/* Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

body {
    font-family: 'Quicksand', sans-serif;
    background: linear-gradient(135deg, #1e1e2f 0%, #2a2a4a 50%, #ff6f61 100%);
    color: #fff;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

/* Hiệu ứng nền động */
body::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle, rgba(255, 111, 97, 0.25) 0%, transparent 70%);
    animation: pulse-bg 8s infinite ease-in-out;
    z-index: -1;
}

/* Overlay */
#overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    transition: opacity 0.5s ease;
}

#play-button {
    padding: 20px 40px;
    font-size: 22px;
    font-weight: bold;
    color: #fff;
    background: linear-gradient(45deg, #ff6f61, #ff3b2f, #ffcc00);
    background-size: 200% 200%;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 10px 25px rgba(255, 111, 97, 0.6);
    transition: all 0.3s ease;
    animation: gradient-shift 4s infinite ease;
}

#play-button:hover {
    transform: scale(1.1) rotate(2deg);
    box-shadow: 0 15px 35px rgba(255, 111, 97, 0.8);
}

/* Container */
.container {
    max-width: 900px;
    margin: 30px auto;
    padding: 25px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 20px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    animation: fade-in 1s ease;
}

/* Navigation */
.nav-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: linear-gradient(45deg, rgba(255, 111, 97, 0.2), rgba(255, 204, 0, 0.2));
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    flex-wrap: nowrap;
    width: 100%;
}

.nav-link {
    color: #fff;
    text-decoration: none;
    font-size: 18px;
    padding: 10px 20px;
    font-family: 'Pattaya', sans-serif;
    transition: all 0.3s ease;
    position: relative;
    flex-shrink: 1;
    white-space: nowrap;
}

.nav-link.active {
    background: linear-gradient(45deg, #ff6f61, #ff3b2f);
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(255, 111, 97, 0.5);
}

.nav-link:hover {
    color: #ffcc00;
    transform: translateY(-2px);
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    background: #ffcc00;
    bottom: 0;
    left: 50%;
    transition: all 0.3s ease;
}

.nav-link:hover::after {
    width: 50%;
    left: 25%;
}

/* Profile */
.profile {
    text-align: center;
    margin: 30px 0;
    animation: slide-up 0.8s ease;
}

.avatar {
    width: 130px;
    height: 130px;
    border-radius: 50%;
    border: 5px solid #ff6f61;
    box-shadow: 0 0 25px rgba(255, 111, 97, 0.7), 0 0 50px rgba(255, 111, 97, 0.3);
    transition: all 0.4s ease;
}

.avatar:hover {
    transform: scale(1.15) rotate(5deg);
    box-shadow: 0 0 35px rgba(255, 111, 97, 0.9), 0 0 70px rgba(255, 111, 97, 0.5);
}

.username {
    font-family: 'Pattaya', sans-serif;
    font-size: 32px;
    margin: 15px 0;
    background: linear-gradient(45deg, #ff6f61, #ffcc00, #ff3b2f);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: gradient-shift 3s infinite ease;
}

.verified-icon {
    width: 22px;
    height: 22px;
    vertical-align: middle;
    filter: drop-shadow(0 0 5px rgba(255, 111, 97, 0.5));
}

.bio {
    font-size: 18px;
    line-height: 1.8;
    color: #e0e0ff;
    text-shadow: 0 0 5px rgba(255, 255, 255, 0.3);
}

/* Section */
.section-title {
    font-family: 'Pattaya', sans-serif;
    font-size: 28px;
    text-align: center;
    margin: 30px 0;
    position: relative;
    background: linear-gradient(45deg, #ff6f61, #ffcc00);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: fade-in 1.2s ease;
}

.section-title::after {
    content: '';
    position: absolute;
    width: 60px;
    height: 3px;
    background: linear-gradient(45deg, #ff6f61, #ffcc00);
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

