/* Original tool presentation, scoped to this detail page. */

        #yk-portal-v2 .yk-legacy-tool {
            --ink: #102a43;
            --body: #486581;
            --muted: #718096;
            --line: #d9e2ec;
            --surface: #ffffff;
            --surface-soft: #f5f9fc;
            --blue: #1261a0;
            --blue-dark: #0b3d63;
            --cyan: #0e9f9a;
            --cyan-soft: #e8f8f6;
            --amber: #d97706;
            --shadow: 0 12px 32px rgba(16, 42, 67, 0.09);
            --shadow-soft: 0 5px 18px rgba(16, 42, 67, 0.07);
            --radius: 12px;
        }

        #yk-portal-v2 .yk-legacy-tool * { box-sizing: border-box; }
        #yk-portal-v2 .yk-legacy-tool { scroll-behavior: smooth; }
        #yk-portal-v2 .yk-legacy-tool {
            padding-top: 60px;
            margin: 0;
            color: var(--body);
            background: #fff;
            font-family: 'Nunito', 'PingFang SC', 'Microsoft YaHei', sans-serif;
            line-height: 1.75;
        }
        #yk-portal-v2 .yk-legacy-tool a { color: var(--blue); }
        #yk-portal-v2 .yk-legacy-tool a:hover { color: var(--blue-dark); }
        /* ===== Navbar ===== */
        #yk-portal-v2 .yk-legacy-tool .navbar {
            z-index: 20;
            background-color: rgba(13, 25, 49, .92);
            backdrop-filter: blur(15px);
            -webkit-backdrop-filter: blur(15px);
            padding: 10px 0;
            transition: all .35s ease;
            box-shadow: 0 5px 20px rgba(0, 0, 0, .14);
        }
        #yk-portal-v2 .yk-legacy-tool .navbar-scrolled {
            padding: 8px 0;
            background-color: rgba(13, 25, 49, .98);
            box-shadow: 0 5px 20px rgba(0, 0, 0, .22);
        }
        #yk-portal-v2 .yk-legacy-tool .navbar-brand { display: flex; align-items: center; padding: 0; }
        #yk-portal-v2 .yk-legacy-tool .navbar-brand img { width: auto; height: 40px; margin-right: 10px; transition: all .3s ease; }
        #yk-portal-v2 .yk-legacy-tool .navbar-scrolled .navbar-brand img { height: 36px; }
        #yk-portal-v2 .yk-legacy-tool .brand-text {
            color: rgba(255, 255, 255, .95) !important;
            font-size: 1.5rem;
            font-weight: 700;
            line-height: 1;
            text-shadow: 0 2px 10px rgba(0, 0, 0, .2);
            transition: all .3s ease;
        }
        #yk-portal-v2 .yk-legacy-tool .navbar-scrolled .brand-text { font-size: 1.3rem; }
        #yk-portal-v2 .yk-legacy-tool .navbar .nav-item { position: relative; margin: 0 5px; }
        #yk-portal-v2 .yk-legacy-tool .navbar .nav-link {
            position: relative;
            display: block;
            margin: 0 15px;
            padding: 10px 0 !important;
            color: rgba(255, 255, 255, .9) !important;
            font-size: 14px;
            font-weight: 600;
            letter-spacing: 1px;
            line-height: 1.25;
            text-transform: uppercase;
            transition: color .25s ease, transform .25s ease;
        }
        #yk-portal-v2 .yk-legacy-tool .navbar .nav-link::before {
            content: '';
            position: absolute;
            left: 50%;
            bottom: 0;
            width: 5px;
            height: 5px;
            border-radius: 50%;
            background: var(--cyan);
            transform: translateX(-50%) scale(0);
            transition: transform .25s ease;
        }
        #yk-portal-v2 .yk-legacy-tool .navbar .nav-link:hover::before,#yk-portal-v2 .yk-legacy-tool 
        .navbar .nav-item.active .nav-link::before { transform: translateX(-50%) scale(1); }
        #yk-portal-v2 .yk-legacy-tool .navbar .nav-item.active .nav-link { color: #61d8cf !important; }
        #yk-portal-v2 .yk-legacy-tool .navbar .nav-item:hover .nav-link { color: #fff !important; transform: translateY(-2px); }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler {
            padding: 0;
            border: 0;
            outline: 0;
            box-shadow: none;
        }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler-icon {
            position: relative;
            display: block;
            width: 24px;
            height: 17px;
            background-image: none;
        }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler-icon::before,#yk-portal-v2 .yk-legacy-tool 
        .navbar-dark .navbar-toggler-icon::after,#yk-portal-v2 .yk-legacy-tool 
        .navbar-dark .navbar-toggler-icon span {
            content: '';
            position: absolute;
            left: 0;
            width: 100%;
            height: 2px;
            border-radius: 3px;
            background: #fff;
            transition: all .25s ease;
        }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler-icon::before { top: 0; }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler-icon span { top: 50%; transform: translateY(-50%); }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler-icon::after { bottom: 0; }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler[aria-expanded='true'] .navbar-toggler-icon::before { transform: translateY(7px) rotate(45deg); }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler[aria-expanded='true'] .navbar-toggler-icon::after { transform: translateY(-7px) rotate(-45deg); }
        #yk-portal-v2 .yk-legacy-tool .navbar-dark .navbar-toggler[aria-expanded='true'] .navbar-toggler-icon span { opacity: 0; }
        @media (max-width: 991px) {
            #yk-portal-v2 .yk-legacy-tool .navbar-collapse {
                margin-top: 15px;
                padding: 16px 20px;
                border-radius: 10px;
                background-color: rgba(13, 25, 49, .98);
                box-shadow: 0 10px 30px rgba(0, 0, 0, .18);
            }
            #yk-portal-v2 .yk-legacy-tool .navbar-nav .nav-item { margin: 5px 0; }
            #yk-portal-v2 .yk-legacy-tool .navbar .nav-link { margin: 0; padding: 9px 0 !important; }
            #yk-portal-v2 .yk-legacy-tool .navbar-brand img { height: 36px; }
            #yk-portal-v2 .yk-legacy-tool .brand-text { font-size: 1.3rem; }
        }
        @media (max-width: 575px) {
            #yk-portal-v2 .yk-legacy-tool .navbar-brand img { height: 32px; }
            #yk-portal-v2 .yk-legacy-tool .brand-text { font-size: 1.2rem; }
        }

