@font-face {
    font-family: 'GameFont';
    src: local('STZhongsong'), local('SimSun'), local('KaiTi'), local('serif');
}

:root {
    --primary: #ff4d2e;
    --primary-dark: #c0392b;
    --secondary: #f39c12;
    --accent: #e74c3c;
    --dark-bg: #0a0a0f;
    --darker-bg: #050508;
    --card-bg: rgba(20, 20, 35, 0.85);
    --text: #e0d5c0;
    --text-muted: #8a8a9a;
    --gold: #f0c050;
    --fire-gradient: linear-gradient(135deg, #ff4d2e 0%, #f39c12 50%, #c0392b 100%);
    --dark-gradient: linear-gradient(180deg, #0a0a0f 0%, #1a0a08 50%, #0a0a0f 100%);
    --card-border: rgba(255, 77, 46, 0.2);
    --glow: 0 0 30px rgba(255, 77, 46, 0.3);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Noto Sans SC', sans-serif;
    background: var(--darker-bg);
    color: var(--text);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* =====粒子背景===== */
#particles-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
}

/* =====导航栏===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 16px 0;
    transition: all 0.4s ease;
    background: transparent;
}

.navbar.scrolled {
    background: rgba(10, 10, 15, 0.95);
    backdrop-filter: blur(20px);
    padding: 10px 0;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.5);
    border-bottom: 1px solid var(--card-border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: nowrap;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.3rem;
    font-weight: 900;
    background: var(--fire-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
    letter-spacing: 2px;
    white-space: nowrap;
    flex-shrink: 0;
}

.nav-logo-icon {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    object-fit: contain;
    flex-shrink: 0;
    border: 1px solid rgba(255, 77, 46, 0.25);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 28px;
    list-style: none;
    flex-wrap: nowrap;
}

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
    letter-spacing: 1px;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s;
}

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

.nav-links a:hover::after {
    width: 100%;
}

.nav-dl-btn {
    display: inline-block;
    padding: 10px 28px;
    background: var(--fire-gradient);
    color: #fff !important;
    border-radius: 50px;
    font-weight: 700;
    text-decoration: none;
    font-size: 0.9rem;
    box-shadow: 0 4px 20px rgba(255, 77, 46, 0.4);
    transition: all 0.3s;
    letter-spacing: 2px;
    white-space: nowrap;
}

.nav-dl-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(255, 77, 46, 0.6);
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    z-index: 1001;
}

.hamburger span {
    width: 28px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: all 0.3s;
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* =====英雄区===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 24px 80px;
    z-index: 1;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse at 30% 20%, rgba(255, 77, 46, 0.15) 0%, transparent 60%),
        radial-gradient(ellipse at 70% 60%, rgba(243, 156, 18, 0.1) 0%, transparent 60%),
        radial-gradient(ellipse at 50% 100%, rgba(192, 57, 43, 0.08) 0%, transparent 50%);
    z-index: -1;
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 200px;
    background: linear-gradient(transparent, var(--darker-bg));
    z-index: -1;
}

.hero-content {
    max-width: 900px;
    animation: fadeInUp 1s ease-out;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(255, 77, 46, 0.6); }
    50% { box-shadow: 0 0 0 25px rgba(255, 77, 46, 0); }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-12px); }
}

@keyframes shimmer {
    0% { background-position: -200% center; }
    100% { background-position: 200% center; }
}

.hero-badge {
    display: inline-block;
    padding: 8px 20px;
    border: 1px solid rgba(240, 192, 80, 0.4);
    border-radius: 50px;
    font-size: 0.85rem;
    color: var(--gold);
    letter-spacing: 3px;
    margin-bottom: 24px;
    backdrop-filter: blur(10px);
    background: rgba(240, 192, 80, 0.08);
}

.hero-title {
    font-size: clamp(2.5rem, 7vw, 5rem);
    font-weight: 900;
    margin-bottom: 16px;
    letter-spacing: 6px;
    background: linear-gradient(180deg, #fff 0%, #f0c050 40%, #ff6b3d 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.4rem);
    color: var(--text-muted);
    margin-bottom: 16px;
    letter-spacing: 4px;
}

