@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800;900&family=Manrope:wght@400;500;600;700;800&display=swap');

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

body {
    font-family: 'Manrope', 'Inter', system-ui, sans-serif;
    background: #0a0e14;
    color: #eef2f6;
    overflow-x: hidden;
}

/* Світло-блакитний акцент */
.aqua {
    color: #7dd3fc;
}
.aqua-bg {
    background: #7dd3fc;
    color: #0a0e14;
    transition: all 0.3s ease;
}
.aqua-bg:hover {
    background: #5bb8e6;
    transform: scale(1.04);
    box-shadow: 0 12px 40px -8px #7dd3fc60;
}
.aqua-border {
    border-color: #7dd3fc;
}

.aqua-gradient {
    background: linear-gradient(135deg, #7dd3fc, #38bdf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Hero */
.hero-aqua {
    background:
        linear-gradient(165deg, rgba(10, 14, 20, 0.92) 0%, rgba(10, 14, 20, 0.70) 100%),
        url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') center/cover no-repeat;
}

/* Картки */
.card-aqua {
    background: #121821;
    border: 1px solid #1e2835;
    transition: all 0.3s ease;
    border-radius: 20px;
}
.card-aqua:hover {
    border-color: #7dd3fc;
    transform: translateY(-8px);
    box-shadow: 0 20px 40px -20px #7dd3fc40;
    background: #161e2a;
}

/* 10 Level badge */
.level-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: linear-gradient(135deg, #7dd3fc20, #38bdf820);
    border: 2px solid #7dd3fc;
    color: #7dd3fc;
    font-weight: 900;
    font-size: 0.85rem;
    padding: 6px 16px 6px 12px;
    border-radius: 50px;
    letter-spacing: 0.05em;
    box-shadow: 0 0 30px -5px #7dd3fc40;
    animation: pulse-glow 2.5s ease-in-out infinite;
}

.level-badge .crown-gold {
    color: #fbbf24;
    font-size: 1.1rem;
    filter: drop-shadow(0 0 8px #fbbf2460);
}

@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 0 20px -5px #7dd3fc30; }
    50% { box-shadow: 0 0 40px 0px #7dd3fc60; }
}

/* Прайс */
.price-aqua {
    background: #121821;
    border: 1px solid #1e2835;
    border-radius: 16px;
    transition: 0.25s;
}
.price-aqua:hover {
    border-color: #7dd3fc;
    background: #161e2a;
    box-shadow: 0 0 30px -10px #7dd3fc20;
}

/* Мобільне меню */
#mobileMenu {
    background: #0a0e14;
    border-top: 1px solid #1e2835;
}
#mobileMenu a {
    border-bottom: 1px solid #161e2a;
    padding: 16px 0;
    font-weight: 500;
}
#mobileMenu a:last-child {
    border-bottom: none;
}

/* Статистика */
.stat-number {
    font-size: 2.1rem;
    line-height: 1.1;
    font-weight: 900;
    background: linear-gradient(135deg, #7dd3fc, #38bdf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Навбар */
.nav-aqua {
    background: transparent;
    border: 1.5px solid #7dd3fc;
    color: #7dd3fc;
    transition: 0.3s;
}
.nav-aqua:hover {
    background: #7dd3fc;
    color: #0a0e14;
}

/* Стрічка */
.ribbon-aqua {
    background: linear-gradient(90deg, #7dd3fc20, #7dd3fc10, #7dd3fc20);
    border-top: 1px solid #7dd3fc30;
    border-bottom: 1px solid #7dd3fc30;
}

/* Кнопка в герої */
.btn-aqua-outline {
    border: 1px solid #2a3442;
    transition: 0.3s;
}
.btn-aqua-outline:hover {
    border-color: #7dd3fc;
    background: #7dd3fc10;
}

.icon-aqua {
    color: #7dd3fc;
}

.footer-level {
    color: #7dd3fc;
    font-weight: 800;
    letter-spacing: 0.05em;
}

.crown-gold-ribbon {
    color: #fbbf24;
    filter: drop-shadow(0 0 6px #fbbf2440);
}

/* Відгуки */
.review-card {
    background: #121821;
    border: 1px solid #1e2835;
    border-radius: 24px;
    transition: all 0.3s ease;
}
.review-card:hover {
    border-color: #7dd3fc;
    transform: translateY(-6px);
    box-shadow: 0 20px 40px -20px #7dd3fc40;
    background: #161e2a;
}
.review-avatar {
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: linear-gradient(135deg, #7dd3fc30, #38bdf830);
    border: 2px solid #7dd3fc;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1.4rem;
    color: #7dd3fc;
    flex-shrink: 0;
}
.review-stars {
    color: #fbbf24;
    letter-spacing: 2px;
}

