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

html, body {
    height: 100%;
}
body {
    font-family: 'Rubik', sans-serif;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background: #1a1a2e;
}

/* ── HERO ── */
.gtsu-hero {
    flex: 1;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2.5rem;
    padding: 3rem 1.5rem;
    background:
        url('../images/gtsu.png')
        center center / cover no-repeat;
}

/* Dark overlay */
.gtsu-hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        to bottom,
        rgba(10, 20, 40, 0.62) 0%,
        rgba(10, 20, 40, 0.50) 50%,
        rgba(10, 20, 40, 0.72) 100%
    );
    z-index: 0;
}
.gtsu-hero > * { position: relative; z-index: 1; }

/* ── HEADER / TITLE ── */
.gtsu-header {
    text-align: center;
    width: 100%;
}
.gtsu-header h1 {
    font-size: clamp(1.6rem, 3.8vw, 3rem);
    font-weight: 700;
    color: #ffffff;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    text-shadow: 0 2px 16px rgba(0,0,0,0.7);
    margin-bottom: 0.5rem;
}
.gtsu-header .subtitle {
    font-size: clamp(0.85rem, 1.6vw, 1.05rem);
    color: rgba(255,255,255,0.70);
    letter-spacing: 0.15em;
    text-transform: uppercase;
    text-align: center;
}

/* ── COMPANY CARDS ── */
.gtsu-cards {
    display: flex;
    gap: 2rem;
    width: 100%;
    max-width: 920px;
    align-items: stretch;
}
.gtsu-card {
    flex: 1;
    background: rgba(10, 20, 40, 0.75);
    border: 1px solid rgba(255,255,255,0.10);
    border-top: 3px solid #1a5fa6;
    border-radius: 0.5rem;
    padding: 1.8rem 1.6rem;
    backdrop-filter: blur(8px);
    display: flex;
    flex-direction: column;
    gap: 1.8rem;
}
.gtsu-card .company-logo {
    display: block;
    height: 52px;
    width: auto;
    max-width: 100%;
    object-fit: contain;
    margin: 0 auto;
}
.gtsu-card ul {
    list-style: none;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
    flex: 1;
}
.gtsu-card ul li {
    font-size: 0.97rem;
    color: rgba(255,255,255,0.72);
    padding-left: 1rem;
    position: relative;
    line-height: 1.5;
}
.gtsu-card ul li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: #1a5fa6;
    font-weight: 700;
}
.btn-gtsu {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.6rem;
    padding: 0.65rem 1.1rem;
    background: rgba(26, 95, 166, 0.20);
    border: 1px solid rgba(26, 95, 166, 0.55);
    border-radius: 0.3rem;
    color: rgba(255,255,255,0.9);
    font-size: 0.95rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    text-decoration: none;
    transition: background 0.2s, border-color 0.2s, color 0.2s;
    width: 100%;
}
.btn-gtsu:hover {
    background: #1a5fa6;
    border-color: #1a5fa6;
    color: #fff;
}
.btn-gtsu .btn-arrow {
    opacity: 0.6;
    flex-shrink: 0;
    transition: transform 0.2s, opacity 0.2s;
}
.btn-gtsu:hover .btn-arrow {
    opacity: 1;
    transform: translateX(3px);
}

/* ── FOOTER ── */
.gtsu-footer {
    background: rgba(10, 20, 40, 0.97);
    color: #7a8fa8;
    font-size: 0.84rem;
    padding: 0.85rem 2rem;
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 1rem;
    border-top: 1px solid rgba(255,255,255,0.07);
}
.gtsu-footer .footer-left  { text-align: left; }
.gtsu-footer .footer-mid   { text-align: center; white-space: nowrap; }
.gtsu-footer .footer-right { text-align: right; }
.gtsu-footer strong {
    color: #b0bfcf;
    display: block;
    margin-bottom: 0.1rem;
}
.gtsu-footer a {
    color: #7a8fa8;
    text-decoration: none;
    transition: color 0.2s;
}
.gtsu-footer a:hover { color: #1a5fa6; }

/* ── RESPONSIVE ── */
@media (max-width: 680px) {
    .gtsu-cards      { flex-direction: column; gap: 1rem; }
    .gtsu-footer     { grid-template-columns: 1fr; text-align: center !important; }
    .gtsu-footer .footer-left,
    .gtsu-footer .footer-right { text-align: center; }
}