@charset "utf-8";
/*
    Theme Name: bubbly AI 官网
    Theme URI: 
    Author: 阿叶
    Author URI: 
    Description:
    Version: 0.0.1
*/

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

:root {
    --pink-100: #fff0f3;
    --pink-200: #ffd6df;
    --pink-300: #ffb1c3;
    --pink-400: #ff8faa;
    --pink-500: #ff7295;
    --pink-600: #e55679;
    --pink-700: #cc3d62;
    --gray-50: #fafafa;
    --gray-100: #f5f5f5;
    --gray-200: #e5e5e5;
    --gray-500: #737373;
    --gray-600: #525252;
    --gray-700: #404040;
    --gray-800: #262626;
    --gray-900: #171717;
    --dark-bg: #1a1a2e;
    --radius: 16px;
    --radius-sm: 12px;
    --shadow: 0 4px 24px rgba(0,0,0,0.06);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.1);
}

html { scroll-behavior: smooth; }

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--gray-800);
    background: #fff;
    line-height: 1.6;
    overflow-x: hidden;
}
a,a:hover {
    color: #333;
    text-decoration: none;
}
.bu_container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navbar ===== */
.bu_navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    transition: box-shadow 0.3s;
}

.bu_navbar.bu_scrolled { box-shadow: 0 2px 20px rgba(0,0,0,0.08); }

.bu_navbar .bu_container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.bu_logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    font-weight: 800;
    font-size: 1.3rem;
    color: var(--pink-500);
}

.bu_logo_icon {
    width: 42px;
    height: 42px;
    border-radius: 10px;
    object-fit: contain;
}

.bu_nav_links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.bu_nav_links a {
    text-decoration: none;
    color: var(--gray-600);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s;
}

.bu_nav_links a:hover { color: var(--pink-500); }
.bu_nav_links a.bu_btn_primary { color: #fff; }

.bu_btn_primary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    color: #fff;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    border: none;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 16px rgba(255,114,149,0.3);
}

.bu_btn_primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(255,114,149,0.4);
}

.bu_btn_secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    background: rgba(255,255,255,0.2);
    backdrop-filter: blur(10px);
    color: #fff;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    border: 2px solid rgba(255,255,255,0.4);
    cursor: pointer;
    transition: all 0.2s;
}

.bu_btn_secondary:hover {
    background: rgba(255,255,255,0.3);
    border-color: rgba(255,255,255,0.6);
}

.bu_nav_right {
    display: none;
}

.bu_mobile_toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.bu_mobile_toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    margin: 6px 0;
    border-radius: 2px;
    transition: 0.3s;
}

/* ===== Hero ===== */
.bu_above {
    padding: 100px 0 0;
    background: #fff;
    position: relative;
}

.bu_above .bu_container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    position: relative;
    z-index: 1;
}

.bu_above_content { text-align: left; }

.bu_above_badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    background: var(--pink-100);
    border-radius: 50px;
    color: var(--pink-600);
    font-size: 0.82rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.bu_above h1 {
    margin-top: 0;
    font-size: clamp(2rem, 4.5vw, 3rem);
    font-weight: 800;
    color: var(--gray-900);
    line-height: 1.3;
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.bu_above h1 span {
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.bu_above_desc {
    font-size: clamp(0.92rem, 1.6vw, 1.05rem);
    color: var(--gray-500);
    max-width: 480px;
    margin-bottom: 28px;
    line-height: 1.75;
}

.bu_above_buttons {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.bu_above .bu_btn_outline {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    background: transparent;
    color: var(--gray-700);
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    border: 1.5px solid var(--gray-200);
    cursor: pointer;
    transition: all 0.2s;
}

.bu_above .bu_btn_outline:hover {
    border-color: var(--pink-300);
    color: var(--pink-500);
}

.bu_above_visual {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 340px;
}

.bu_above_visual_bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--pink-300) 0%, var(--pink-500) 60%, var(--pink-600) 100%);
    border-radius: 32px 32px 0 0;
}

.bu_above_visual_cards {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    gap: 14px;
    padding: 40px 32px;
    width: 100%;
}

.bu_above_card {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    border-radius: 14px;
    padding: 18px 20px;
    display: flex;
    align-items: center;
    gap: 14px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: transform 0.3s;
}

.bu_above_card:hover { transform: translateX(4px); }

.bu_above_card_icon {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--pink-100), var(--pink-200));
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--pink-600);
    font-size: 1rem;
    flex-shrink: 0;
}

