:root {
            color-scheme: light;
            --bg: #f3f7f8;
            --panel: #ffffff;
            --text: #102033;
            --muted: #5e7084;
            --line: #d6e0e6;
            --accent: #0b7285;
            --accent-strong: #075866;
            --success: #267553;
            --warn: #9a6a14;
            --soft: #e6f4f2;
        }
        * { box-sizing: border-box; }
        body {
            margin: 0;
            background: var(--bg);
            color: var(--text);
            font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
        }
        a { color: inherit; text-decoration: none; }
        .shell {
            width: min(1160px, 100%);
            margin: 0 auto;
            padding: 0 22px;
        }
        header {
            border-bottom: 1px solid var(--line);
            background: rgba(255,255,255,.92);
        }
        .topbar {
            min-height: 70px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 18px;
        }
        .brand-row {
            display: flex;
            align-items: center;
            gap: 14px;
            flex: 0 0 auto;
        }
        .brand {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 900;
            letter-spacing: 0;
        }
        .brand-logo {
            width: 42px;
            height: 42px;
            display: block;
        }
        nav {
            display: flex;
            align-items: center;
            gap: 10px;
            flex-wrap: wrap;
            justify-content: flex-end;
        }
        nav a {
            min-height: 38px;
            display: inline-flex;
            align-items: center;
            border: 1px solid transparent;
            border-radius: 8px;
            padding: 0 12px;
            color: var(--muted);
            font-weight: 800;
            font-size: 14px;
        }
        nav a.primary {
            border-color: var(--accent);
            background: var(--accent);
            color: #fff;
        }
        .language-select {
            min-height: 38px;
            border: 1px solid var(--line);
            border-radius: 8px;
            background: #fff;
            color: var(--text);
            padding: 0 10px;
            font: inherit;
            font-weight: 800;
        }
        main {
            padding: 54px 0 58px;
        }
        .hero {
            display: grid;
            grid-template-columns: 1fr minmax(360px, 460px);
            gap: 34px;
            align-items: center;
        }
        .eyebrow {
            color: var(--accent-strong);
            font-weight: 900;
            font-size: 14px;
            margin-bottom: 12px;
        }
        h1 {
            margin: 0;
            max-width: 760px;
            font-size: 52px;
            line-height: 1.08;
            letter-spacing: 0;
        }
        .lead {
            max-width: 690px;
            margin: 18px 0 0;
            color: var(--muted);
            font-size: 19px;
            line-height: 1.75;
        }
        .actions {
            display: flex;
            flex-wrap: wrap;
            gap: 12px;
            margin-top: 28px;
        }
        .button {
            min-height: 46px;
            border-radius: 8px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            padding: 0 18px;
            font: inherit;
            font-weight: 900;
            border: 1px solid var(--line);
            background: #fff;
            color: var(--text);
            cursor: pointer;
        }
        .button.primary {
            background: var(--accent);
            border-color: var(--accent);
            color: #fff;
        }
        .button:hover, nav a:hover {
            border-color: var(--accent);
        }
        .product-visual {
            border: 1px solid var(--line);
            border-radius: 8px;
            background: var(--panel);
            padding: 18px;
            box-shadow: 0 18px 45px rgba(21, 42, 56, .08);
        }
        .visual-head {
            display: flex;
            align-items: center;
            justify-content: space-between;
            border-bottom: 1px solid var(--line);
            padding-bottom: 12px;
            margin-bottom: 14px;
        }
        .visual-title {
            font-size: 14px;
            font-weight: 900;
        }
        .pill {
            border-radius: 999px;
            background: var(--soft);
            color: var(--success);
            padding: 6px 10px;
            font-size: 12px;
            font-weight: 900;
        }
        .metric-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 10px;
        }
        .metric {
            border: 1px solid var(--line);
            border-radius: 8px;
            padding: 12px;
            min-height: 82px;
            background: #fbfdfe;
        }
        .metric span {
            display: block;
            color: var(--muted);
            font-size: 12px;
            font-weight: 800;
        }
        .metric strong {
            display: block;
            margin-top: 7px;
            font-size: 23px;
            letter-spacing: 0;
        }
        .workflow {
            margin-top: 14px;
            display: grid;
            gap: 8px;
        }
        .step {
            border: 1px solid var(--line);
            border-radius: 8px;