        /* style.css reserves a full viewport hero for the home page. */
        #yk-portal-v2 .yk-legacy-tool .hero {
            height: auto !important;
            min-height: auto !important;
            padding: 4.7rem 0 4.2rem;
            color: #fff;
            text-align: left;
            background: linear-gradient(125deg, #0b3d63 0%, #1261a0 55%, #0e8580 100%);
            position: relative;
            overflow: hidden;
        }
        #yk-portal-v2 .yk-legacy-tool .hero::after {
            content: '';
            position: absolute;
            inset: 0;
            opacity: .14;
            background-image: linear-gradient(90deg, rgba(255,255,255,.12) 1px, transparent 1px), linear-gradient(rgba(255,255,255,.12) 1px, transparent 1px);
            background-size: 44px 44px;
            pointer-events: none;
        }
        #yk-portal-v2 .yk-legacy-tool .hero .container { position: relative; z-index: 1; }
        #yk-portal-v2 .yk-legacy-tool .hero-grid { display: grid; grid-template-columns: minmax(0, 1.08fr) minmax(360px, .92fr); gap: 3.5rem; align-items: center; }
        #yk-portal-v2 .yk-legacy-tool .eyebrow,#yk-portal-v2 .yk-legacy-tool  .section-kicker {
            display: inline-flex;
            align-items: center;
            gap: .45rem;
            font-size: .78rem;
            font-weight: 800;
            letter-spacing: 1.5px;
            text-transform: uppercase;
        }
        #yk-portal-v2 .yk-legacy-tool .eyebrow { color: #d9fffb; margin-bottom: 1rem; }
        #yk-portal-v2 .yk-legacy-tool .eyebrow i { color: #ffd166; }
        #yk-portal-v2 .yk-legacy-tool .hero h1 { margin: 0 0 1rem; color: #fff; font-size: clamp(2rem, 4vw, 3.35rem); line-height: 1.2; font-weight: 800; letter-spacing: 0; }
        #yk-portal-v2 .yk-legacy-tool .hero .subtitle { max-width: 700px; margin: 0; color: rgba(255,255,255,.9); font-size: 1.08rem; line-height: 1.9; }
        #yk-portal-v2 .yk-legacy-tool .hero-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.7rem; }
        #yk-portal-v2 .yk-legacy-tool .hero-actions a { display: inline-flex; align-items: center; gap: .55rem; min-height: 46px; padding: .7rem 1.15rem; border-radius: 7px; font-weight: 800; text-decoration: none; transition: transform .2s, box-shadow .2s, background .2s; }
        #yk-portal-v2 .yk-legacy-tool .hero-actions .primary { color: #08304f; background: #ffd166; box-shadow: 0 8px 20px rgba(0,0,0,.15); }
        #yk-portal-v2 .yk-legacy-tool .hero-actions .primary:hover { color: #08304f; background: #ffe09a; transform: translateY(-2px); }
        #yk-portal-v2 .yk-legacy-tool .hero-actions .secondary { color: #fff; border: 1px solid rgba(255,255,255,.45); background: rgba(255,255,255,.1); }
        #yk-portal-v2 .yk-legacy-tool .hero-actions .secondary:hover { color: #fff; background: rgba(255,255,255,.18); transform: translateY(-2px); }
        #yk-portal-v2 .yk-legacy-tool .hero-points { display: flex; flex-wrap: wrap; gap: .65rem 1.1rem; margin: 1.35rem 0 0; padding: 0; list-style: none; color: rgba(255,255,255,.83); font-size: .88rem; }
        #yk-portal-v2 .yk-legacy-tool .hero-points li { display: inline-flex; align-items: center; gap: .42rem; }
        #yk-portal-v2 .yk-legacy-tool .hero-points i { color: #8de1d6; }
        #yk-portal-v2 .yk-legacy-tool .hero-preview { padding: .65rem; border: 1px solid rgba(255,255,255,.28); border-radius: 13px; background: rgba(7,37,61,.32); box-shadow: 0 18px 45px rgba(0,0,0,.2); }
        #yk-portal-v2 .yk-legacy-tool .hero-preview img { display: block; width: 100%; height: auto; border-radius: 8px; }
        #yk-portal-v2 .yk-legacy-tool .hero-preview figcaption { margin: .7rem .35rem .15rem; color: rgba(255,255,255,.7); font-size: .78rem; text-align: center; }

