:root {
    --f-blue:#2C80C6;--f-blue-light:#e0effb;--f-blue-dark:#1e6aa8;
    --f-border:#d1d5db;--f-bg:#f9fafb;--f-white:#ffffff;
    --f-text:#1f2937;--f-text-light:#6b7280;
    --f-green:#059669;--f-green-light:#d1fae5;
    --f-red:#dc2626;--f-red-light:#fee2e2;
    --f-orange:#f59e0b;--f-radius:8px;
}
*{box-sizing:border-box;}
.f-container{max-width:1100px;margin:0 auto;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;color:var(--f-text);line-height:1.6;padding:0 10px;}

/* Top Bar - only for logged in users */
.f-top-bar{display:flex;justify-content:space-between;align-items:center;padding:12px 18px;background:var(--f-white);border:1px solid var(--f-border);border-radius:var(--f-radius);margin-bottom:20px;flex-wrap:wrap;gap:10px;}
.f-top-bar-left{font-size:14px;color:var(--f-text-light);}
.f-top-bar-left strong{color:var(--f-text);}
.f-top-bar-right{display:flex;gap:8px;flex-wrap:wrap;}
.f-top-bar-btn{display:inline-block;padding:7px 16px;border-radius:6px;font-size:13px;font-weight:600;text-decoration:none;color:var(--f-text);background:var(--f-bg);border:1px solid var(--f-border);transition:all .2s;cursor:pointer;}
.f-top-bar-btn:hover{border-color:var(--f-blue);color:var(--f-blue);background:var(--f-white);}
.f-logout-btn{color:var(--f-red)!important;border-color:var(--f-red)!important;}
.f-logout-btn:hover{background:var(--f-red)!important;color:#fff!important;}

/* Category Cards */
.f-cat-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:20px;margin-bottom:30px;}
.f-cat-card{background:var(--f-white);border:1px solid var(--f-border);border-radius:var(--f-radius);padding:24px;cursor:pointer;transition:all .2s;}
.f-cat-card:hover{border-color:var(--f-blue);box-shadow:0 4px 12px rgba(44,128,198,.12);transform:translateY(-2px);}
.f-cat-icon{font-size:36px;margin-bottom:12px;}
.f-cat-title{font-size:16px;font-weight:700;color:var(--f-blue);margin:0 0 10px 0;}
.f-cat-stats{display:flex;gap:16px;font-size:13px;color:var(--f-text-light);margin-bottom:10px;}
.f-cat-latest{font-size:12px;color:var(--f-text-light);margin-bottom:14px;padding-top:10px;border-top:1px solid var(--f-border);}
.f-cat-latest a{color:var(--f-blue);text-decoration:none;}
.f-cat-latest a:hover{text-decoration:underline;}
.f-cat-btn{background:var(--f-blue);color:#fff;border:none;padding:8px 18px;border-radius:6px;font-size:13px;font-weight:600;cursor:pointer;transition:background .2s;}
.f-cat-btn:hover{background:var(--f-blue-dark);}

/* Stats Bar */
.f-stats-bar{display:flex;gap:30px;background:var(--f-blue-light);border:1px solid #a8d4f0;border-radius:var(--f-radius);padding:20px 30px;justify-content:center;}
.f-stat-item{text-align:center;}
.f-stat-num{display:block;font-size:24px;font-weight:800;color:var(--f-blue);}
.f-stat-label{font-size:13px;color:var(--f-text-light);}

/* Breadcrumb */
.f-breadcrumb{font-size:13px;color:var(--f-text-light);margin-bottom:16px;padding:10px 0;border-bottom:1px solid var(--f-border);}
.f-breadcrumb a{color:var(--f-blue);text-decoration:none;}
.f-breadcrumb a:hover{text-decoration:underline;}
.f-bc-sep{margin:0 8px;color:#9ca3af;}

/* Category Header */
.f-cat-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:20px;flex-wrap:wrap;gap:12px;}
.f-cat-header h2{font-size:22px;margin:0;}

/* Buttons */
.f-btn{background:var(--f-blue);color:#fff;border:none;padding:10px 22px;border-radius:6px;font-size:14px;font-weight:600;cursor:pointer;transition:background .2s;text-decoration:none;display:inline-block;}
.f-btn:hover{background:var(--f-blue-dark);color:#fff;}
.f-btn-full{width:100%;text-align:center;display:block;}
.f-btn-small{padding:6px 14px;font-size:12px;}
.f-btn-cancel{background:#9ca3af;margin-left:8px;}
.f-btn-cancel:hover{background:#6b7280;}