.bu_above_card_text .bu_h4 {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 10px;
}

.bu_above_card_text p {
    font-size: 0.78rem;
    color: var(--gray-500);
    line-height: 1.4;
    margin: 0;
}

/* ===== Stats ===== */
.bu_stats {
    margin-top: -40px;
    position: relative;
    z-index: 10;
    padding-bottom: 48px;
}

.bu_stats_grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}

.bu_stat_card {
    background: #fff;
    border-radius: var(--radius-sm);
    padding: 24px 20px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    transition: transform 0.3s;
}

.bu_stat_card:hover { transform: translateY(-3px); }

.bu_stat_number {
    font-size: 1.8rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.bu_stat_label {
    font-size: 0.88rem;
    color: var(--gray-500);
    font-weight: 500;
}

/* ===== Section Common ===== */
.bu_section { padding: 100px 0; }
.bu_section_alt { background: var(--gray-50); }

.bu_section_header {
    text-align: center;
    margin-bottom: 64px;
}

.bu_section_tag {
    display: inline-block;
    padding: 6px 16px;
    background: var(--pink-100);
    color: var(--pink-600);
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 16px;
}

.bu_section_header .bu_h2 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 16px;
    letter-spacing: -0.02em;
}

.bu_section_header p {
    font-size: 1.1rem;
    color: var(--gray-500);
    max-width: 560px;
    margin: 0 auto;
}

/* ===== Features ===== */
.bu_features_grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.bu_feature_card {
    background: #fff;
    border-radius: var(--radius);
    padding: 36px 28px;
    border: 1px solid var(--gray-200);
    transition: all 0.3s;
}

.bu_section_alt .bu_feature_card { border-color: transparent; box-shadow: var(--shadow); }

.bu_feature_card:hover {
    border-color: var(--pink-200);
    box-shadow: 0 8px 32px rgba(255,114,149,0.1);
    transform: translateY(-4px);
}

.bu_feature_icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--pink-100), var(--pink-200));
    color: var(--pink-600);
}

.bu_feature_card .bu_h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.bu_feature_card p {
    font-size: 0.95rem;
    color: var(--gray-500);
    line-height: 1.7;
}

/* ===== Why Choose ===== */
.bu_why_grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.bu_why_card {
    background: linear-gradient(135deg, #fff 0%, var(--pink-100) 100%);
    border-radius: var(--radius);
    padding: 48px 36px;
    text-align: center;
    border: 1px solid var(--pink-200);
    transition: all 0.3s;
}

.bu_why_card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 40px rgba(255,114,149,0.15);
}

.bu_why_icon {
    width: 72px;
    height: 72px;
    border-radius: 20px;
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    color: #fff;
    margin: 0 auto 24px;
    box-shadow: 0 8px 24px rgba(255,114,149,0.3);
}

.bu_why_card .bu_h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 14px;
}

.bu_why_card p {
    font-size: 0.95rem;
    color: var(--gray-500);
    line-height: 1.7;
}

/* ===== News ===== */
.bu_news_grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.bu_news_card {
    display: flex;
    gap: 20px;
    background: #fff;
    border-radius: var(--radius);
    transition: all 0.3s;
    align-items: flex-start;
}

.bu_news_card:hover {
    border-color: var(--pink-200);
    box-shadow: 0 4px 20px rgba(255,114,149,0.08);
}

.bu_news_dot {
    flex-shrink: 0;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    margin-top: 6px;
}



/* ===== Reviews ===== */
.bu_reviews_grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.bu_review_card {
    background: #fff;
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.bu_review_card:hover { transform: translateY(-4px); }

.bu_review_stars {
    color: #fbbf24;
    font-size: 1rem;
    margin-bottom: 16px;
}

.bu_review_text {
    font-size: 0.95rem;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 20px;
}

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

.bu_review_avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--pink-200), var(--pink-400));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 0.9rem;
}

.bu_review_name {
    font-weight: 600;
    color: var(--gray-800);
    font-size: 0.95rem;
}

.bu_review_role {
    font-size: 0.8rem;
    color: var(--gray-500);
}

/* ===== FAQ ===== */
.bu_faq_list {
    max-width: 800px;
    margin: 0 auto;
}

.bu_faq_item {
    border-bottom: 1px solid var(--gray-200);
}

.bu_faq_question {
    width: 100%;
    padding: 24px 0;
    background: none;
    border: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--gray-800);
    text-align: left;
    font-family: inherit;
    transition: color 0.2s;
}

