/* リセットとベーススタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #1e6bb8;
    --primary-dark: #155a9a;
    --primary-light: #3b82f6;
    --secondary-color: #fbbf24;
    --text-dark: #1f2937;
    --text-gray: #6b7280;
    --bg-light: #f0f7ff;
    --bg-white: #ffffff;
    --border-color: #bfdbfe;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-light);
}

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

@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 12px;
    }
}

/* ヘッダー */
.header {
    background-color: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

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

.logo-image {
    height: 50px;
    width: auto;
}

.nav {
    display: flex;
    gap: 2rem;
}

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

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

/* ヒーローセクション */
.hero {
    background: linear-gradient(135deg, #1e6bb8 0%, #3b82f6 100%);
    color: white;
    padding: 5rem 0;
    position: relative;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(30, 107, 184, 0.95) 0%, rgba(59, 130, 246, 0.9) 100%);
    z-index: 1;
}

.hero-container {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
}

.hero-content {
    text-align: left;
}

.hero-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    line-height: 1.3;
    word-break: keep-all;
    overflow-wrap: break-word;
}

.hero-brand {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: #fbbf24;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    word-break: keep-all;
    overflow-wrap: break-word;
}

.hero-images {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.hero-image {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease;
}

.hero-image:hover {
    transform: scale(1.05);
}

/* ボタン */
.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background-color: var(--secondary-color);
    color: var(--text-dark);
    font-weight: 700;
}

.btn-primary:hover {
    background-color: #f59e0b;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-large {
    padding: 1rem 3rem;
    font-size: 1.125rem;
}

/* セクション共通 */
.section {
    padding: 5rem 0;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-dark);
    word-break: keep-all;
    overflow-wrap: break-word;
    line-height: 1.4;
}

.section-subtitle {
    text-align: center;
    color: var(--text-gray);
    font-size: 1.125rem;
    margin-bottom: 3rem;
    word-break: keep-all;
    overflow-wrap: break-word;
    line-height: 1.6;
}

/* 会員登録セクション */
.registration-section {
    background-color: var(--bg-white);
}

.registration-tabs {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 2rem;
}

.tab-btn {
    padding: 1rem 2rem;
    background-color: var(--bg-light);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    white-space: nowrap;
}

.tab-btn i {
    font-size: 1.25rem;
}

.tab-btn:hover {
    border-color: var(--primary-color);
    background-color: var(--bg-white);
}

.tab-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.tab-content {
    display: none;
    background-color: var(--bg-light);
    padding: 2rem;
    border-radius: 12px;
    max-width: 900px;
    margin: 0 auto;
}

.tab-content.active {
    display: block;
}

.form-description {
    margin-bottom: 2rem;
    text-align: center;
}

.form-description h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.form-description p {
    color: var(--text-gray);
}

.iframe-container {
    background-color: var(--bg-white);
    border-radius: 8px;
    padding: 1rem;
    min-height: 600px;
    height: auto;
}

.iframe-container iframe {
    border-radius: 8px;
    min-height: 600px;
}

/* 体験後の購入案内セクション */
.purchase-guide-section {
    background-color: var(--bg-white);
}

.purchase-guide-content {
    max-width: 900px;
    margin: 0 auto;
}

.purchase-guide-card {
    background-color: var(--bg-light);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: var(--shadow-md);
}

.purchase-step {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.purchase-step:last-child {
    margin-bottom: 0;
}

.step-number {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #1e6bb8 0%, #3b82f6 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.step-description {
    color: var(--text-gray);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.step-description strong {
    color: var(--primary-color);
    font-weight: 700;
}

.plan-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
}

.plan-option {
    background-color: var(--bg-white);
    padding: 1rem;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    border: 2px solid var(--border-color);
    transition: all 0.3s;
}

.plan-option:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.plan-option i {
    font-size: 1.5rem;
    color: var(--primary-color);
}

.plan-option span {
    font-weight: 600;
    color: var(--text-dark);
}

.purchase-notice {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: #dbeafe;
    border-left: 4px solid var(--primary-color);
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 1rem;
}