.hero-tagline {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(255, 77, 46, 0.12);
    border: 1px solid var(--card-border);
    border-radius: 4px;
    font-size: 0.95rem;
    color: var(--primary);
    letter-spacing: 2px;
    margin-bottom: 32px;
}

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

.btn-primary-wrapper {
    position: relative;
    display: flex;
}

.hero-qr-popup {
    position: absolute;
    top: calc(100% + 16px);
    left: 50%;
    transform: translateX(-50%);
    background: rgba(20, 20, 35, 0.98);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 16px;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: all 0.3s ease;
    z-index: 100;
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.6);
}

.hero-qr-popup::before {
    content: '';
    position: absolute;
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-bottom: 8px solid rgba(20, 20, 35, 0.98);
}

.hero-qr-popup.visible {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

.qr-popup-inner {
    text-align: center;
}

.qr-popup-inner canvas,
.qr-popup-inner img {
    display: block;
    width: 150px;
    height: 150px;
    border-radius: 8px;
}

.qr-popup-inner span {
    display: block;
    margin-top: 10px;
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 1px;
}

.btn-primary {
    padding: 16px 48px;
    background: var(--fire-gradient);
    color: #fff;
    text-decoration: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 700;
    letter-spacing: 3px;
    box-shadow: 0 8px 35px rgba(255, 77, 46, 0.5);
    transition: all 0.3s;
    animation: pulse 2.5s infinite;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 45px rgba(255, 77, 46, 0.7);
}

.btn-outline {
    padding: 16px 40px;
    background: transparent;
    color: var(--text);
    text-decoration: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    letter-spacing: 2px;
    border: 2px solid rgba(224, 213, 192, 0.3);
    transition: all 0.3s;
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-3px);
}

.hero-stats {
    display: flex;
    gap: 48px;
    justify-content: center;
    margin-top: 48px;
    flex-wrap: wrap;
}

.hero-stat {
    text-align: center;
}

.hero-stat .num {
    font-size: 2.2rem;
    font-weight: 900;
    background: var(--fire-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-stat .label {
    font-size: 0.8rem;
    color: var(--text-muted);
    letter-spacing: 2px;
    margin-top: 4px;
}

.hero-scroll {
    position: absolute;
    bottom: 40px;
    left: 50%;
    transform: translateX(-50%);
    animation: float 2s ease-in-out infinite;
    color: var(--text-muted);
    font-size: 0.8rem;
    letter-spacing: 2px;
    cursor: pointer;
}

.hero-scroll::after {
    content: '';
    display: block;
    width: 1px;
    height: 40px;
    background: var(--text-muted);
    margin: 8px auto 0;
}

/* =====通用区块===== */
.section {
    position: relative;
    padding: 100px 24px;
    z-index: 1;
}

.section-container {
    max-width: 1200px;
    margin: 0 auto;
}

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

.section-label {
    font-size: 0.85rem;
    color: var(--primary);
    letter-spacing: 4px;
    margin-bottom: 12px;
    display: block;
}

.section-title {
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    font-weight: 900;
    letter-spacing: 4px;
    margin-bottom: 16px;
    color: #fff;
}

.section-title span {
    color: var(--primary);
}

.section-desc {
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
    font-size: 1rem;
}

.divider {
    width: 60px;
    height: 3px;
    background: var(--fire-gradient);
    margin: 20px auto;
    border-radius: 2px;
}

/* =====游戏介绍===== */
#about {
    background: var(--dark-gradient);
}

.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-image-wrapper {
    position: relative;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--glow);
}

.about-image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 16px;
    transition: transform 0.5s;
}

.about-image-wrapper:hover img {
    transform: scale(1.03);
}

.about-image-wrapper::before {
    content: '';
    position: absolute;
    inset: 0;
    border: 1px solid var(--card-border);
    border-radius: 16px;
    z-index: 1;
    pointer-events: none;
}

.about-text h3 {
    font-size: 1.8rem;
    font-weight: 900;
    margin-bottom: 24px;
    letter-spacing: 2px;
    color: #fff;
}