.bu_faq_question:hover { color: var(--pink-500); }

.bu_faq_icon {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--pink-100);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.3s, background 0.3s;
    margin-left: 16px;
}

.bu_faq_icon i {
    font-size: 0.75rem;
    color: var(--pink-500);
    transition: transform 0.3s;
}

.bu_faq_item.bu_active .bu_faq_icon {
    background: var(--pink-500);
}

.bu_faq_item.bu_active .bu_faq_icon i {
    color: #fff;
    transform: rotate(180deg);
}

.bu_faq_answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.bu_faq_item.bu_active .bu_faq_answer { max-height: 200px; }

.bu_page_body .bu_faq_item.bu_active .bu_faq_answer { max-height: 800px; }

.bu_faq_answer p {
    padding-bottom: 24px;
    font-size: 0.95rem;
    color: var(--gray-500);
    line-height: 1.8;
}

/* ===== CTA ===== */
.bu_cta {
    padding: 100px 0;
    background: linear-gradient(135deg, var(--pink-400) 0%, var(--pink-500) 40%, var(--pink-600) 100%);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.bu_cta::before {
    content: '';
    position: absolute;
    top: -40%;
    left: -10%;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    border-radius: 50%;
}

.bu_cta .bu_container { position: relative; z-index: 1; }

.bu_cta .bu_h2 {
    font-size: clamp(2rem, 4vw, 2.8rem);
    font-weight: 800;
    color: #fff;
    margin-bottom: 20px;
}

.bu_cta p {
    font-size: 1.15rem;
    color: rgba(255,255,255,0.9);
    margin-bottom: 40px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.bu_cta .bu_btn_primary {
    background: #fff;
    color: var(--pink-600);
    padding: 16px 40px;
    font-size: 1.1rem;
    box-shadow: 0 4px 24px rgba(0,0,0,0.15);
}

.bu_cta .bu_btn_primary:hover { box-shadow: 0 8px 36px rgba(0,0,0,0.2); }

/* ===== Footer ===== */
.bu_footer {
    background: var(--dark-bg);
    padding: 32px 0;
    color: rgba(255,255,255,0.6);
}

.bu_footer .bu_container > p {
    margin: 0;
    text-align: center;
    font-size: 0.85rem;
}

/* ===== Responsive ===== */
@media (max-width: 968px) {
    .bu_nav_links { display: none; }
    .bu_nav_right {
        display: flex;
        align-items: center;
        gap: 12px;
    }
    .bu_nav_right .bu_mobile_cta {
        display: inline-flex;
        align-items: center;
        gap: 6px;
        padding: 8px 18px;
        background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
        color: #fff;
        text-decoration: none;
        border-radius: 50px;
        font-weight: 600;
        font-size: 0.82rem;
        box-shadow: 0 2px 10px rgba(255,114,149,0.3);
        white-space: nowrap;
    }
    .bu_mobile_toggle { display: block; }

    .bu_nav_links.bu_open {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #fff;
        padding: 24px;
        gap: 20px;
        box-shadow: 0 8px 24px rgba(0,0,0,0.1);
    }

    .bu_above .bu_container { grid-template-columns: 1fr 1fr; gap: 24px; }
    .bu_above_visual { min-height: 300px; }

    .bu_features_grid,
    .bu_why_grid { grid-template-columns: repeat(2, 1fr); }

    .bu_stats_grid { grid-template-columns: repeat(3, 1fr); gap: 16px; }
}

@media (max-width: 640px) {
    .bu_above { padding: 90px 0 0; }
    .bu_above .bu_container { grid-template-columns: 1fr; gap: 32px; }
    .bu_above_content { text-align: center; }
    .bu_above_buttons { justify-content: center; }
    .bu_above_visual { min-height: 260px; }
    .bu_above_visual_bg { border-radius: 24px 24px 0 0; }
    .bu_above_visual_cards { padding: 28px 20px; }

    .bu_features_grid,
    .bu_why_grid,
    .bu_reviews_grid,
    .bu_stats_grid { grid-template-columns: 1fr; }

    .bu_section { padding: 72px 0; }
    .bu_stat_card { padding: 20px 16px; }
    .bu_stat_number { font-size: 1.5rem; }
    .bu_page_header { padding: 100px 0 40px; }
    .bu_page_header h1 { font-size: 1.8rem; }
    .bu_page_body { padding: 40px 0 60px; }
    .bu_news_grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ===== Inner Page ===== */
.bu_page_header {
    padding: 120px 0 48px;
    background: linear-gradient(135deg, var(--pink-300) 0%, var(--pink-500) 60%, var(--pink-600) 100%);
    text-align: center;
    color: #fff;
}