.purchase-notice i {
    font-size: 1.5rem;
    color: var(--primary-color);
    flex-shrink: 0;
}

.purchase-notice p {
    margin: 0;
    color: var(--text-dark);
    line-height: 1.6;
}

/* 掲載コンテンツセクション */
.contents-section {
    background-color: var(--bg-light);
}

.subject-tabs {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.subject-tab-btn {
    padding: 0.75rem 1.5rem;
    background-color: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.subject-tab-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.subject-tab-btn.active {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.subject-content {
    display: none;
}

.subject-content.active {
    display: block;
}

.grade-section {
    margin-bottom: 3rem;
}

.grade-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

.content-card {
    background-color: var(--bg-white);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s, box-shadow 0.3s;
}

.content-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.content-badge {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.content-list {
    list-style: none;
}

.content-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    position: relative;
    padding-left: 1.5rem;
}

.content-list li:last-child {
    border-bottom: none;
}

.content-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

.content-list .note {
    display: inline-block;
    background-color: var(--secondary-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    margin-left: 0.5rem;
}

/* 活用事例セクション */
.case-studies-section {
    background-color: var(--bg-white);
}

.case-studies-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.case-study-card {
    background-color: var(--bg-light);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: transform 0.3s, box-shadow 0.3s;
}

.case-study-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.case-study-header {
    background: linear-gradient(135deg, #1e6bb8 0%, #3b82f6 100%);
    color: white;
    padding: 2rem;
    text-align: center;
}

.case-study-icon {
    width: 60px;
    height: 60px;
    background-color: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
}

.case-study-icon i {
    font-size: 1.75rem;
}

.case-study-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.case-study-meta {
    font-size: 0.875rem;
    opacity: 0.9;
    word-break: keep-all;
}

.case-study-body {
    padding: 2rem;
}

.case-study-body p {
    line-height: 1.8;
    margin-bottom: 1.5rem;
    color: var(--text-gray);
}

.case-study-points {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.point {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
}

.point i {
    color: var(--success-color);
    font-size: 1.125rem;
}

/* CTAセクション */
.cta-section {
    background: linear-gradient(135deg, #1e6bb8 0%, #3b82f6 100%);
    color: white;
    padding: 5rem 0;
    text-align: center;
}

.cta-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.cta-subtitle {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

/* フッター */
.footer {
    background-color: var(--text-dark);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer p {
    opacity: 0.8;
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    .hero {
        padding: 3rem 0;
    }

    .hero-container {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .hero-content {
        text-align: center;
    }

    .hero-images {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .hero-title {
        font-size: 1.5rem;
        line-height: 1.4;
        margin-bottom: 0.75rem;
    }

    .hero-brand {
        font-size: 1.25rem;
        margin-bottom: 0.75rem;
    }

    .hero-subtitle {
        font-size: 0.95rem;
        margin-bottom: 1.5rem;
    }

    .btn-large {
        padding: 0.875rem 1.75rem;
        font-size: 0.95rem;
    }

    .section-title {
        font-size: 1.5rem;
        line-height: 1.4;
        padding: 0 10px;
    }

    .section-subtitle {
        font-size: 0.95rem;
        margin-bottom: 2rem;
        padding: 0 10px;
    }

    .section {
        padding: 2.5rem 0;
    }

    .nav {
        gap: 0.5rem;
        font-size: 0.75rem;
        flex-wrap: wrap;
    }

    .nav-link {
        padding: 0.25rem 0.5rem;
    }

    .logo-image {
        height: 35px;
    }

    .registration-tabs {
        flex-direction: column;
        max-width: 100%;
        margin: 0 auto 1.5rem;
        gap: 0.75rem;
    }

    .tab-btn {
        width: 100%;
        justify-content: center;
        padding: 0.875rem 1.5rem;
        font-size: 0.95rem;
    }

    .form-description h3 {
        font-size: 1.25rem;
    }

    .form-description p {
        font-size: 0.9rem;
    }

    .subject-tabs {
        gap: 0.5rem;
        padding: 0 5px;
    }

    .subject-tab-btn {
        padding: 0.625rem 0.875rem;
        font-size: 0.875rem;
    }

