:root {
    --color-dark: #454553;
    --color-blue: #4aa0d5;
    --color-light-bg: #d8e9f0;
    --color-accent: #eb586f;
    --color-white: #ffffff;
    --color-bg: #f5f7fa;
    --color-border: #e8ecf1;
    --color-text: #333;
    --color-text-light: #6b7280;
    --color-card: #ffffff;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.10);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: 0.25s ease;
    --max-width: 1320px;
    --sidebar-width: 340px;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.site-header {
    width: 100%;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition);
}
.site-header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    height: 64px;
    gap: 16px;
    flex-wrap: wrap;
}

.header-logo {
    flex-shrink: 0;
}
.header-logo h1 {
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--color-dark);
    letter-spacing: 0.5px;
    white-space: nowrap;
    margin: 0;
    line-height: 1;
}
.header-logo h1 span {
    color: var(--color-blue);
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
    list-style: none;
}
.header-nav a {
    display: inline-block;
    padding: 8px 14px;
    text-decoration: none;
    color: var(--color-dark);
    font-size: 0.93rem;
    font-weight: 500;
    border-radius: 6px;
    transition: all var(--transition);
    white-space: nowrap;
}
.header-nav a:hover,
.header-nav a:focus {
    color: var(--color-blue);
    background-color: var(--color-light-bg);
    outline: none;
}

.header-actions {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: 10px;
}
.btn-login {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 20px;
    background: var(--color-blue);
    color: #fff;
    border: none;
    border-radius: 22px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    transition: all var(--transition);
    white-space: nowrap;
    letter-spacing: 0.3px;
}
.btn-login:hover {
    background: #3a8db8;
    box-shadow: 0 4px 14px rgba(74, 160, 213, 0.35);
    transform: translateY(-1px);
}
.btn-login:active {
    transform: scale(0.97);
}

.mobile-nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    color: var(--color-dark);
    font-size: 1.5rem;
    line-height: 1;
}

@media (max-width: 900px) {
    .header-nav {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 16px 20px;
        gap: 4px;
        border-bottom: 2px solid var(--color-border);
        box-shadow: var(--shadow-md);
        z-index: 999;
    }
    .header-nav.open {
        display: flex;
    }
    .header-nav a {
        width: 100%;
        padding: 12px 16px;
        font-size: 1rem;
        border-radius: 8px;
    }
    .mobile-nav-toggle {
        display: block;
    }
    .header-inner {
        height: 56px;
        padding: 0 16px;
        gap: 10px;
    }
    .header-logo h1 {
        font-size: 1.3rem;
    }
}
@media (max-width: 480px) {
    .btn-login {
        padding: 7px 14px;
        font-size: 0.82rem;
        border-radius: 18px;
    }
    .header-logo h1 {
        font-size: 1.15rem;
    }
    .header-inner {
        height: 50px;
        padding: 0 12px;
    }
}

.main-container {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    gap: 28px;
    padding: 28px 24px;
    min-height: 60vh;
}

.content-left {
    flex: 1;
    min-width: 0;
}
.content-right {
    flex: 0 0 var(--sidebar-width);
    width: var(--sidebar-width);
    min-width: 300px;
    display: flex;
    flex-direction: column;
    gap: 22px;
}

@media (max-width: 1100px) {
    .main-container {
        gap: 20px;
        padding: 20px 16px;
    }
    .content-right {
        flex: 0 0 300px;
        width: 300px;
        min-width: 280px;
    }
}
@media (max-width: 900px) {
    .main-container {
        flex-direction: column;
        gap: 24px;
        padding: 16px 12px;
    }
    .content-right {
        flex: 1 1 auto;
        width: 100%;
        min-width: 0;
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 16px;
    }
}
@media (max-width: 600px) {
    .content-right {
        grid-template-columns: 1fr;
        gap: 14px;
    }
    .main-container {
        padding: 12px 8px;
        gap: 16px;
    }
}

.section-block {
    background: var(--color-card);
    border-radius: var(--radius-lg);
    padding: 24px 22px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    transition: box-shadow var(--transition);
}
.section-block:hover {
    box-shadow: var(--shadow-md);
}
.section-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--color-light-bg);
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: 0.3px;
}
.section-title .title-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--color-accent);
    flex-shrink: 0;
    display: inline-block;
}
.section-title .title-bar {
    width: 4px;
    height: 20px;
    border-radius: 2px;
    background: var(--color-blue);
    flex-shrink: 0;
    display: inline-block;
}

