/* roulang page: index */
:root {
            --bg-primary: #0f0f0f;
            --bg-secondary: #181818;
            --bg-card: #1e1e1e;
            --bg-nav: rgba(30, 30, 30, 0.85);
            --text-primary: #f0ece6;
            --text-secondary: #9c9994;
            --text-body: #cbc8c3;
            --accent-copper: #c49b5c;
            --accent-teal: #2dd4bf;
            --accent-teal-hover: #5ee8d4;
            --accent-green: #22c55e;
            --border-subtle: rgba(255, 255, 255, 0.06);
            --border-light: rgba(255, 255, 255, 0.25);
            --border-copper: rgba(196, 155, 92, 0.4);
            --radius-sm: 6px;
            --radius-md: 8px;
            --radius-lg: 16px;
            --radius-full: 9999px;
            --shadow-card: 0 1px 2px rgba(0, 0, 0, 0.4), 0 4px 16px rgba(0, 0, 0, 0.25);
            --shadow-card-hover: 0 2px 4px rgba(0, 0, 0, 0.5), 0 8px 32px rgba(0, 0, 0, 0.35);
            --shadow-nav: 0 2px 20px rgba(0, 0, 0, 0.5);
            --font-sans: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
            --font-mono: "SF Mono", "JetBrains Mono", "Fira Code", "Consolas", monospace;
            --max-width: 1200px;
            --section-padding: 120px;
            --section-padding-mobile: 80px;
            --transition-fast: 0.25s ease;
            --transition-smooth: 0.35s cubic-bezier(0.25, 0.1, 0.25, 1);
        }

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

        html {
            scroll-behavior: smooth;
            scroll-padding-top: 100px;
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
        }

        body {
            font-family: var(--font-sans);
            background-color: var(--bg-primary);
            color: var(--text-primary);
            line-height: 1.75;
            font-size: 1rem;
            min-height: 100vh;
            overflow-x: hidden;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: color var(--transition-fast);
        }

        button {
            cursor: pointer;
            font-family: inherit;
            border: none;
            background: none;
        }

        input {
            font-family: inherit;
        }

        .container {
            max-width: var(--max-width);
            margin: 0 auto;
            padding-left: 24px;
            padding-right: 24px;
        }

        @media (max-width: 479px) {
            .container {
                padding-left: 16px;
                padding-right: 16px;
            }
        }

        .section {
            padding-top: var(--section-padding);
            padding-bottom: var(--section-padding);
        }

        @media (max-width: 767px) {
            .section {
                padding-top: var(--section-padding-mobile);
                padding-bottom: var(--section-padding-mobile);
            }
        }

        .section-alt {
            background-color: var(--bg-secondary);
        }

        .section-dark {
            background-color: var(--bg-primary);
        }

        .section-heading {
            text-align: center;
            margin-bottom: 3.5rem;
        }

        .section-heading h2 {
            font-size: clamp(2rem, 4vw, 2.75rem);
            font-weight: 600;
            letter-spacing: -0.01em;
            color: var(--text-primary);
            margin-bottom: 0.75rem;
        }

        .section-heading .subtitle {
            color: var(--text-secondary);
            font-size: 1.1rem;
            max-width: 560px;
            margin: 0 auto;
        }

        .section-divider {
            width: 100%;
            height: 2px;
            background: linear-gradient(90deg, transparent, var(--accent-copper), transparent);
            opacity: 0.5;
            margin: 0 auto;
        }

        /* ========== 导航胶囊 ========== */
        .nav-capsule-wrapper {
            position: fixed;
            top: 24px;
            left: 50%;
            transform: translateX(-50%) translateY(-140%);
            z-index: 1000;
            transition: transform 0.45s cubic-bezier(0.25, 0.1, 0.25, 1), opacity 0.45s ease;
            opacity: 0;
            pointer-events: none;
        }

        .nav-capsule-wrapper.visible {
            transform: translateX(-50%) translateY(0);
            opacity: 1;
            pointer-events: auto;
        }