/* ПРЕМІАЛЬНІ ЕФЕКТИ */
.glass-effect {
    background: rgba(18, 24, 33, 0.6);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid rgba(125, 211, 252, 0.1);
}

.section-divider {
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, #7dd3fc, transparent);
    border-radius: 10px;
    margin: 0 auto;
}

.hover-lift {
    transition: all 0.4s cubic-bezier(0.22, 1, 0.36, 1);
}
.hover-lift:hover {
    transform: translateY(-6px) scale(1.01);
}

.input-premium {
    background: rgba(18, 24, 33, 0.8);
    border: 1px solid #1e2835;
    transition: all 0.3s ease;
}
.input-premium:focus {
    border-color: #7dd3fc;
    box-shadow: 0 0 0 4px #7dd3fc20;
    outline: none;
}

.btn-premium {
    background: linear-gradient(135deg, #7dd3fc, #38bdf8);
    color: #0a0e14;
    font-weight: 800;
    transition: all 0.3s ease;
    border: none;
    box-shadow: 0 8px 32px -8px #7dd3fc50;
}
.btn-premium:hover {
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 12px 48px -8px #7dd3fc80;
}

/* Зменшуємо іконки керування відео */
video::-webkit-media-controls-play-button,
video::-webkit-media-controls-volume-slider,
video::-webkit-media-controls-mute-button,
video::-webkit-media-controls-fullscreen-button {
    transform: scale(0.75);
}

video::-webkit-media-controls-timeline {
    height: 4px;
}

/* Мобільні виправлення */
h1 {
    font-size: 2.25rem;
    line-height: 1.1;
}
@media (min-width: 640px) {
    h1 { font-size: 3rem; }
}

.stat-number {
    font-size: 2.1rem;
    line-height: 1.1;
}
@media (min-width: 640px) {
    .stat-number { font-size: 3.5rem; }
}

.ribbon-aqua span {
    font-size: 0.875rem;
    line-height: 1.35;
}

.price-aqua {
    padding: 1.25rem;
}

@media (max-width: 640px) {
    .hero-aqua h1 {
        font-size: 2.1rem;
    }
    .review-card {
        margin-bottom: 1rem;
    }
    .price-aqua {
        padding: 1rem;
    }
}

/* Lightbox */
#lightbox {
    backdrop-filter: blur(4px);
}

/* Сховати скролбар у прев'ю */
.scrollbar-hide::-webkit-scrollbar {
    display: none;
}
.scrollbar-hide {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

/* REVEAL ON SCROLL */
.reveal-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal-on-scroll.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* BENEFIT ITEM HOVER */
.benefit-item {
    transition: transform 0.3s ease;
}

.benefit-item:hover {
    transform: translateX(4px);
}

.benefit-item:hover .w-7.h-7 {
    transform: scale(1.2) rotate(-8deg);
    background: #22c55e30;
}

/* FAQ */
.faq-item {
    background: #121821;
    border: 1px solid #1e2835;
    border-radius: 16px;
    transition: all 0.3s ease;
    overflow: hidden;
}

.faq-item[open] {
    border-color: #7dd3fc60;
    background: #161e2a;
}

.faq-item summary {
    padding: 20px 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: #fff;
    list-style: none;
    gap: 16px;
}

.faq-item summary::-webkit-details-marker {
    display: none;
}

.faq-item summary i {
    color: #7dd3fc;
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.faq-item[open] summary i {
    transform: rotate(180deg);
}

.faq-item p {
    padding: 0 24px 20px;
    color: #9ca3af;
    line-height: 1.7;
    font-size: 0.95rem;
}

.faq-item:hover {
    border-color: #7dd3fc40;
}

/* BREAKDOWN */
.breakdown-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px dashed #1e2835;
    gap: 12px;
}

.breakdown-item:last-child {
    border-bottom: none;
}

.breakdown-item.total {
    padding-top: 14px;
    margin-top: 6px;
    border-top: 1px solid #1e2835;
    font-weight: 800;
    color: #7dd3fc;
    font-size: 1.05rem;
}

.breakdown-item .label {
    color: #9ca3af;
    font-size: 0.9rem;
}

.breakdown-item .label small {
    display: block;
    color: #6b7280;
    font-size: 0.75rem;
    margin-top: 2px;
    font-weight: 400;
}

.breakdown-item .value {
    color: #fff;
    font-weight: 700;
    white-space: nowrap;
}