        #yk-portal-v2 .yk-legacy-tool .section { padding: 4.6rem 0; }
        #yk-portal-v2 .yk-legacy-tool .section.alt { background: var(--surface-soft); }
        #yk-portal-v2 .yk-legacy-tool .section-heading { max-width: 760px; margin: 0 auto 2.7rem; text-align: center; }
        #yk-portal-v2 .yk-legacy-tool .section-kicker { color: var(--cyan); margin-bottom: .65rem; }
        #yk-portal-v2 .yk-legacy-tool .section-heading h2 { margin: 0; color: var(--ink); font-size: clamp(1.65rem, 3vw, 2.3rem); line-height: 1.3; letter-spacing: 0; }
        #yk-portal-v2 .yk-legacy-tool .section-heading p { margin: .85rem auto 0; color: var(--muted); font-size: 1rem; }
        #yk-portal-v2 .yk-legacy-tool .section-heading::after { content: ''; display: block; width: 56px; height: 4px; margin: 1rem auto 0; border-radius: 2px; background: linear-gradient(90deg, var(--blue), var(--cyan)); }

        #yk-portal-v2 .yk-legacy-tool .pain-grid,#yk-portal-v2 .yk-legacy-tool  .feature-grid,#yk-portal-v2 .yk-legacy-tool  .scenario-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.15rem; }
        #yk-portal-v2 .yk-legacy-tool .pain-item,#yk-portal-v2 .yk-legacy-tool  .feature-item,#yk-portal-v2 .yk-legacy-tool  .scenario-item { height: 100%; padding: 1.55rem; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); box-shadow: var(--shadow-soft); }
        #yk-portal-v2 .yk-legacy-tool .pain-item { border-top: 3px solid #e76f51; }
        #yk-portal-v2 .yk-legacy-tool .pain-item h3,#yk-portal-v2 .yk-legacy-tool  .feature-item h3,#yk-portal-v2 .yk-legacy-tool  .scenario-item h3 { margin: .8rem 0 .4rem; color: var(--ink); font-size: 1.1rem; line-height: 1.4; }
        #yk-portal-v2 .yk-legacy-tool .pain-item p,#yk-portal-v2 .yk-legacy-tool  .feature-item p,#yk-portal-v2 .yk-legacy-tool  .scenario-item p { margin: 0; color: var(--body); font-size: .94rem; }
        #yk-portal-v2 .yk-legacy-tool .icon-box { display: inline-flex; align-items: center; justify-content: center; width: 46px; height: 46px; border-radius: 10px; color: #fff; font-size: 1.15rem; }
        #yk-portal-v2 .yk-legacy-tool .icon-box.blue { background: linear-gradient(135deg, #1261a0, #3c91c9); }
        #yk-portal-v2 .yk-legacy-tool .icon-box.teal { background: linear-gradient(135deg, #0e8580, #1eb5a7); }
        #yk-portal-v2 .yk-legacy-tool .icon-box.amber { background: linear-gradient(135deg, #b45309, #f59e0b); }
        #yk-portal-v2 .yk-legacy-tool .icon-box.red { background: linear-gradient(135deg, #c2413c, #e76f51); }

