/* Biến hệ thống */
:root {
    --bg-main: #050816;
    --bg-secondary: #0B1026;
    --primary: #6C4AB6;
    --secondary: #9B6DFF;
    --accent: #F5D98B;
    --text-main: #FFFFFF;
    --text-muted: #A0A5BD;
    --glass-bg: rgba(11, 16, 38, 0.4);
    --glass-border: rgba(255, 255, 255, 0.1);
    --glow: 0 0 20px rgba(155, 109, 255, 0.4);
    --font: 'Public Sans', sans-serif;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* Reset Base */
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; overflow-x: hidden; }
body { font-family: var(--font); background-color: var(--bg-main); color: var(--text-main); line-height: 1.6; overflow-x: hidden; }

canvas#starfield { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: -1; pointer-events: none; background: radial-gradient(circle at top right, rgba(108, 74, 182, 0.15), transparent 50%), radial-gradient(circle at bottom left, rgba(11, 16, 38, 0.8), var(--bg-main) 70%); }

.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section { padding: 100px 0; position: relative; }
.text-center { text-align: center; }
.mb-5 { margin-bottom: 3rem; }
.mt-3 { margin-top: 1.5rem; }
.w-100 { width: 100%; }
.max-w-700 { max-width: 700px; }
.mx-auto { margin-left: auto; margin-right: auto; }

/* Text */
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.3; }
.gradient-text { background: linear-gradient(90deg, var(--accent), var(--secondary), var(--text-main)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; display: inline-block; }
.section-title { font-size: 2.3rem; margin-bottom: 2rem; text-transform: uppercase; letter-spacing: 2px; }
.h3-subtitle { font-size: 1.5rem; }

/* Buttons */
.btn { display: inline-block; padding: 14px 30px; border-radius: 50px; font-family: var(--font); font-weight: 700; font-size: 1rem; text-decoration: none; text-transform: uppercase; letter-spacing: 1px; cursor: pointer; transition: var(--transition); border: none; text-align: center; }
.btn-primary { background: linear-gradient(135deg, var(--primary), var(--secondary)); color: var(--text-main); box-shadow: var(--glow); }
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 5px 25px rgba(155, 109, 255, 0.6); }
.btn-outline { background: transparent; color: var(--text-main); border: 1px solid var(--glass-border); backdrop-filter: blur(5px); }
.btn-outline:hover { background: var(--glass-border); border-color: var(--secondary); }

.btn-submit-anim { animation: pulseGlowBtn 2s infinite; }
.btn-submit-anim:hover { animation: none; transform: translateY(-3px) scale(1.02); box-shadow: 0 8px 30px rgba(155, 109, 255, 0.7); }
.border-glow { border: 1px solid rgba(155, 109, 255, 0.5) !important; box-shadow: inset 0 0 20px rgba(155, 109, 255, 0.1); }

.glass-card { background: var(--glass-bg); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border: 1px solid var(--glass-border); border-radius: 20px; padding: 40px; transition: var(--transition); }
.glass-card:hover { border-color: rgba(155, 109, 255, 0.4); box-shadow: 0 10px 30px rgba(0,0,0,0.6); }

/* Nút MXH Float */
.float-group { position: fixed; bottom: 30px; right: 25px; display: flex; flex-direction: column; gap: 12px; z-index: 999; }
.float-btn { width: 45px; height: 45px; border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; text-decoration: none; font-size: 1.3rem; border: none; cursor: pointer; transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); opacity: 0; pointer-events: none; transform: translateY(30px); box-shadow: 0 5px 15px rgba(0,0,0,0.5); }
.float-btn.show { opacity: 1; pointer-events: auto; transform: translateY(0); }
.float-btn:hover { transform: scale(1.15) translateY(-3px); }
.fb { background: #1877F2; transition-delay: 0.1s; }
.ig { background: radial-gradient(circle at 30% 107%, #fdf497 0%, #fdf497 5%, #fd5949 45%, #d6249f 60%, #285AEB 90%); transition-delay: 0.15s; }
.tt { background: #000; border: 1px solid #444; transition-delay: 0.2s; }
.btt { background: var(--secondary); transition-delay: 0.25s; margin-top: 10px; }

