn:hover{opacity:.9}.page-title{text-align:center;max-width:900px;margin:10px auto 0;font-size:20px;font-weight:600}.a4-page{background:#fff;border:1px solid #d1d5db;border-radius:6px;width:100%;max-width:900px;margin:10px auto 20px;padding:24px;font-family:Times New Roman,serif;font-size:14px;line-height:1.6;box-shadow:0 4px 10px #00000014}.date{margin-bottom:16px}.to-section{margin-bottom:20px}.block{margin-bottom:6px}.title{text-align:center;margin:20px 0;font-size:18px;font-weight:700}.body{white-space:pre-line;text-align:justify;margin-bottom:30px}.signature{margin-top:40px}@media (width<=768px){.a4-page{padding:16px;font-size:13px}.title{font-size:16px}}@media print{body *{visibility:hidden}.a4-page,.a4-page *{visibility:visible}.a4-page{width:210mm;min-height:297mm;box-shadow:none;border:none;padding:25mm;font-size:12pt;position:absolute;top:0;left:0}.letter-toolbar,.page-title{display:none}}.login-container{background:var(--color-bg);height:100vh;font-family:"Intel", var(--font-sans);justify-content:center;align-items:center;display:flex}.login-card{border:1px solid var(--color-border);background:var(--color-bg);text-align:center;border-radius:12px;width:320px;padding:28px;box-shadow:0 10px 20px #0000000d}.login-card h2{color:var(--color-text-heading);margin:0 0 8px;font-size:20px}.login-card p{color:var(--color-text);margin:0 0 16px;font-size:14px}.login-input{border:1px solid var(--color-border);width:100%;height:40px;font-size:14px;font-family:"Intel", var(--font-sans);background:#fff;border-radius:8px;outline:none;padding:0 12px;transition:all .2s}.login-input::placeholder{color:#9ca3af}.login-input:focus{border-color:var(--color-primary);box-shadow:0 0 0 2px #2563eb26}.login-btn{background:var(--color-primary);width:100%;height:40px;color:var(--color-primary-foreground);font-size:14px;font-family:"Intel", var(--font-sans);cursor:pointer;border:none;border-radius:8px;margin-top:14px;transition:all .2s}.login-btn:hover{background:var(--color-primary-hover)}.login-btn:active{transform:scale(.98)}.app-container{height:100vh;font-family:"Intel", var(--font-sans);display:flex;overflow:hidden}.sidebar{border-right:1px solid var(--color-border);background:#f9fafb;width:260px;min-width:260px;padding:16px;transition:transform .3s;overflow-y:auto}@media (width<=768px){.sidebar{z-index:1000;height:100%;position:fixed;top:0;left:0;transform:translate(-100%)}.sidebar.open{transform:translate(0)}}.overlay{z-index:999;background:#0000004d;position:fixed;inset:0}.sidebar-header{justify-content:space-between;align-items:center;margin-bottom:12px;display:flex}.sidebar-title{color:var(--color-text-heading);font-size:16px}.clear-btn{border:1px solid var(--color-border);background:var(--color-bg);color:var(--color-primary);cursor:pointer;border-radius:6px;padding:6px 10px;font-size:12px}.history-item{cursor:pointer;color:var(--color-text);white-space:nowrap;text-overflow:ellipsis;border-radius:6px;margin-bottom:8px;padding:10px;font-size:14px;overflow:hidden}.history-item:hover{background:#e5e7eb}.history-item.active{background:var(--color-primary);color:var(--color-primary-foreground)}.main{flex-direction:column;flex:1;display:flex;overflow:hidden}.tabs{border-bottom:1px solid var(--color-border);flex-wrap:wrap;align-items:center;gap:10px;padding:12px 16px;display:flex}.menu-btn{cursor:pointer;background:0 0;border:none;font-size:20px;display:none}.tab{border:1px solid var(--color-border);background:var(--color-bg);cursor:pointer;border-radius:8px;padding:8px 12px;font-size:13px}.tab.active{background:var(--color-primary);color:#fff;border-color:var(--color-primary)}.tab-content{flex:1;padding:16px;overflow-y:auto}.user-section{align-items:center;gap:10px;margin-left:auto;display:flex}.user-name{font-size:14px}.user-name strong{color:var(--color-primary)}.logout-btn{border:1px solid var(--color-border);background:var(--color-bg);width:32px;height:32px;color:var(--color-primary);cursor:pointer;border-radius:6px}.logout-btn:hover{background:var(--color-primary);color:#fff}@media (width<=768px){.menu-btn{display:block}.tabs{gap:6px}.tab{text-align:center;flex:1;padding:6px;font-size:12px}.user-name{display:none}.tab-content{padding:12px}}