:root {
            --c-primary: #007B9F;
            --c-primary-deep: #005A82;
            --c-primary-soft: #ECF9FB;
            --c-blue: #075EA3;
            --c-green: #20C96B;
            --c-bg: #FFFFFF;
            --c-bg-soft: #F3FAFB;
            --c-ink: #10384C;
            --c-ink-soft: #456777;
            --c-ink-muted: #78919D;
            --c-line: #DCECEF;
            --c-line-soft: #EAF4F6;
            --c-success: #18B861;
            --c-success-bg: #EFFBF4;
            --c-success-line: #BFEBD1;
            --shadow-sm: 0 1px 2px rgba(0, 62, 83, 0.05), 0 1px 3px rgba(0, 62, 83, 0.04);
            --shadow-md: 0 8px 24px rgba(0, 83, 112, 0.09), 0 2px 6px rgba(0, 62, 83, 0.05);
            --shadow-lg: 0 18px 48px rgba(0, 123, 159, 0.16), 0 6px 16px rgba(0, 62, 83, 0.07);
        }

        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            -webkit-tap-highlight-color: transparent;
        }

        html { scroll-behavior: smooth; }

        body {
            font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Microsoft YaHei', sans-serif;
            font-size: 15px;
            line-height: 1.6;
            color: var(--c-ink);
            background: var(--c-bg);
            min-height: 100vh;
            -webkit-font-smoothing: antialiased;
        }

        img { display: block; max-width: 100%; }
        button { font-family: inherit; }
        a { color: var(--c-blue); text-decoration: none; }

        .container {
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 24px;
        }

        /* ===== Nav ===== */
        .nav {
            position: sticky;
            top: 0;
            z-index: 50;
            background: rgba(255, 255, 255, 0.9);
            backdrop-filter: saturate(180%) blur(16px);
            -webkit-backdrop-filter: saturate(180%) blur(16px);
            border-bottom: 1px solid var(--c-line);
        }
        .nav-inner {
            display: flex;
            align-items: center;
            justify-content: space-between;
            height: 64px;
        }
        .nav-logo {
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 700;
            font-size: 17px;
            color: var(--c-ink);
            letter-spacing: 1px;
        }
        .nav-logo img {
            width: 38px;
            height: 38px;
            filter: drop-shadow(0 4px 8px rgba(0, 93, 126, 0.12));
        }
        .nav-links {
            display: flex;
            gap: 28px;
            list-style: none;
        }
        .nav-links a {
            color: var(--c-ink-soft);
            font-size: 14px;
            font-weight: 500;
            transition: color 180ms ease;
        }
        .nav-links a:hover { color: var(--c-primary); }
        .nav-cta {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            padding: 8px 18px;
            background: linear-gradient(135deg, var(--c-primary), var(--c-blue));
            color: #fff !important;
            border-radius: 8px;
            font-size: 14px;
            font-weight: 500;
            transition: background 180ms ease;
        }
        .nav-cta:hover { background: linear-gradient(135deg, var(--c-primary-deep), #064C8A); }

        @media (max-width: 720px) {
            .nav-links { display: none; }
            .nav-inner { height: 56px; }
            .nav-logo { font-size: 15px; }
            .nav-logo img { width: 28px; height: 28px; }
        }

