:root {
    --primary-color: #0056b3;
    --secondary-color: #004494;
    --text-color: #333;
    --bg-color: #f8f9fa;
    --white: #ffffff;
    --border-color: #e9ecef;
}

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

body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
.site-header {
    background-color: var(--white);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.branding h1 {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin: 0;
}

.subtitle {
    font-size: 0.9rem;
    color: #666;
    margin: 0;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
    margin: 0;
    padding: 0;
}

.main-nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Sections General */
section {
    padding: 4rem 0;
}

section:nth-child(even) {
    background-color: var(--bg-color);
}

h2 {
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-align: center;
    font-size: 2rem;
}

.section-subtitle {
    text-align: center;
    color: #666;
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* Intro Section */
.intro-content {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.intro-text {
    flex: 1;
}

.intro-image {
    flex: 1;
    text-align: center;
}

.intro-image img {
    max-width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

/* Cards Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    text-align: center;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
}

.card .icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

/* Usage Section */
.usage-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.usage-item {
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.usage-item img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.usage-item h3, .usage-item p {
    padding: 0 1.5rem;
}

.usage-item h3 {
    margin-top: 1rem;
    color: var(--primary-color);
}

.usage-item p {
    margin-bottom: 1.5rem;
    color: #555;
}

/* Advantages List */
.advantages-list {
    max-width: 800px;
    margin: 0 auto;
    list-style: none;
    padding: 0;
}

.advantages-list li {
    background: var(--white);
    padding: 1rem 1.5rem;
    margin-bottom: 1rem;
    border-radius: 4px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border-left: 4px solid var(--primary-color);
}

/* Form */
.contact-form {
    max-width: 600px;
    margin: 0 auto;
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-family: inherit;
}

.submit-btn {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 1rem 2rem;
    border-radius: 4px;
    cursor: pointer;
    width: 100%;
    font-size: 1rem;
    transition: background 0.3s;
}

.submit-btn:hover {
    background-color: var(--secondary-color);
}

/* Footer */
.site-footer {
    background-color: #333;
    color: var(--white);
    padding: 2rem 0;
    margin-top: 2rem;
    text-align: center;
}

.footer-nav {
    margin-top: 1rem;
}

.footer-nav a {
    color: #ccc;
    text-decoration: none;
    margin: 0 10px;
}

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

/* Media Queries */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .main-nav ul {
        flex-direction: column;
        gap: 0.5rem;
        align-items: center;
    }

    .intro-content {
        flex-direction: column;
    }
}