        .nav-capsule {
            display: flex;
            align-items: center;
            gap: 32px;
            background: var(--bg-nav);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border-radius: var(--radius-full);
            padding: 10px 24px;
            box-shadow: var(--shadow-nav);
            border: 1px solid var(--border-subtle);
            white-space: nowrap;
        }

        .nav-logo {
            font-family: var(--font-mono);
            font-weight: 700;
            font-size: 1.1rem;
            color: var(--accent-copper);
            letter-spacing: 0.03em;
            flex-shrink: 0;
        }

        .nav-links {
            display: flex;
            align-items: center;
            gap: 24px;
            list-style: none;
        }

        .nav-links a {
            color: var(--text-secondary);
            font-size: 0.9rem;
            font-weight: 500;
            transition: color var(--transition-fast);
            position: relative;
            padding: 2px 0;
        }

        .nav-links a:hover,
        .nav-links a.active {
            color: var(--text-primary);
        }

        .nav-links a.active::after {
            content: '';
            position: absolute;
            bottom: -2px;
            left: 0;
            right: 0;
            height: 1.5px;
            background: var(--accent-teal);
            border-radius: 1px;
        }

        .nav-cta-btn {
            background: var(--accent-teal);
            color: var(--bg-primary);
            font-size: 0.875rem;
            font-weight: 600;
            padding: 8px 20px;
            border-radius: var(--radius-full);
            transition: all var(--transition-fast);
            flex-shrink: 0;
            cursor: pointer;
            border: none;
        }

        .nav-cta-btn:hover {
            background: var(--accent-teal-hover);
            transform: scale(1.03);
            box-shadow: 0 0 24px rgba(45, 212, 191, 0.35);
        }

        .nav-hamburger {
            display: none;
            font-size: 1.4rem;
            color: var(--accent-copper);
            cursor: pointer;
            flex-shrink: 0;
            background: none;
            border: none;
            padding: 4px;
        }

        @media (max-width: 767px) {
            .nav-capsule {
                gap: 16px;
                padding: 10px 16px;
            }
            .nav-links {
                display: none;
            }
            .nav-hamburger {
                display: block;
            }
            .nav-capsule-wrapper {
                top: 12px;
            }
            .nav-cta-btn {
                font-size: 0.8rem;
                padding: 6px 16px;
            }
            .nav-logo {
                font-size: 0.95rem;
            }
        }

        /* 移动端全屏导航面板 */
        .nav-mobile-panel {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100vh;
            background: rgba(15, 15, 15, 0.97);
            z-index: 999;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            gap: 32px;
            opacity: 0;
            pointer-events: none;
            transition: opacity 0.35s ease;
        }

        .nav-mobile-panel.open {
            opacity: 1;
            pointer-events: auto;
        }

        .nav-mobile-panel a {
            font-size: 1.4rem;
            color: var(--text-primary);
            font-weight: 600;
            transition: color var(--transition-fast);
        }

        .nav-mobile-panel a:hover {
            color: var(--accent-teal);
        }

        .nav-mobile-close {
            position: absolute;
            top: 20px;
            right: 24px;
            font-size: 1.6rem;
            color: var(--text-secondary);
            cursor: pointer;
            background: none;
            border: none;
            padding: 8px;
        }

        /* ========== Hero ========== */
        #hero {
            min-height: 90vh;
            display: flex;
            align-items: center;
            background-color: var(--bg-primary);
            background-image:
                linear-gradient(rgba(255, 255, 255, 0.018) 1px, transparent 1px),
                linear-gradient(90deg, rgba(255, 255, 255, 0.018) 1px, transparent 1px);
            background-size: 80px 80px;
            background-position: center center;
            position: relative;
            overflow: hidden;
        }

        .hero-inner {
            display: flex;
            align-items: center;
            gap: 60px;
            width: 100%;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        .hero-content {
            flex: 1;
            max-width: 620px;
        }