        /* ===== Hero ===== */
        .hero {
            position: relative;
            padding: 80px 0 60px;
            overflow: hidden;
            background:
                radial-gradient(circle at 14% 18%, rgba(32, 201, 107, 0.11), transparent 36%),
                radial-gradient(circle at 86% 38%, rgba(0, 143, 180, 0.15), transparent 39%),
                linear-gradient(180deg, #F8FDFD 0%, #FFFFFF 100%);
        }
        .hero-grid {
            display: grid;
            grid-template-columns: 1.1fr 1fr;
            gap: 60px;
            align-items: center;
        }
        .hero-eyebrow {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            padding: 6px 14px;
            background: var(--c-primary-soft);
            color: var(--c-primary-deep);
            border: 1px solid #BFE7ED;
            border-radius: 999px;
            font-size: 12.5px;
            font-weight: 500;
            margin-bottom: 24px;
        }
        .hero-eyebrow::before {
            content: '';
            width: 6px; height: 6px;
            background: var(--c-green);
            border-radius: 50%;
        }
        .hero h1 {
            font-size: 48px;
            font-weight: 900;
            line-height: 1.2;
            letter-spacing: -0.5px;
            color: var(--c-ink);
            margin-bottom: 24px;
        }
        .hero h1 .accent {
            color: var(--c-primary);
            background: linear-gradient(120deg, var(--c-primary) 0%, var(--c-blue) 58%, var(--c-green) 100%);
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .hero-sub {
            font-size: 17px;
            color: var(--c-ink-soft);
            line-height: 1.75;
            margin-bottom: 36px;
            max-width: 540px;
        }
        .hero-actions {
            display: flex;
            gap: 14px;
            flex-wrap: wrap;
        }
        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            padding: 14px 28px;
            border: none;
            border-radius: 10px;
            background: linear-gradient(135deg, var(--c-primary), var(--c-blue));
            color: #fff;
            font-size: 16px;
            font-weight: 500;
            cursor: pointer;
            transition: background 180ms ease, transform 180ms ease, box-shadow 180ms ease;
            text-decoration: none;
            box-shadow: var(--shadow-md);
        }
        .btn-primary:hover {
            background: linear-gradient(135deg, var(--c-primary-deep), #064C8A);
            transform: translateY(-1px);
            box-shadow: var(--shadow-lg);
        }
        .btn-primary svg { width: 18px; height: 18px; }
        .btn-ghost {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            padding: 14px 24px;
            border: 1px solid var(--c-line);
            border-radius: 10px;
            background: #fff;
            color: var(--c-ink);
            font-size: 15px;
            font-weight: 500;
            cursor: pointer;
            transition: border-color 180ms ease, background 180ms ease;
            text-decoration: none;
        }
        .btn-ghost:hover { border-color: #91CAD4; background: var(--c-primary-soft); color: var(--c-primary-deep); }

        .hero-meta {
            display: flex;
            gap: 28px;
            margin-top: 28px;
            font-size: 13px;
            color: var(--c-ink-muted);
            flex-wrap: wrap;
        }
        .hero-meta span {
            display: inline-flex;
            align-items: center;
            gap: 6px;
        }
        .hero-meta svg {
            width: 14px; height: 14px;
            color: var(--c-success);
        }