.breakdown-item.total .value {
    color: #7dd3fc;
    font-size: 1.15rem;
}

/* КАЛЬКУЛЯТОР */
.calc-block {
    padding-bottom: 8px;
}

.calc-block-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.calc-block-header i {
    font-size: 1.5rem;
    color: #7dd3fc;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #7dd3fc15;
    border: 1px solid #7dd3fc30;
    border-radius: 12px;
}

.calc-block-header h3 {
    font-size: 1.25rem;
    font-weight: 800;
    color: #fff;
    letter-spacing: -0.01em;
}

.calc-sublabel {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: #6b7280;
    font-weight: 700;
    margin-bottom: 10px;
}

.calc-type {
    background: #121821;
    border: 2px solid #1e2835;
    border-radius: 16px;
    padding: 14px 8px;
    color: #d1d5db;
    font-weight: 600;
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    text-align: center;
    min-height: 78px;
    gap: 2px;
}

.calc-type:hover {
    border-color: #7dd3fc60;
    background: #161e2a;
    transform: translateY(-2px);
}

.calc-type.active {
    border-color: #7dd3fc;
    background: linear-gradient(135deg, #7dd3fc15, #38bdf815);
    color: #7dd3fc;
    box-shadow: 0 0 30px -10px #7dd3fc40;
}

.calc-shower {
    background: #121821;
    border: 2px solid #1e2835;
    border-radius: 16px;
    padding: 16px 10px;
    color: #d1d5db;
    font-weight: 600;
    transition: all 0.25s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    text-align: center;
    min-height: 110px;
    gap: 3px;
}

.calc-shower i {
    color: #7dd3fc;
    opacity: 0.7;
    transition: all 0.25s ease;
}

.calc-shower:hover {
    border-color: #7dd3fc60;
    background: #161e2a;
    transform: translateY(-2px);
}

.calc-shower.active {
    border-color: #7dd3fc;
    background: linear-gradient(135deg, #7dd3fc15, #38bdf815);
    box-shadow: 0 0 30px -10px #7dd3fc40;
}

.calc-shower.active i {
    opacity: 1;
    filter: drop-shadow(0 0 8px #7dd3fc60);
    transform: scale(1.1);
}

.calc-shower.active .text-sm {
    color: #7dd3fc;
}

.calc-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 14px 18px;
    background: #121821;
    border: 2px solid #1e2835;
    border-radius: 14px;
    transition: all 0.25s ease;
}

.calc-row:hover {
    border-color: #7dd3fc40;
    background: #161e2a;
}

.calc-row-label {
    display: flex;
    align-items: center;
    gap: 14px;
    flex: 1;
    min-width: 0;
}

.calc-row-label i {
    font-size: 1.2rem;
    width: 24px;
    text-align: center;
    flex-shrink: 0;
}

.calc-row-input {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.calc-input {
    width: 100px;
    background: #0a0e14;
    border: 1px solid #1e2835;
    border-radius: 10px;
    padding: 10px 12px;
    text-align: center;
    font-size: 1.1rem;
    font-weight: 700;
    color: #fff;
    outline: none;
    transition: all 0.25s ease;
    -moz-appearance: textfield;
}

.calc-input::-webkit-outer-spin-button,
.calc-input::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
}

.calc-input:focus {
    border-color: #7dd3fc;
    box-shadow: 0 0 0 3px #7dd3fc20;
}

.calc-unit {
    color: #6b7280;
    font-size: 0.85rem;
    font-weight: 600;
    min-width: 30px;
}

.calc-checkbox {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 14px 18px;
    background: #121821;
    border: 2px solid #1e2835;
    border-radius: 14px;
    cursor: pointer;
    transition: all 0.25s ease;
    user-select: none;
    position: relative;
}

.calc-checkbox:hover {
    border-color: #7dd3fc60;
    background: #161e2a;
}

.calc-checkbox input {
    position: absolute;
    opacity: 0;
    pointer-events: none;
}

.calc-checkbox .checkmark {
    width: 22px;
    height: 22px;
    border-radius: 6px;
    border: 2px solid #2a3442;
    flex-shrink: 0;
    position: relative;
    transition: all 0.25s ease;
}

.calc-checkbox input:checked ~ .checkmark {
    background: #7dd3fc;
    border-color: #7dd3fc;
    box-shadow: 0 0 20px -4px #7dd3fc80;
}

.calc-checkbox input:checked ~ .checkmark::after {
    content: '✓';
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #0a0e14;
    font-weight: 900;
    font-size: 14px;
}

.calc-checkbox input:checked ~ span:last-child .font-semibold {
    color: #7dd3fc;
}

.price-flash {
    animation: priceFlash 0.4s ease;
}

@keyframes priceFlash {
    0% { transform: scale(1); }
    50% { transform: scale(1.08); }
    100% { transform: scale(1); }
}