        .hero-content h1 {
            font-size: clamp(3rem, 6vw, 5rem);
            font-weight: 700;
            letter-spacing: -0.02em;
            line-height: 1.1;
            color: var(--text-primary);
            margin-bottom: 1.25rem;
        }

        .hero-content .hero-subtitle {
            font-size: 1.25rem;
            color: var(--text-secondary);
            max-width: 560px;
            margin-bottom: 2.5rem;
            line-height: 1.6;
        }

        .hero-buttons {
            display: flex;
            align-items: center;
            gap: 20px;
            flex-wrap: wrap;
        }

        .hero-image {
            flex: 1;
            max-width: 520px;
            display: flex;
            align-items: center;
            justify-content: center;
        }

        .hero-image img {
            border-radius: 20px;
            box-shadow: var(--shadow-card-hover);
            width: 100%;
            height: auto;
            object-fit: cover;
        }

        @media (max-width: 1023px) {
            .hero-inner {
                flex-direction: column;
                text-align: center;
                gap: 40px;
                padding-top: 100px;
                padding-bottom: 60px;
            }
            .hero-content {
                max-width: 100%;
            }
            .hero-content .hero-subtitle {
                max-width: 100%;
            }
            .hero-buttons {
                justify-content: center;
            }
            .hero-image {
                max-width: 400px;
                margin: 0 auto;
            }
        }

        @media (max-width: 479px) {
            #hero {
                min-height: auto;
                padding-top: 80px;
                padding-bottom: 40px;
            }
            .hero-inner {
                padding-top: 60px;
                padding-bottom: 40px;
                gap: 28px;
            }
            .hero-buttons {
                flex-direction: column;
                width: 100%;
            }
            .hero-buttons .btn-primary,
            .hero-buttons .text-link {
                width: 100%;
                text-align: center;
                justify-content: center;
            }
            .hero-image {
                max-width: 100%;
            }
        }

        /* ========== 按钮系统 ========== */
        .btn-primary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            background: var(--accent-teal);
            color: var(--bg-primary);
            font-weight: 600;
            padding: 14px 36px;
            border-radius: var(--radius-full);
            font-size: 1rem;
            transition: all var(--transition-fast);
            cursor: pointer;
            border: none;
            white-space: nowrap;
        }

        .btn-primary:hover {
            background: var(--accent-teal-hover);
            transform: scale(1.03);
            box-shadow: 0 0 24px rgba(45, 212, 191, 0.35);
        }

        .btn-secondary {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            border: 1.5px solid var(--border-light);
            color: var(--text-primary);
            background: transparent;
            padding: 14px 36px;
            border-radius: var(--radius-full);
            font-size: 1rem;
            font-weight: 500;
            transition: all var(--transition-fast);
            cursor: pointer;
            white-space: nowrap;
        }

        .btn-secondary:hover {
            border-color: var(--accent-copper);
            color: var(--accent-copper);
            background: rgba(196, 155, 92, 0.06);
        }

        .text-link {
            display: inline-flex;
            align-items: center;
            gap: 6px;
            color: var(--accent-teal);
            font-weight: 500;
            border-bottom: 1px dashed var(--accent-teal);
            transition: all var(--transition-fast);
            cursor: pointer;
            padding: 2px 0;
        }

        .text-link:hover {
            color: var(--accent-teal-hover);
            border-bottom-style: solid;
        }

        .text-link-copper {
            color: var(--accent-copper);
            border-bottom: 1px dashed var(--accent-copper);
            display: inline-flex;
            align-items: center;
            gap: 4px;
            font-weight: 500;
            transition: all var(--transition-fast);
            cursor: pointer;
        }

        .text-link-copper:hover {
            border-bottom-style: solid;
            color: #d4af6e;
        }

        /* ========== 痛点区块 ========== */
        .pain-list {
            max-width: 720px;
            margin: 0 auto;
            display: flex;
            flex-direction: column;
            gap: 28px;
        }

