:root {
    --primary-color: #FF385C;
    --primary-dark: #E31C5F;
    --secondary-color: #00A699;
    --text-dark: #222222;
    --text-gray: #717171;
    --bg-light: #F7F7F7;
    --white: #FFFFFF;
    --border-color: #DDDDDD;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 16px rgba(0,0,0,0.15);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Yu Gothic', 'Hiragino Sans', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--white);
}

/* ヘッダーナビゲーション */
header {
    background: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
    flex-wrap: wrap;
}

.nav-links a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

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

.nav-links a.active {
    color: var(--primary-color);
}

.download-btn {
    background: var(--primary-color);
    color: var(--white) !important;
    padding: 0.6rem 1.5rem;
    border-radius: 8px;
    transition: background 0.2s, transform 0.2s;
}

.download-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

/* メインコンテンツ */
main {
    min-height: calc(100vh - 200px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.container.narrow {
    max-width: 800px;
}

/* ヒーローセクション */
.hero {
    text-align: center;
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #1a73e8 0%, #0d47a1 100%);
    color: var(--white);
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero .cta-button {
    display: inline-block;
    background: var(--white);
    color: var(--primary-color);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
    box-shadow: var(--shadow-hover);
    transition: transform 0.2s;
}

.hero .cta-button:hover {
    transform: translateY(-3px);
}

/* セクション */
section {
    padding: 3rem 0;
}

h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

/* カードグリッド */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.card h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.card-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

/* バージョンリスト */
.version-list {
    list-style: none;
    margin-top: 2rem;
}

.version-item {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
}

.version-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.version-number {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.version-date {
    color: var(--text-gray);
    font-size: 0.9rem;
}

.version-badge {
    background: var(--primary-color);
    color: var(--white);
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.download-link {
    display: inline-block;
    background: var(--primary-color);
    color: var(--white);
    padding: 0.8rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    margin-top: 1rem;
    transition: background 0.2s, transform 0.2s;
}

.download-link:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.changelog {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.changelog h4 {
    font-size: 1rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.changelog ul {
    list-style: none;
    padding-left: 0;
}

.changelog li {
    padding: 0.3rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.changelog li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* FAQ */
.faq-item {
    background: var(--white);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.faq-question {
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* リスト */
.feature-list, .step-list {
    list-style: none;
    padding-left: 0;
}

.feature-list li, .step-list li {
    padding: 0.8rem 0;
    padding-left: 2rem;
    position: relative;
}

.feature-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: 700;
    font-size: 1.2rem;
}

.step-list {
    counter-reset: step-counter;
}

.step-list li {
    counter-increment: step-counter;
}

.step-list li::before {
    content: counter(step-counter);
    position: absolute;
    left: 0;
    background: var(--primary-color);
    color: var(--white);
    width: 1.5rem;
    height: 1.5rem;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    font-weight: 700;
}

/* 警告ボックス */
.warning-box {
    background: #FFF3CD;
    border-left: 4px solid #FFC107;
    padding: 1.5rem;
    margin: 2rem 0;
    border-radius: 4px;
}

.warning-box strong {
    color: #856404;
}

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

.footer-links {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--white);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.footer-links a:hover {
    opacity: 1;
}

.copyright {
    opacity: 0.6;
    font-size: 0.9rem;
}

/* レスポンシブ */

/* ハンバーガーメニューボタン（デフォルトは非表示） */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    z-index: 200;
}

.menu-toggle span {
    display: block;
    width: 26px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

/* ハンバーガー → × アニメーション */
.menu-toggle.active span:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* スクリーンショット画像 */
.screenshot-img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: var(--shadow);
}

/* 料金カード */
.pricing-card {
    max-width: 480px;
    margin: 0 auto;
    border: 2px solid var(--primary-color);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-hover);
}

.pricing-header {
    background: var(--primary-color);
    color: var(--white);
    padding: 1.5rem;
    text-align: center;
}

.pricing-header h3 {
    margin: 0;
    color: var(--white);
    font-size: 1.3rem;
}

.pricing-body {
    padding: 2rem;
    text-align: center;
}

.pricing-price {
    margin: 1.5rem 0;
}

.price-amount {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
}

.price-period {
    font-size: 1rem;
    color: var(--text-gray);
}

.pricing-body .feature-list {
    text-align: left;
    max-width: 360px;
    margin: 0 auto 1rem auto;
}

/* CTA ボタン（ヒーロー外でも使用可能） */
.cta-button {
    display: inline-block;
    background: var(--primary-color);
    color: var(--white);
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
    transition: background 0.2s, transform 0.2s;
}

.cta-button:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

@media (max-width: 768px) {
    /* スマホ：sticky解除＆ハンバーガーメニュー表示 */
    header {
        position: relative;
    }

    nav {
        flex-direction: row;
        flex-wrap: nowrap;
        justify-content: space-between;
        padding: 0.8rem 1rem;
    }

    .menu-toggle {
        display: flex;
    }

    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        padding: 1rem 0;
        gap: 0;
        z-index: 150;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        text-align: center;
    }

    .nav-links a {
        display: block;
        padding: 0.8rem 1.5rem;
    }

    .nav-links a:hover {
        background: var(--bg-light);
    }

    .download-btn {
        margin: 0.5rem 1.5rem;
        text-align: center;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .hero p {
        font-size: 1rem;
    }

    .card-grid {
        grid-template-columns: 1fr;
    }

    .version-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .pricing-card {
        margin: 0 auto;
    }

    .price-amount {
        font-size: 2.5rem;
    }

    .footer-links {
        flex-direction: column;
        gap: 0.8rem;
    }
}