@media (max-width: 640px) {
    .calc-row {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    .calc-row-input {
        justify-content: flex-end;
    }
    .calc-input {
        width: 100%;
        flex: 1;
    }
    .calc-type {
        min-height: 70px;
        padding: 12px 6px;
    }
    .calc-type .text-sm {
        font-size: 0.8rem;
    }
    .calc-shower {
        min-height: 100px;
        padding: 12px 8px;
    }
    .calc-block-header h3 {
        font-size: 1.1rem;
    }
}

/* БЛОК ГІДРОІЗОЛЯЦІЇ */
.hydro-block {
    background: linear-gradient(135deg, #1a2333, #121821);
    border: 2px solid #38bdf840;
    border-radius: 16px;
    padding: 18px;
    position: relative;
    overflow: hidden;
}

.hydro-block::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #38bdf8, #7dd3fc, #38bdf8);
}

.hydro-header {
    display: flex;
    align-items: center;
    gap: 14px;
}

.hydro-header i {
    font-size: 1.5rem;
    color: #38bdf8;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #38bdf815;
    border: 1px solid #38bdf840;
    border-radius: 12px;
    flex-shrink: 0;
    filter: drop-shadow(0 0 8px #38bdf860);
}

/* ============================================================
   СВІТЛА / ТЕМНА ТЕМА
   ============================================================ */
:root,
[data-theme="dark"] {
  --bg: #0a0e14;
  --bg2: #0a1019;
  --card: #121821;
  --card-hover: #161e2a;
  --border: #1e2835;
  --text: #eef2f6;
  --text-muted: #9ca3af;
  --text-dim: #6b7280;
  --header-bg: rgba(10, 14, 20, 0.95);
  --aqua: #7dd3fc;
  --input-bg: #0a0e14;
}

[data-theme="light"] {
  --bg: #f1f5f9;
  --bg2: #e2e8f0;
  --card: #ffffff;
  --card-hover: #f8fafc;
  --border: #cbd5e1;
  --text: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;
  --header-bg: rgba(255, 255, 255, 0.92);
  --aqua: #0284c7;
  --input-bg: #f8fafc;
}

[data-theme="light"] body {
  background: var(--bg) !important;
  color: var(--text) !important;
}

[data-theme="light"] header {
  background: var(--header-bg) !important;
  border-bottom-color: var(--border) !important;
}

[data-theme="light"] .aqua,
[data-theme="light"] .text-\[\#7dd3fc\],
[data-theme="light"] a.text-\[\#7dd3fc\] {
  color: #0284c7 !important;
}

[data-theme="light"] .aqua-bg {
  background: #0ea5e9 !important;
  color: #fff !important;
}
[data-theme="light"] .aqua-bg:hover {
  background: #0284c7 !important;
}

[data-theme="light"] .aqua-gradient {
  background: linear-gradient(135deg, #0ea5e9, #0284c7);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="light"] .card-aqua,
[data-theme="light"] .price-aqua,
[data-theme="light"] .review-card,
[data-theme="light"] .faq-item,
[data-theme="light"] .accordion-item {
  background: var(--card) !important;
  border-color: var(--border) !important;
  color: var(--text);
}
[data-theme="light"] .card-aqua:hover,
[data-theme="light"] .price-aqua:hover,
[data-theme="light"] .review-card:hover {
  background: var(--card-hover) !important;
  border-color: #0ea5e9 !important;
  box-shadow: 0 12px 32px -12px rgba(14, 165, 233, 0.25);
}

[data-theme="light"] h1,
[data-theme="light"] h2,
[data-theme="light"] h3,
[data-theme="light"] .text-white,
[data-theme="light"] .font-black.text-white {
  color: #0f172a !important;
}

[data-theme="light"] .text-gray-300,
[data-theme="light"] .text-gray-400,
[data-theme="light"] nav a {
  color: #475569 !important;
}
[data-theme="light"] nav a:hover,
[data-theme="light"] .hover\:text-\[\#7dd3fc\]:hover {
  color: #0284c7 !important;
}

[data-theme="light"] #mobileMenu {
  background: #fff !important;
  border-top-color: var(--border) !important;
}
[data-theme="light"] #mobileMenu a {
  border-bottom-color: #e2e8f0 !important;
  color: #334155 !important;
}

[data-theme="light"] .hero-aqua {
  background:
    linear-gradient(165deg, rgba(241, 245, 249, 0.92) 0%, rgba(226, 232, 240, 0.75) 100%),
    url('https://images.unsplash.com/photo-1581094794329-c8112a89af12?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') center/cover no-repeat !important;
}