        .pain-item {
            display: flex;
            align-items: flex-start;
            gap: 20px;
            padding: 0;
            opacity: 0;
            transform: translateX(-30px);
            transition: opacity 0.6s ease, transform 0.6s ease;
        }

        .pain-item.visible {
            opacity: 1;
            transform: translateX(0);
        }

        .pain-item:nth-child(1) {
            transition-delay: 0.05s;
        }
        .pain-item:nth-child(2) {
            transition-delay: 0.15s;
        }
        .pain-item:nth-child(3) {
            transition-delay: 0.25s;
        }

        .pain-icon {
            flex-shrink: 0;
            width: 44px;
            height: 44px;
            border-radius: var(--radius-md);
            background: rgba(196, 155, 92, 0.1);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.2rem;
            color: #b0894e;
        }

        .pain-text h3 {
            font-size: 1.15rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 4px;
        }

        .pain-text p {
            color: var(--text-body);
            font-size: 0.95rem;
            line-height: 1.6;
            max-width: 540px;
        }

        /* ========== 解决方案卡片 ========== */
        .solution-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 32px;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        @media (max-width: 1023px) {
            .solution-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 767px) {
            .solution-grid {
                grid-template-columns: 1fr;
                max-width: 480px;
            }
        }

        .solution-card {
            background: var(--bg-card);
            border-radius: var(--radius-lg);
            padding: 40px;
            border: 1px solid var(--border-subtle);
            box-shadow: var(--shadow-card);
            transition: all var(--transition-smooth);
            display: flex;
            flex-direction: column;
            position: relative;
            overflow: hidden;
            opacity: 0;
            transform: translateY(30px);
        }

        .solution-card.visible {
            opacity: 1;
            transform: translateY(0);
        }

        .solution-card:nth-child(1).visible {
            transition-delay: 0.05s;
        }
        .solution-card:nth-child(2).visible {
            transition-delay: 0.15s;
        }
        .solution-card:nth-child(3).visible {
            transition-delay: 0.25s;
        }

        .solution-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-card-hover);
            border-color: var(--border-copper);
        }

        .solution-card.featured {
            border-top: 3px solid var(--accent-copper);
        }

        .solution-card-img {
            width: 100%;
            height: 160px;
            object-fit: cover;
            border-radius: var(--radius-md);
            margin-bottom: 20px;
            background: var(--bg-secondary);
        }

        .solution-card-icon {
            font-size: 2rem;
            color: var(--accent-teal);
            margin-bottom: 16px;
            display: block;
        }

        .solution-card h3 {
            font-size: 1.25rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 10px;
        }

        .solution-card p {
            color: var(--text-body);
            font-size: 0.95rem;
            line-height: 1.65;
            flex-grow: 1;
            margin-bottom: 16px;
        }

        .solution-card .card-link {
            margin-top: auto;
        }

        /* ========== 成果数据 ========== */
        .results-grid {
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            gap: 32px;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
            text-align: center;
        }

        @media (max-width: 767px) {
            .results-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 28px;
            }
        }

        @media (max-width: 479px) {
            .results-grid {
                grid-template-columns: 1fr 1fr;
                gap: 20px;
            }
        }

        .result-item {
            padding: 20px;
        }

        .result-number {
            font-family: var(--font-mono);
            font-size: clamp(2.5rem, 5vw, 4rem);
            font-weight: 700;
            color: var(--accent-teal);
            line-height: 1;
            margin-bottom: 8px;
            display: flex;
            align-items: baseline;
            justify-content: center;
            gap: 2px;
        }

        .result-number .unit {
            font-size: 1.5rem;
            font-weight: 500;
            color: var(--accent-teal);
        }

        .result-label {
            color: var(--text-secondary);
            font-size: 0.9rem;
            font-weight: 500;
        }

        .result-check {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            width: 32px;
            height: 32px;
            border-radius: 50%;
            background: rgba(34, 197, 94, 0.15);
            color: var(--accent-green);
            font-size: 0.9rem;
            margin-bottom: 8px;
        }