/* Delete Button */
.f-delete-btn{padding:4px 10px;border:1px solid var(--f-red);border-radius:4px;background:transparent;color:var(--f-red);font-size:12px;font-weight:600;cursor:pointer;transition:all .15s;}
.f-delete-btn:hover{background:var(--f-red);color:#fff;}

/* Form Box */
.f-form-box{background:var(--f-white);border:1px solid var(--f-border);border-radius:var(--f-radius);padding:24px;margin-bottom:24px;}
.f-form-box h3{margin:0 0 16px 0;font-size:18px;}
.f-form-hidden{display:none;}
.f-form-hidden.f-show{display:block;}
.f-field{margin-bottom:14px;}
.f-field label{display:block;font-size:13px;font-weight:600;margin-bottom:6px;}
.f-input,.f-textarea{width:100%;padding:10px 14px;border:1px solid var(--f-border);border-radius:6px;font-size:14px;font-family:inherit;transition:border .2s;box-sizing:border-box;}
.f-input:focus,.f-textarea:focus{outline:none;border-color:var(--f-blue);box-shadow:0 0 0 3px rgba(44,128,198,.1);}
.f-textarea{resize:vertical;min-height:100px;}
.f-msg{display:block;margin-top:10px;font-size:13px;font-weight:600;}
.f-msg.error{color:var(--f-red);}
.f-msg.success{color:var(--f-green);}

/* Auth Box */
.f-auth-box{max-width:460px;margin:40px auto;box-shadow:0 2px 12px rgba(0,0,0,.08);padding:32px;}
.f-auth-box h2{text-align:center;margin:0 0 24px 0;font-size:24px;color:var(--f-blue);}
.f-auth-link{text-align:center;margin-top:16px;font-size:14px;color:var(--f-text-light);}
.f-auth-link a{color:var(--f-blue);font-weight:600;text-decoration:none;}
.f-auth-link a:hover{text-decoration:underline;}

/* Section Title */
.f-section-title{font-size:14px;font-weight:700;color:var(--f-text-light);text-transform:uppercase;letter-spacing:.5px;margin:0 0 12px 0;padding:8px 12px;background:var(--f-bg);border-radius:6px;}
.f-section{margin-bottom:24px;}

/* Thread List */
.f-thread-list{border:1px solid var(--f-border);border-radius:var(--f-radius);overflow:hidden;}
.f-thread-row{display:flex;justify-content:space-between;align-items:center;padding:14px 18px;border-bottom:1px solid var(--f-border);cursor:pointer;transition:background .15s;gap:16px;}
.f-thread-row:last-child{border-bottom:none;}
.f-thread-row:hover{background:var(--f-blue-light);}
.f-thread-row.f-sticky{background:#fffbeb;}
.f-thread-row.f-sticky:hover{background:#fef3c7;}
.f-thread-info{flex:1;min-width:0;}
.f-sticky-badge{margin-right:6px;}
.f-thread-title{display:block;font-size:15px;font-weight:600;color:var(--f-blue);text-decoration:none;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;}
.f-thread-title:hover{text-decoration:underline;}
.f-thread-author{font-size:12px;color:var(--f-text-light);}
.f-thread-meta{display:flex;gap:16px;font-size:13px;color:var(--f-text-light);white-space:nowrap;flex-shrink:0;}
.f-date{color:#9ca3af;font-size:12px;}

/* Pagination */
.f-pagination{display:flex;gap:6px;justify-content:center;margin-top:24px;flex-wrap:wrap;}
.f-page-btn{padding:8px 14px;border:1px solid var(--f-border);border-radius:6px;background:var(--f-white);color:var(--f-text);text-decoration:none;font-size:14px;transition:all .15s;}
.f-page-btn:hover{border-color:var(--f-blue);color:var(--f-blue);}
.f-page-btn.active{background:var(--f-blue);color:#fff;border-color:var(--f-blue);}
.f-dots{padding:8px 4px;color:var(--f-text-light);}

