/* ========== Reset & Variables ========== */
:root {
    --primary: #6c3ce0;
    --primary-light: #8b5cf6;
    --primary-dark: #4c1d95;
    --gold: #f0b90b;
    --gold-dark: #c7920a;
    --gradient-1: linear-gradient(135deg, #1a0533 0%, #0d0220 30%, #1a0a2e 60%, #120326 100%);
    --gradient-2: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-3: linear-gradient(180deg, #f8f9ff 0%, #ede4ff 100%);
    --text: #e2dce8;
    --text-dark: #1a1a2e;
    --text-muted: #9b8eaa;
    --card-bg: rgba(255,255,255,0.05);
    --card-border: rgba(255,255,255,0.1);
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 8px 32px rgba(0,0,0,0.3);
    --shadow-glow: 0 0 40px rgba(108,60,224,0.3);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', sans-serif;
    background: var(--gradient-1);
    color: var(--text);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* ========== Star Particle Background ========== */
.stars-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

.star {
    position: absolute;
    border-radius: 50%;
    background: white;
    animation: twinkle var(--duration) ease-in-out infinite;
    animation-delay: var(--delay);
    opacity: 0;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.2; transform: scale(1); }
    50% { opacity: 0.8; transform: scale(1.3); }
}

/* ========== Floating Orbs ========== */
.orb {
    position: fixed;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.15;
    pointer-events: none;
    z-index: 0;
    animation: float var(--float-duration) ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -50px) scale(1.05); }
    66% { transform: translate(-20px, 30px) scale(0.95); }
}

/* ========== Navigation ========== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    transition: var(--transition);
    padding: 16px 0;
}

.navbar.scrolled {
    background: rgba(10, 3, 25, 0.92);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 10px 0;
    box-shadow: 0 4px 30px rgba(0,0,0,0.4);
    border-bottom: 1px solid rgba(255,255,255,0.06);
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.nav-logo img {
    width: 42px;
    height: 42px;
    border-radius: 10px;
    object-fit: cover;
}

.nav-logo span {
    font-size: 1.25rem;
    font-weight: 700;
    color: #fff;
    background: linear-gradient(135deg, #c084fc, #a78bfa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-light);
    transition: var(--transition);
    border-radius: 1px;
}

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

.nav-cta {
    background: var(--gradient-2);
    color: #fff !important;
    padding: 10px 24px;
    border-radius: 25px;
    font-weight: 600 !important;
    box-shadow: 0 4px 15px rgba(108,60,224,0.4);
    transition: var(--transition);
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(108,60,224,0.5);
}
.nav-cta::after { display: none !important; }

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 8px;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: #fff;
    border-radius: 2px;
    transition: var(--transition);
}

.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ========== Hero Section ========== */
.hero {
    position: relative;
    z-index: 1;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 24px 80px;
    overflow: hidden;
    background: url('images/banner/banner8d60c6821a1fe5042defa43d7fe4223e1780889212.png') center/cover no-repeat;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(10,3,25,0.65) 0%, rgba(10,3,25,0.85) 50%, rgba(13,2,32,0.95) 100%);
    z-index: 0;
}

.hero::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(ellipse at center, rgba(108,60,224,0.15) 0%, transparent 60%);
    animation: rotate 30s linear infinite;
    z-index: 0;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 900px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(240,185,11,0.15);
    border: 1px solid rgba(240,185,11,0.3);
    color: var(--gold);
    padding: 8px 20px;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 24px;
    animation: fadeInUp 0.6s ease;
}

.hero-badge .dot {
    width: 8px;
    height: 8px;
    background: var(--gold);
    border-radius: 50%;
    animation: pulse-dot 1.5s ease-in-out infinite;
}

@keyframes pulse-dot {
    0%, 100% { box-shadow: 0 0 0 0 rgba(240,185,11,0.6); }
    50% { box-shadow: 0 0 0 10px rgba(240,185,11,0); }
}

.hero h1 {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(135deg, #ffffff 0%, #c084fc 50%, #a78bfa 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.6s ease 0.1s both;
}

.hero .subtitle {
    font-size: clamp(1rem, 2.5vw, 1.3rem);
    color: var(--text-muted);
    margin-bottom: 36px;
    animation: fadeInUp 0.6s ease 0.2s both;
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 0.6s ease 0.3s both;
}

/* QR Code Tooltip */
.btn-qr-wrapper {
    position: relative;
    display: inline-flex;
}

.qr-tooltip {
    position: absolute;
    bottom: calc(100% + 12px);
    left: 50%;
    transform: translateX(-50%);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
    z-index: 100;
    pointer-events: none;
}

.btn-qr-wrapper:hover .qr-tooltip {
    opacity: 1;
    visibility: visible;
}

.qr-tooltip-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    background: rgba(20, 10, 40, 0.95);
    backdrop-filter: blur(16px);
    border: 1px solid rgba(240, 185, 11, 0.3);
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.5);
}

.qr-tooltip-inner canvas {
    display: block;
    border-radius: 8px;
}

.qr-tooltip-title {
    color: #f0b90b;
    font-size: 0.9rem;
    font-weight: 600;
    white-space: nowrap;
}