            background: #fff;
            padding: 10px 12px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            gap: 14px;
            font-size: 14px;
            font-weight: 800;
        }
        .step small {
            color: var(--muted);
            font-weight: 800;
        }
        section {
            margin-top: 58px;
        }
        h2 {
            margin: 0 0 14px;
            font-size: 30px;
            letter-spacing: 0;
        }
        .section-lead {
            max-width: 780px;
            margin: 0 0 22px;
            color: var(--muted);
            line-height: 1.7;
            font-size: 16px;
        }
        .grid {
            display: grid;
            grid-template-columns: repeat(3, minmax(0, 1fr));
            gap: 16px;
        }
        .item {
            border: 1px solid var(--line);
            border-radius: 8px;
            background: var(--panel);
            padding: 20px;
            min-height: 170px;
        }
        .item h3 {
            margin: 0;
            font-size: 20px;
            letter-spacing: 0;
        }
        .item p {
            margin: 10px 0 0;
            color: var(--muted);
            line-height: 1.65;
        }
        .loop {
            border: 1px solid var(--line);
            border-radius: 8px;
            background: var(--panel);
            padding: 22px;
            display: grid;
            grid-template-columns: repeat(6, minmax(0, 1fr));
            gap: 10px;
        }
        .loop span {
            border: 1px solid var(--line);
            border-radius: 8px;
            min-height: 58px;
            display: flex;
            align-items: center;
            justify-content: center;
            text-align: center;
            padding: 8px;
            font-size: 14px;
            font-weight: 900;
            background: #fbfdfe;
        }
        .notice {
            border: 1px solid #d8c18b;
            border-radius: 8px;
            background: #fff8e8;
            padding: 18px;
            color: #5d420f;
            line-height: 1.7;
        }
        .pricing-panel {
            border: 1px solid var(--line);
            border-radius: 8px;
            background: var(--panel);
            padding: 24px;
            display: grid;
            grid-template-columns: minmax(0, 1.4fr) minmax(240px, .6fr);
            gap: 22px;
            align-items: center;
        }
        .pricing-panel p {
            margin: 10px 0 0;
            color: var(--muted);
            line-height: 1.7;
        }
        .pricing-actions {
            display: flex;
            justify-content: flex-end;
            gap: 12px;
            flex-wrap: wrap;
        }
        .support-overlay {
            position: fixed;
            inset: 0;
            z-index: 40;
            display: none;
            align-items: center;
            justify-content: flex-end;
            padding: 20px;
            background: rgba(9, 20, 33, .46);
        }
        .support-overlay.is-open {
            display: flex;
        }
        .support-panel {
            width: min(720px, 100%);
            max-height: min(880px, 96vh);
            overflow: auto;
            border: 1px solid var(--line);
            border-radius: 8px;
            background: var(--panel);
            box-shadow: 0 22px 65px rgba(10, 27, 42, .22);
        }
        .support-fab {
            position: fixed;
            right: 24px;
            bottom: 24px;
            z-index: 30;
            min-width: 72px;
            min-height: 72px;
            border-radius: 999px;
            border: 1px solid rgba(255,255,255,.7);
            background: var(--accent);
            color: #fff;
            box-shadow: 0 18px 42px rgba(11, 114, 133, .32);
            display: inline-flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 4px;
            font-size: 12px;
            font-weight: 900;
        }
        .support-fab svg {
            width: 28px;
            height: 28px;
            display: block;
        }
        .support-fab:hover {
            background: var(--accent-strong);
            color: #fff;
        }
        .support-fab.has-unread {
            animation: support-bounce 1.1s ease-in-out infinite;
        }
        .support-fab.has-unread::after {
            content: "";
            position: absolute;
            right: 8px;
            top: 8px;
            width: 12px;
            height: 12px;
            border-radius: 999px;
            background: #f44336;
            border: 2px solid #fff;
        }
        @keyframes support-bounce {
            0%, 100% { transform: translateY(0); }
            35% { transform: translateY(-7px); }
            60% { transform: translateY(0); }
            78% { transform: translateY(-3px); }
        }
        .support-head {
            display: flex;
            align-items: flex-start;
            justify-content: space-between;
            gap: 16px;
            padding: 22px 22px 14px;
            border-bottom: 1px solid var(--line);
        }
        .support-head h2 {
            margin: 0;
            font-size: 24px;
        }
        .support-head p {
            margin: 6px 0 0;
            color: var(--muted);
            line-height: 1.6;
        }
        .support-close {
            width: 38px;