.about-text p {
    color: var(--text-muted);
    margin-bottom: 20px;
    line-height: 1.9;
}

.about-tags {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    margin-top: 20px;
}

.about-tag {
    padding: 8px 16px;
    background: rgba(255, 77, 46, 0.08);
    border: 1px solid var(--card-border);
    border-radius: 50px;
    font-size: 0.85rem;
    color: var(--primary);
    letter-spacing: 1px;
}

/* =====特色玩法===== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.feature-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 40px 28px;
    text-align: center;
    transition: all 0.4s;
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 77, 46, 0.04), transparent);
    transition: left 0.6s;
}

.feature-card:hover::before {
    left: 100%;
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary);
    box-shadow: 0 20px 50px rgba(255, 77, 46, 0.15);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 20px;
    display: block;
    filter: drop-shadow(0 4px 10px rgba(255, 77, 46, 0.3));
}

.feature-card h4 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 12px;
    color: #fff;
    letter-spacing: 2px;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
}

/* =====福利区===== */
#rewards {
    background: var(--dark-gradient);
}

.rewards-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.reward-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 32px 24px;
    transition: all 0.4s;
    position: relative;
    overflow: hidden;
}

.reward-card:hover {
    border-color: var(--secondary);
    box-shadow: 0 15px 40px rgba(243, 156, 18, 0.15);
    transform: translateY(-5px);
}

.reward-card .reward-icon {
    font-size: 2.2rem;
    margin-bottom: 16px;
}

.reward-card h4 {
    font-size: 1.1rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
    letter-spacing: 1px;
}

.reward-card p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.reward-card .reward-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: var(--fire-gradient);
    color: #fff;
    font-size: 0.7rem;
    padding: 4px 12px;
    border-radius: 50px;
    letter-spacing: 1px;
    font-weight: 700;
}

.reward-highlight {
    grid-column: span 3;
    background: linear-gradient(135deg, rgba(255, 77, 46, 0.12), rgba(243, 156, 18, 0.08));
    border: 2px solid rgba(240, 192, 80, 0.3);
    border-radius: 16px;
    padding: 40px;
    text-align: center;
}

.reward-highlight h3 {
    font-size: 1.6rem;
    font-weight: 900;
    color: var(--gold);
    letter-spacing: 3px;
    margin-bottom: 12px;
}

.reward-highlight p {
    color: var(--text-muted);
    font-size: 1rem;
}

.reward-highlight .big-num {
    font-size: 3.5rem;
    font-weight: 900;
    background: linear-gradient(180deg, #f0c050, #ff4d2e);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: block;
    margin: 12px 0;
}

/* =====截图画廊===== */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.gallery-item {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    aspect-ratio: 16 / 9;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s;
}

.gallery-item:hover img {
    transform: scale(1.08);
}

.gallery-item::after {
    content: '';
    position: absolute;
    inset: 0;
    border: 1px solid rgba(255, 255, 255, 0.06);
    border-radius: 12px;
    pointer-events: none;
    transition: border-color 0.3s;
}

.gallery-item:hover::after {
    border-color: var(--card-border);
}

/* =====下载区===== */
#download {
    background: var(--dark-gradient);
}

.download-box {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 56px 40px;
    position: relative;
    overflow: hidden;
}

.download-box::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 77, 46, 0.06) 0%, transparent 60%);
    animation: shimmer 8s linear infinite;
}

.download-box h3 {
    font-size: 2rem;
    font-weight: 900;
    color: #fff;
    letter-spacing: 3px;
    margin-bottom: 8px;
    position: relative;
    z-index: 1;
}

.download-box .game-name {
    font-size: 1rem;
    color: var(--text-muted);
    letter-spacing: 2px;
    margin-bottom: 16px;
    position: relative;
    z-index: 1;
}

.download-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
    margin-top: 8px;
}

.btn-download {
    padding: 16px 40px;
    border-radius: 50px;
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: 2px;
    text-decoration: none;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    border: none;
}

.btn-android {
    background: var(--fire-gradient);
    color: #fff;
    box-shadow: 0 8px 35px rgba(255, 77, 46, 0.5);
    animation: pulse 2.5s infinite;
}

