/* Reset & Khóa cứng khung viền toàn cục chống tràn mobile */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Plus Jakarta Sans', sans-serif;
    min-width: 0;
}

:root {
    --bg-color: #0b0f19;
    --card-bg: #121826;
    --border-color: rgba(255, 255, 255, 0.08);
    --text-main: #f3f4f6;
    --text-muted: #9ca3af;
    --primary-color: #a855f7;
    --secondary-color: #ec4899;
    --gradient: linear-gradient(135deg, #a855f7 0%, #ec4899 100%);
}

html {
    scroll-behavior: smooth;
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
}

body {
    background-color: var(--bg-color);
    color: var(--text-main);
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
    position: relative;
    line-height: 1.5;
}

/* Hiệu ứng Scroll Reveal */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Hiệu ứng ánh sáng nền */
.ambient-glow {
    position: absolute;
    width: 250px;
    height: 250px;
    border-radius: 50%;
    filter: blur(100px);
    z-index: -1;
    opacity: 0.1;
    pointer-events: none;
}
.glow-1 {
    top: 20px;
    left: -20px;
    background: var(--primary-color);
}
.glow-2 {
    top: 600px;
    right: -20px;
    background: var(--secondary-color);
}

/* Header & Navigation */
header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(11, 15, 25, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    width: 100%;
    max-width: 100vw;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 14px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    box-sizing: border-box;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    text-decoration: none;
    letter-spacing: -0.5px;
    white-space: nowrap;
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover, .nav-links a.donate-link {
    color: var(--text-main);
}

.menu-toggle {
    background: none;
    border: none;
    color: var(--text-main);
    cursor: pointer;
    display: none;
    padding: 4px;
}

/* Menu Mobile Drawer */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    max-width: 80vw;
    height: 100vh;
    background: var(--card-bg);
    border-left: 1px solid var(--border-color);
    padding: 24px 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: right 0.3s ease;
    z-index: 1100;
    box-shadow: -10px 0 30px rgba(0,0,0,0.5);
    box-sizing: border-box;
}

.mobile-menu.active {
    right: 0;
}

.close-menu {
    align-self: flex-end;
    background: none;
    border: none;
    color: var(--text-main);
    font-size: 2rem;
    cursor: pointer;
    line-height: 1;
}

.mobile-link {
    color: var(--text-main);
    text-decoration: none;
    font-size: 1.05rem;
    font-weight: 500;
    padding: 8px 0;
    border-bottom: 1px solid var(--border-color);
}

.donate-btn-mobile {
    color: var(--secondary-color) !important;
}

/* Hero Section */
.hero {
    max-width: 800px;
    margin: 40px auto 20px;
    padding: 0 16px;
    text-align: center;
    width: 100%;
    box-sizing: border-box;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(168, 85, 247, 0.1);
    border: 1px solid rgba(168, 85, 247, 0.3);
    padding: 6px 12px;
    border-radius: 50px;
    font-size: 0.8rem;
    color: #c084fc;
    margin-bottom: 16px;
    max-width: 100%;
    box-sizing: border-box;
}

.hero h1 {
    font-size: 1.75rem;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 14px;
    word-break: break-word;
}

.hero p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 24px;
    word-break: break-word;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    width: 100%;
}

.cta-btn, .outline-btn {
    padding: 11px 24px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    transition: opacity 0.2s, transform 0.2s, border-color 0.2s;
    text-align: center;
}

.cta-btn {
    background: var(--gradient);
    color: white;
    box-shadow: 0 4px 20px rgba(168, 85, 247, 0.3);
}

.cta-btn:hover {
    opacity: 0.9;
    transform: translateY(-2px);
}

.outline-btn {
    background: transparent;
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.outline-btn:hover {
    border-color: var(--text-muted);
    transform: translateY(-2px);
}

/* Partners Marquee Bar */
.partners-bar {
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    padding: 14px 0;
    margin: 30px 0;
    background: rgba(18, 24, 38, 0.4);
    width: 100%;
    max-width: 100vw;
    overflow: hidden;
}

.partners-marquee {
    display: flex;
    width: max-content;
    animation: scrollMarquee 25s linear infinite;
}

.partners-track {
    display: flex;
    gap: 30px;
    padding-right: 30px;
    align-items: center;
}

.partner-pill {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.85rem;
    white-space: nowrap;
}

@keyframes scrollMarquee {
    0% { transform: translateX(0); }
    100% { transform: translateX(-50%); }
}

/* Stats Section */
.stats-section {
    padding: 10px 16px 20px;
    width: 100%;
    box-sizing: border-box;
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
    box-sizing: border-box;
}
.stat-card {
    background: rgba(18, 24, 38, 0.5);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 14px 8px;
    text-align: center;
    box-sizing: border-box;
}
.stat-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 4px;
}
.stat-card p {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 500;
}

/* Container chung */
.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 30px 16px;
    width: 100%;
    box-sizing: border-box;
}

.section-header {
    text-align: center;
    margin-bottom: 24px;
}

.section-tag {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--primary-color);
    font-weight: 700;
    display: block;
    margin-bottom: 6px;
}

.section-header h2 {
    font-size: 1.35rem;
    font-weight: 700;
    line-height: 1.3;
}

/* Spotify Grid & Cards */
.spotify-grid {
    display: flex;
    flex-direction: column;
    gap: 14px;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
}