.hot-comics-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 16px;
}
.comic-card {
    background: #fff;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--color-border);
    transition: all var(--transition);
    cursor: pointer;
    display: flex;
    flex-direction: column;
}
.comic-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-blue);
}
.comic-card-img-wrap {
    position: relative;
    width: 100%;
    aspect-ratio: 2 / 3;
    overflow: hidden;
    background: #eef2f7;
}
.comic-card-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
    transition: transform 0.35s ease;
}
.comic-card:hover .comic-card-img-wrap img {
    transform: scale(1.06);
}
.comic-card-type-badge {
    position: absolute;
    top: 8px;
    left: 8px;
    background: var(--color-accent);
    color: #fff;
    font-size: 0.72rem;
    font-weight: 600;
    padding: 3px 10px;
    border-radius: 12px;
    letter-spacing: 0.4px;
    z-index: 2;
}
.comic-card-info {
    padding: 10px 12px 12px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px;
}
.comic-card-info h3 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-dark);
    line-height: 1.3;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    margin: 0;
}
.comic-card-meta {
    font-size: 0.75rem;
    color: var(--color-text-light);
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    line-height: 1.4;
}
.comic-card-meta span {
    background: #f3f5f8;
    padding: 2px 8px;
    border-radius: 10px;
    white-space: nowrap;
    font-size: 0.7rem;
}

@media (max-width: 1200px) {
    .hot-comics-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 14px;
    }
}
@media (max-width: 768px) {
    .hot-comics-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 10px;
    }
    .comic-card-info h3 {
        font-size: 0.82rem;
    }
    .comic-card-meta {
        font-size: 0.68rem;
        gap: 3px;
    }
    .comic-card-meta span {
        font-size: 0.65rem;
        padding: 2px 6px;
    }
}
@media (max-width: 480px) {
    .hot-comics-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }
    .comic-card-info {
        padding: 8px 8px 10px;
    }
    .comic-card-info h3 {
        font-size: 0.78rem;
    }
    .section-block {
        padding: 16px 10px;
        border-radius: var(--radius-md);
    }
}

.featured-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.featured-card {
    display: flex;
    gap: 14px;
    background: #fafcfd;
    border-radius: var(--radius-md);
    padding: 14px;
    border: 1px solid var(--color-border);
    transition: all var(--transition);
    cursor: pointer;
    align-items: center;
}
.featured-card:hover {
    border-color: var(--color-blue);
    box-shadow: var(--shadow-md);
    background: #fff;
}
.featured-card-img {
    flex: 0 0 90px;
    height: 125px;
    border-radius: 6px;
    overflow: hidden;
    background: #eef2f7;
}
.featured-card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.featured-card-info h4 {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-dark);
    margin: 0 0 6px;
}
.featured-card-info p {
    font-size: 0.78rem;
    color: var(--color-text-light);
    line-height: 1.5;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.featured-badge {
    display: inline-block;
    background: var(--color-accent);
    color: #fff;
    font-size: 0.68rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 10px;
    margin-bottom: 6px;
    letter-spacing: 0.4px;
}

@media (max-width: 1200px) {
    .featured-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 768px) {
    .featured-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }
    .featured-card {
        gap: 10px;
        padding: 10px;
    }
    .featured-card-img {
        flex: 0 0 70px;
        height: 100px;
    }
}

.characters-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
}
.character-card {
    text-align: center;
    background: #fafcfd;
    border-radius: var(--radius-md);
    padding: 16px 10px;
    border: 1px solid var(--color-border);
    transition: all var(--transition);
}
.character-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-blue);
}
.character-avatar {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto 10px;
    background: #eef2f7;
    border: 3px solid var(--color-light-bg);
    transition: border-color var(--transition);
}
.character-card:hover .character-avatar {
    border-color: var(--color-blue);
}
.character-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.character-card h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-dark);
    margin: 0 0 4px;
}
.character-card .char-role {
    font-size: 0.72rem;
    color: var(--color-blue);
    font-weight: 500;
    margin-bottom: 6px;
}
.character-card p {
    font-size: 0.73rem;
    color: var(--color-text-light);
    line-height: 1.4;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