/* Header */
.header { position: fixed; top: 0; left: 0; width: 100%; z-index: 1000; transition: var(--transition); padding: 20px 0; }
.header.scrolled { background: rgba(5, 8, 22, 0.9); backdrop-filter: blur(10px); border-bottom: 1px solid var(--glass-border); padding: 12px 0; box-shadow: 0 4px 20px rgba(0,0,0,0.5); }
.header-inner { display: flex; justify-content: space-between; align-items: center; }
.header-logo-img { height: 40px; width: auto; display: block; transition: var(--transition); }
.header-logo-img:hover { filter: drop-shadow(0 0 10px rgba(155, 109, 255, 0.8)); }

.nav-menu { display: flex; gap: 30px; align-items: center; }
.nav-link { color: var(--text-muted); text-decoration: none; font-size: 0.95rem; font-weight: 600; text-transform: uppercase; transition: var(--transition); }
.nav-link:hover { color: var(--secondary); }
.btn-register-nav { background: var(--glass-border); padding: 10px 22px; border-radius: 50px; color: var(--text-main); border: 1px solid var(--secondary); }
.btn-register-nav:hover { background: var(--primary); color: #fff; border-color: transparent; }
.hamburger { display: none; font-size: 1.5rem; cursor: pointer; color: var(--text-main); z-index: 1002; }

/* Hero */
.hero { height: 100vh; display: flex; align-items: center; justify-content: center; text-align: center; padding-top: 60px; }
.hero-subtitle { font-size: 1.1rem; color: var(--text-muted); letter-spacing: 3px; margin-bottom: 1.2rem; }
.hero-logo { max-width: 90%; width: 550px; margin: 0 auto 1.5rem auto; display: block; }
.hero-tagline { font-size: 1.8rem; font-weight: 400; margin-bottom: 2.5rem; letter-spacing: 1px; }

/* Highlight Badge */
.hero-info-container { display: flex; gap: 20px; justify-content: center; margin-bottom: 3.5rem; flex-wrap: wrap; }
.hero-badge { background: rgba(255, 255, 255, 0.03); border: 1px solid rgba(245, 217, 139, 0.3); padding: 12px 28px; border-radius: 50px; color: var(--text-main); font-size: 1.05rem; font-weight: 600; display: flex; align-items: center; gap: 10px; backdrop-filter: blur(10px); box-shadow: 0 0 20px rgba(245, 217, 139, 0.1); animation: floatBadge 3s ease-in-out infinite; transition: var(--transition); }
.hero-badge i { color: var(--accent); font-size: 1.2rem; }
.hero-badge:nth-child(2) { animation-delay: 1.5s; }
.hero-badge:hover { transform: translateY(-5px); box-shadow: 0 0 30px rgba(245, 217, 139, 0.3); border-color: var(--accent); background: rgba(245, 217, 139, 0.1); }

.hero-cta { display: flex; gap: 20px; justify-content: center; }
.scroll-indicator { position: absolute; bottom: 40px; left: 50%; transform: translateX(-50%); display: flex; flex-direction: column; align-items: center; color: var(--text-muted); font-size: 0.85rem; text-transform: uppercase; letter-spacing: 2px; }

/* Thư ngỏ */
.letter-card { text-align: center; padding: 70px 50px; }
.moon-icon { font-size: 3.5rem; color: var(--accent); margin-bottom: 1.5rem; text-shadow: 0 0 25px rgba(245, 217, 139, 0.6); }
.quote-container { min-height: 120px; }
.quote { font-size: 1.25rem; font-style: italic; color: var(--text-main); line-height: 1.9; font-weight: 300; display: block; }
.word-anim { display: inline-block; opacity: 0; transform: translateY(15px); transition: opacity 0.5s ease, transform 0.5s ease; margin-right: 4px; }
.start-anim .word-anim { opacity: 1; transform: translateY(0); }

/* Tổng quan */
.overview-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.overview-card { background: var(--bg-secondary); border: 1px solid var(--glass-border); padding: 35px 25px; border-radius: 15px; text-align: center; transition: var(--transition); }
.overview-card:hover { border-color: var(--primary); transform: translateY(-5px) scale(1.02); box-shadow: var(--glow); background: rgba(108, 74, 182, 0.05); }
.overview-card h4 { color: var(--accent); margin-bottom: 10px; font-size: 1.1rem; text-transform: uppercase; letter-spacing: 1px; }
.overview-card p { font-size: 1.05rem; font-weight: 500; }