.spotify-card {
    background: rgba(18, 24, 38, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 14px;
    overflow: hidden;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
    transition: transform 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.spotify-card iframe {
    width: 100% !important;
    max-width: 100% !important;
    display: block;
    border: none;
    box-sizing: border-box;
}

.spotify-card:hover {
    transform: translateY(-2px);
    border-color: rgba(168, 85, 247, 0.35);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

/* Khung Quảng Cáo Style */
.ad-wrapper {
    width: 100%;
    box-sizing: border-box;
    margin: 10px auto;
}

.ad-banner-box {
    background: rgba(18, 24, 38, 0.7);
    border: 1px dashed rgba(168, 85, 247, 0.3);
    border-radius: 12px;
    padding: 12px;
    text-align: center;
    position: relative;
    width: 100%;
    box-sizing: border-box;
}

.ad-label {
    position: absolute;
    top: -8px;
    left: 16px;
    background: var(--card-bg);
    color: var(--text-muted);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    padding: 0 6px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
}

.ad-slot-placeholder {
    padding: 16px;
    color: var(--text-muted);
}

.ad-slot-placeholder p {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-main);
    margin-bottom: 4px;
}

.ad-slot-placeholder small {
    font-size: 0.75rem;
    opacity: 0.8;
}

@media(min-width: 768px) {
    .spotify-grid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    .hero h1 {
        font-size: 2.2rem;
    }
    .hero {
        margin: 60px auto 30px;
    }
    .stat-card h3 {
        font-size: 1.6rem;
    }
    .stat-card p {
        font-size: 0.8rem;
    }
}

/* Footer (Canh Giữa Hoàn Toàn) */
footer {
    border-top: 1px solid var(--border-color);
    padding: 40px 0 20px;
    background: var(--card-bg);
    margin-top: 40px;
    width: 100%;
    max-width: 100vw;
    box-sizing: border-box;
}

.footer-center-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 36px;
    max-width: 600px;
    margin: 0 auto;
    width: 100%;
    box-sizing: border-box;
}

.footer-brand-col p, .footer-donate-col .dmca-desc {
    max-width: 480px;
    margin: 12px auto 0;
    color: var(--text-muted);
    font-size: 0.85rem;
    word-break: break-word;
}

.footer-links-col h4, .footer-donate-col h4 {
    font-size: 0.95rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.footer-links-col ul {
    list-style: none;
    padding: 0;
}

.footer-links-col ul li {
    margin-bottom: 10px;
}

.footer-links-col ul li a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-links-col ul li a:hover {
    color: var(--text-main);
}

.dmca-badge-link img {
    max-width: 110px;
    margin: 0 auto 8px;
    display: block;
    height: auto;
}

/* Khung Donate PayPal chuẩn */
.paypal-box {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 12px;
    width: 100%;
    max-width: 350px;
    margin: 0 auto;
    box-sizing: border-box;
}

.paypal-box p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 10px;
}

.paypal-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    background: #0070ba;
    color: white;
    text-decoration: none;
    padding: 9px 16px;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    width: 100%;
    box-sizing: border-box;
    transition: background 0.2s, transform 0.2s;
}

.paypal-btn:hover {
    background: #005ea6;
    transform: translateY(-1px);
}

.footer-bottom {
    max-width: 1000px;
    margin: 40px auto 0;
    padding: 16px 16px 0;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
    font-size: 0.75rem;
    width: 100%;
    box-sizing: border-box;
    text-align: center;
}

.footer-bottom-flex {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 16px;
}

/* Nút Back to Top */
#backToTopBtn {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--card-bg);
    color: var(--text-main);
    border: 1px solid var(--border-color);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.2s;
    z-index: 999;
    box-shadow: 0 4px 15px rgba(0,0,0,0.4);
}
#backToTopBtn.show {
    opacity: 1;
    visibility: visible;
}
#backToTopBtn:hover {
    transform: translateY(-3px);
    border-color: var(--primary-color);
}

/* Modal Gửi Demo */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(6px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 16px;
    box-sizing: border-box;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal-overlay.show {
    opacity: 1;
    visibility: visible;
}

.modal-content {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    width: 100%;
    max-width: 420px;
    border-radius: 16px;
    padding: 20px;
    box-sizing: border-box;
    box-shadow: 0 15px 50px rgba(0, 0, 0, 0.6);
    transform: scale(0.95);
    transition: transform 0.3s ease;
}

.modal-overlay.show .modal-content {
    transform: scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.modal-header h3 {
    font-size: 1.05rem;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.4rem;
    cursor: pointer;
    transition: color 0.2s;
    line-height: 1;
}

.close-btn:hover {
    color: var(--text-main);
}

.form-group {
    margin-bottom: 14px;
}

.form-group label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 5px;
}

.form-group input {
    width: 100%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    padding: 10px 12px;
    border-radius: 8px;
    color: var(--text-main);
    font-size: 0.9rem;
    box-sizing: border-box;
    outline: none;
    transition: border-color 0.2s, background 0.2s;
}

.form-group input:focus {
    border-color: var(--primary-color);
    background: rgba(255, 255, 255, 0.05);
}

.submit-btn {
    width: 100%;
    background: var(--gradient);
    color: white;
    border: none;
    padding: 11px;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    margin-top: 8px;
    box-sizing: border-box;
    transition: opacity 0.2s, transform 0.2s;
}

.submit-btn:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

/* Responsive cho Mobile Header */
@media(max-width: 768px) {
    .nav-links {
        display: none;
    }
    .menu-toggle {
        display: block;
    }
}