/* Post Box */
.f-post-box{background:var(--f-white);border:1px solid var(--f-border);border-radius:var(--f-radius);margin-bottom:16px;overflow:hidden;}
.f-post-header{display:flex;align-items:center;gap:14px;padding:16px 20px;background:var(--f-bg);border-bottom:1px solid var(--f-border);flex-wrap:wrap;}
.f-avatar-link{text-decoration:none;display:inline-block;}
.f-avatar-img{border-radius:50%;object-fit:cover;border:2px solid var(--f-blue-light);}
.f-user-info{flex:1;min-width:120px;}
.f-username{display:inline-block;font-size:15px;font-weight:700;color:var(--f-blue);text-decoration:none;}
.f-username:hover{text-decoration:underline;}
.f-user-meta{font-size:12px;color:var(--f-text-light);display:block;}
.f-post-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap;}
.f-post-date{font-size:13px;color:var(--f-text-light);white-space:nowrap;}
.f-post-title-main{font-size:18px;font-weight:700;padding:18px 20px 8px;margin:0;}
.f-post-content{padding:8px 20px 20px;font-size:15px;line-height:1.7;}
.f-post-content p{margin:0 0 12px;}

/* Reply & Tip Buttons */
.f-reply-to-btn{padding:4px 10px;border:1px solid var(--f-blue);border-radius:4px;background:transparent;color:var(--f-blue);font-size:12px;font-weight:600;cursor:pointer;transition:all .15s;}
.f-reply-to-btn:hover{background:var(--f-blue);color:#fff;}
.f-tip-btn{padding:4px 10px;border:1px solid var(--f-orange);border-radius:4px;background:transparent;color:var(--f-orange);font-size:12px;font-weight:600;cursor:pointer;transition:all .15s;}
.f-tip-btn:hover{background:var(--f-orange);color:#fff;}

/* Threaded Replies */
.f-replies-section{margin-top:30px;}
.f-replies-title{font-size:18px;font-weight:700;margin:0 0 16px 0;padding-bottom:12px;border-bottom:2px solid var(--f-blue);}
.f-reply-box{margin-bottom:4px;border:1px solid var(--f-border);border-radius:var(--f-radius);overflow:hidden;background:var(--f-white);transition:border-color .2s;}
.f-reply-box:hover{border-color:#93c5fd;}
.f-depth-0{margin-left:0;}
.f-depth-1{margin-left:40px;}
.f-depth-2{margin-left:80px;}
.f-depth-3{margin-left:120px;}
.f-depth-4{margin-left:160px;}
.f-depth-5{margin-left:200px;}
.f-replying-to{font-size:12px;color:var(--f-green);display:block;margin-top:2px;}
.f-replying-indicator{display:flex;align-items:center;gap:10px;padding:8px 14px;background:var(--f-green-light);border-radius:6px;margin-bottom:14px;font-size:13px;color:var(--f-green);}
.f-cancel-btn{padding:2px 8px;border:none;background:var(--f-red);color:#fff;border-radius:4px;font-size:12px;cursor:pointer;}

/* Share Bar */
.f-share-bar{display:flex;align-items:center;gap:8px;padding:12px 20px;border-top:1px solid var(--f-border);background:var(--f-bg);font-size:13px;flex-wrap:wrap;}
.f-share-btn{padding:5px 12px;border-radius:4px;font-size:12px;font-weight:600;text-decoration:none;color:#fff;border:none;cursor:pointer;transition:opacity .2s;}
.f-share-btn:hover{opacity:.85;color:#fff;}
.f-fb{background:#1877f2;}.f-tw{background:#1da1f2;}.f-wa{background:#25d366;}.f-copy{background:#6b7280;}

/* Login Required */
.f-login-req{background:var(--f-red-light);border:1px solid #fecaca;border-radius:var(--f-radius);padding:24px;text-align:center;font-size:15px;margin-top:24px;}
.f-login-req a{color:var(--f-blue);font-weight:700;text-decoration:none;}
.f-login-req a:hover{text-decoration:underline;}

/* Empty State */
.f-empty{text-align:center;padding:30px;color:var(--f-text-light);font-size:14px;}

/* Sidebar Widgets */
.f-latest-list{display:flex;flex-direction:column;gap:6px;}
.f-latest-item{padding:10px 12px;background:var(--f-white);border:1px solid var(--f-border);border-radius:6px;font-size:13px;}
.f-latest-item a{color:var(--f-blue);text-decoration:none;display:block;margin-bottom:4px;font-weight:500;}
.f-latest-item a:hover{text-decoration:underline;}
.f-latest-date{font-size:11px;color:var(--f-text-light);}
.f-stats-widget{background:var(--f-white);border:1px solid var(--f-border);border-radius:var(--f-radius);padding:16px;}
.f-stat-row{display:flex;justify-content:space-between;padding:8px 0;border-bottom:1px solid var(--f-border);font-size:14px;}
.f-stat-row:last-child{border-bottom:none;}
.f-stat-row strong{color:var(--f-blue);}