/* Giá vé */
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; align-items: center; }
.pricing-card { background: var(--glass-bg); border: 1px solid var(--glass-border); border-radius: 20px; padding: 50px 30px; text-align: center; position: relative; overflow: hidden; transition: var(--transition); }
.pricing-card:hover { transform: translateY(-5px); border-color: rgba(255,255,255,0.3); }
.pricing-card.highlight { border-color: var(--secondary); transform: scale(1.05); background: rgba(108, 74, 182, 0.1); padding: 60px 30px; }
.pricing-card.highlight:hover { transform: scale(1.05) translateY(-5px); }
.badge { position: absolute; top: 20px; right: -40px; background: var(--accent); color: var(--bg-main); padding: 5px 45px; font-size: 0.75rem; font-weight: 800; transform: rotate(45deg); letter-spacing: 1px; }
.pricing-card h3 { font-size: 1.3rem; margin-bottom: 1rem; color: var(--text-muted); letter-spacing: 2px; }
.pricing-card .price { font-size: 2.8rem; font-weight: 800; color: var(--text-main); margin-bottom: 2rem; }
.pricing-card .price span { font-size: 1rem; font-weight: 400; color: var(--text-muted); }

/* Giá trị */
.values-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.value-card { background: transparent; padding: 40px 30px; border-top: 3px solid var(--secondary); transition: var(--transition); border-radius: 10px; background: rgba(255,255,255,0.02); }
.value-card:hover { background: var(--glass-bg); transform: translateY(-10px); box-shadow: 0 10px 30px rgba(0,0,0,0.3); border-color: var(--accent); }
.value-number { font-size: 4rem; font-weight: 800; color: rgba(255,255,255,0.05); margin-bottom: -20px; transition: var(--transition); line-height: 1; }
.value-card:hover .value-number { color: rgba(245, 217, 139, 0.2); transform: translateX(10px); }
.value-card h4 { margin-bottom: 15px; color: var(--secondary); font-size: 1.2rem; line-height: 1.4; }

/* Concept */
.highlight-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 25px; }
.highlight-card { padding: 40px; }
.highlight-card h4 { color: var(--accent); margin-bottom: 15px; font-size: 1.3rem; letter-spacing: 1px; }
.highlight-card p { font-size: 1.05rem; color: var(--text-muted); }

/* Timeline */
.timeline-container { position: relative; max-width: 900px; margin: 0 auto; }
.timeline-line { position: absolute; top: 0; bottom: 0; left: 50%; width: 2px; background: linear-gradient(to bottom, transparent, var(--secondary), transparent); transform: translateX(-50%); }
.timeline-item { display: flex; justify-content: flex-end; padding-right: 50%; position: relative; margin-bottom: 40px; width: 100%; }
.timeline-item:nth-child(even) { justify-content: flex-start; padding-right: 0; padding-left: 50%; }

.timeline-dot { position: absolute; top: 25px; left: 50%; transform: translate(-50%, -50%); width: 16px; height: 16px; background: var(--accent); border-radius: 50%; box-shadow: 0 0 15px var(--accent); z-index: 2; }

.timeline-content { width: calc(100% - 50px); padding: 25px 30px; font-weight: 500; font-size: 1.05rem; }
.timeline-item:nth-child(odd) .timeline-content { margin-right: 40px; text-align: left; }
.timeline-item:nth-child(even) .timeline-content { margin-left: 40px; text-align: left; }

.timeline-time { display: inline-block; background: rgba(245, 217, 139, 0.1); padding: 6px 16px; border-radius: 50px; color: var(--accent); font-weight: 700; font-size: 0.95rem; margin-bottom: 15px; border: 1px solid rgba(245, 217, 139, 0.3); letter-spacing: 1px; }

/* Form & QR */
.register-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.form-group { margin-bottom: 22px; text-align: left; }
.form-group label { display: block; margin-bottom: 8px; font-size: 0.95rem; color: var(--text-muted); font-weight: 600; }
.form-group input, .form-group select { width: 100%; padding: 16px; background: rgba(255,255,255,0.03); border: 1px solid var(--glass-border); border-radius: 12px; color: var(--text-main); font-family: var(--font); font-size: 1rem; transition: var(--transition); }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--secondary); background: rgba(255,255,255,0.08); box-shadow: 0 0 15px rgba(155,109,255,0.2); }
.form-group option { background: var(--bg-secondary); color: var(--text-main); }
.error-msg { display: none; color: #ff6b6b; font-size: 0.85rem; margin-top: 6px; font-weight: 500; }
.form-group.error .error-msg { display: block; }
.form-group.error input, .form-group.error select { border-color: #ff6b6b; background: rgba(255,107,107,0.05); }