        #yk-portal-v2 .yk-legacy-tool .feature-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
        #yk-portal-v2 .yk-legacy-tool .feature-item { transition: transform .25s, box-shadow .25s, border-color .25s; }
        #yk-portal-v2 .yk-legacy-tool .feature-item:hover,#yk-portal-v2 .yk-legacy-tool  .scenario-item:hover { transform: translateY(-4px); border-color: #9fc4dc; box-shadow: var(--shadow); }
        #yk-portal-v2 .yk-legacy-tool .feature-item h3 { font-size: 1.02rem; }
        #yk-portal-v2 .yk-legacy-tool .feature-item p { font-size: .9rem; }
        #yk-portal-v2 .yk-legacy-tool .feature-note { display: flex; align-items: flex-start; gap: .6rem; margin: 1.4rem auto 0; max-width: 900px; padding: .9rem 1rem; border-left: 4px solid var(--cyan); background: var(--cyan-soft); color: #255e5a; font-size: .9rem; }
        #yk-portal-v2 .yk-legacy-tool .feature-note i { margin-top: .25rem; color: var(--cyan); }

        #yk-portal-v2 .yk-legacy-tool .scenario-item { position: relative; padding-top: 1.8rem; }
        #yk-portal-v2 .yk-legacy-tool .scenario-item .scenario-label { position: absolute; top: 0; right: 0; padding: .28rem .7rem; border-radius: 0 var(--radius) 0 8px; color: #fff; background: var(--blue); font-size: .72rem; font-weight: 800; }
        #yk-portal-v2 .yk-legacy-tool .scenario-item h3 { margin-top: .5rem; }

        #yk-portal-v2 .yk-legacy-tool .steps { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1rem; counter-reset: steps; }
        #yk-portal-v2 .yk-legacy-tool .step { position: relative; min-height: 190px; padding: 1.5rem 1.35rem 1.35rem 1.35rem; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; box-shadow: var(--shadow-soft); }
        #yk-portal-v2 .yk-legacy-tool .step::before { counter-increment: steps; content: counter(steps, decimal-leading-zero); display: flex; align-items: center; justify-content: center; width: 40px; height: 40px; border-radius: 50%; color: #fff; background: var(--blue); font-size: .82rem; font-weight: 800; }
        #yk-portal-v2 .yk-legacy-tool .step h3 { margin: 1rem 0 .45rem; color: var(--ink); font-size: 1.04rem; }
        #yk-portal-v2 .yk-legacy-tool .step p { margin: 0; color: var(--body); font-size: .9rem; }
        #yk-portal-v2 .yk-legacy-tool .usage-tip { margin-top: 1.35rem; padding: 1rem 1.2rem; border: 1px solid #f3d49a; border-radius: 9px; background: #fffaf0; color: #7a4a10; font-size: .9rem; }
        #yk-portal-v2 .yk-legacy-tool .usage-tip strong { color: #9a5c13; }

        #yk-portal-v2 .yk-legacy-tool .faq-list { max-width: 900px; margin: 0 auto; }
        #yk-portal-v2 .yk-legacy-tool .faq-list details { margin-bottom: .7rem; border: 1px solid var(--line); border-radius: 9px; background: #fff; overflow: hidden; }
        #yk-portal-v2 .yk-legacy-tool .faq-list summary { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: 1rem 1.15rem; color: var(--ink); cursor: pointer; list-style: none; font-weight: 800; }
        #yk-portal-v2 .yk-legacy-tool .faq-list summary::-webkit-details-marker { display: none; }
        #yk-portal-v2 .yk-legacy-tool .faq-list summary::after { content: '+'; flex: 0 0 auto; color: var(--cyan); font-size: 1.35rem; font-weight: 400; }
        #yk-portal-v2 .yk-legacy-tool .faq-list details[open] summary::after { content: '−'; }
        #yk-portal-v2 .yk-legacy-tool .faq-answer { padding: 0 1.15rem 1.1rem; color: var(--body); font-size: .94rem; }
        #yk-portal-v2 .yk-legacy-tool .faq-answer p { margin: 0; }