        /* ========== 客户证言 ========== */
        .testimonials-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 32px;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        @media (max-width: 1023px) {
            .testimonials-grid {
                grid-template-columns: repeat(2, 1fr);
            }
        }

        @media (max-width: 767px) {
            .testimonials-grid {
                grid-template-columns: 1fr;
                max-width: 480px;
            }
        }

        .testimonial-card {
            background: var(--bg-card);
            border-radius: var(--radius-lg);
            padding: 36px;
            border: 1px solid var(--border-subtle);
            border-left: 3px solid transparent;
            box-shadow: var(--shadow-card);
            transition: all var(--transition-smooth);
            position: relative;
        }

        .testimonial-card:hover {
            transform: scale(1.02);
            border-left-color: var(--accent-copper);
            box-shadow: var(--shadow-card-hover);
        }

        .testimonial-quote {
            font-size: 1.05rem;
            color: var(--text-body);
            line-height: 1.7;
            margin-bottom: 20px;
            font-style: italic;
            position: relative;
            padding-left: 28px;
        }

        .testimonial-quote::before {
            content: '\201C';
            position: absolute;
            left: 0;
            top: -8px;
            font-size: 3rem;
            color: var(--accent-copper);
            font-family: Georgia, serif;
            font-style: normal;
            line-height: 1;
            opacity: 0.7;
        }

        .testimonial-divider {
            height: 1px;
            background: var(--border-subtle);
            margin-bottom: 16px;
        }

        .testimonial-author {
            display: flex;
            align-items: center;
            gap: 12px;
        }

        .testimonial-avatar {
            width: 44px;
            height: 44px;
            border-radius: 50%;
            object-fit: cover;
            background: var(--bg-secondary);
            flex-shrink: 0;
        }

        .testimonial-info h3 {
            font-size: 1rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 2px;
        }

        .testimonial-info span {
            font-size: 0.85rem;
            color: var(--text-secondary);
        }

        /* ========== CTA 区块 ========== */
        #cta {
            text-align: center;
            position: relative;
        }

        #cta .cta-content {
            max-width: 640px;
            margin: 0 auto;
            padding: 0 24px;
        }

        #cta h2 {
            font-size: clamp(1.75rem, 3.5vw, 2.5rem);
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 1rem;
        }

        #cta .cta-desc {
            color: var(--text-secondary);
            font-size: 1.05rem;
            margin-bottom: 2rem;
            line-height: 1.6;
        }

        .cta-buttons {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 20px;
            flex-wrap: wrap;
        }

        @media (max-width: 479px) {
            .cta-buttons {
                flex-direction: column;
                width: 100%;
            }
            .cta-buttons .btn-primary,
            .cta-buttons .btn-secondary {
                width: 100%;
            }
        }

        /* ========== FAQ 手风琴 ========== */
        .faq-list {
            max-width: 760px;
            margin: 0 auto;
            padding: 0 24px;
        }

        .faq-item {
            border-bottom: 1px solid rgba(255, 255, 255, 0.04);
            overflow: hidden;
        }

        .faq-question {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 20px 0;
            cursor: pointer;
            font-size: 1.05rem;
            font-weight: 500;
            color: var(--text-primary);
            transition: color var(--transition-fast);
            user-select: none;
            gap: 16px;
        }

        .faq-question:hover {
            color: var(--accent-teal);
        }

        .faq-question.active {
            color: var(--accent-teal);
        }

        .faq-arrow {
            flex-shrink: 0;
            font-size: 0.85rem;
            color: var(--text-secondary);
            transition: transform 0.35s ease;
        }

        .faq-question.active .faq-arrow {
            transform: rotate(180deg);
            color: var(--accent-teal);
        }

        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease, padding 0.35s ease;
        }

        .faq-answer.open {
            max-height: 400px;
            padding-bottom: 20px;
        }

        .faq-answer p {
            color: var(--text-body);
            font-size: 0.95rem;
            line-height: 1.7;
        }