.payment-title { margin-bottom: 25px; border-bottom: 1px solid var(--glass-border); padding-bottom: 15px; font-size: 1.4rem; color: var(--accent); }
.detail-row { display: flex; justify-content: space-between; margin-bottom: 15px; font-size: 1.1rem; align-items: center; }
.qr-container { margin-top: 35px; position: relative; width: 260px; height: 260px; margin-left: auto; margin-right: auto; border: 2px dashed var(--glass-border); border-radius: 20px; display: flex; align-items: center; justify-content: center; overflow: hidden; background: #fff; padding: 10px; }
.qr-image { width: 100%; height: 100%; object-fit: contain; transition: var(--transition); }
.blur-initial { filter: blur(15px); opacity: 0.2; }
.qr-overlay { position: absolute; text-align: center; padding: 20px; color: #111; font-size: 0.95rem; font-weight: 800; background: rgba(255,255,255,0.85); width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; }

/* Footer */
.footer { background: var(--bg-secondary); padding: 70px 0 25px; border-top: 1px solid rgba(255,255,255,0.05); }
.footer-content { display: grid; grid-template-columns: 1.5fr 1fr 1fr; gap: 40px; margin-bottom: 50px; }

.footer-brand h2 { font-size: 2.2rem; color: var(--text-main); letter-spacing: 2px; margin-bottom: 10px; }
.footer-brand p { color: var(--accent); font-style: italic; font-size: 1.1rem; margin-bottom: 20px; }
.footer-map iframe { width: 100%; height: 150px; border-radius: 12px; border: 1px solid var(--glass-border); opacity: 0.8; transition: var(--transition); }
.footer-map iframe:hover { opacity: 1; border-color: var(--accent); box-shadow: 0 0 15px rgba(245, 217, 139, 0.2); }

.footer-sponsors h4 { margin-bottom: 20px; color: var(--secondary); font-size: 1.2rem; }
.footer-sponsors ul { list-style: none; padding: 0; }
.footer-sponsors ul li { margin-bottom: 12px; }
/* Sửa màu thẻ <a> phần nhà tài trợ thành màu trắng */
.footer-sponsors ul li a { color: #ffffff; text-decoration: none; font-size: 1.05rem; transition: var(--transition); display: inline-block; }
.footer-sponsors ul li a:hover { color: var(--accent); transform: translateX(5px); }

.footer-contact h4 { margin-bottom: 20px; color: var(--secondary); font-size: 1.2rem; }
.footer-contact p { color: var(--text-muted); margin-bottom: 10px; font-size: 1.05rem; }

.footer-bottom { text-align: center; padding-top: 25px; border-top: 1px solid rgba(255,255,255,0.05); color: var(--text-muted); font-size: 0.95rem; display: flex; justify-content: space-between; align-items: center; }
.footer-bottom a { color: var(--secondary); text-decoration: none; font-weight: 600; transition: var(--transition); }
.footer-bottom a:hover { color: var(--accent); }

/* Modal */
.modal { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.85); backdrop-filter: blur(8px); display: flex; align-items: center; justify-content: center; z-index: 2000; opacity: 0; pointer-events: none; transition: var(--transition); }
.modal.active { opacity: 1; pointer-events: auto; }
.modal-content { max-width: 450px; width: 90%; text-align: center; transform: scale(0.8); transition: var(--transition); }
.modal.active .modal-content { transform: scale(1); }
.success-icon { font-size: 4.5rem; color: #4cd137; margin-bottom: 20px; }
.modal-info { background: rgba(255,255,255,0.05); padding: 20px; border-radius: 12px; margin: 25px 0; text-align: left; border: 1px solid rgba(255,255,255,0.1); }
.modal-info p { margin-bottom: 10px; font-size: 1.05rem; }
.text-small { font-size: 0.9rem; line-height: 1.5; margin-bottom: 25px; }

