:root {
            --bg: #0b0f1a;
            --bg-warm: #111622;
            --ink: #eef2ff;
            --ink-soft: #b4c0e0;
            --muted: #7b89b0;
            --accent: #4f8cff;
            --accent-light: rgba(79, 140, 255, 0.12);
            --coral: #ff6b7a;
            --coral-light: rgba(255, 107, 122, 0.12);
            --mint: #3dd9a6;
            --mint-light: rgba(61, 217, 166, 0.12);
            --amber: #f5b042;
            --violet: #9f6eff;
            --line: rgba(238, 242, 255, 0.07);
            --line-dark: rgba(238, 242, 255, 0.13);
            --card: #151a28;
            --card-hover: #1c2132;
            --shadow: 0 6px 24px rgba(0, 0, 0, 0.3);
            --shadow-lg: 0 18px 48px rgba(0, 0, 0, 0.45);
        }

        *,
        *::before,
        *::after {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        html {
            scroll-behavior: smooth;
            font-size: 16px;
            overflow-x: hidden;
        }

        body {
            font-family: 'DM Sans', sans-serif;
            background: var(--bg);
            color: var(--ink);
            overflow-x: hidden;
            line-height: 1.6;
            -webkit-font-smoothing: antialiased;
        }

        ::selection {
            background: var(--accent);
            color: #fff;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: all 0.3s cubic-bezier(.22, 1, .36, 1);
        }

        ul {
            list-style: none;
        }

        .container {
            width: 100%;
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 clamp(20px, 4vw, 48px);
        }

        h1,
        h2,
        h3,
        h4 {
            font-family: 'Instrument Serif', serif;
            font-weight: 400;
            letter-spacing: -.02em;
        }

        /* NAV */
        nav {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            z-index: 999;
            backdrop-filter: blur(24px) saturate(1.8);
            -webkit-backdrop-filter: blur(24px) saturate(1.8);
            background: rgba(11, 15, 26, 0.78);
            border-bottom: 1px solid var(--line);
            transition: box-shadow 0.35s ease;
        }

        nav.scrolled {
            box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
            background: rgba(11, 15, 26, 0.9);
        }

        .nav-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 62px;
        }

        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-family: 'Instrument Serif', serif;
            font-size: 1.3rem;
            font-weight: 400;
            color: var(--ink);
            letter-spacing: -.01em;
        }

        .logo-icon {
            width: 30px;
            height: 30px;
            border-radius: 8px;
            background: linear-gradient(135deg, var(--accent), var(--violet));
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 2px 10px rgba(79, 140, 255, 0.3);
            transition: transform 0.35s cubic-bezier(.34, 1.56, .64, 1);
        }

        .logo:hover .logo-icon {
            transform: rotate(-8deg) scale(1.1);
        }

        .nav-right {
            display: flex;
            align-items: center;
            gap: 4px;
        }
        .nav-right a {
            padding: 8px 15px;
            border-radius: 8px;
            font-size: .86rem;
            font-weight: 500;
            color: var(--ink-soft);
            transition: all 0.22s ease;
        }
        .nav-right a:hover {
            background: rgba(255, 255, 255, 0.05);
            color: var(--ink);
        }
        .nav-right a.active {
            background: var(--accent-light);
            color: var(--accent);
            font-weight: 600;
        }
        .mobile-btn {
            display: none;
            background: none;
            border: none;
            color: var(--ink);
            font-size: 1.5rem;
            cursor: pointer;
        }

        .breadcrumb {
            padding: 84px 0 0;
            font-family: 'JetBrains Mono', monospace;
            font-size: .78rem;
            color: var(--muted);
            position: relative;
            z-index: 1;
        }
        .breadcrumb a { color: var(--muted); }
        .breadcrumb a:hover { color: var(--accent); }
        .breadcrumb .sep { margin: 0 8px; opacity: .4; }

        .hero {
            padding: clamp(24px, 4vh, 48px) 0 clamp(40px, 6vh, 72px);
            position: relative;
            z-index: 1;
        }
        .hero-head { margin-bottom: clamp(32px, 4vw, 56px); }
        .hero-head h1 {
            font-size: clamp(2.4rem, 5vw, 4rem);
            line-height: 1.05;
            margin-bottom: 12px;
        }
        .hero-head h1 em {
            font-style: italic;
            background: linear-gradient(135deg, var(--accent), var(--violet));
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }
        .hh-meta {
            display: flex;
            gap: 20px;
            flex-wrap: wrap;
            font-family: 'JetBrains Mono', monospace;
            font-size: .78rem;
            color: var(--muted);
        }
        .hh-meta span { display: flex; align-items: center; gap: 6px; }
        .hm-dot { width: 5px; height: 5px; border-radius: 50%; display: inline-block; }