        /* Hero Visual */
        .hero-visual {
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-left: auto;
        }
        .phone-mock {
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .phone-mock::before {
            content: '';
            position: absolute;
            top: 8%;
            left: -10%;
            right: -10%;
            bottom: 8%;
            background: radial-gradient(circle, rgba(0, 143, 180, 0.23), transparent 68%);
            filter: blur(40px);
            z-index: 0;
        }
        .phone-mock::after {
            content: '';
            position: absolute;
            width: 390px;
            height: 390px;
            border: 1px solid rgba(0, 123, 159, 0.15);
            border-radius: 50%;
            box-shadow:
                0 0 0 34px rgba(0, 123, 159, 0.035),
                0 0 0 72px rgba(32, 201, 107, 0.025);
            z-index: 0;
        }
        .phone-frame {
            position: relative;
            width: 280px;
            height: 560px;
            background: linear-gradient(155deg, #0C3146, #061F32);
            border-radius: 42px;
            padding: 12px;
            box-shadow: 0 30px 60px rgba(0, 0, 0, 0.18), 0 10px 20px rgba(0, 0, 0, 0.08);
            z-index: 1;
        }
        .phone-screen {
            width: 100%;
            height: 100%;
            background: linear-gradient(160deg, #F5FCFD 0%, #DDF5F8 52%, #DDF8E8 100%);
            border-radius: 32px;
            position: relative;
            overflow: hidden;
            display: flex;
            flex-direction: column;
            padding: 50px 18px 18px;
        }
        .phone-screen::before {
            content: '';
            position: absolute;
            top: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 96px; height: 22px;
            background: #071F31;
            border-radius: 0 0 14px 14px;
        }
        .phone-brand {
            display: flex;
            align-items: center;
            gap: 9px;
            margin-bottom: 18px;
            padding: 0 2px 12px;
            border-bottom: 1px solid rgba(0, 123, 159, 0.12);
            color: var(--c-primary-deep);
            font-size: 13px;
            font-weight: 700;
        }
        .phone-brand img {
            width: 32px;
            height: 32px;
            border-radius: 50%;
            filter: drop-shadow(0 3px 6px rgba(0, 94, 130, 0.14));
        }
        .phone-brand small {
            display: block;
            color: var(--c-ink-muted);
            font-size: 9px;
            font-weight: 500;
            line-height: 1.3;
        }
        .chat-row {
            display: flex;
            align-items: flex-end;
            gap: 8px;
            margin-bottom: 10px;
        }
        .chat-row.me { justify-content: flex-end; }
        .chat-avatar {
            width: 28px; height: 28px;
            border-radius: 50%;
            background: linear-gradient(135deg, #74E6A6, var(--c-green));
            flex-shrink: 0;
        }
        .chat-row.me .chat-avatar {
            background: linear-gradient(135deg, #65CCE1, var(--c-blue));
        }
        .chat-bubble {
            padding: 8px 12px;
            border-radius: 14px;
            font-size: 12px;
            color: var(--c-ink);
            background: #fff;
            max-width: 70%;
            box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
        }
        .chat-row.me .chat-bubble {
            background: linear-gradient(135deg, var(--c-primary), var(--c-blue));
            color: #fff;
        }

        @media (max-width: 960px) {
            .hero { padding: 60px 0 48px; }
            .hero-grid { grid-template-columns: 1fr; gap: 48px; }
            .hero h1 { font-size: 36px; }
            .hero-sub { font-size: 15.5px; }
            .hero-visual { margin: 0 auto; }
            .phone-frame { width: 240px; height: 480px; border-radius: 36px; padding: 10px; }
            .phone-screen { border-radius: 28px; padding: 44px 16px 16px; }
            .phone-mock::after { width: 320px; height: 320px; }
        }
        @media (max-width: 480px) {
            .hero { padding: 40px 0 32px; }
            .hero h1 { font-size: 30px; }
            .btn-primary, .btn-ghost { width: 100%; }
            .hero-actions { flex-direction: column; gap: 10px; }
        }

        /* ===== Section ===== */
        .section {
            padding: 96px 0;
        }
        .section-soft {
            background: linear-gradient(180deg, var(--c-bg-soft) 0%, #F9FCFC 100%);
        }
        .section-head {
            text-align: center;
            max-width: 720px;
            margin: 0 auto 56px;
        }
        .section-eyebrow {
            display: inline-block;
            font-size: 13px;
            font-weight: 500;
            color: var(--c-primary);
            letter-spacing: 2px;
            margin-bottom: 14px;
            text-transform: uppercase;
        }
        .section-head h2 {
            font-size: 36px;
            font-weight: 700;
            color: var(--c-ink);
            line-height: 1.25;
            letter-spacing: -0.3px;
            margin-bottom: 16px;
        }
        .section-head p {
            font-size: 16px;
            color: var(--c-ink-soft);
            line-height: 1.75;
        }

        @media (max-width: 720px) {
            .section { padding: 64px 0; }
            .section-head { margin-bottom: 40px; }
            .section-head h2 { font-size: 26px; }
            .section-head p { font-size: 14.5px; }
        }