/* CTA QR Code */
.cta-qr {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    margin-top: 32px;
}

.cta-qr-code canvas {
    display: block;
    border-radius: 12px;
    border: 2px solid rgba(240, 185, 11, 0.25);
    background: #fff;
    padding: 8px;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, #f0b90b, #e8a804);
    color: #1a0533;
    box-shadow: 0 8px 25px rgba(240,185,11,0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 35px rgba(240,185,11,0.5);
}

.btn-secondary {
    background: rgba(255,255,255,0.1);
    color: #fff;
    border: 1px solid rgba(255,255,255,0.2);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255,255,255,0.18);
    transform: translateY(-3px);
}

.hero-info {
    display: flex;
    gap: 40px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 56px;
    animation: fadeInUp 0.6s ease 0.4s both;
}

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

.hero-stat .number {
    font-size: 2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #c084fc, #f0b90b);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-stat .label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ========== Section Common ========== */
section {
    position: relative;
    z-index: 1;
    padding: 100px 24px;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--primary-light);
    margin-bottom: 12px;
}

.section-header h2 {
    font-size: clamp(1.8rem, 4vw, 2.8rem);
    font-weight: 800;
    color: #fff;
    margin-bottom: 16px;
}

.section-header p {
    color: var(--text-muted);
    font-size: 1.05rem;
    max-width: 600px;
    margin: 0 auto;
}

/* ========== Features Section ========== */
#features {
    background: linear-gradient(180deg, transparent 0%, rgba(108,60,224,0.05) 100%);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    max-width: var(--max-width);
    margin: 0 auto;
}

.feature-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius);
    padding: 36px 28px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-2);
    opacity: 0;
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-glow);
    border-color: rgba(108,60,224,0.3);
}

.feature-card:hover::before { opacity: 1; }

.feature-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    background: rgba(108,60,224,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ========== Classes Section ========== */
#classes {
    background: linear-gradient(180deg, rgba(108,60,224,0.03) 0%, transparent 100%);
}

.classes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 20px;
    max-width: var(--max-width);
    margin: 0 auto;
}

.class-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius);
    padding: 28px 16px;
    text-align: center;
    transition: var(--transition);
}

.class-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-glow);
    border-color: rgba(108,60,224,0.4);
}

.class-icon {
    width: 64px;
    height: 64px;
    border-radius: 50%;
    background: rgba(108,60,224,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 14px;
    font-size: 1.8rem;
}

.class-card h4 {
    font-weight: 700;
    color: #fff;
    font-size: 0.95rem;
}

/* ========== Gallery Section ========== */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    max-width: var(--max-width);
    margin: 0 auto;
}

.gallery-item {
    border-radius: var(--radius);
    overflow: hidden;
    cursor: pointer;
    position: relative;
    aspect-ratio: 16 / 9;
    transition: var(--transition);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.gallery-item:hover {
    transform: scale(1.03);
    box-shadow: var(--shadow-glow);
}

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

.gallery-item .overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.7) 0%, transparent 50%);
    opacity: 0;
    transition: var(--transition);
    display: flex;
    align-items: flex-end;
    padding: 20px;
}

.gallery-item:hover .overlay { opacity: 1; }

.gallery-item .overlay span {
    color: #fff;
    font-weight: 600;
    font-size: 0.9rem;
}

/* ========== Lightbox ========== */
.lightbox {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: rgba(0,0,0,0.92);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.lightbox.active {
    opacity: 1;
    pointer-events: auto;
}

.lightbox img {
    max-width: 90vw;
    max-height: 85vh;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.6);
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.lightbox.active img { transform: scale(1); }

.lightbox-close {
    position: absolute;
    top: 24px;
    right: 24px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255,255,255,0.15);
    border: none;
    color: #fff;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.lightbox-close:hover { background: rgba(255,255,255,0.25); }

.lightbox-prev,
.lightbox-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(255,255,255,0.15);
    border: none;
    color: #fff;
    font-size: 1.3rem;
    cursor: pointer;
    transition: var(--transition);
}

.lightbox-prev { left: 24px; }
.lightbox-next { right: 24px; }
.lightbox-prev:hover, .lightbox-next:hover { background: rgba(255,255,255,0.25); }

/* ========== Benefits Section ========== */
#benefits {
    background: linear-gradient(180deg, transparent 0%, rgba(240,185,11,0.04) 100%);
}

.benefits-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.benefit-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius);
    padding: 24px;
    transition: var(--transition);
}

.benefit-item:hover {
    border-color: rgba(240,185,11,0.3);
    background: rgba(255,255,255,0.08);
    transform: translateX(6px);
}

.benefit-icon {
    width: 44px;
    height: 44px;
    min-width: 44px;
    border-radius: 12px;
    background: rgba(240,185,11,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
}

.benefit-content h4 {
    color: #fff;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.benefit-content p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ========== Video Section ========== */
.video-wrapper {
    max-width: 900px;
    margin: 0 auto;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    aspect-ratio: 16 / 9;
}