        .journey { display: flex; flex-direction: column; gap: 12px; }
        .j-row {
            display: flex;
            align-items: center;
            justify-content: space-between;
            background: var(--card);
            border: 1px solid var(--line);
            border-radius: 20px;
            padding: clamp(18px, 2.5vw, 28px);
            transition: all 0.3s ease;
            cursor: pointer;
            text-decoration: none;
            color: inherit;
        }
        .j-row:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-lg);
            background: var(--card-hover);
            border-color: transparent;
        }
        .j-left { display: flex; flex-direction: column; gap: 8px; }
        .jl-top { display: flex; align-items: center; gap: 12px; }
        .jl-icon {
            width: 36px; height: 36px;
            border-radius: 10px;
            display: flex; align-items: center; justify-content: center;
            flex-shrink: 0;
        }
        .jr-win .jl-icon { background: var(--accent-light); color: var(--accent); }
        .jr-mac .jl-icon { background: rgba(159, 110, 255, 0.1); color: var(--violet); }
        .jr-ios .jl-icon { background: var(--mint-light); color: var(--mint); }
        .jr-and .jl-icon { background: var(--coral-light); color: var(--coral); }
        .jl-name { font-family: 'Instrument Serif', serif; font-size: 1.3rem; }
        .jl-badge {
            padding: 2px 10px; border-radius: 100px;
            font-family: 'JetBrains Mono', monospace;
            font-size: .68rem; font-weight: 500;
            letter-spacing: .04em;
            background: rgba(255,255,255,0.05); color: var(--muted);
        }
        .jl-desc {
            font-size: .8rem; color: var(--muted);
            font-family: 'JetBrains Mono', monospace;
            padding-left: 48px;
        }
        .j-right { display: flex; align-items: center; gap: 20px; }
        .jr-steps { display: flex; align-items: center; gap: 0; }
        .jr-node { display: flex; flex-direction: column; align-items: center; gap: 4px; }
        .jr-circle {
            width: 28px; height: 28px; border-radius: 50%;
            background: var(--bg); border: 2px solid var(--line-dark);
            display: flex; align-items: center; justify-content: center;
            font-family: 'JetBrains Mono', monospace;
            font-size: .72rem; font-weight: 600; color: var(--ink-soft);
        }
        .jr-connector { width: 24px; height: 2px; background: var(--line-dark); margin: 0 6px; }
        .jr-label { font-size: .7rem; color: var(--muted); font-family: 'JetBrains Mono', monospace; }
        .jr-goto { display: flex; align-items: center; gap: 6px; font-size: .85rem; font-weight: 500; color: var(--accent); }

        .editorial-section { padding: clamp(50px, 7vh, 90px) 0; border-top: 1px solid var(--line); }
        .ed-inner { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(30px, 5vw, 60px); align-items: start; }
        .ed-inner.reversed { direction: rtl; }
        .ed-inner.reversed>* { direction: ltr; }
        .ed-header { position: sticky; top: 80px; }
        .ed-num {
            font-family: 'JetBrains Mono', monospace; font-size: .8rem;
            font-weight: 500; color: var(--muted); margin-bottom: 12px; letter-spacing: .1em;
        }
        .ed-tag { display: inline-block; padding: 4px 12px; border-radius: 6px; font-family: 'JetBrains Mono', monospace; font-size: .7rem; font-weight: 500; letter-spacing: .04em; margin-bottom: 16px; }
        .tag-blue { background: var(--accent-light); color: var(--accent); }
        .tag-violet { background: rgba(159, 110, 255, 0.1); color: var(--violet); }
        .tag-mint { background: var(--mint-light); color: var(--mint); }
        .tag-coral { background: var(--coral-light); color: var(--coral); }
        .ed-header h2 { font-size: clamp(2rem, 3.5vw, 2.6rem); margin-bottom: 12px; }
        .ed-header p { color: var(--muted); font-size: .95rem; margin-bottom: 20px; max-width: 90%; }
        .ed-meta { display: flex; gap: 16px; flex-wrap: wrap; font-family: 'JetBrains Mono', monospace; font-size: .75rem; color: var(--muted); }
        .ed-meta span { display: flex; align-items: center; gap: 6px; }
        .em-dot { width: 4px; height: 4px; border-radius: 50%; background: var(--accent); display: inline-block; }

