/* --- 変数定義 (ここで色などを一括管理) --- */
:root {
    --bg-color: #F8F9FA;
    --text-color: #343A40;
    --primary-color: #FF7A59; /* 温かみのあるオレンジ */
    --secondary-color: #34D399; /* フレッシュな緑 */
    --surface-color: #FFFFFF;
    --heading-color: #2c2c2c;
    /* ↓↓ ここから2行を変更 ↓↓ */
    --font-main: 'Noto Sans JP', sans-serif;
    --font-heading: 'Oswald', 'Noto Sans JP', sans-serif;
}

/* --- 基本スタイル --- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.8;
}

h1, h2, h3 {
    font-family: var(--font-main);
    font-weight: 700;
    color: var(--heading-color);
}

h1 {
    font-size: clamp(2.2rem, 6vw, 3.5rem);
    line-height: 1.3;
}

h2 {
    font-size: 2.2rem;
    text-align: center;
    margin-bottom: 3rem;
}

h3 {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
    border-radius: 8px;
}

/* --- ヘッダー --- */
.header {
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
    background: rgba(248, 249, 250, 0.85);
    backdrop-filter: blur(10px);
    z-index: 100;
    border-bottom: 1px solid #e9ecef;
}

.logo {
    font-family: var(--font-heading);
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 2rem;
    font-weight: 700;
    transition: color 0.3s;
}

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

/* --- ヒーローセクション --- */
.hero {
    min-height: 80vh;
    display: flex;
    align-items: center;
    padding: 100px 5% 50px;
    text-align: center;
    background-image: linear-gradient(135deg, #FFF1EB 0%, #ACE0F9 100%);
}

.hero-text {
    max-width: 800px;
    margin: 0 auto;
}

.hero-text p {
    font-size: 1.1rem;
    margin: 1.5rem 0 2rem;
}

.cta-button {
    display: inline-block;
    background: var(--primary-color);
    color: #fff;
    padding: 0.8rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 15px rgba(255, 122, 89, 0.4);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 7px 20px rgba(255, 122, 89, 0.5);
}


/* --- コンテンツセクション --- */
.content-section {
    padding: 6rem 5%;
    max-width: 1100px;
    margin: 0 auto;
}

/* --- 特徴セクション --- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    text-align: center;
}

.feature-item {
    background: var(--surface-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

/* --- 機能紹介セクション --- */
.function-card {
    display: flex;
    align-items: center;
    gap: 3rem;
    margin-bottom: 4rem;
    background: var(--surface-color);
    padding: 3rem;
    border-radius: 16px;
    box-shadow: 0 4px 25px rgba(0,0,0,0.06);
}
.function-card.reverse {
    flex-direction: row-reverse;
}
.function-card img {
    width: 50%;
    flex-shrink: 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

/* --- ダウンロードセクション --- */
.download-section {
    padding: 6rem 5%;
    background-color: var(--secondary-color);
    text-align: center;
    color: #fff;
}

.download-section h2, .download-section h3 {
    color: #fff;
}
.download-section h2 {
    margin-bottom: 1rem;
}

.download-button {
    display: inline-flex;
    align-items: center;
    gap: 0.7rem;
    background: #fff;
    color: var(--secondary-color);
    padding: 1rem 2.5rem;
    margin: 2rem 0 1rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}
.download-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 7px 20px rgba(0,0,0,0.15);
}
.download-section small {
    display: block;
    opacity: 0.8;
}

/* --- フッター --- */
.footer {
    text-align: center;
    padding: 2rem 5%;
    background: #e9ecef;
    font-size: 0.9rem;
}

/* --- アニメーション --- */
.animated {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}
.animated.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* --- レスポンシブ対応 --- */
@media (max-width: 768px) {
    .function-card, .function-card.reverse {
        flex-direction: column;
        padding: 2rem;
        gap: 2rem;
    }
    .function-card img {
        width: 100%;
    }
}


/* --- 以下を追記: サブページ用スタイル --- */

.logo a {
    text-decoration: none;
    color: var(--primary-color);
}

.sub-page {
    padding-top: 80px; /* 固定ヘッダー分の余白 */
}

.page-header {
    text-align: center;
    padding: 4rem 5%;
    background-color: var(--surface-color);
}

.page-header h1 {
    font-size: 2.8rem;
    color: var(--primary-color);
}

.usage-step {
    display: flex;
    align-items: center;
    gap: 3rem;
    padding: 4rem 0;
    border-bottom: 1px solid #e9ecef;
}
.usage-step:last-child {
    border-bottom: none;
}

.usage-step.reverse {
    flex-direction: row-reverse;
}

.step-image {
    flex: 1;
    min-width: 40%;
}
.step-image img {
     box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.step-description {
    flex: 1;
}

.step-number {
    display: inline-block;
    font-family: var(--font-heading);
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.step-description h2 {
    text-align: left;
    margin-bottom: 1rem;
    font-size: 2rem;
}

/* --- レスポンシブ対応 (サブページ) --- */
@media (max-width: 768px) {
    .usage-step, .usage-step.reverse {
        flex-direction: column;
        gap: 2rem;
        padding: 3rem 0;
    }
    .step-description h2 {
        font-size: 1.8rem;
    }
}


/* --- 以下を追記: サブページ用スタイル --- */

.logo a {
    text-decoration: none;
    color: var(--primary-color);
}

.sub-page {
    padding-top: 80px; /* 固定ヘッダー分の余白 */
}

.page-header {
    text-align: center;
    padding: 4rem 5%;
    background-color: var(--surface-color);
}

.page-header h1 {
    font-size: 2.8rem;
    color: var(--primary-color);
}

.usage-step {
    display: flex;
    align-items: center;
    gap: 3rem;
    padding: 4rem 0;
    border-bottom: 1px solid #e9ecef;
}
.usage-step:last-child {
    border



/* --- 以下を追記: 更新履歴ページ用スタイル --- */

.update-log {
    max-width: 800px;
    margin: 0 auto;
}

.update-item {
    background-color: var(--surface-color);
    border-radius: 12px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.05);
}

.update-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #e9ecef;
    padding-bottom: 1rem;
    margin-bottom: 1rem;
}

.update-header .version {
    font-size: 1.8rem;
    color: var(--heading-color);
    margin: 0;
}

.update-header .date {
    font-weight: 700;
    color: #6c757d;
}

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

.update-details li {
    margin-bottom: 0.8rem;
    display: flex;
    align-items: flex-start;
}

.update-details .label {
    flex-shrink: 0;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.2rem 0.6rem;
    border-radius: 50px;
    color: #fff;
    margin-right: 0.8rem;
    margin-top: 0.2rem;
}

.label.new { background-color: #0d6efd; } /* 青 */
.label.improved { background-color: var(--secondary-color); } /* 緑 */
.label.fixed { background-color: #dc3545; } /* 赤 */





/* --- 以下を追記: バナー広告スペース用スタイル --- */

.ad-banner-space {
    width: 100%;
    max-width: 728px; /* 一般的なバナーサイズ */
    min-height: 90px; /* 一般的なバナーサイズ */
    margin: 3rem auto; /* 上下に間隔を空け、中央に配置 */
    background-color: #e9ecef;
    border: 2px dashed #ced4da;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: #6c757d;
    font-weight: 700;
}