    .content-grid {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .content-card {
        padding: 1.25rem;
    }

    .content-badge {
        font-size: 0.8rem;
        padding: 0.4rem 0.875rem;
    }

    .content-list li {
        font-size: 0.9rem;
        padding: 0.625rem 0 0.625rem 1.25rem;
    }

    .case-studies-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .case-study-header {
        padding: 1.5rem;
    }

    .case-study-title {
        font-size: 1.1rem;
    }

    .case-study-body {
        padding: 1.5rem;
    }

    .case-study-body p {
        font-size: 0.9rem;
    }

    .tab-content {
        padding: 0.875rem;
    }

    .iframe-container {
        padding: 0.5rem;
        min-height: 500px;
    }

    .iframe-container iframe {
        min-height: 500px;
    }

    .grade-title {
        font-size: 1.25rem;
    }

    .purchase-step {
        gap: 1rem;
    }

    .step-number {
        width: 40px;
        height: 40px;
        font-size: 1.25rem;
    }

    .step-title {
        font-size: 1.1rem;
    }

    .step-description {
        font-size: 0.9rem;
    }

    .plan-options {
        grid-template-columns: 1fr;
        gap: 0.75rem;
    }

    .plan-option {
        padding: 0.875rem;
        font-size: 0.9rem;
    }

    .purchase-guide-card {
        padding: 1.25rem;
    }

    .purchase-notice {
        padding: 1.25rem;
        font-size: 0.9rem;
    }

    .cta-title {
        font-size: 1.375rem;
    }

    .cta-subtitle {
        font-size: 0.95rem;
    }
}

@media (max-width: 480px) {
    .hero {
        padding: 2rem 0;
    }

    .hero-title {
        font-size: 1.25rem;
        line-height: 1.5;
    }

    .hero-brand {
        font-size: 1.1rem;
    }

    .hero-subtitle {
        font-size: 0.875rem;
    }

    .btn-large {
        padding: 0.75rem 1.5rem;
        font-size: 0.9rem;
        width: 100%;
        max-width: 280px;
    }

    .logo-image {
        height: 30px;
    }

    .header {
        padding: 0.75rem 0;
    }

    .header .container {
        gap: 0.75rem;
    }

    .nav {
        width: 100%;
        justify-content: center;
        gap: 0.375rem;
        font-size: 0.7rem;
    }

    .nav-link {
        padding: 0.25rem 0.375rem;
    }

    .section {
        padding: 2rem 0;
    }

    .section-title {
        font-size: 1.25rem;
    }

    .section-subtitle {
        font-size: 0.875rem;
        margin-bottom: 1.5rem;
    }

    .tab-btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.875rem;
    }

    .form-description h3 {
        font-size: 1.125rem;
    }

    .form-description p {
        font-size: 0.85rem;
    }

    .subject-tab-btn {
        padding: 0.5rem 0.75rem;
        font-size: 0.8rem;
    }

    .grade-title {
        font-size: 1.125rem;
    }

    .content-card {
        padding: 1rem;
    }

    .content-list li {
        font-size: 0.85rem;
    }

    .case-study-title {
        font-size: 1rem;
    }

    .case-study-body p {
        font-size: 0.85rem;
    }

    .step-title {
        font-size: 1rem;
    }

    .step-description {
        font-size: 0.85rem;
    }

    .plan-option {
        font-size: 0.85rem;
    }

    .purchase-notice {
        font-size: 0.85rem;
        padding: 1rem;
    }

    .cta-title {
        font-size: 1.25rem;
    }

    .cta-subtitle {
        font-size: 0.875rem;
    }

    .iframe-container {
        padding: 0.5rem;
        min-height: 450px;
    }

    .iframe-container iframe {
        min-height: 450px;
    }

    .tab-content {
        padding: 0.75rem;
    }
}

/* スムーススクロール */
html {
    scroll-behavior: smooth;
}

/* アニメーション */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.tab-content.active {
    animation: fadeIn 0.5s ease-in-out;
}

.subject-content.active {
    animation: fadeIn 0.5s ease-in-out;
}