:root {
    --primary: #2b5876;
    --secondary: #4e4376;
    --text-main: #333;
    --text-light: #666;
    --bg-main: #fafafa;
    --bg-card: #ffffff;
    --gradient-hero: linear-gradient(135deg, #e0c3fc 0%, #8ec5fc 100%);
    --gradient-accent: linear-gradient(135deg, #2b5876 0%, #4e4376 100%);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-main);
    color: var(--text-main);
    line-height: 1.6;
}

/* Navbar Sticky */
.navbar {
    position: fixed;
    top: 0; width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    display: flex; justify-content: space-between; align-items: center;
    padding: 15px 5%;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    z-index: 1000;
}
.nav-brand { font-weight: 700; font-size: 1.2rem; color: var(--primary); }
.nav-links { list-style: none; display: flex; gap: 20px; }
.nav-links a { text-decoration: none; color: var(--text-main); font-weight: 600; transition: color 0.3s; }
.nav-links a:hover { color: var(--primary); }

/* Layout chung */
.section { padding: 100px 5% 50px; }
.container { max-width: 1100px; margin: 0 auto; }
h2 { text-align: center; margin-bottom: 40px; font-size: 2.2rem; color: var(--primary); }
.bg-light { background: #f0f4f8; }

/* Hero Section */
.hero {
    background: var(--gradient-hero);
    min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    padding-top: 80px;
}
.hero-content {
    max-width: 1100px; display: flex; align-items: center; gap: 50px; flex-wrap: wrap;
}
.hero-text { flex: 1; min-width: 300px; }
.hero-text h1 { font-size: 3rem; color: #1a1a1a; margin-bottom: 10px; }
.hero-text h3 { font-size: 1.5rem; color: var(--primary); font-weight: 400; margin-bottom: 20px; }
.institution { font-size: 1.1rem; color: var(--text-light); margin-bottom: 30px; }
blockquote {
    font-style: italic; font-size: 1.2rem; color: var(--secondary);
    border-left: 4px solid var(--primary); padding-left: 15px;
}
.hero-image { position: relative; flex-basis: 350px; }
.hero-image img {
    width: 100%; border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    border: 5px solid white;
}
.metrics-badge {
    position: absolute; bottom: -20px; right: -20px;
    background: var(--gradient-accent); color: white;
    padding: 15px 25px; border-radius: 30px; font-weight: bold;
    box-shadow: 0 10px 20px rgba(0,0,0,0.15);
}

/* About & Cards */
.about-grid { display: flex; gap: 40px; flex-wrap: wrap; }
.about-text { flex: 1; min-width: 300px; }
.about-text h3 { margin-top: 20px; color: var(--primary); }
.interests-cards { flex: 1; display: grid; grid-template-columns: 1fr 1fr; gap: 20px; min-width: 300px; }
.card {
    background: var(--bg-card); padding: 25px; border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05); transition: transform 0.3s;
    text-align: center;
}
.card:hover { transform: translateY(-5px); }
.card i { font-size: 2.5rem; color: var(--primary); margin-bottom: 15px; }

/* Metrics Row */
.metrics-row { display: flex; justify-content: center; gap: 30px; margin-bottom: 30px; flex-wrap: wrap;}
.metric-box {
    background: white; padding: 20px 40px; border-radius: 10px;
    text-align: center; box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}
.metric-box h4 { font-size: 2rem; color: var(--primary); }

/* Accordion (Thành tích click mở rộng) */
.accordion-item {
    background: white; margin-bottom: 15px; border-radius: 10px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.03); overflow: hidden;
}
.accordion-header {
    width: 100%; text-align: left; padding: 20px; border: none;
    background: transparent; font-size: 1.1rem; font-weight: 600;
    cursor: pointer; display: flex; justify-content: space-between;
    transition: background 0.3s; color: var(--text-main);
}
.accordion-header:hover { background: #f9f9f9; }
.accordion-header i { transition: transform 0.3s; }
.accordion-header.active i { transform: rotate(180deg); color: var(--primary); }
.accordion-content {
    max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
    padding: 0 20px; background: #fafafa;
}
.accordion-content ul { padding: 20px; }
.accordion-content li { margin-bottom: 10px; }

/* Footer */
.footer { background: var(--gradient-accent); color: white; padding: 60px 5% 30px; text-align: center; }
.footer h2 { color: white; }
.social-links { margin: 20px 0; }
.social-links a {
    color: white; font-size: 1.2rem; margin: 0 10px; text-decoration: none;
    display: inline-flex; align-items: center; gap: 8px;
}
.copyright { margin-top: 30px; font-size: 0.9rem; opacity: 0.7; }

/* Animations Scroll */
.fade-in { opacity: 0; transition: opacity 1s ease-out; }
.fade-in.visible { opacity: 1; }
.slide-up { opacity: 0; transform: translateY(50px); transition: opacity 0.8s ease-out, transform 0.8s ease-out; }
.slide-up.visible { opacity: 1; transform: translateY(0); }

@media (max-width: 768px) {
    .nav-links { display: none; } /* Mobile menu ẩn cơ bản */
    .hero-content { text-align: center; justify-content: center; }
    blockquote { text-align: left; }
    .interests-cards { grid-template-columns: 1fr; }
}