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

        /* 基础大底色：沉稳浅灰 */
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
            background-color: #f1f5f9;
            color: #1e293b;
            padding: 40px 0;
            display: flex;
            justify-content: center;
        }

        .container {
            width: 100%;
            max-width: 1240px;
            padding: 0 20px;
        }

        /* 顶部大标题区 */
        .page-header {
            text-align: center;
            margin-bottom: 35px;
        }

        .page-header h1 {
            font-size: 34px;
            font-weight: 800;
            letter-spacing: 2px;
            color: #0f172a;
            margin-bottom: 10px;
        }

        .page-header p {
            font-size: 14px;
            color: #64748b;
        }

        /* 统一的主标签头 */
        .section-header {
            font-size: 16px;
            font-weight: 700;
            margin-bottom: 22px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .section-header::before {
            content: "";
            display: inline-block;
            width: 4px;
            height: 18px;
            background-color: #3b82f6;
            border-radius: 2px;
        }

        /* =========================================================================
           大版块一：选择服务器地域（极客深色系 - 科技感爆棚）
           ========================================================================= */
        .section-region-block {
            background-color: #0f172a; /* 酷炫深蓝黑底 */
            border-radius: 16px;
            padding: 35px 30px;
            margin-bottom: 35px;
            box-shadow: 0 10px 25px -5px rgba(15, 23, 42, 0.3);
        }

        .section-region-block .section-header {
            color: #f8fafc; /* 深色区标题加白 */
        }

        .region-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 16px;
        }

        @media (max-width: 768px) {
            .region-grid { grid-template-columns: 1fr; }
        }

        /* 深色底色上的卡片，带点高级透明感 */
        .region-card {
            background-color: rgba(30, 41, 59, 0.7);
            border: 1px solid #334155;
            border-radius: 10px;
            padding: 20px 24px;
            display: flex;
            align-items: center;
            justify-content: space-between;
            position: relative;
            cursor: pointer;
            transition: all 0.25s ease;
        }

        .region-card:hover {
            border-color: #475569;
            background-color: rgba(30, 41, 59, 0.9);
            transform: translateY(-1px);
        }

        /* 地域激活（高亮强对比） */
        .region-card.active {
            background-color: #1e293b !important;
            border: 2px solid #3b82f6 !important;
            box-shadow: 0 0 15px rgba(59, 130, 246, 0.3);
            opacity: 1 !important;
        }

        .region-left-box {
            display: flex;
            align-items: center;
            gap: 18px;
        }

        .region-checkbox {
            width: 22px;
            height: 22px;
            border: 1px solid #475569;
            border-radius: 6px;
            display: flex;
            align-items: center;
            justify-content: center;
            background: #1e293b;
            transition: all 0.15s;
        }

        .check-icon {
            display: none;
            font-size: 13px;
            color: #fff;
            font-weight: bold;
        }

        .region-card.active .region-checkbox {
            background-color: #3b82f6;
            border-color: #3b82f6;
        }

        .region-card.active .check-icon {
            display: block;
        }

        .flag-span {
            font-size: 26px;
            filter: drop-shadow(0 2px 4px rgba(0,0,0,0.15));
        }

        .region-info {
            display: flex;
            flex-direction: column;
            align-items: flex-end;
            gap: 6px;
        }

        .region-text {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .region-code {
            font-size: 22px;
            font-weight: 700;
            color: #f8fafc; /* 亮白色编码 */
            font-family: monospace, sans-serif;
        }

        .region-name {
            font-size: 15px;
            font-weight: 500;
            color: #94a3b8; /* 稍暗的辅助字 */
        }

        .region-card.active .region-name {
            color: #cbd5e1;
        }

        /* 标签样式 */
        .badge {
            font-size: 10px;
            padding: 2px 8px;
            border-radius: 4px;
            color: #ffffff;
            font-weight: 600;
            letter-spacing: 0.5px;
        }
        .badge-premium { background-color: #f97316; }
        .badge-premium-plus { background-color: #ef4444; }
        .badge-ipv4 { background-color: #0d9488; }
        