/* Avatar Upload Area */
.f-avatar-upload-area{text-align:center;padding:20px 0;margin-bottom:16px;border:2px dashed var(--f-border);border-radius:var(--f-radius);}
.f-avatar-preview{width:80px;height:80px;border-radius:50%;background:var(--f-bg);border:2px solid var(--f-border);display:flex;align-items:center;justify-content:center;margin:0 auto 10px;overflow:hidden;font-size:32px;}
.f-avatar-preview img{width:100%;height:100%;object-fit:cover;border-radius:50%;}
.f-avatar-preview-lg{width:120px;height:120px;border-radius:50%;background:var(--f-bg);border:2px solid var(--f-border);display:flex;align-items:center;justify-content:center;margin:0 auto 10px;overflow:hidden;font-size:40px;}
.f-avatar-preview-lg img{width:100%;height:100%;object-fit:cover;border-radius:50%;}
.f-avatar-label{display:block;font-size:13px;font-weight:600;color:var(--f-text-light);margin-bottom:8px;}
.f-avatar-hint{display:block;font-size:11px;color:#9ca3af;margin-top:6px;}

/* Profile Page - Centered */
.f-profile-card{background:var(--f-white);border:1px solid var(--f-border);border-radius:var(--f-radius);padding:40px 30px;margin-bottom:24px;display:flex;flex-direction:column;align-items:center;text-align:center;}
.f-profile-avatar-wrap{display:flex;flex-direction:column;align-items:center;margin-bottom:20px;}
.f-profile-avatar-wrap .f-avatar-img{width:120px;height:120px;}
.f-avatar-change-btn{display:block;margin-top:10px;padding:6px 14px;background:var(--f-blue);color:#fff;border-radius:6px;font-size:12px;font-weight:600;cursor:pointer;transition:background .2s;text-align:center;}
.f-avatar-change-btn:hover{background:var(--f-blue-dark);}
.f-profile-info{width:100%;max-width:500px;}
.f-profile-name{font-size:24px;margin:0 0 6px;color:var(--f-text);}
.f-profile-joined{font-size:13px;color:var(--f-text-light);display:block;margin-bottom:16px;}
.f-profile-stats{display:flex;gap:24px;justify-content:center;flex-wrap:wrap;}
.f-ps-item{text-align:center;}
.f-ps-num{display:block;font-size:20px;font-weight:800;color:var(--f-blue);}
.f-ps-label{font-size:12px;color:var(--f-text-light);}

/* Payment Modal */
.f-modal{position:fixed;top:0;left:0;width:100%;height:100%;z-index:99999;}
.f-modal-overlay{position:absolute;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,.5);}
.f-modal-box{position:relative;max-width:440px;margin:80px auto;background:var(--f-white);border-radius:var(--f-radius);padding:28px;box-shadow:0 8px 32px rgba(0,0,0,.2);z-index:2;}
.f-modal-box h3{margin:0 0 20px 0;font-size:20px;color:var(--f-text);}

/* Payment History List */
.f-payment-list{border:1px solid var(--f-border);border-radius:var(--f-radius);overflow:hidden;}
.f-payment-row{display:flex;align-items:center;gap:12px;padding:12px 16px;border-bottom:1px solid var(--f-border);font-size:13px;flex-wrap:wrap;}
.f-payment-row:last-child{border-bottom:none;}
.f-pay-type{padding:3px 10px;border-radius:4px;font-size:11px;font-weight:700;color:#fff;white-space:nowrap;}
.f-pay-sent{background:var(--f-red);}
.f-pay-received{background:var(--f-green);}
.f-pay-amount{font-weight:700;color:var(--f-text);min-width:70px;}
.f-pay-detail{flex:1;color:var(--f-text-light);}
.f-pay-date{color:#9ca3af;white-space:nowrap;}

/* Responsive */
@media(max-width:768px){
    .f-cat-grid{grid-template-columns:1fr 1fr;}
    .f-thread-row{flex-direction:column;align-items:flex-start;gap:6px;}
    .f-thread-meta{width:100%;justify-content:flex-start;}
    .f-stats-bar{flex-direction:column;gap:12px;}
    .f-post-header{flex-direction:column;text-align:center;}
    .f-post-actions{justify-content:center;}
    .f-share-bar{justify-content:center;}
    .f-cat-header{flex-direction:column;align-items:flex-start;}
    .f-depth-1,.f-depth-2,.f-depth-3,.f-depth-4,.f-depth-5{margin-left:20px;}
    .f-modal-box{margin:20px;margin-top:60px;}
}
@media(max-width:480px){
    .f-cat-grid{grid-template-columns:1fr;}
    .f-profile-stats{gap:12px;}
}