        /* ===== Features ===== */
        .features {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 20px;
        }
        .feature {
            padding: 28px 24px;
            background: #fff;
            border: 1px solid var(--c-line);
            border-radius: 14px;
            transition: border-color 240ms ease, transform 240ms ease, box-shadow 240ms ease;
            position: relative;
        }
        .feature:hover {
            border-color: #A9DBE4;
            transform: translateY(-3px);
            box-shadow: var(--shadow-lg);
        }
        .feature-icon {
            width: 44px; height: 44px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: var(--c-primary-soft);
            color: var(--c-primary);
            border-radius: 10px;
            margin-bottom: 18px;
        }
        .feature-icon svg {
            width: 22px; height: 22px;
        }
        .feature h3 {
            font-size: 17px;
            font-weight: 700;
            color: var(--c-ink);
            margin-bottom: 10px;
        }
        .feature p {
            font-size: 14px;
            color: var(--c-ink-soft);
            line-height: 1.7;
        }

        @media (max-width: 960px) {
            .features { grid-template-columns: repeat(2, 1fr); }
        }
        @media (max-width: 560px) {
            .features { grid-template-columns: 1fr; gap: 14px; }
            .feature { padding: 22px 20px; }
        }

        /* ===== Security ===== */
        .security-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 60px;
            align-items: center;
        }
        .security-text h2 {
            font-size: 34px;
            font-weight: 700;
            line-height: 1.25;
            margin-bottom: 18px;
            letter-spacing: -0.3px;
        }
        .security-text > p {
            font-size: 15.5px;
            color: var(--c-ink-soft);
            line-height: 1.75;
            margin-bottom: 28px;
        }
        .security-list {
            list-style: none;
            display: grid;
            gap: 14px;
        }
        .security-list li {
            display: flex;
            align-items: flex-start;
            gap: 12px;
            font-size: 14.5px;
            color: var(--c-ink);
            line-height: 1.7;
        }
        .security-list .ok {
            flex-shrink: 0;
            width: 22px; height: 22px;
            border-radius: 50%;
            background: var(--c-success);
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-top: 2px;
        }
        .security-list .ok svg { width: 12px; height: 12px; }
        .security-list strong { font-weight: 700; color: var(--c-ink); }
        .security-list span { color: var(--c-ink-soft); }

        .security-card {
            position: relative;
            padding: 36px 32px;
            background: linear-gradient(140deg, #0B344B 0%, #075C79 58%, #087E8E 100%);
            border-radius: 20px;
            color: #fff;
            overflow: hidden;
        }
        .security-card::before {
            content: '';
            position: absolute;
            top: -40%; right: -30%;
            width: 80%; height: 80%;
            background: radial-gradient(circle, rgba(42, 230, 124, 0.44), transparent 70%);
            filter: blur(50px);
        }
        .security-card-inner {
            position: relative;
            z-index: 1;
        }
        .shield {
            width: 64px; height: 64px;
            background: rgba(32, 201, 107, 0.18);
            border: 1px solid rgba(100, 238, 159, 0.4);
            border-radius: 16px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: #7BF0AD;
            margin-bottom: 24px;
        }
        .shield svg { width: 30px; height: 30px; }
        .security-card h3 {
            font-size: 22px;
            font-weight: 700;
            margin-bottom: 12px;
        }
        .security-card p {
            font-size: 14.5px;
            color: rgba(255, 255, 255, 0.75);
            line-height: 1.75;
            margin-bottom: 24px;
        }
        .security-stats {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 16px;
            padding-top: 20px;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
        }
        .stat-num {
            font-size: 22px;
            font-weight: 700;
            color: #fff;
            margin-bottom: 4px;
        }
        .stat-label {
            font-size: 12px;
            color: rgba(255, 255, 255, 0.6);
        }

        @media (max-width: 880px) {
            .security-grid { grid-template-columns: 1fr; gap: 40px; }
            .security-text h2 { font-size: 26px; }
        }