/* Tool Downloads */
.tool-downloads {
    margin: 30px 0;
}

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

.tool-item {
    background: linear-gradient(45deg, rgba(255, 255, 255, 0.05), rgba(255, 111, 97, 0.1));
    padding: 20px;
    border-radius: 12px;
    max-width: 300px;
    text-align: center;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
    transition: all 0.4s ease;
}

.tool-item:hover {
    transform: translateY(-8px) scale(1.03);
    box-shadow: 0 10px 30px rgba(255, 111, 97, 0.5);
}

.tool-name {
    font-family: 'Pattaya', sans-serif;
    font-size: 20px;
    margin-bottom: 10px;
    color: #ffcc00;
}

.tool-desc {
    font-size: 14px;
    color: #e0e0ff;
    margin-bottom: 15px;
}

.download-btn {
    display: inline-block;
    background: linear-gradient(45deg, #ff6f61, #ff3b2f);
    padding: 12px 20px;
    border-radius: 10px;
    color: #fff;
    text-decoration: none;
    font-size: 16px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(255, 111, 97, 0.5);
}

.download-btn:hover {
    background: linear-gradient(45deg, #ff3b2f, #ff6f61);
    transform: scale(1.05);
}

/* Video Hướng Dẫn */
.tutorial-video {
    margin: 30px 0;
}

.video-container {
    position: relative;
    max-width: 700px;
    margin: 0 auto;
    padding: 15px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
    transition: transform 0.4s ease;
}

.video-container:hover {
    transform: scale(1.02);
}

.tutorial-iframe {
    width: 100%;
    height: 400px;
    border: none;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(255, 111, 97, 0.5);
}

/* Contact Info */
.contact-info {
    margin: 30px 0;
}

.contact-details {
    background: linear-gradient(45deg, rgba(255, 255, 255, 0.05), rgba(255, 111, 97, 0.1));
    padding: 20px;
    border-radius: 12px;
    max-width: 320px;
    margin: 12px auto;
    text-align: left;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
    transition: transform 0.4s ease;
}

.contact-details:hover {
    transform: translateY(-5px);
}

.contact-details p {
    font-size: 16px;
    line-height: 1.8;
    margin: 10px 0;
}

.contact-details a {
    color: #ffcc00;
    text-decoration: none;
}

.contact-details a:hover {
    color: #ff6f61;
    text-decoration: underline;
}

/* Footer */
.footer {
    text-align: center;
    padding: 30px 0;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 0 0 20px 20px;
}

.copyright {
    font-size: 14px;
    color: #e0e0ff;
    text-shadow: 0 0 5px rgba(255, 255, 255, 0.3);
}

.author {
    color: #ffcc00;
    text-decoration: none;
    font-weight: bold;
    transition: color 0.3s ease;
}

.author:hover {
    color: #ff6f61;
    text-decoration: underline;
}

/* Animations */
@keyframes pulse-bg {
    0%, 100% { opacity: 0.5; transform: scale(1); }
    50% { opacity: 0.8; transform: scale(1.1); }
}

@keyframes gradient-shift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

@keyframes fade-in {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slide-up {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        margin: 15px;
        padding: 20px;
    }

    .avatar {
        width: 110px;
        height: 110px;
    }

    .username {
        font-size: 26px;
    }

    .bio, .tool-desc, .contact-details p {
        font-size: 16px;
    }

    .nav-bar {
        padding: 10px;
    }

    .nav-link {
        font-size: 16px;
        padding: 8px 12px;
    }

    .section-title {
        font-size: 24px;
    }

    .tool-item {
        max-width: 100%;
    }

    .tutorial-iframe {
        height: 300px;
    }
}

@media (max-width: 480px) {
    .avatar {
        width: 90px;
        height: 90px;
    }

    .username {
        font-size: 22px;
    }

    .section-title {
        font-size: 20px;
    }

    .tool-item, .contact-details {
        max-width: 280px;
        padding: 15px;
    }

    .bio, .tool-desc, .contact-details p, .download-btn {
        font-size: 14px;
    }

    .tutorial-iframe {
        height: 200px;
    }
}