.btn-android:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 45px rgba(255, 77, 46, 0.7);
}

.btn-ios {
    background: linear-gradient(135deg, #007aff, #5856d6);
    color: #fff;
    border: none;
    box-shadow: 0 4px 20px rgba(0, 122, 255, 0.4);
}

.btn-ios:hover {
    background: linear-gradient(135deg, #0a84ff, #6e6bff);
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(0, 122, 255, 0.6);
}

.download-info {
    display: flex;
    gap: 32px;
    justify-content: center;
    margin: 32px 0;
    flex-wrap: wrap;
    position: relative;
    z-index: 1;
}

.download-info-item {
    text-align: center;
}

.download-info-item .info-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    letter-spacing: 2px;
    margin-bottom: 4px;
}

.download-info-item .info-val {
    font-size: 1.2rem;
    font-weight: 700;
    color: #fff;
}

.download-qrcode {
    width: 150px;
    height: 150px;
    margin: 0 auto 24px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 1;
    border: 1px solid var(--card-border);
    font-size: 0.8rem;
    color: var(--text-muted);
    letter-spacing: 2px;
    overflow: hidden;
}

.download-qrcode canvas,
.download-qrcode img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    border-radius: 12px;
}

/* =====友情链接===== */
.friend-links {
    text-align: center;
    padding: 36px 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    max-width: 1100px;
    margin: 0 auto;
    line-height: 2.4;
}

.friend-links-title {
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 2px;
    margin-right: 4px;
}

.friend-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.85rem;
    margin: 0 8px;
    transition: color 0.3s;
    white-space: nowrap;
    letter-spacing: 0.5px;
}

.friend-links a:hover {
    color: var(--primary);
}

/* =====页脚===== */
.footer {
    background: var(--darker-bg);
    padding: 48px 24px 32px;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    z-index: 1;
    position: relative;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
}

.footer p {
    color: var(--text-muted);
    font-size: 0.8rem;
    letter-spacing: 1px;
}

.footer p + p {
    margin-top: 8px;
}

/* =====光箱===== */
.lightbox {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.92);
    z-index: 9999;
    display: none;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.lightbox.active {
    display: flex;
}

.lightbox img {
    max-width: 90vw;
    max-height: 85vh;
    border-radius: 12px;
    border: 1px solid var(--card-border);
}

.lightbox-close {
    position: absolute;
    top: 24px;
    right: 32px;
    font-size: 2rem;
    color: #fff;
    cursor: pointer;
    z-index: 2;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.08);
    transition: all 0.3s;
}

.lightbox-close:hover {
    background: rgba(255, 77, 46, 0.3);
}

/* =====响应式===== */
@media (max-width: 1024px) {
    .about-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

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

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

@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        height: 100vh;
        background: rgba(10, 10, 15, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 40px;
        transition: right 0.4s ease;
    }

    .nav-links.active {
        right: 0;
    }

    .hamburger {
        display: flex;
    }

    .features-grid,
    .rewards-grid {
        grid-template-columns: 1fr;
    }

    .reward-highlight {
        grid-column: span 1;
    }

    .gallery-grid {
        grid-template-columns: 1fr;
    }

    .hero-stats {
        gap: 24px;
    }

    .hero-stat .num {
        font-size: 1.6rem;
    }

    .download-box {
        padding: 40px 20px;
    }

    .btn-download {
        width: 100%;
        justify-content: center;
    }

    .download-buttons {
        flex-direction: column;
        width: 100%;
    }
}

/* =====滚动淡入===== */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease-out;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* =====选中文字===== */
::selection {
    background: rgba(255, 77, 46, 0.3);
    color: #fff;
}

/* =====返回顶部===== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--fire-gradient);
    color: #fff;
    border: none;
    cursor: pointer;
    font-size: 1.4rem;
    font-weight: 700;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    box-shadow: 0 4px 20px rgba(255, 77, 46, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(255, 77, 46, 0.7);
}

/* =====滚动条===== */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: var(--darker-bg);
}

::-webkit-scrollbar-thumb {
    background: rgba(255, 77, 46, 0.4);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 77, 46, 0.7);
}