        .ed-steps { display: flex; flex-direction: column; gap: 12px; }
        .ed-step { background: var(--card); border: 1px solid var(--line); border-radius: 16px; overflow: hidden; transition: box-shadow 0.3s ease; }
        .ed-step:hover { box-shadow: var(--shadow); background: var(--card-hover); }
        .ed-step-head { display: flex; align-items: center; gap: 14px; padding: 18px 22px; cursor: pointer; user-select: none; }
        .ed-step-dot { width: 10px; height: 10px; border-radius: 50%; flex-shrink: 0; }
        .sd1 { background: var(--accent); } .sd2 { background: var(--violet); } .sd3 { background: var(--mint); } .sd4 { background: var(--coral); }
        .esh-title { font-family: 'DM Sans', sans-serif; font-weight: 700; font-size: 1rem; flex: 1; letter-spacing: 0; color: var(--ink); }
        .esh-brief { font-size: .78rem; color: var(--muted); font-family: 'JetBrains Mono', monospace; }
        .esh-toggle { transition: transform 0.3s ease; color: var(--muted); }
        .ed-step.open .esh-toggle { transform: rotate(180deg); }
        .ed-step-body { max-height: 0; overflow: hidden; transition: max-height 0.4s ease; }
        .ed-step.open .ed-step-body { max-height: 600px; }
        .ed-step-body-inner { padding: 0 22px 20px 46px; font-size: .9rem; line-height: 1.8; color: var(--ink-soft); }
        .ed-step-body-inner ol { padding-left: 18px; margin-bottom: 14px; }
        .ed-step-body-inner li { margin-bottom: 6px; }
        .ed-step-body-inner code { font-family: 'JetBrains Mono', monospace; font-size: .82rem; padding: 2px 8px; border-radius: 4px; background: rgba(255,255,255,0.05); color: var(--ink-soft); }
        .tip-box { display: flex; align-items: flex-start; gap: 10px; padding: 12px 16px; border-radius: 10px; font-size: .85rem; line-height: 1.6; }
        .tb-info { background: var(--accent-light); color: var(--accent); }
        .tb-warn { background: rgba(245,176,66,0.1); color: var(--amber); }
        .tb-ok { background: var(--mint-light); color: var(--mint); }
        .tb-icon { font-style: normal; flex-shrink: 0; font-weight: 700; }

        .knowledge-section { padding: clamp(50px, 7vh, 90px) 0; }
        .section-head { text-align: center; margin-bottom: clamp(36px, 4.5vw, 58px); }
        .section-tag {
            display: inline-flex; align-items: center; gap: 8px;
            font-family: 'JetBrains Mono', monospace; font-size: .73rem; font-weight: 500;
            color: var(--accent); letter-spacing: .13em; text-transform: uppercase; margin-bottom: 14px;
        }
        .section-tag::before, .section-tag::after { content: ''; width: 18px; height: 1px; background: var(--accent); opacity: .4; }
        .section-head h2 { font-size: clamp(1.9rem, 4vw, 3rem); line-height: 1.1; margin-bottom: 12px; }
        .section-head p { color: var(--muted); font-size: .98rem; max-width: 480px; margin: 0 auto; }
        .kb-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
        .kb-card { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: clamp(20px, 2.5vw, 28px); transition: all 0.3s ease; }
        .kb-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); background: var(--card-hover); }
        .kb-head { display: flex; align-items: center; gap: 12px; margin-bottom: 12px; }
        .kb-icon { width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
        .ki1 { background: var(--accent-light); color: var(--accent); }
        .ki2 { background: var(--coral-light); color: var(--coral); }
        .ki3 { background: var(--mint-light); color: var(--mint); }
        .kb-head h3 { font-family: 'DM Sans', sans-serif; font-weight: 700; font-size: 1rem; letter-spacing: 0; }
        .kb-body { color: var(--muted); font-size: .88rem; line-height: 1.7; }
        .kb-body code { font-family: 'JetBrains Mono', monospace; font-size: .78rem; padding: 2px 6px; border-radius: 4px; background: rgba(255,255,255,0.05); }