[data-theme="light"] .stat-number {
  background: linear-gradient(135deg, #0ea5e9, #0284c7);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="light"] .level-badge {
  background: linear-gradient(135deg, #e0f2fe, #bae6fd);
  border-color: #0ea5e9;
  color: #0369a1;
  box-shadow: 0 0 20px -5px rgba(14, 165, 233, 0.3);
}

[data-theme="light"] .ribbon-aqua {
  background: linear-gradient(90deg, #e0f2fe, #f0f9ff, #e0f2fe);
  border-color: #bae6fd;
  color: #334155;
}

[data-theme="light"] .btn-aqua-outline {
  border-color: #94a3b8;
  color: #0f172a;
}
[data-theme="light"] .btn-aqua-outline:hover {
  border-color: #0ea5e9;
  background: #e0f2fe;
  color: #0284c7;
}

[data-theme="light"] section.bg-\[\#0a1019\],
[data-theme="light"] section.bg-\[\#0a0e14\] {
  background: var(--bg2) !important;
}

[data-theme="light"] .filter-btn:not(.active) {
  background: #fff !important;
  color: #64748b !important;
  border-color: #cbd5e1 !important;
}
[data-theme="light"] .filter-btn.active {
  background: #0ea5e9 !important;
  color: #fff !important;
}

[data-theme="light"] #worksPrev,
[data-theme="light"] #worksNext,
[data-theme="light"] #reviewsPrev,
[data-theme="light"] #reviewsNext {
  background: #fff !important;
  border-color: #cbd5e1 !important;
  color: #0284c7 !important;
}
[data-theme="light"] #worksPrev:hover,
[data-theme="light"] #worksNext:hover,
[data-theme="light"] #reviewsPrev:hover,
[data-theme="light"] #reviewsNext:hover {
  background: #0ea5e9 !important;
  color: #fff !important;
  border-color: #0ea5e9 !important;
}

[data-theme="light"] .accordion-header:hover {
  background: #f1f5f9 !important;
}
[data-theme="light"] .accordion-item h3 {
  color: #0f172a !important;
}
[data-theme="light"] .accordion-body p,
[data-theme="light"] .text-gray-300 {
  color: #475569 !important;
}

#themeToggle {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  border: 1.5px solid #1e2835;
  background: #121821;
  color: #7dd3fc;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: 0.25s;
  font-size: 1.1rem;
}
#themeToggle:hover {
  border-color: #7dd3fc;
  background: #7dd3fc15;
}
[data-theme="light"] #themeToggle {
  border-color: #cbd5e1;
  background: #fff;
  color: #0284c7;
}
[data-theme="light"] #themeToggle:hover {
  border-color: #0ea5e9;
  background: #e0f2fe;
}

[data-theme="light"] footer {
  background: #e2e8f0 !important;
  border-top-color: #cbd5e1 !important;
}
[data-theme="light"] footer .text-gray-500 {
  color: #64748b !important;
}
[data-theme="light"] .footer-level {
  color: #0284c7 !important;
}

/* ============================================================
   КНОПКА ВГОРУ
   ============================================================ */
#scrollTopBtn {
    position: fixed;
    right: 24px;
    bottom: 24px;
    width: 52px;
    height: 52px;
    border-radius: 16px;
    border: 2px solid #7dd3fc;
    background: #121821;
    color: #7dd3fc;
    font-size: 1.15rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 90;
    opacity: 0;
    visibility: hidden;
    transform: translateY(16px) scale(0.9);
    transition: opacity 0.3s ease, transform 0.3s ease, background 0.25s, color 0.25s, box-shadow 0.25s;
    box-shadow: 0 10px 30px -10px #7dd3fc40;
}

#scrollTopBtn.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0) scale(1);
}

#scrollTopBtn:hover {
    background: #7dd3fc;
    color: #0a0e14;
    box-shadow: 0 14px 40px -8px #7dd3fc80;
    transform: translateY(-3px) scale(1.05);
}

#scrollTopBtn:active {
    transform: translateY(0) scale(0.97);
}

@media (max-width: 640px) {
    #scrollTopBtn {
        right: 16px;
        bottom: 16px;
        width: 46px;
        height: 46px;
        border-radius: 14px;
        font-size: 1rem;
    }
}

[data-theme="light"] #scrollTopBtn {
    background: #fff;
    color: #0284c7;
    border-color: #0ea5e9;
    box-shadow: 0 10px 30px -10px rgba(14, 165, 233, 0.35);
}
[data-theme="light"] #scrollTopBtn:hover {
    background: #0ea5e9;
    color: #fff;
}