.video-wrapper video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* ========== CTA Section ========== */
#cta {
    text-align: center;
    background: linear-gradient(180deg, transparent 0%, rgba(108,60,224,0.08) 50%, transparent 100%);
    padding: 120px 24px;
}

#cta h2 {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
    font-weight: 800;
    color: #fff;
    margin-bottom: 16px;
}

#cta p {
    color: var(--text-muted);
    margin-bottom: 32px;
    font-size: 1.05rem;
}

.cta-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-lg {
    padding: 18px 40px;
    font-size: 1.1rem;
}

/* ========== Friendly Links ========== */
.friendly-links {
    position: relative;
    z-index: 1;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    padding: 32px 24px;
}

.links-inner {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.links-title {
    color: var(--text-muted);
    font-size: 0.85rem;
    font-weight: 600;
    white-space: nowrap;
}

.links-list {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    justify-content: center;
}

.links-list a {
    color: rgba(255, 255, 255, 0.45);
    font-size: 0.82rem;
    text-decoration: none;
    transition: color 0.3s;
}

.links-list a:hover {
    color: #f0b90b;
}

/* ========== Footer ========== */
footer {
    position: relative;
    z-index: 1;
    border-top: 1px solid rgba(255,255,255,0.08);
    padding: 40px 24px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
}

footer .footer-info {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 8px;
}

/* ========== Responsive ========== */
@media (max-width: 900px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    .menu-toggle { display: flex; }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 75%;
        max-width: 320px;
        height: 100vh;
        background: rgba(10, 3, 25, 0.97);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 100px 32px 40px;
        transition: var(--transition);
        gap: 24px;
        align-items: flex-start;
    }

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

    .hero { padding: 100px 20px 60px; }
    .hero-info { gap: 28px; }

    .features-grid { grid-template-columns: 1fr; }
    .classes-grid { grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); }
    .gallery-grid { grid-template-columns: 1fr; }

    section { padding: 70px 20px; }

    .lightbox-prev, .lightbox-next {
        width: 38px;
        height: 38px;
        font-size: 1rem;
    }
    .lightbox-prev { left: 12px; }
    .lightbox-next { right: 12px; }
}

@media (max-width: 480px) {
    .hero h1 { font-size: 2rem; }
    .btn { padding: 12px 24px; font-size: 0.9rem; }
    .hero-buttons { flex-direction: column; align-items: center; }
    .cta-buttons { flex-direction: column; align-items: center; }
    .cta-buttons .btn { width: 100%; justify-content: center; }
    .benefit-item { padding: 18px; }
}

/* ========== Scroll Animations ========== */
.reveal {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ========== Guide Section ========== */
#guide {
    background: linear-gradient(180deg, transparent 0%, rgba(108,60,224,0.04) 100%);
}

.guide-container {
    max-width: 900px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.guide-item {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
    transition: var(--transition);
}

.guide-item:hover {
    border-color: rgba(108,60,224,0.3);
}

.guide-header {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 18px 24px;
    background: none;
    border: none;
    color: #fff;
    cursor: pointer;
    font-size: 1rem;
    font-family: inherit;
    text-align: left;
    transition: var(--transition);
}

.guide-header:hover {
    background: rgba(255,255,255,0.04);
}

.guide-icon {
    font-size: 1.25rem;
    flex-shrink: 0;
}

.guide-title {
    flex: 1;
    font-weight: 700;
    font-size: 1rem;
}

.guide-arrow {
    font-size: 0.85rem;
    color: var(--text-muted);
    transition: transform 0.3s ease;
    flex-shrink: 0;
}

.guide-item.open .guide-arrow {
    transform: rotate(180deg);
    color: var(--primary-light);
}

.guide-item.open {
    border-color: rgba(108,60,224,0.4);
    box-shadow: var(--shadow-glow);
}

.guide-body {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease, padding 0.4s ease;
    padding: 0 24px;
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.75;
}

.guide-item.open .guide-body {
    max-height: 2000px;
    padding: 0 24px 24px;
}

.guide-body p {
    margin-bottom: 10px;
}

.guide-body p:last-child {
    margin-bottom: 0;
}

.guide-subsection {
    margin-bottom: 16px;
}

.guide-subsection:last-child {
    margin-bottom: 0;
}

.guide-subsection h4 {
    color: #fff;
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 6px;
}

.guide-body strong {
    color: var(--primary-light);
    font-weight: 600;
}

@media (max-width: 768px) {
    .guide-header {
        padding: 16px 18px;
    }
    .guide-item.open .guide-body {
        padding: 0 18px 18px;
    }
}

/* ========== Back to Top ========== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: rgba(108, 60, 224, 0.85);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.15);
    color: #fff;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease;
    box-shadow: 0 4px 20px rgba(108,60,224,0.4);
}

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

.back-to-top:hover {
    background: rgba(108, 60, 224, 1);
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(108,60,224,0.6);
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 24px;
        right: 24px;
        width: 42px;
        height: 42px;
    }
}