        .tips-scroll { padding: clamp(50px, 7vh, 90px) 0; }
        .tips-track { display: flex; gap: 16px; overflow-x: auto; padding-bottom: 16px; scrollbar-width: thin; scrollbar-color: var(--line-dark) transparent; }
        .tips-track::-webkit-scrollbar { height: 4px; }
        .tips-track::-webkit-scrollbar-track { background: transparent; }
        .tips-track::-webkit-scrollbar-thumb { background: var(--line-dark); border-radius: 2px; }
        .tip-card { flex: 0 0 280px; background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: 24px; transition: background 0.3s; }
        .tip-card:hover { background: var(--card-hover); }
        .tc-num { font-family: 'JetBrains Mono', monospace; font-size: .7rem; font-weight: 500; letter-spacing: .1em; display: block; margin-bottom: 10px; }
        .tcn1 { color: var(--accent); } .tcn2 { color: var(--coral); } .tcn3 { color: var(--mint); } .tcn4 { color: var(--violet); } .tcn5 { color: var(--amber); }
        .tip-card h4 { font-family: 'DM Sans', sans-serif; font-weight: 700; font-size: 1rem; margin-bottom: 8px; letter-spacing: 0; color: var(--ink); }
        .tip-card p { font-size: .85rem; color: var(--muted); line-height: 1.6; }

        .troubleshoot-section { padding: clamp(50px, 7vh, 90px) 0; border-top: 1px solid var(--line); }
        .ts-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
        .ts-card { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: clamp(22px, 2.5vw, 32px); transition: all 0.3s ease; display: flex; flex-direction: column; }
        .ts-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); background: var(--card-hover); }
        .ts-card .ts-num { font-family: 'JetBrains Mono', monospace; font-size: .75rem; font-weight: 500; color: var(--accent); margin-bottom: 12px; }
        .ts-card h3 { font-family: 'DM Sans', sans-serif; font-weight: 700; font-size: 1.1rem; margin-bottom: 8px; letter-spacing: 0; color: var(--ink); }
        .ts-card p { color: var(--muted); font-size: .9rem; line-height: 1.7; flex: 1; }
        .ts-card .ts-solution { margin-top: 14px; padding: 12px 16px; background: var(--bg); border-radius: 12px; font-size: .85rem; color: var(--ink-soft); border-left: 3px solid var(--accent); }

        .optimize-section { padding: clamp(50px, 7vh, 90px) 0; }
        .opt-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
        .opt-card { background: var(--card); border: 1px solid var(--line); border-radius: 20px; padding: clamp(20px, 2vw, 28px); text-align: center; transition: all 0.3s ease; }
        .opt-card:hover { transform: translateY(-5px); box-shadow: var(--shadow); background: var(--card-hover); }
        .opt-icon { width: 48px; height: 48px; border-radius: 14px; display: flex; align-items: center; justify-content: center; margin: 0 auto 14px; font-size: 1.5rem; }
        .opt-card:nth-child(1) .opt-icon { background: var(--accent-light); color: var(--accent); }
        .opt-card:nth-child(2) .opt-icon { background: var(--coral-light); color: var(--coral); }
        .opt-card:nth-child(3) .opt-icon { background: var(--mint-light); color: var(--mint); }
        .opt-card h3 { font-family: 'DM Sans', sans-serif; font-weight: 700; font-size: 1rem; margin-bottom: 6px; letter-spacing: 0; color: var(--ink); }
        .opt-card p { font-size: .85rem; color: var(--muted); line-height: 1.6; }