        /* ===== Download ===== */
        .download-wrap {
            max-width: 520px;
            margin: 0 auto;
        }
        .download-card {
            background: #fff;
            border: 1px solid var(--c-line);
            border-radius: 16px;
            padding: 32px 28px;
            box-shadow: var(--shadow-md);
        }
        .download-head {
            text-align: center;
            margin-bottom: 28px;
        }
        .download-head img {
            width: 84px; height: 84px;
            margin: 0 auto 14px;
            filter: drop-shadow(0 10px 20px rgba(0, 105, 139, 0.16));
        }
        .download-head h3 {
            font-size: 19px;
            font-weight: 700;
            margin-bottom: 4px;
        }
        .download-head p {
            font-size: 13px;
            color: var(--c-ink-muted);
        }
        .picker { margin-bottom: 22px; }
        .picker-label {
            font-size: 13px;
            color: var(--c-ink-muted);
            margin-bottom: 10px;
            padding-left: 2px;
        }
        .options {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }
        .option {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 14px 16px;
            border: 1px solid var(--c-line);
            border-radius: 10px;
            cursor: pointer;
            background: #fff;
            transition: border-color 180ms ease, background 180ms ease;
        }
        .option:hover { border-color: #A9D3DC; }
        .option input {
            position: absolute;
            opacity: 0;
            pointer-events: none;
        }
        .option .dot {
            flex-shrink: 0;
            width: 18px; height: 18px;
            border: 1.5px solid #AFC4CC;
            border-radius: 50%;
            position: relative;
            transition: border-color 180ms ease;
        }
        .option .dot::after {
            content: '';
            position: absolute;
            inset: 3px;
            background: var(--c-primary);
            border-radius: 50%;
            transform: scale(0);
            transition: transform 180ms ease;
        }
        .option input:checked + .dot { border-color: var(--c-primary); }
        .option input:checked + .dot::after { transform: scale(1); }
        .option:has(input:checked) {
            border-color: var(--c-primary);
            background: var(--c-primary-soft);
        }
        .option-text { flex: 1; min-width: 0; }
        .option-title {
            font-size: 14.5px;
            font-weight: 500;
            color: var(--c-ink);
            line-height: 1.4;
        }
        .option-tag {
            display: inline-block;
            margin-left: 6px;
            padding: 1px 6px;
            background: var(--c-primary);
            color: #fff;
            font-size: 10.5px;
            font-weight: 500;
            border-radius: 3px;
            vertical-align: 1px;
        }
        .option-meta {
            font-size: 12px;
            color: var(--c-ink-muted);
            margin-top: 2px;
        }
        .btn-dl {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 8px;
            width: 100%;
            min-height: 50px;
            padding: 14px 20px;
            border: none;
            border-radius: 10px;
            background: linear-gradient(135deg, var(--c-primary), var(--c-blue));
            color: #fff;
            font-size: 16px;
            font-weight: 500;
            cursor: pointer;
            transition: background 180ms ease;
            text-decoration: none;
        }
        .btn-dl:hover { background: linear-gradient(135deg, var(--c-primary-deep), #064C8A); }
        .btn-dl svg { width: 18px; height: 18px; }
        .btn-note {
            text-align: center;
            font-size: 12px;
            color: var(--c-ink-muted);
            margin-top: 12px;
            line-height: 1.6;
        }
        .secure {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-top: 18px;
            padding: 12px 14px;
            background: var(--c-success-bg);
            border: 1px solid var(--c-success-line);
            border-radius: 8px;
            color: #08783B;
            font-size: 13px;
            font-weight: 500;
        }
        .secure-icon {
            flex-shrink: 0;
            width: 28px; height: 28px;
            border-radius: 50%;
            background: var(--c-success);
            color: #fff;
            display: flex;
            align-items: center;
            justify-content: center;
        }
        .secure-icon svg { width: 16px; height: 16px; }
        .secure-text { flex: 1; line-height: 1.4; }
        .secure-text small {
            display: block;
            font-size: 11.5px;
            font-weight: 400;
            color: #477361;
            margin-top: 1px;
        }
        .install-info {
            margin-top: 24px;
            padding-top: 20px;
            border-top: 1px solid var(--c-line);
            font-size: 13px;
            color: var(--c-ink-soft);
        }
        .install-info h4 {
            font-size: 13px;
            font-weight: 500;
            color: var(--c-ink);
            margin-bottom: 10px;
        }
        .install-info ol {
            padding-left: 20px;
            line-height: 1.85;
        }
        .install-info ol li::marker { color: var(--c-ink-muted); }