            height: 38px;
            border: 1px solid var(--line);
            border-radius: 8px;
            background: #fff;
            color: var(--text);
            font-size: 22px;
            font-weight: 800;
            line-height: 1;
            cursor: pointer;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }
        .support-window-actions {
            display: flex;
            gap: 8px;
            align-items: center;
        }
        .support-minimize {
            width: 38px;
            height: 38px;
            border: 1px solid var(--line);
            border-radius: 8px;
            background: #fff;
            color: var(--text);
            font-size: 22px;
            font-weight: 800;
            line-height: 1;
            cursor: pointer;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }
        .support-body {
            padding: 20px 22px 22px;
        }
        .support-chat {
            display: grid;
            gap: 14px;
        }
        .support-log {
            min-height: 260px;
            max-height: 46vh;
            overflow: auto;
            border: 1px solid var(--line);
            border-radius: 8px;
            background: #fbfdfe;
            padding: 14px;
            display: grid;
            align-content: start;
            gap: 10px;
        }
        .support-bubble {
            max-width: 86%;
            border: 1px solid var(--line);
            border-radius: 8px;
            padding: 11px 12px;
            line-height: 1.6;
            white-space: pre-wrap;
        }
        .support-bubble.assistant {
            justify-self: start;
            background: #fff;
            color: var(--text);
        }
        .support-bubble.typing {
            color: var(--muted);
            display: inline-flex;
            align-items: center;
            gap: 8px;
        }
        .support-dots {
            display: inline-flex;
            gap: 4px;
        }
        .support-dots span {
            width: 6px;
            height: 6px;
            border-radius: 999px;
            background: var(--muted);
            opacity: .45;
            animation: support-dot 1s ease-in-out infinite;
        }
        .support-dots span:nth-child(2) { animation-delay: .16s; }
        .support-dots span:nth-child(3) { animation-delay: .32s; }
        @keyframes support-dot {
            0%, 80%, 100% { transform: translateY(0); opacity: .35; }
            40% { transform: translateY(-4px); opacity: .9; }
        }
        .support-bubble.visitor {
            justify-self: end;
            background: var(--accent);
            border-color: var(--accent);
            color: #fff;
        }
        .support-input-row {
            display: grid;
            grid-template-columns: 1fr auto;
            gap: 10px;
            align-items: end;
        }
        .support-input-row textarea {
            min-height: 78px;
            max-height: 180px;
            resize: vertical;
            width: 100%;
            border: 1px solid var(--line);
            border-radius: 8px;
            background: #fff;
            color: var(--text);
            padding: 11px 12px;
            font: inherit;
        }
        .support-status {
            min-height: 22px;
            color: var(--muted);
            font-size: 13px;
            font-weight: 800;
        }
        .support-actions {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            justify-content: flex-end;
        }
        footer {
            border-top: 1px solid var(--line);
            padding: 28px 0;
            color: var(--muted);
            font-size: 13px;
        }
        @media (max-width: 880px) {
            .topbar {
                align-items: center;
                flex-wrap: wrap;
                padding: 16px 0;
            }
            .brand-row {
                width: 100%;
                justify-content: space-between;
            }
            nav {
                justify-content: flex-start;
                width: 100%;
            }
            .hero {
                grid-template-columns: 1fr;
            }
            h1 {
                font-size: 38px;
            }
            .grid,
            .loop {
                grid-template-columns: 1fr;
            }
            .pricing-panel {
                grid-template-columns: 1fr;
            }
            .pricing-actions {
                justify-content: flex-start;
            }
            .support-overlay {
                align-items: flex-end;
                padding: 12px;
            }
            .support-panel {
                width: 100%;
                max-height: 88vh;
            }
            .support-input-row {
                grid-template-columns: 1fr;
            }
            .support-actions {
                justify-content: flex-start;
            }
        }
        @media (max-width: 520px) {
            main { padding-top: 34px; }
            h1 { font-size: 32px; }
            .lead { font-size: 16px; }
            .metric-grid { grid-template-columns: 1fr; }
            .button { width: 100%; }
            .support-fab {
                right: 16px;
                bottom: 16px;
                min-width: 64px;
                min-height: 64px;
            }
        }