        .cta-section { padding: clamp(60px, 8vh, 100px) 0; }
        .cta-inner { background: linear-gradient(135deg, #1b2235 0%, #0f1422 100%); border-radius: 28px; padding: clamp(50px, 6vw, 80px); text-align: center; position: relative; overflow: hidden; color: #fff; border: 1px solid var(--line-dark); }
        .cta-inner::before { content: ''; position: absolute; top: -150px; left: 50%; width: 500px; height: 500px; transform: translateX(-50%); background: radial-gradient(circle, rgba(79,140,255,0.2), transparent 60%); pointer-events: none; }
        .cta-inner h2 { font-size: clamp(2rem, 4vw, 3rem); line-height: 1.1; margin-bottom: 14px; position: relative; z-index: 1; }
        .cta-inner h2 em { font-style: italic; color: #7ba4ff; }
        .cta-inner p { color: rgba(255,255,255,0.55); font-size: 1.05rem; margin-bottom: 36px; max-width: 480px; margin-left: auto; margin-right: auto; position: relative; z-index: 1; }
        .cta-btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; position: relative; z-index: 1; }
        .btn-solid { display: inline-flex; align-items: center; gap: 10px; padding: 14px 28px; border-radius: 12px; background: var(--accent); color: #fff; font-weight: 600; font-size: .95rem; border: none; cursor: pointer; transition: all 0.3s ease; box-shadow: 0 4px 16px rgba(79,140,255,0.3); text-decoration: none; }
        .btn-solid:hover { background: #6a9fff; box-shadow: 0 8px 28px rgba(79,140,255,0.5); transform: translateY(-2px); }
        .btn-outline { display: inline-flex; align-items: center; gap: 10px; padding: 14px 28px; border-radius: 12px; background: transparent; color: var(--ink); font-weight: 600; font-size: .95rem; border: 1.5px solid var(--line-dark); cursor: pointer; transition: all 0.3s ease; text-decoration: none; }
        .btn-outline:hover { border-color: var(--accent); background: var(--accent-light); color: var(--accent); transform: translateY(-2px); }
        .cta-section .btn-solid { background: #fff; color: #0b0f1a; }
        .cta-section .btn-solid:hover { background: var(--accent); color: #fff; }
        .cta-section .btn-outline { background: transparent; color: #fff; border-color: rgba(255,255,255,0.2); }
        .cta-section .btn-outline:hover { border-color: #7ba4ff; background: rgba(79,140,255,0.15); }

        .footer { border-top: 1px solid var(--line); padding: 50px 0 24px; background: #0d1120; }
        .footer-grid { display: grid; grid-template-columns: 2.5fr 1fr 1fr 1fr; gap: clamp(24px, 4vw, 60px); margin-bottom: 40px; }
        .footer-brand p { color: var(--muted); font-size: .85rem; max-width: 260px; line-height: 1.7; margin-top: 12px; }
        .footer-col h4 { font-family: 'JetBrains Mono', monospace; font-size: .72rem; font-weight: 500; color: var(--ink); margin-bottom: 16px; letter-spacing: .1em; text-transform: uppercase; }
        .footer-col li { margin-bottom: 9px; }
        .footer-col a { color: var(--muted); font-size: .85rem; }
        .footer-col a:hover { color: var(--accent); }
        .footer-bottom { display: flex; justify-content: space-between; align-items: center; padding-top: 20px; border-top: 1px solid var(--line); font-size: .75rem; color: var(--muted); font-family: 'JetBrains Mono', monospace; }

        .back-top { position: fixed; bottom: 30px; right: 30px; width: 44px; height: 44px; border-radius: 50%; background: var(--card); border: 1px solid var(--line); box-shadow: var(--shadow); display: flex; align-items: center; justify-content: center; cursor: pointer; opacity: 0; visibility: hidden; transition: all 0.3s ease; z-index: 99; }
        .back-top.show { opacity: 1; visibility: visible; }

        .reveal { opacity: 0; transform: translateY(28px); transition: all 0.7s cubic-bezier(.22,1,.36,1); }
        .reveal.show { opacity: 1; transform: translateY(0); }
        .reveal-d1 { transition-delay: .1s; } .reveal-d2 { transition-delay: .2s; } .reveal-d3 { transition-delay: .3s; } .reveal-d4 { transition-delay: .4s; }

        @media(max-width:1024px) {
            .ed-inner { grid-template-columns: 1fr; }
            .ed-inner.reversed { direction: ltr; }
            .kb-grid { grid-template-columns: 1fr 1fr; }
            .ts-grid { grid-template-columns: 1fr; }
            .opt-grid { grid-template-columns: 1fr 1fr; }
            .footer-grid { grid-template-columns: 1fr 1fr; }
        }
        @media(max-width:768px) {
            .nav-right a:not(.nav-right a.active) { display: none; }
            .nav-right a.active { display: block; }
            .mobile-btn { display: block; }
            .j-row { flex-direction: column; align-items: flex-start; gap: 16px; }
            .jr-steps { flex-wrap: wrap; justify-content: flex-start; }
            .kb-grid { grid-template-columns: 1fr; }
            .opt-grid { grid-template-columns: 1fr; }
            .footer-grid { grid-template-columns: 1fr; }
            .footer-bottom { flex-direction: column; gap: 6px; text-align: center; }
        }