.bu_page_header h1 {
    font-size: clamp(1.8rem, 4vw, 2.4rem);
    font-weight: 800;
    margin-bottom: 12px;
}

.bu_page_header p {
    font-size: 1.05rem;
    opacity: 0.9;
    max-width: 500px;
    margin: 0 auto;
}

.bu_page_body {
    padding: 64px 0 80px;
}

.bu_page_body .bu_container { max-width: 860px; }

.bu_page_body .bu_h2 {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--gray-900);
    margin: 40px 0 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--pink-100);
}

.bu_page_body .bu_h2:first-child { margin-top: 0; }

.bu_page_body .bu_h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--gray-800);
    margin: 28px 0 10px;
}

.bu_page_body p,
.bu_page_body li {
    font-size: 0.95rem;
    color: var(--gray-600);
    line-height: 1.85;
}

.bu_page_body ul, .bu_page_body ol {
    padding-left: 24px;
    margin: 12px 0;
}

.bu_page_body li { margin-bottom: 6px; }

.bu_page_body .bu_last_updated {
    font-size: 0.85rem;
    color: var(--gray-500);
    margin-bottom: 32px;
}

.bu_page_body .bu_guide_toc {
    background: var(--gray-50);
    border-radius: var(--radius);
    padding: 28px 32px;
    margin-bottom: 40px;
    border: 1px solid var(--gray-200);
}

.bu_page_body .bu_guide_toc .bu_h3 {
    margin-top: 0;
    margin-bottom: 12px;
    color: var(--gray-900);
}

.bu_page_body .bu_guide_toc ul { list-style: none; padding: 0; }

.bu_page_body .bu_guide_toc li {
    margin-bottom: 8px;
}

.bu_page_body .bu_guide_toc a {
    color: var(--pink-500);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.bu_page_body .bu_guide_toc a:hover { color: var(--pink-600); }

.bu_page_body .bu_contact_cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
    margin: 24px 0;
}

.bu_page_body .bu_contact_card {
    background: var(--gray-50);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-sm);
    padding: 24px;
    text-align: center;
    transition: all 0.3s;
}

.bu_page_body .bu_contact_card:hover {
    border-color: var(--pink-200);
    box-shadow: 0 4px 16px rgba(255,114,149,0.08);
}

.bu_page_body .bu_contact_card i {
    font-size: 1.5rem;
    color: var(--pink-500);
    margin-bottom: 12px;
}

.bu_page_body .bu_contact_card .bu_h4 {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 6px;
}

.bu_page_body .bu_contact_card p {
    font-size: 0.85rem;
    margin: 0;
}

.bu_page_body .bu_contact_card a {
    color: var(--pink-500);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.bu_page_body .bu_contact_card a:hover {
    color: var(--pink-600);
}

.bu_page_body a {
    color: var(--pink-500);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.bu_page_body a:hover {
    color: var(--pink-600);
    text-decoration: underline;
}

.bu_feedback_form { margin-top: 24px; }

.bu_form_group {
    margin-bottom: 20px;
}

.bu_form_group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--gray-700);
    margin-bottom: 6px;
}

.bu_form_group input,
.bu_form_group select,
.bu_form_group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1.5px solid var(--gray-200);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: inherit;
    color: var(--gray-800);
    background: #fff;
    transition: border-color 0.2s;
}

.bu_form_group input:focus,
.bu_form_group select:focus,
.bu_form_group textarea:focus {
    outline: none;
    border-color: var(--pink-400);
}

.bu_form_group textarea { resize: vertical; min-height: 120px; }

.bu_form_submit {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 13px 32px;
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    color: #fff;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    border: none;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    box-shadow: 0 4px 16px rgba(255,114,149,0.3);
}

.bu_form_submit:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 24px rgba(255,114,149,0.4);
}

/* ===== Back to Top ===== */
.bu_back_to_top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--pink-400), var(--pink-600));
    color: #fff;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    box-shadow: 0 4px 16px rgba(255,114,149,0.3);
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s;
    z-index: 999;
}

.bu_back_to_top.bu_visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.bu_back_to_top:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 24px rgba(255,114,149,0.4);
}