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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial, sans-serif;
    line-height: 1.6;
    color: #222;
    background-color: #f5f5f5;
}

a {
    color: inherit;
    text-decoration: none;
}

.container {
    width: 90%;
    max-width: 1100px;
    margin: 0 auto;
}

/* Κοινό navigation */

.main-header {
    background-color: #0d47a1;
    color: white;
    padding: 14px 0;
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-weight: 700;
    font-size: 1.15rem;
    letter-spacing: 0.04em;
}

.nav-links a {
    margin-left: 20px;
    font-size: 0.9rem;
    opacity: 0.9;
}

.nav-links a:hover {
    opacity: 1;
    text-decoration: underline;
}

.nav-links .active {
    font-weight: 600;
    text-decoration: underline;
}

/* Hero αρχικής σελίδας με background image */

.hero-header {
    background-image:
        linear-gradient(to bottom right, rgba(13, 71, 161, 0.9), rgba(25, 118, 210, 0.7)),
        url("../images/it-hero.jpg");
    background-size: cover;
    background-position: center;
    color: white;
    padding: 24px 0 70px 0;
}

.hero {
    display: grid;
    grid-template-columns: 2fr 1.3fr;
    gap: 30px;
    align-items: center;
}

.hero h1 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.hero p {
    margin-bottom: 15px;
    font-size: 1rem;
}

.hero-highlight {
    font-weight: 500;
    margin-bottom: 10px;
}

.hero-cta {
    margin-top: 20px;
}

.btn {
    display: inline-block;
    padding: 10px 18px;
    border-radius: 6px;
    font-size: 0.95rem;
    border: 1px solid white;
    cursor: pointer;
}

.btn-primary {
    background-color: white;
    color: #0d47a1;
    font-weight: 600;
    margin-right: 10px;
}

.btn-outline {
    background-color: transparent;
    color: white;
}

.hero-card {
    background-color: rgba(0, 0, 0, 0.35);
    border-radius: 10px;
    padding: 18px;
    font-size: 0.9rem;
}

/* Sub headers για τις εσωτερικές σελίδες */

.sub-header {
    background: linear-gradient(to bottom right, #0d47a1, #1976d2);
    color: white;
    padding: 18px 0 28px 0;
}

.sub-header-title {
    margin-top: 18px;
    font-size: 1.6rem;
}

/* Βασική δομή sections */

section {
    padding: 40px 0;
}

section:nth-of-type(even) {
    background-color: #ffffff;
}

section:nth-of-type(odd) {
    background-color: #f5f5f5;
}

section h2 {
    font-size: 1.4rem;
    margin-bottom: 18px;
}

p {
    margin-bottom: 10px;
}

.grid {
    display: grid;
    gap: 20px;
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.card {
    background-color: white;
    border-radius: 10px;
    padding: 18px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    font-size: 0.95rem;
}

.card h3 {
    font-size: 1.05rem;
    margin-bottom: 10px;
}

ul {
    list-style: none;
    padding-left: 0;
}

ul li::before {
    content: "• ";
    color: #1976d2;
}

.two-columns {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 30px;
}

/* Επικοινωνία */

.contact-box {
    background-color: white;
    border-radius: 10px;
    padding: 18px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.contact-line {
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.contact-line span {
    font-weight: 600;
}

form {
    display: grid;
    gap: 10px;
    margin-top: 10px;
}

input,
textarea {
    padding: 8px;
    border-radius: 6px;
    border: 1px solid #ccc;
    font-family: inherit;
    font-size: 0.95rem;
}

textarea {
    min-height: 90px;
    resize: vertical;
}

/* Footer */

footer {
    background-color: #0b274d;
    color: #ddd;
    padding: 18px 0;
    font-size: 0.85rem;
}

footer .container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 10px;
}

/* Responsive */

@media (max-width: 768px) {
    .hero {
        grid-template-columns: 1fr;
    }

    .hero-header {
        padding-bottom: 45px;
    }

    .nav {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .nav-links {
        display: flex;
        flex-wrap: wrap;
    }
}