@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;600;800&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
    --accent: #00f2ff;
    --accent-dark: #0066ff;
    --bg: #050505;
    --glass: rgba(255, 255, 255, 0.05);
    --border: rgba(255, 255, 255, 0.1);
    --text-primary: #ffffff;
    --text-secondary: #a1a1aa;
}

* { box-sizing: border-box; }

body {
    margin: 0;
    padding: 0;
    font-family: 'Plus Jakarta Sans', sans-serif;
    background-color: var(--bg);
    color: var(--text-primary);
    overflow-x: hidden;
}

/* Fix nền Mesh không đè lên nội dung */
.mesh {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background:
        radial-gradient(circle at 20% 30%, rgba(0, 242, 255, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 80% 70%, rgba(0, 102, 255, 0.08) 0%, transparent 40%);
    z-index: 0; /* Đẩy xuống dưới cùng */
}

.hero {
    position: relative;
    z-index: 10; /* Đảm bảo nội dung luôn ở trên lớp nền */
    display: flex;
    flex-direction: column;
    align-items: center;
    max-width: 1000px;
    margin: 0 auto;
    padding: 100px 2rem;
    text-align: center;
}

.badge {
    background: var(--glass);
    border: 1px solid var(--border);
    padding: 0.6rem 1.4rem;
    border-radius: 100px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 2px;
    color: var(--accent);
    margin-bottom: 1.5rem;
    text-transform: uppercase;
}

h1 {
    font-size: clamp(3.5rem, 10vw, 6rem);
    font-weight: 800;
    margin: 0;
    line-height: 1.1;
    letter-spacing: -3px;
    /* Hiệu ứng đổ bóng để chữ nổi hơn */
    text-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.gradient-text {
    background: linear-gradient(to bottom, #ffffff, #666);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.description {
    max-width: 700px;
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin: 2rem 0;
}

/* Container Video */
.video-container {
    width: 100%;
    max-width: 850px;
    margin: 3rem 0;
    aspect-ratio: 16 / 9;
    background: #000;
    border-radius: 24px;
    padding: 8px; /* Tạo viền bao quanh video */
    border: 1px solid var(--border);
    box-shadow: 0 0 100px rgba(0, 242, 255, 0.15);
}

.video-container iframe {
    width: 100%;
    height: 100%;
    border-radius: 18px;
    display: block;
}

.btn {
    background: #fff;
    color: #000;
    padding: 1.2rem 4rem;
    border-radius: 14px;
    font-weight: 800;
    text-decoration: none;
    font-size: 1.2rem;
    transition: 0.3s cubic-bezier(0.19, 1, 0.22, 1);
    box-shadow: 0 10px 40px rgba(255,255,255,0.1);
}

.btn:hover {
    background: var(--accent);
    transform: translateY(-5px) scale(1.02);
    box-shadow: 0 20px 60px rgba(0, 242, 255, 0.4);
}

/* GIF Showcase */
.gif-showcase {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    width: 100%;
    margin-top: 5rem;
}

.gif-box {
    background: var(--glass);
    border: 1px solid var(--border);
    border-radius: 20px;
    overflow: hidden;
}

.gif-box img {
    width: 100%;
    height: 220px;
    object-fit: cover;
}

.gif-label {
    padding: 15px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--accent);
    text-transform: uppercase;
}
/* --- Optimized Button & Demo List Styles --- */

.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 12px;
    font-weight: 800;
    text-decoration: none;
    font-size: 1rem;
    transition: all 0.3s cubic-bezier(0.19, 1, 0.22, 1);
    white-space: nowrap;
    text-align: center;
    width: 100%;
    max-width: 240px;
}

/* Accent highlight button for Core project */
.btn-primary {
    background: #fff;
    color: #000;
    box-shadow: 0 10px 30px rgba(255, 255, 255, 0.1);
}

.btn-primary:hover {
    background: var(--accent);
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(0, 242, 255, 0.35);
}

/* Secondary ghost-style button for additional sub-demos */
.btn-secondary {
    background: var(--glass);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--text-primary);
    transform: translateY(-3px);
}

/* Demo Showcase Container */
.demo-showcase {
    width: 100%;
    max-width: 850px;
    margin: 3rem 0;
    text-align: left;
}

.section-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    letter-spacing: 1px;
    text-transform: uppercase;
}

.demo-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Individual Demo Item Row Layout */
.demo-item {
    display: flex;
    align-items: center;
    background: var(--glass);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 2rem;
    gap: 2.5rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

/* Special subtle left border glow for the core package to stand out */
.demo-item.core-package {
    border-left: 4px solid var(--accent);
    box-shadow: 0 10px 40px rgba(0, 242, 255, 0.03);
}

.demo-item:hover {
    border-color: rgba(0, 242, 255, 0.3);
    box-shadow: 0 15px 50px rgba(0, 242, 255, 0.05);
}

/* Left Column: Action Button Container */
.demo-action {
    flex: 0 0 240px; /* Rigid width to perfectly align all buttons vertically */
    display: flex;
    justify-content: center;
}

/* Right Column: Text Information */
.demo-info {
    flex: 1;
}

.demo-info h3 {
    margin: 0 0 0.5rem 0;
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text-primary);
}

.demo-info p {
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* Footer spacing alignment adjustment */
footer {
    margin-top: 5rem;
    color: #444;
    font-size: 0.9rem;
}

/* --- Responsive Adaptability for Tablets and Mobile Devices --- */
@media (max-width: 768px) {
    .demo-item {
        flex-direction: column; /* Stack vertically on small screens */
        align-items: flex-start;
        gap: 1.2rem;
        padding: 1.5rem;
    }

    .demo-action {
        flex: none;
        width: 100%;
    }

    .btn {
        max-width: 100%; /* Full width action buttons on mobile devices */
    }
}