        .faq-footer-link {
            text-align: center;
            margin-top: 2rem;
        }

        /* ========== 页脚 ========== */
        .site-footer {
            background: var(--bg-primary);
            border-top: 1px solid var(--border-subtle);
            padding-top: 60px;
            padding-bottom: 30px;
        }

        .footer-grid {
            display: grid;
            grid-template-columns: 2fr 1fr 1fr 1.5fr;
            gap: 40px;
            max-width: var(--max-width);
            margin: 0 auto;
            padding: 0 24px;
        }

        @media (max-width: 1023px) {
            .footer-grid {
                grid-template-columns: 1fr 1fr;
            }
        }

        @media (max-width: 767px) {
            .footer-grid {
                grid-template-columns: 1fr;
                gap: 32px;
            }
        }

        .footer-col h4 {
            font-size: 0.9rem;
            font-weight: 600;
            color: var(--text-primary);
            margin-bottom: 16px;
            text-transform: uppercase;
            letter-spacing: 0.04em;
        }

        .footer-col p,
        .footer-col a {
            font-size: 0.875rem;
            color: var(--text-secondary);
            line-height: 1.7;
            display: block;
            margin-bottom: 6px;
            transition: color var(--transition-fast);
        }

        .footer-col a:hover {
            color: var(--accent-teal);
        }

        .footer-logo {
            font-family: var(--font-mono);
            font-weight: 700;
            font-size: 1.1rem;
            color: var(--accent-copper);
            letter-spacing: 0.03em;
            margin-bottom: 12px;
            display: inline-block;
        }

        .footer-social {
            display: flex;
            gap: 12px;
            flex-wrap: wrap;
            margin-top: 8px;
        }

        .footer-social a {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 38px;
            height: 38px;
            border-radius: 50%;
            border: 1.5px solid var(--border-light);
            color: var(--text-secondary);
            font-size: 0.9rem;
            transition: all var(--transition-fast);
        }

        .footer-social a:hover {
            border-color: var(--accent-copper);
            color: var(--accent-copper);
            background: rgba(196, 155, 92, 0.08);
        }

        .footer-bottom {
            max-width: var(--max-width);
            margin: 40px auto 0;
            padding: 20px 24px 0;
            border-top: 1px solid var(--border-subtle);
            display: flex;
            flex-wrap: wrap;
            justify-content: space-between;
            align-items: center;
            gap: 12px;
            font-size: 0.8rem;
            color: var(--text-secondary);
        }

        @media (max-width: 479px) {
            .footer-bottom {
                flex-direction: column;
                text-align: center;
            }
        }

        /* ========== 动画关键帧 ========== */
        @keyframes fadeInUp {
            from {
                opacity: 0;
                transform: translateY(36px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .animate-fade-in-up {
            animation: fadeInUp 0.8s ease-out forwards;
        }

        .animate-delay-1 {
            animation-delay: 0.2s;
            opacity: 0;
        }
        .animate-delay-2 {
            animation-delay: 0.35s;
            opacity: 0;
        }
        .animate-delay-3 {
            animation-delay: 0.5s;
            opacity: 0;
        }

        /* ========== 通用徽章 ========== */
        .badge {
            display: inline-block;
            padding: 4px 12px;
            font-size: 0.75rem;
            border-radius: var(--radius-sm);
            background: rgba(45, 212, 191, 0.1);
            color: var(--accent-teal);
            font-weight: 500;
        }

        /* ========== 图片占位背景 ========== */
        img {
            background: var(--bg-card);
        }

        /* ========== 焦点可见 ========== */
        a:focus-visible,
        button:focus-visible {
            outline: 2px solid var(--accent-teal);
            outline-offset: 3px;
            border-radius: 4px;
        }

        /* ========== 平滑滚动偏移补偿 ========== */
        @media (min-width: 768px) {
            html {
                scroll-padding-top: 100px;
            }
        }
        @media (max-width: 767px) {
            html {
                scroll-padding-top: 80px;
            }
        }