        #yk-portal-v2 .yk-legacy-tool .download-panel { position: relative; overflow: hidden; padding: 2.8rem 2rem; border-radius: 14px; color: #fff; background: linear-gradient(120deg, #0b3d63, #1261a0 60%, #0e8580); box-shadow: var(--shadow); }
        #yk-portal-v2 .yk-legacy-tool .download-panel::after { content: ''; position: absolute; right: -80px; bottom: -100px; width: 300px; height: 220px; border: 1px solid rgba(255,255,255,.16); border-radius: 50%; transform: rotate(-17deg); }
        #yk-portal-v2 .yk-legacy-tool .download-panel > * { position: relative; z-index: 1; }
        #yk-portal-v2 .yk-legacy-tool .download-panel h2 { margin: 0 0 .55rem; color: #fff; font-size: clamp(1.55rem, 3vw, 2.2rem); }
        #yk-portal-v2 .yk-legacy-tool .download-panel p { max-width: 720px; margin: 0; color: rgba(255,255,255,.86); }
        #yk-portal-v2 .yk-legacy-tool .download-actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.4rem; }
        #yk-portal-v2 .yk-legacy-tool .download-actions a { display: inline-flex; align-items: center; gap: .55rem; min-height: 46px; padding: .7rem 1.05rem; border-radius: 7px; text-decoration: none; font-weight: 800; }
        #yk-portal-v2 .yk-legacy-tool .download-actions .download-main { color: #08304f; background: #ffd166; }
        #yk-portal-v2 .yk-legacy-tool .download-actions .download-alt { color: #fff; border: 1px solid rgba(255,255,255,.45); background: rgba(255,255,255,.1); }
        #yk-portal-v2 .yk-legacy-tool .download-actions a:hover { transform: translateY(-2px); }
        #yk-portal-v2 .yk-legacy-tool .download-meta { display: flex; flex-wrap: wrap; gap: 1rem 1.3rem; margin-top: 1.1rem; color: rgba(255,255,255,.76); font-size: .85rem; }
        #yk-portal-v2 .yk-legacy-tool .download-meta span { display: inline-flex; align-items: center; gap: .4rem; }

        #yk-portal-v2 .yk-legacy-tool .screenshot-block { margin-top: 2.4rem; text-align: center; }
        #yk-portal-v2 .yk-legacy-tool .screenshot-block img { max-width: 100%; height: auto; border: 1px solid var(--line); border-radius: 10px; box-shadow: var(--shadow); }
        #yk-portal-v2 .yk-legacy-tool .screenshot-block figcaption { margin-top: .7rem; color: var(--muted); font-size: .85rem; }

        @media (max-width: 991px) {
            #yk-portal-v2 .yk-legacy-tool .hero-grid { grid-template-columns: 1fr; gap: 2rem; }
            #yk-portal-v2 .yk-legacy-tool .hero { padding-top: 3.6rem; }
            #yk-portal-v2 .yk-legacy-tool .hero-preview { max-width: 680px; margin: 0 auto; }
            #yk-portal-v2 .yk-legacy-tool .feature-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
            #yk-portal-v2 .yk-legacy-tool .steps { grid-template-columns: repeat(2, minmax(0, 1fr)); }
        }
        @media (max-width: 767px) {
            #yk-portal-v2 .yk-legacy-tool { padding-top: 56px; }
            #yk-portal-v2 .yk-legacy-tool .section { padding: 3.6rem 0; }
            #yk-portal-v2 .yk-legacy-tool .pain-grid,#yk-portal-v2 .yk-legacy-tool  .scenario-grid { grid-template-columns: 1fr; }
            #yk-portal-v2 .yk-legacy-tool .hero h1 { font-size: 2.1rem; }
            #yk-portal-v2 .yk-legacy-tool .hero .subtitle { font-size: 1rem; }
            #yk-portal-v2 .yk-legacy-tool .download-panel { padding: 2.1rem 1.25rem; }
        }
        @media (max-width: 520px) {
            #yk-portal-v2 .yk-legacy-tool .feature-grid,#yk-portal-v2 .yk-legacy-tool  .steps { grid-template-columns: 1fr; }
            #yk-portal-v2 .yk-legacy-tool .hero-actions a,#yk-portal-v2 .yk-legacy-tool  .download-actions a { width: 100%; justify-content: center; }
            #yk-portal-v2 .yk-legacy-tool .hero-points { display: grid; gap: .45rem; }
        }