/* Reset & Base Styles */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Zen Kaku Gothic New', sans-serif;
    color: #333;
    line-height: 1.6;
    background-color: #fff;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

img {
    max-width: 100%;
    height: auto;
}

/* Common Styles */
.container {
    width: 100%;
    max-width: 1300px;
    margin: 0 auto;
    padding: 0 30px;
}

.center {
    text-align: center;
}

.section {
    padding: 120px 0;
    position: relative;
}

.section-title {
    font-size: 38px;
    font-weight: 700;
    margin-bottom: 60px;
    letter-spacing: -0.02em;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -10px;
    width: 50px;
    height: 2px;
    background-color: #6B8F8C;
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.active {
    opacity: 1;
    transform: translateY(0);
}

/* Header Styles */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 20px 0;
    transition: all 0.3s ease;
    background-color: rgba(255, 255, 255, 0.98);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.logo {
    display: flex;
    align-items: center;
    z-index: 1001;
}

.logo img {
    height: 30px;
    margin-right: 10px;
}

.logo-text {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.03em;
    color: #333;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 1001;
    width: 30px;
    height: 24px;
    position: relative;
}

.nav-toggle span {
    display: block;
    position: absolute;
    height: 2px;
    width: 100%;
    background: #333;
    border-radius: 2px;
    opacity: 1;
    left: 0;
    transform: rotate(0deg);
    transition: .25s ease-in-out;
}

.nav-toggle span:nth-child(1) {
    top: 0px;
}

.nav-toggle span:nth-child(2), .nav-toggle span:nth-child(3) {
    top: 10px;
}

.nav-toggle span:nth-child(4) {
    top: 20px;
}

.nav-toggle.active span:nth-child(1) {
    top: 10px;
    width: 0%;
    left: 50%;
}

.nav-toggle.active span:nth-child(2) {
    transform: rotate(45deg);
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg);
}

.nav-toggle.active span:nth-child(4) {
    top: 10px;
    width: 0%;
    left: 50%;
}

.nav-menu {
    display: flex;
    align-items: center;
}

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

.nav-item {
    margin-left: 40px;
}

.nav-link {
    font-size: 16px;
    font-weight: 500;
    color: #333;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link.current {
    color: #6B8F8C;
}

.nav-link::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: #6B8F8C;
    transition: width 0.3s ease;
}

.nav-link:hover::after, .nav-link.current::after {
    width: 100%;
}

/* Page Title */
.page-title-section {
    background-color: #f9f9f9;
    padding: 120px 0 60px;
    margin-bottom: 40px;
}

.page-title {
    font-size: 36px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 20px;
}

.page-description {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
    color: #666;
    font-size: 16px;
    line-height: 1.8;
}

/* Case Grid */
.case-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    margin-bottom: 80px;
}

.case-card {
    background-color: #fff;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    position: relative;
}

.case-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
}

.case-image {
    position: relative;
    width: 100%;
    height: 280px;
    overflow: hidden;
}

.case-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.case-card:hover .case-image img {
    transform: scale(1.05);
}

.case-tag {
    position: absolute;
    top: 20px;
    left: 20px;
    background-color: #6B8F8C;
    color: #fff;
    padding: 6px 12px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 500;
}

.case-content {
    padding: 30px;
}

.case-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 15px;
    color: #333;
    line-height: 1.4;
}

.case-description {
    color: #666;
    font-size: 15px;
    line-height: 1.7;
    margin-bottom: 20px;
}

/* Footer */
footer {
    background-color: #333;
    color: #fff;
    padding: 40px 0;
    text-align: center;
    margin-top: 80px;
}

.footer-content {
    opacity: 0.7;
}

/* Media Queries */
@media (max-width: 992px) {
    .case-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .page-title-section {
        padding: 100px 0 50px;
    }
    
    .page-title {
        font-size: 32px;
    }
    
    .section-title {
        font-size: 32px;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 20px;
    }
    
    .nav-toggle {
        display: block;
    }
    
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 400px;
        height: 100vh;
        background-color: #fff;
        flex-direction: column;
        align-items: flex-start;
        padding: 100px 40px 40px;
        transition: right 0.3s ease;
        box-shadow: -10px 0 30px rgba(0, 0, 0, 0.1);
        z-index: 1000;
    }
    
    .nav-menu.active {
        right: 0;
    }
    
    .nav-list {
        flex-direction: column;
        width: 100%;
    }
    
    .nav-item {
        margin: 15px 0;
    }
    
    .nav-link {
        font-size: 18px;
    }
    
    .page-title-section {
        padding: 90px 0 40px;
    }
    
    .page-title {
        font-size: 28px;
    }
    
    .case-grid {
        gap: 25px;
    }
    
    .case-image {
        height: 220px;
    }
    
    .case-content {
        padding: 25px;
    }
    
    .case-title {
        font-size: 20px;
    }
}

@media (max-width: 576px) {
    .case-content {
        padding: 20px;
    }
    
    .case-title {
        font-size: 18px;
    }
    
    .case-description {
        font-size: 14px;
    }
}