:root{--primary: #003366;--primary-light: #004c99;--accent: #00A0C8;--bg: #f0f2f5;--surface: #ffffff;--surface2: #f8f9fa;--border: #e0e4e8;--text: #1a2332;--text-muted: #6b7a8d;--unread-bg: #eef4ff;--selected-bg: #dbeafe;--danger: #dc2626;--success: #16a34a;--shadow: 0 1px 4px rgba(0,0,0,.08);--shadow-md: 0 4px 16px rgba(0,0,0,.12)}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Pretendard,-apple-system,sans-serif;font-size:14px;color:var(--text);background:var(--bg)}.login-page{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#001f4d,#003a7a,#005c99)}.login-box{background:var(--surface);border-radius:16px;padding:40px;width:400px;box-shadow:var(--shadow-md)}.login-logo{display:flex;align-items:center;gap:16px;margin-bottom:32px}.logo-mark{font-size:40px}.logo-title{font-size:20px;font-weight:700;color:var(--primary)}.logo-sub{font-size:13px;color:var(--text-muted)}.login-form{display:flex;flex-direction:column;gap:16px}.form-group label{display:block;font-size:13px;font-weight:600;color:var(--text-muted);margin-bottom:6px}.form-group input{width:100%;padding:10px 14px;border:1.5px solid var(--border);border-radius:8px;font-size:14px;outline:none;transition:.2s}.form-group input:focus{border-color:var(--accent)}.login-error{color:var(--danger);font-size:13px;background:#fef2f2;padding:10px;border-radius:8px}.btn-login{padding:12px;background:var(--primary);color:#fff;border:none;border-radius:8px;font-size:15px;font-weight:600;cursor:pointer;transition:.2s}.btn-login:hover:not(:disabled){background:var(--primary-light)}.btn-login:disabled{opacity:.6}.login-footer{text-align:center;color:var(--text-muted);font-size:12px;margin-top:20px}.mail-app{display:flex;flex-direction:column;height:100vh;overflow:hidden}.mail-header{display:flex;align-items:center;gap:16px;padding:0 20px;height:54px;background:var(--primary);color:#fff;flex-shrink:0;box-shadow:0 2px 8px #0003}.header-brand{display:flex;align-items:center;gap:8px;font-weight:700;font-size:16px;flex-shrink:0}.header-icon{font-size:20px}.header-center{flex:1}.header-actions{display:flex;align-items:center;gap:10px;flex-shrink:0}.btn-compose{background:var(--accent);color:#fff;border:none;padding:7px 14px;border-radius:8px;font-size:13px;font-weight:600;cursor:pointer}.btn-compose:hover{opacity:.9}.btn-refresh,.btn-icon{background:transparent;color:#fff;border:1px solid rgba(255,255,255,.3);padding:6px 10px;border-radius:6px;cursor:pointer}.header-user{font-size:13px;opacity:.85}.btn-logout{background:transparent;color:#ffffffb3;border:1px solid rgba(255,255,255,.2);padding:5px 10px;border-radius:6px;font-size:12px;cursor:pointer}.btn-logout:hover{background:#ffffff1a}.mail-body{display:flex;flex:1;overflow:hidden}.mail-sidebar{width:200px;flex-shrink:0;background:var(--surface);border-right:1px solid var(--border);overflow-y:auto;padding:8px 0}.folder-tree-title{padding:12px 16px 6px;font-size:11px;font-weight:700;color:var(--text-muted);letter-spacing:.05em;text-transform:uppercase}.folder-item{display:flex;align-items:center;gap:8px;width:100%;padding:8px 16px;background:none;border:none;cursor:pointer;font-size:13px;color:var(--text);text-align:left;border-radius:0;transition:.15s}.folder-item:hover{background:var(--bg)}.folder-item.active{background:var(--selected-bg);color:var(--primary);font-weight:600}.folder-icon{font-size:15px}.folder-name{flex:1}.folder-badge{background:var(--accent);color:#fff;border-radius:10px;padding:1px 7px;font-size:11px;font-weight:700}.mail-list-pane{width:300px;flex-shrink:0;border-right:1px solid var(--border);display:flex;flex-direction:column;overflow:hidden}.mail-list{display:flex;flex-direction:column;height:100%}.mail-list-header{display:flex;align-items:center;justify-content:space-between;padding:10px 14px;border-bottom:1px solid var(--border);font-size:12px;color:var(--text-muted);flex-shrink:0}.mail-count{font-weight:600}.mail-items{flex:1;overflow-y:auto;list-style:none}.mail-item{position:relative;padding:12px 14px;border-bottom:1px solid var(--border);cursor:pointer;transition:.15s}.mail-item:hover{background:var(--surface2)}.mail-item.unread{background:var(--unread-bg)}.mail-item.selected{background:var(--selected-bg)}.mail-item-top{display:flex;justify-content:space-between;margin-bottom:4px}.mail-sender{font-size:13px;font-weight:600;color:var(--text);flex:1;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.mail-item.unread .mail-sender{color:var(--primary)}.mail-date{font-size:11px;color:var(--text-muted);flex-shrink:0;margin-left:8px}.mail-item-subject{font-size:13px;font-weight:500;margin-bottom:3px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.mail-item.unread .mail-item-subject{font-weight:700}.mail-item-preview{font-size:12px;color:var(--text-muted);overflow:hidden;text-overflow:ellipsis;white-space:nowrap;padding-right:24px}.mail-size{float:right;font-size:11px}.btn-delete{position:absolute;right:10px;top:50%;transform:translateY(-50%);opacity:0;background:none;border:none;cursor:pointer;font-size:14px}.mail-item:hover .btn-delete{opacity:.5}.btn-delete:hover{opacity:1!important}.mail-list-loading,.mail-list-empty{display:flex;flex-direction:column;align-items:center;justify-content:center;height:200px;color:var(--text-muted);gap:12px}.empty-icon{font-size:40px}.pagination{display:flex;align-items:center;justify-content:center;gap:12px;padding:10px;border-top:1px solid var(--border);flex-shrink:0}.pagination button{padding:4px 10px;border:1px solid var(--border);border-radius:4px;cursor:pointer;background:var(--surface)}.pagination button:disabled{opacity:.4;cursor:default}.mail-view-pane{flex:1;overflow:hidden;display:flex;flex-direction:column}.mail-view{display:flex;flex-direction:column;height:100%;overflow-y:auto}.mail-view-empty{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;color:var(--text-muted);gap:12px}.mail-view-header{padding:20px 24px;border-bottom:1px solid var(--border);background:var(--surface);flex-shrink:0}.mail-subject{font-size:18px;font-weight:700;color:var(--text);margin-bottom:14px}.mail-meta{display:flex;flex-direction:column;gap:6px;font-size:13px}.meta-label{font-weight:600;color:var(--text-muted);width:80px;display:inline-block}.mail-actions{display:flex;gap:8px;margin-top:14px}.btn-reply,.btn-forward{padding:7px 14px;border:1px solid var(--border);border-radius:6px;cursor:pointer;background:var(--surface);font-size:13px}.btn-reply:hover,.btn-forward:hover{background:var(--bg)}.mail-attachments{padding:12px 24px;background:var(--surface2);border-bottom:1px solid var(--border)}.attach-title{font-size:12px;font-weight:600;color:var(--text-muted);margin-bottom:8px}.attach-list{display:flex;flex-wrap:wrap;gap:8px}.attach-item{display:flex;align-items:center;gap:4px;padding:6px 12px;background:var(--surface);border:1px solid var(--border);border-radius:6px;text-decoration:none;color:var(--primary);font-size:12px}.attach-item:hover{background:var(--bg)}.attach-size{color:var(--text-muted)}.mail-body-content{flex:1;padding:20px 24px;overflow-y:auto}.mail-html-body{line-height:1.6;max-width:100%;overflow-x:auto}.mail-html-body img{max-width:100%}.mail-text-body{white-space:pre-wrap;font-family:inherit;line-height:1.7;color:var(--text)}.search-bar{display:flex;align-items:center;gap:8px;background:#ffffff26;border-radius:8px;padding:6px 12px;max-width:400px}.search-bar input{background:none;border:none;color:#fff;font-size:13px;outline:none;width:200px}.search-bar input::placeholder{color:#fff9}.search-icon{font-size:14px;opacity:.8}.search-clear{background:none;border:none;color:#ffffffb3;cursor:pointer;font-size:12px}.compose-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#0006;display:flex;align-items:center;justify-content:center;z-index:1000}.compose-box{background:var(--surface);border-radius:12px;width:620px;max-width:95vw;max-height:90vh;display:flex;flex-direction:column;box-shadow:var(--shadow-md)}.compose-header{display:flex;justify-content:space-between;align-items:center;padding:14px 20px;border-bottom:1px solid var(--border);font-weight:600;font-size:15px}.compose-close{background:none;border:none;cursor:pointer;font-size:18px;color:var(--text-muted)}.compose-fields{padding:8px 20px;display:flex;flex-direction:column;gap:2px}.compose-field{display:flex;align-items:center;gap:10px;padding:8px 0;border-bottom:1px solid var(--border)}.compose-field label{font-size:12px;font-weight:600;color:var(--text-muted);width:70px;flex-shrink:0}.compose-field input{flex:1;border:none;font-size:13px;outline:none}.compose-from{font-size:13px;color:var(--text-muted)}.btn-cc-toggle{background:none;border:1px solid var(--border);border-radius:4px;padding:3px 8px;font-size:11px;cursor:pointer;color:var(--text-muted)}.compose-body{flex:1;min-height:280px;padding:16px 20px;border:none;border-top:1px solid var(--border);font-size:14px;font-family:inherit;outline:none;resize:none;line-height:1.6}.compose-error{margin:0 20px;padding:8px 12px;background:#fef2f2;color:var(--danger);border-radius:6px;font-size:13px}.compose-success{margin:0 20px;padding:8px 12px;background:#f0fdf4;color:var(--success);border-radius:6px;font-size:13px}.compose-footer{display:flex;gap:10px;padding:14px 20px;border-top:1px solid var(--border)}.btn-send{padding:9px 20px;background:var(--primary);color:#fff;border:none;border-radius:8px;font-size:14px;font-weight:600;cursor:pointer}.btn-send:hover:not(:disabled){background:var(--primary-light)}.btn-send:disabled{opacity:.6}.btn-cancel{padding:9px 14px;background:none;border:1px solid var(--border);border-radius:8px;font-size:14px;cursor:pointer;color:var(--text-muted)}@media (max-width:768px){.mail-sidebar{display:none}.mail-list-pane{width:100%;border-right:none}.mail-view-pane,.header-title{display:none}}