        .alt-version {
            margin-top: 18px;
            padding-top: 18px;
            border-top: 1px dashed var(--c-line);
            text-align: center;
            font-size: 12.5px;
            color: var(--c-ink-muted);
        }
        .alt-version a {
            color: var(--c-ink-soft);
            text-decoration: underline;
            text-underline-offset: 3px;
            text-decoration-color: var(--c-line);
            transition: color 180ms ease, text-decoration-color 180ms ease;
        }
        .alt-version a:hover {
            color: var(--c-primary);
            text-decoration-color: var(--c-primary);
        }

        /* ===== Footer ===== */
        .footer {
            background: linear-gradient(145deg, #082B40 0%, #063C54 60%, #075267 100%);
            color: rgba(255, 255, 255, 0.6);
            padding: 56px 0 32px;
        }
        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }
        .footer-brand {
            display: flex;
            align-items: center;
            gap: 10px;
            color: #fff;
            font-weight: 700;
            font-size: 18px;
            margin-bottom: 14px;
            letter-spacing: 1px;
        }
        .footer-brand img {
            width: 42px;
            height: 42px;
            filter: drop-shadow(0 6px 12px rgba(32, 201, 107, 0.18));
        }
        .footer-desc {
            font-size: 13.5px;
            line-height: 1.75;
            max-width: 360px;
        }
        .footer-col h5 {
            color: #fff;
            font-size: 13px;
            font-weight: 500;
            margin-bottom: 14px;
        }
        .footer-col ul { list-style: none; }
        .footer-col li { margin-bottom: 10px; }
        .footer-col a {
            color: rgba(255, 255, 255, 0.6);
            font-size: 13px;
            transition: color 180ms ease;
        }
        .footer-col a:hover { color: #fff; text-decoration: none; }
        .footer-bottom {
            padding-top: 28px;
            border-top: 1px solid rgba(255, 255, 255, 0.08);
            display: flex;
            justify-content: space-between;
            font-size: 12.5px;
            flex-wrap: wrap;
            gap: 12px;
        }

        @media (max-width: 720px) {
            .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
            .footer-grid > :first-child { grid-column: span 2; }
            .footer-bottom { justify-content: center; text-align: center; flex-direction: column; }
        }

        /* ===== Toast ===== */
        .toast {
            position: fixed;
            bottom: 28px;
            left: 50%;
            transform: translateX(-50%) translateY(20px);
            background: rgba(7, 38, 55, 0.94);
            color: #fff;
            padding: 10px 18px;
            border-radius: 6px;
            font-size: 13px;
            opacity: 0;
            pointer-events: none;
            transition: opacity 220ms ease, transform 220ms ease;
            z-index: 100;
            max-width: 86%;
            text-align: center;
        }
        .toast.show {
            opacity: 1;
            transform: translateX(-50%) translateY(0);
        }

        button:focus-visible, a:focus-visible, label:focus-within {
            outline: 2px solid var(--c-primary);
            outline-offset: 2px;
        }

        @media (prefers-reduced-motion: reduce) {
            *, *::before, *::after {
                transition-duration: 0.01ms !important;
                scroll-behavior: auto !important;
            }
        }