:root {
    --bg-dark: #040814;
    --neon-blue: #00f0ff;
    --neon-blue-dim: rgba(0, 240, 255, 0.2);
    --card-bg: rgba(6, 12, 28, 0.7);
    --text-main: #e2f1f8;
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-main);
    font-family: 'Rajdhani', sans-serif;
    min-height: 100vh;
    overflow-x: hidden;
    display: flex;
    justify-content: center;
}

/* Background Lưới Điện Tử */
.cyber-grid {
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    background-image: 
        linear-gradient(var(--neon-blue-dim) 1px, transparent 1px),
        linear-gradient(90deg, var(--neon-blue-dim) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.15;
    z-index: -2;
}

#techCanvas { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: -1; }

.container {
    max-width: 900px;
    width: 100%;
    padding: 3rem 1.5rem;
    z-index: 1;
}

/* Header & Glitch Effect */
.profile-header { text-align: center; margin-bottom: 4rem; }

.hud-box {
    display: flex; align-items: center; justify-content: center; gap: 1rem;
    margin-bottom: 1rem;
}

.hud-line { height: 2px; width: 50px; background: var(--neon-blue); box-shadow: 0 0 10px var(--neon-blue); }

h1.glitch {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.5rem;
    font-weight: 900;
    color: var(--neon-blue);
    text-shadow: 0 0 15px rgba(0, 240, 255, 0.5);
    letter-spacing: 4px;
    position: relative;
}

.terminal-text {
    font-family: 'Courier New', Courier, monospace;
    font-size: 1.1rem;
    color: #8892b0;
    background: rgba(0, 240, 255, 0.05);
    padding: 10px 20px;
    display: inline-block;
    border-radius: 4px;
    border: 1px solid var(--neon-blue-dim);
}

.terminal-text .prefix { color: var(--neon-blue); font-weight: bold; margin-right: 8px; }
.cursor { animation: blink 1s step-end infinite; color: var(--neon-blue); font-weight: bold;}
@keyframes blink { 50% { opacity: 0; } }

/* Cấu trúc Danh mục */
.category-wrapper { margin-bottom: 3rem; }

.category-title {
    font-family: 'Orbitron', sans-serif;
    font-size: 1.1rem;
    color: var(--neon-blue);
    letter-spacing: 2px;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 10px;
    text-transform: uppercase;
    border-bottom: 1px solid var(--neon-blue-dim);
    padding-bottom: 10px;
}

/* Các Nút Bấm / Cards */
.links-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.link-item {
    background: var(--card-bg);
    border: 1px solid var(--neon-blue-dim);
    border-radius: 8px;
    padding: 1.2rem;
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-main);
    backdrop-filter: blur(10px);
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
    box-shadow: inset 0 0 20px rgba(0, 240, 255, 0.02);
}

/* Tia sáng lướt ngang khi hover */
.scan-line {
    position: absolute; top: 0; left: -100%; width: 50%; height: 100%;
    background: linear-gradient(90deg, transparent, rgba(0, 240, 255, 0.3), transparent);
    transform: skewX(-20deg);
    transition: 0.5s ease;
}

.link-item:hover .scan-line { left: 200%; transition: 0.7s ease; }

.link-item:hover {
    border-color: var(--neon-blue);
    box-shadow: 0 0 15px rgba(0, 240, 255, 0.2), inset 0 0 15px rgba(0, 240, 255, 0.1);
    transform: translateY(-2px);
}

.link-icon-box {
    font-size: 1.8rem; color: var(--neon-blue);
    margin-right: 15px; width: 40px; text-align: center;
}

.link-info { display: flex; flex-direction: column; flex-grow: 1; }

.link-title { font-size: 1.2rem; font-weight: 600; letter-spacing: 1px; margin-bottom: 4px; }

.link-desc { font-family: 'Courier New', monospace; font-size: 0.8rem; color: #8892b0; text-transform: uppercase; }

.nav-arrow { font-size: 1.2rem; color: var(--neon-blue-dim); transition: 0.3s; }
.link-item:hover .nav-arrow { color: var(--neon-blue); transform: translateX(5px); }

/* Footer */
footer {
    text-align: center; padding-top: 2rem;
    font-family: 'Courier New', monospace; font-size: 0.8rem; color: #5a6b8c;
    border-top: 1px dashed rgba(255, 255, 255, 0.1); margin-top: 2rem;
}