        .badge-oos {
            position: absolute;
            top: 0;
            left: 0;
            background-color: #475569;
            color: #cbd5e1;
            font-size: 10px;
            font-weight: 600;
            padding: 3px 8px;
            border-bottom-right-radius: 8px;
            border-top-left-radius: 8px;
        }

        .oos-card {
            opacity: 0.45;
        }

        /* =========================================================================
           大版块二：选择实例配置（明亮纯白系 - 干净整洁）
           ========================================================================= */
        .section-plan-block {
            background-color: #ffffff; /* 纯白底色 */
            border: 1px solid #e2e8f0;
            border-radius: 16px;
            padding: 35px 30px;
            box-shadow: 0 4px 20px rgba(0,0,0,0.03);
        }

        .section-plan-block .section-header {
            color: #0f172a;
        }

        .plan-wrapper {
            display: none;
        }

        .plan-wrapper.active {
            display: block;
            animation: fadeIn 0.25s ease-out;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(4px); }
            to { opacity: 1; transform: translateY(0); }
        }

        .plan-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 20px;
        }

        @media (max-width: 1024px) { .plan-grid { grid-template-columns: repeat(2, 1fr); } }
        @media (max-width: 640px) { .plan-grid { grid-template-columns: 1fr; } }

        .plan-card {
            background: #ffffff;
            border: 1px solid #e2e8f0;
            border-radius: 10px;
            padding: 24px;
            position: relative;
            display: flex;
            flex-direction: column;
            justify-content: space-between;
            min-height: 320px;
            cursor: pointer;
            transition: all 0.2s ease;
        }

        .plan-card:hover {
            border-color: #cbd5e1;
            box-shadow: 0 6px 16px rgba(0,0,0,0.04);
        }

        .plan-card.active {
            border: 2px solid #3b82f6 !important;
            box-shadow: 0 6px 16px rgba(59, 130, 246, 0.08);
        }

        .plan-check-tag {
            display: none;
            position: absolute;
            top: 0;
            right: 0;
            background: #3b82f6;
            color: #fff;
            font-size: 10px;
            font-weight: bold;
            padding: 4px 8px;
            border-bottom-left-radius: 8px;
            border-top-right-radius: 8px;
        }

        .plan-card.active .plan-check-tag {
            display: block;
        }

        .plan-name {
            font-size: 15px;
            font-weight: bold;
            color: #0f172a;
            background: #f1f5f9;
            padding: 4px 10px;
            border-radius: 6px;
            display: inline-block;
            align-self: flex-start;
        }

        .plan-specs {
            font-size: 13px;
            color: #334155;
            line-height: 2.2;
            text-align: center;
            margin: 20px 0;
            background: #f8fafc;
            padding: 12px;
            border-radius: 8px;
            border: 1px solid #f1f5f9;
        }

        /* 成功替换：大陆cn2优化标签样式 */
        .cn2-tag {
            font-size: 11px;
            color: #2563eb;
            background-color: #eff6ff;
            padding: 2px 8px;
            border-radius: 4px;
            margin-top: 6px;
            display: inline-block;
            font-weight: 600;
            letter-spacing: 0.5px;
        }

        .plan-footer {
            border-top: 1px solid #f1f5f9;
            padding-top: 14px;
            text-align: center;
        }

        .plan-price {
            font-size: 20px;
            font-weight: 700;
            color: #0f172a;
            margin-bottom: 12px;
        }

        .plan-price span {
            font-size: 12px;
            color: #64748b;
            font-weight: normal;
        }

        .buy-btn {
            display: block;
            width: 100%;
            background-color: #f8fafc;
            color: #3b82f6;
            border: 1px solid #e2e8f0;
            text-decoration: none;
            font-size: 13px;
            font-weight: 600;
            padding: 9px 0;
            border-radius: 6px;
            text-align: center;
            transition: all 0.15s ease;
        }

        .plan-card:hover .buy-btn, .plan-card.active .buy-btn {
            background-color: #3b82f6;
            color: #ffffff;
            border-color: #3b82f6;
            box-shadow: 0 2px 4px rgba(59, 130, 246, 0.2);
        }