/* Animations */
@keyframes pulseGlowBtn { 0% { box-shadow: 0 0 0 0 rgba(155, 109, 255, 0.7); } 70% { box-shadow: 0 0 0 15px rgba(155, 109, 255, 0); } 100% { box-shadow: 0 0 0 0 rgba(155, 109, 255, 0); } }
@keyframes float { 0% { transform: translateY(0px); } 50% { transform: translateY(-12px); } 100% { transform: translateY(0px); } }
@keyframes floatBadge { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); box-shadow: 0 0 25px rgba(245, 217, 139, 0.3); } }

.animate-fade-up { opacity: 0; transform: translateY(50px); transition: opacity 0.8s cubic-bezier(0.2, 0.8, 0.2, 1), transform 0.8s cubic-bezier(0.2, 0.8, 0.2, 1); }
.animate-fade-up.in-view { opacity: 1; transform: translateY(0); }
.animate-pulse-glow { animation: pulseGlow 3s infinite alternate ease-in-out; }
@keyframes pulseGlow { 0% { transform: scale(1); filter: drop-shadow(0 0 10px rgba(155, 109, 255, 0.2)); } 100% { transform: scale(1.03); filter: drop-shadow(0 0 30px rgba(155, 109, 255, 0.8)); } }
.float-anim { animation: float 4s ease-in-out infinite; }
.hover-float:hover { transform: translateY(-10px); border-color: var(--secondary); box-shadow: var(--glow); }

/* Responsive Mobile Layouts */
@media (max-width: 1024px) {
    .hero-logo { width: 450px; }
    .hero-info-container { flex-direction: column; align-items: center; gap: 15px; }
    .overview-grid, .values-grid { grid-template-columns: repeat(2, 1fr); }
    .pricing-card.highlight { transform: scale(1); padding: 50px 30px; }
    .footer-content { grid-template-columns: 1fr 1fr; }
    .footer-brand { grid-column: span 2; }
}

@media (max-width: 768px) {
    /* Menu mobile */
    .nav-menu { position: fixed; top: 0; right: -100%; width: 75%; height: 100vh; background: rgba(5,8,22,0.98); backdrop-filter: blur(15px); flex-direction: column; justify-content: center; transition: right 0.5s cubic-bezier(0.77, 0, 0.175, 1); border-left: 1px solid var(--glass-border); box-shadow: -10px 0 30px rgba(0,0,0,0.5); }
    .nav-menu.active { right: 0; }
    .nav-link { opacity: 0; transform: translateX(30px); transition: all 0.4s ease; margin: 15px 0; font-size: 1.1rem; }
    .nav-menu.active .nav-link { opacity: 1; transform: translateX(0); }
    .nav-menu.active .nav-link:nth-child(1) { transition-delay: 0.1s; }
    .nav-menu.active .nav-link:nth-child(2) { transition-delay: 0.15s; }
    .nav-menu.active .nav-link:nth-child(3) { transition-delay: 0.2s; }
    .nav-menu.active .nav-link:nth-child(4) { transition-delay: 0.25s; }
    .nav-menu.active .nav-link:nth-child(5) { transition-delay: 0.3s; }
    .nav-menu.active .nav-link:nth-child(6) { transition-delay: 0.35s; }
    .nav-menu.active .nav-link:nth-child(7) { transition-delay: 0.4s; }
    
    .hamburger { display: block; z-index: 1001; }
    
    .hero-logo { width: 320px; }
    .hero-tagline { font-size: 1.3rem; }
    .hero-cta { flex-direction: column; gap: 15px; padding: 0 20px; }
    
    .pricing-grid, .highlight-grid, .register-layout { grid-template-columns: 1fr; }
    .overview-grid, .values-grid { grid-template-columns: 1fr; }
    
    /* Timeline Mobile */
    .timeline-line { left: 25px; }
    .timeline-item { justify-content: flex-start; padding-left: 60px !important; padding-right: 0 !important; }
    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content { margin-right: 0; margin-left: 0; width: 100%; }
    .timeline-dot { left: 25px; top: 30px; }
    
    /* Footer Mobile fix */
    .footer-content { display: flex; flex-direction: column; text-align: center; gap: 40px; }
    .footer-brand { width: 100%; }
    .footer-sponsors ul li { margin-bottom: 15px; }
    .footer-sponsors ul li a:hover { transform: translateY(-3px); }
    .footer-bottom { flex-direction: column; gap: 20px; }
    .float-group { bottom: 20px; right: 15px; }
}