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

body {
    font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
    line-height: 1.6;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    max-width: 1200px;
    margin: 0 auto;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin-left: 2rem;
}

nav ul li a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #0066cc;
}

.hero {
    height: 100vh;
    background: linear-gradient(
        rgba(0, 0, 0, 0.5),
        rgba(0, 0, 0, 0.5)
    ), url('https://ohskensetu.com/images/excavator.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    color: white;
    text-align: center;
    padding: 0 20px;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    max-width: 600px;
}

section {
    padding: 5rem 1rem;
}

section h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 3rem;
}

.content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

#services {
    position: relative;
    padding: 5rem 1rem;
    color: white;
    background: linear-gradient(
        rgba(0, 0, 0, 0.7),
        rgba(0, 0, 0, 0.7)
    ), url('https://ohskensetu.com/images/事業内容.jpg');
    background-size: cover;
    background-position: center;
}

.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.service-item {
    background: rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: 10px;
    backdrop-filter: blur(5px);
}

.service-item h3 {
    margin-bottom: 1rem;
}

.contact-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2.5rem;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

.contact-info {
    margin-bottom: 2.5rem;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 5px;
    font-size: 0.95rem;
}

.contact-info h3 {
    margin-bottom: 1rem;
    color: #333;
    text-align: center;
}

.contact-info p {
    line-height: 2;
    color: #666;
    text-align: center;
}

.form-group {
    margin-bottom: 1.5rem;
    display: grid;
    grid-template-columns: 180px 1fr;
    align-items: center;
    gap: 1rem;
}

.form-group.textarea-group {
    align-items: start;
    margin-top: 1.5rem;
}

.form-group label {
    font-size: 0.95rem;
    font-weight: 500;
    color: #333;
    padding-top: 0.5rem;
}

.required {
    color: #ff4444;
    margin-left: 0.3rem;
    font-size: 0.8rem;
}

.input-wrapper {
    position: relative;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 0.95rem;
}

.form-group input,
.form-group select {
    height: 45px;
}

.form-group textarea {
    height: 120px;
    resize: vertical;
    min-height: 120px;
    max-height: 300px;
}

.error-message {
    position: absolute;
    bottom: -20px;
    left: 0;
    color: #ff4444;
    font-size: 0.8rem;
}

.submit-button-container {
    text-align: center;
    margin-top: 2rem;
}

.submit-btn {
    width: 300px;
    height: 50px;
    background: #0066cc;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

.submit-btn:hover {
    background: #0052a3;
}

footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 1rem;
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .hero p {
        font-size: 1rem;
    }
    
    .service-grid {
        grid-template-columns: 1fr;
    }

    .contact-container {
        padding: 1.5rem;
    }

    .form-group {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .form-group label {
        padding-top: 0;
    }

    .submit-btn {
        width: 100%;
    }

    .contact-info {
        padding: 1rem;
    }
}