:root {
    /* Colors */
    --primary-color: #0F52BA; /* Μπλε */
    --secondary-color: #2ECC71; /* Πράσινο */
    --background-color: #F0F8FF; /* Ανοιχτό Μπλε/Λευκό */
    --footer-bg-color: #0A1F2E; /* Σκούρο Μπλε/Μαύρο */
    --button-color: #FF8C00; /* Πορτοκαλί */
    --text-color: #333333;
    --light-text-color: #F0F8FF;
    --accent-color: #FF8C00; /* Χρησιμοποιείται για μικρές λεπτομέρειες */

    /* Section Backgrounds */
    --section-bg-1: #f0f8ff;
    --section-bg-2: #e6f2f8;
    --section-bg-3: #f8fdfc;

    /* Fonts */
    --font-heading: 'Montserrat', sans-serif;
    --font-body: 'Lato', sans-serif;

    /* Spacing */
    --spacing-unit: 1rem;
    --section-padding: 6rem 0;

    /* Border Radius */
    --border-radius-sm: 0.25rem;
    --border-radius-md: 0.5rem;
    --border-radius-lg: 1rem;

    /* Shadows */
    --shadow-light: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-medium: 0 8px 25px rgba(0, 0, 0, 0.15);
    --shadow-glass: 0 8px 32px 0 rgba(31, 38, 135, 0.37);

    /* Glassmorphism */
    --glass-blur: 10px;
    --glass-border: 1px solid rgba(255, 255, 255, 0.18);
    --glass-bg: rgba(255, 255, 255, 0.25);
}

/* Base Styles */
html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    color: var(--text-color);
    background-color: var(--background-color);
    line-height: 1.7;
    margin: 0;
    padding: 0;
    overflow-x: hidden; /* Prevent horizontal scroll */
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--primary-color);
    line-height: 1.2;
    margin-top: 1.5em;
    margin-bottom: 0.8em;
}

h1 {
    font-size: 3.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
}

h2 {
    font-size: 2.5rem;
    font-weight: 600;
    margin-top: 2em;
}

h3 {
    font-size: 1.8rem;
    font-weight: 500;
}

p {
    margin-bottom: 1.2rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease, transform 0.3s ease;
}

a:hover {
    color: var(--accent-color);
    transform: translateY(-1px);
}

/* Utility Classes for Layout and Spacing (complementing Tailwind) */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.section-padding {
    padding: var(--section-padding);
}

/* Section Backgrounds */
.section-bg-1 {
    background-color: var(--section-bg-1);
}

.section-bg-2 {
    background-color: var(--section-bg-2);
}

.section-bg-3 {
    background-color: var(--section-bg-3);
}

/* Header Styles */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: transparent; /* Default transparent */
    transition: background-color 0.4s ease, backdrop-filter 0.4s ease;
    padding: 1rem 0;
}

.header.scrolled {
    background: var(--glass-bg);
    backdrop-filter: blur(var(--glass-blur));
    -webkit-backdrop-filter: blur(var(--glass-blur));
    border-bottom: var(--glass-border);
    box-shadow: var(--shadow-glass);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.header-logo {
    height: 50px; /* Adjust as needed */
    display: block;
}

.header-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 2rem;
}

.header-nav li a {
    font-family: var(--font-heading);
    color: var(--text-color);
    font-weight: 500;
    font-size: 1.1rem;
    position: relative;
}

.header-nav li a:hover {
    color: var(--primary-color);
}

.header-nav li a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    bottom: -5px;
    left: 0;
    transition: width 0.3s ease;
}

.header-nav li a:hover::after {
    width: 100%;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2.5rem;
    border: none;
    border-radius: var(--border-radius-md);
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.3s ease, background-color 0.3s ease, box-shadow 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    box-shadow: var(--shadow-light);
}

.btn-primary {
    background-color: var(--button-color);
    color: var(--light-text-color);
}

.btn-primary:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: var(--light-text-color);
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

/* Cards */
.card {
    background-color: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-light);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-medium);
}

.card-image {
    width: 100%;
    height: 200px; /* Or aspect-ratio for flexible height */
    object-fit: cover;
    display: block;
}

.card-content {
    padding: 1.5rem;
    flex-grow: 1;
}

.card-title {
    font-size: 1.4rem;
    margin-top: 0;
    margin-bottom: 0.8rem;
    color: var(--primary-color);
}

.card-text {
    font-size: 0.95rem;
    color: #666;
    margin-bottom: 1rem;
}

.card-link {
    display: inline-block;
    font-weight: 500;
    color: var(--accent-color);
}

.card-link:hover {
    text-decoration: underline;
}

/* Forms */
.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--primary-color);
}

.form-control {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid #ddd;
    border-radius: var(--border-radius-sm);
    font-family: var(--font-body);
    font-size: 1rem;
    color: var(--text-color);
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(15, 82, 186, 0.2);
}

textarea.form-control {
    min-height: 120px;
    resize: vertical;
}

/* Gradients (example usage, apply to specific elements as needed) */
.gradient-overlay {
    position: relative;
}

.gradient-overlay::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(15, 82, 186, 0.8), rgba(46, 204, 113, 0.8));
    opacity: 0.8;
    z-index: 1;
}

/* Footer */
.footer {
    background-color: var(--footer-bg-color);
    color: var(--light-text-color);
    padding: 3rem 0;
    text-align: center;
    font-size: 0.9rem;
}

.footer a {
    color: var(--light-text-color);
    margin: 0 0.5rem;
}

.footer a:hover {
    color: var(--accent-color);
}

/* Media Queries for Responsiveness */
@media (max-width: 1024px) {
    h1 {
        font-size: 3rem;
    }

    h2 {
        font-size: 2rem;
    }

    .header-nav ul {
        gap: 1.5rem;
    }

    .section-padding {
        padding: 4rem 0;
    }
}

@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 1.8rem;
    }

    .header-nav ul {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
        background: var(--glass-bg);
        backdrop-filter: blur(var(--glass-blur));
        -webkit-backdrop-filter: blur(var(--glass-blur));
        border: var(--glass-border);
        border-radius: var(--border-radius-md);
        padding: 1rem;
        position: absolute;
        top: 100%;
        right: 1rem;
        width: 200px;
        box-shadow: var(--shadow-medium);
        display: none; /* Hidden by default, toggle with JS */
    }

    .header-nav.active ul {
        display: flex;
    }

    .header-nav li a {
        padding: 0.5rem 0;
        display: block;
    }

    .header-content {
        padding: 0 1rem;
    }

    .btn {
        padding: 0.8rem 2rem;
        font-size: 1rem;
    }

    .card {
        margin-bottom: 1.5rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 2rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .section-padding {
        padding: 3rem 0;
    }

    .btn {
        width: 100%;
        padding: 0.75rem 1.5rem;
    }
}


/* Cookie Banner Additional Styles for Tailwind */
.cookie-banner-hover-effect:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

@media (prefers-reduced-motion: reduce) {
    .cookie-banner-hover-effect:hover {
        transform: none;
    }
}