@media (max-width: 768px) {
    .characters-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
    .character-avatar {
        width: 65px;
        height: 65px;
    }
}
@media (max-width: 480px) {
    .characters-grid {
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }
    .character-card {
        padding: 12px 6px;
    }
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 14px;
}
.advantage-item {
    background: #fafcfd;
    border-radius: var(--radius-md);
    padding: 18px 16px;
    text-align: center;
    border: 1px solid var(--color-border);
    transition: all var(--transition);
}
.advantage-item:hover {
    border-color: var(--color-blue);
    box-shadow: var(--shadow-sm);
}
.advantage-icon-circle {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--color-light-bg);
    margin: 0 auto 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    color: var(--color-blue);
    font-weight: 700;
}
.advantage-item h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-dark);
    margin: 0 0 6px;
}
.advantage-item p {
    font-size: 0.78rem;
    color: var(--color-text-light);
    line-height: 1.5;
    margin: 0;
}

@media (max-width: 768px) {
    .advantages-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
}
@media (max-width: 480px) {
    .advantages-grid {
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }
    .advantage-item {
        padding: 14px 10px;
    }
}

.tags-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.tag-item {
    display: inline-block;
    padding: 7px 16px;
    background: var(--color-light-bg);
    color: var(--color-dark);
    border-radius: 20px;
    font-size: 0.82rem;
    font-weight: 500;
    text-decoration: none;
    transition: all var(--transition);
    cursor: pointer;
    border: 1px solid transparent;
}
.tag-item:hover {
    background: var(--color-blue);
    color: #fff;
    border-color: var(--color-blue);
}
.tag-item.hot-tag {
    background: #fef0f2;
    color: var(--color-accent);
    border-color: #fdd4da;
    font-weight: 600;
}
.tag-item.hot-tag:hover {
    background: var(--color-accent);
    color: #fff;
    border-color: var(--color-accent);
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.faq-item {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    transition: all var(--transition);
    background: #fafcfd;
}
.faq-question {
    padding: 14px 16px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--color-dark);
    display: flex;
    justify-content: space-between;
    align-items: center;
    user-select: none;
    transition: background var(--transition);
}
.faq-question:hover {
    background: #f0f5f8;
}
.faq-arrow {
    font-size: 0.7rem;
    color: var(--color-blue);
    transition: transform 0.3s ease;
    flex-shrink: 0;
    margin-left: 8px;
}
.faq-item.open .faq-arrow {
    transform: rotate(180deg);
}
.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s ease, padding 0.35s ease;
    padding: 0 16px;
    font-size: 0.82rem;
    color: var(--color-text-light);
    line-height: 1.6;
    background: #fff;
}
.faq-item.open .faq-answer {
    max-height: 200px;
    padding: 0 16px 14px;
}

.platform-intro-text {
    font-size: 0.9rem;
    color: var(--color-text-light);
    line-height: 1.8;
}
.platform-intro-text strong {
    color: var(--color-dark);
}

.app-download-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 14px;
}
.app-download-card {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 16px;
    background: #fafcfd;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    text-decoration: none;
    color: var(--color-dark);
    transition: all var(--transition);
    cursor: pointer;
}
.app-download-card:hover {
    border-color: var(--color-blue);
    box-shadow: var(--shadow-md);
    background: #fff;
}
.app-download-card .app-icon {
    flex-shrink: 0;
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
}
.app-download-card .app-icon img {
    width: 34px;
    height: 34px;
    object-fit: contain;
    display: block;
}
.app-download-card .app-info {
    font-size: 0.82rem;
    font-weight: 600;
    line-height: 1.3;
}
.app-download-card .app-info small {
    display: block;
    font-weight: 400;
    font-size: 0.7rem;
    color: var(--color-text-light);
}

@media (max-width: 768px) {
    .app-download-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
}
@media (max-width: 480px) {
    .app-download-grid {
        grid-template-columns: 1fr 1fr;
        gap: 8px;
    }
    .app-download-card {
        padding: 10px 12px;
        gap: 6px;
    }
    .app-download-card .app-icon img {
        width: 26px;
        height: 26px;
    }
}

.sidebar-card {
    background: #fff;
    border-radius: var(--radius-md);
    padding: 18px 16px;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}
.sidebar-card h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-dark);
    margin-bottom: 12px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--color-light-bg);
    letter-spacing: 0.3px;
}
.rank-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.rank-list li {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px;
    border-radius: 6px;
    transition: all var(--transition);
    cursor: pointer;
}
.rank-list li:hover {
    background: #f8fafb;
}
.rank-num {
    flex-shrink: 0;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.78rem;
    color: #fff;
    background: #b0bec5;
    letter-spacing: 0;
}
.rank-list li:nth-child(1) .rank-num {
    background: #eb586f;
}
.rank-list li:nth-child(2) .rank-num {
    background: #f59e0b;
}
.rank-list li:nth-child(3) .rank-num {
    background: #4aa0d5;
}
.rank-thumb {
    flex-shrink: 0;
    width: 44px;
    height: 58px;
    border-radius: 4px;
    overflow: hidden;
    background: #eef2f7;
}
.rank-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}
.rank-info {
    flex: 1;
    min-width: 0;
}
.rank-info .rank-title {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--color-dark);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}
.rank-info .rank-sub {
    font-size: 0.7rem;
    color: var(--color-text-light);
    margin-top: 2px;
}
.rank-change {
    font-size: 0.72rem;
    font-weight: 600;
    flex-shrink: 0;
}
.rank-change.up {
    color: #eb586f;
}
.rank-change.down {
    color: #6b7280;
}

.stats-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.stat-mini-card {
    flex: 1;
    min-width: 60px;
    text-align: center;
    background: #fafcfd;
    border-radius: 8px;
    padding: 12px 8px;
    border: 1px solid var(--color-border);
}
.stat-mini-card .stat-value {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--color-accent);
    line-height: 1;
    margin-bottom: 4px;
}
.stat-mini-card .stat-label {
    font-size: 0.68rem;
    color: var(--color-text-light);
}
.update-time {
    font-size: 0.7rem;
    color: #aaa;
    text-align: right;
    margin-top: 8px;
}

.comment-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-height: 700px;
    overflow-y: auto;
    padding-right: 4px;
}
.comment-list::-webkit-scrollbar {
    width: 4px;
}
.comment-list::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 2px;
}
.comment-item {
    display: flex;
    gap: 10px;
    padding: 10px;
    border-radius: 8px;
    background: #fafcfd;
    transition: all var(--transition);
    border: 1px solid transparent;
}
.comment-item:hover {
    background: #fff;
    border-color: var(--color-border);
}
.comment-body {
    flex: 1;
    min-width: 0;
}
.comment-body .comment-user {
    font-weight: 600;
    font-size: 0.8rem;
    color: var(--color-dark);
}
.comment-body .comment-time {
    font-size: 0.68rem;
    color: #b0b8c1;
    margin-left: 6px;
}
.comment-body .comment-text {
    font-size: 0.78rem;
    color: #555;
    line-height: 1.5;
    margin-top: 3px;
    word-break: break-word;
}

.site-footer {
    width: 100%;
    background: var(--color-dark);
    color: #c5cdd5;
    padding: 32px 24px 20px;
    margin-top: 20px;
}
.footer-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    justify-content: space-between;
}
.footer-col {
    flex: 1;
    min-width: 140px;
}
.footer-col h4 {
    color: #fff;
    font-size: 0.95rem;
    margin-bottom: 12px;
    letter-spacing: 0.3px;
}
.footer-col a {
    display: block;
    color: #b0b8c1;
    text-decoration: none;
    font-size: 0.8rem;
    padding: 4px 0;
    transition: color var(--transition);
}
.footer-col a:hover {
    color: var(--color-blue);
}
.footer-bottom {
    max-width: var(--max-width);
    margin: 20px auto 0;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    text-align: center;
    font-size: 0.75rem;
    color: #8899a6;
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
    justify-content: center;
    align-items: center;
}
.footer-bottom a {
    color: #c5cdd5;
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition);
    white-space: nowrap;
}
.footer-bottom a:hover {
    color: var(--color-blue);
}
.footer-bottom .sep {
    color: #555;
}

@media (max-width: 600px) {
    .site-footer {
        padding: 20px 12px 14px;
    }
    .footer-inner {
        gap: 16px;
    }
    .footer-col {
        min-width: 120px;
        flex: 1 1 45%;
    }
}

.back-to-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--color-blue);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 700;
    box-shadow: var(--shadow-md);
    z-index: 999;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    text-decoration: none;
}
.back-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}
.back-to-top:hover {
    background: #3a8db8;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}