:root {
    /* Brand Colors */
    --brand-primary: #25A4AC;
    --brand-secondary: #EEFAF9;
    --brand-tertiary: #D4F9F4;
    
    /* Background Colors */
    --background-primary: #ECF4F3;
    --background-white: #FFFFFF;
    --background-accent: #FDFFEA;
    
    /* Text Colors */
    --text-primary: #2F4646;
    --text-secondary: #4E6062;
    --text-tertiary: #688184;
    --text-inactive: #8EA5A8;
    --text-positive: #318762;
    --text-accent: #D66883;
    --text-white: #FFFFFF;
    
    /* Border Colors */
    --border-light: #D0E2E0;
    
    /* Device Colors */
    --device-background: #C4C4C4;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(180deg, var(--brand-secondary) 0%, var(--brand-tertiary) 100%);
    overflow-x: hidden;
    min-height: 100vh;
}

.container {
    max-width: 375px;
    margin: 0 auto;
    padding: 0 16px;
}

/* ===== ヒーローセクション ===== */
.hero {
    min-height: 100vh;
    padding: 80px 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.hero-title {
    font-size: 2rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    line-height: 1.5;
    letter-spacing: -0.02em;
}

.hero-title-highlight {
    color: var(--brand-primary);
    display: inline-block;
}

.hero-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    margin-bottom: 24px;
    line-height: 1.8;
    font-weight: 400;
    max-width: 100%;
    margin-left: auto;
    margin-right: auto;
}

.app-store-btn {
    display: inline-block;
    text-decoration: none;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    height: 60px;
}

.app-store-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.app-store-button {
    height: 60px;
    max-width: 160px;
    transition: transform 0.3s ease;
}

.hero-device {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 2rem;
}

.hero-device-image {
    width: 100%;
    max-width: 300px;
    height: auto;
    border-radius: 24px;
}


/* ===== 共通コンポーネント ===== */
/* セクションヘッダーコンポーネント */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    line-height: 1.5;
    letter-spacing: 1px;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.8;
    font-weight: 400;
    max-width: 100%;
    margin: 0 auto;
}

/* モディファイア */
.section-header--compact .section-title {
    margin-bottom: 1rem;
}

.section-header--compact {
    margin-bottom: 40px;
}

.section-subtitle--narrow {
    max-width: 500px;
}

/* ===== 機能セクション ===== */
.features {
    background: var(--background-white);
    padding: 80px 0;
    position: relative;
}

.features-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 1;
}

/* features-headerは.section-headerを使用 */

.features-cards {
    display: flex;
    flex-direction: column;
    gap: 40px;
    max-width: 600px;
    margin: 0 auto;
}

.feature-card {
    background: var(--background-white);
    border-radius: 20px;
    padding: 20px 20px 0 20px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    text-align: center;
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
}

.feature-card.animate-in {
    opacity: 1;
    transform: translateY(0);
}


.feature-card-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    line-height: 1.4;
    letter-spacing: 1px;
}

.feature-title-highlight {
    color: var(--brand-primary);
    font-weight: 600;
}

.feature-card-description {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
    font-weight: 400;
}

.feature-card-image {
    display: flex;
    justify-content: center;
    align-items: flex-end;
    margin-top: auto;
    padding-bottom: 0;
}

.feature-image {
    width: 100%;
    height: auto;
    border-radius: 12px;
}



/* ===== UseCaseセクション ===== */
.usecase {
    background: linear-gradient(180deg, var(--brand-secondary) 0%, var(--brand-tertiary) 100%);
    padding: 80px 0;
    position: relative;
}


.usecase-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 1;
}

/* usecase-headerは.section-header--compactを使用 */

.usecase-list {
    display: flex;
    flex-direction: column;
    gap: 50px;
}

.usecase-item {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.usecase-item.animate-in {
    opacity: 1;
    transform: translateY(0);
}




.usecase-label {
    position: absolute;
    top: 50px;
    left: -10px;
    background: var(--text-primary);
    color: var(--text-white);
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    z-index: 10;
    transform: rotate(-7deg);
}

.usecase-image {
    position: relative;
    width: 100%;
    border-radius: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 60px 0 0 0;
}


.usecase-image-content {
    width: 100%;
    height: auto;
    border-radius: 16px;
    transition: transform 0.3s ease;
}


.usecase-description {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    font-weight: 400;
    max-width: 100%;
    margin: 0 auto;
    padding: 0 20px;
}


/* ===== アニメーション ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.hero-title,
.hero-subtitle,
.hero-cta,
.hero-device {
    opacity: 0;
    animation: fadeInUp 0.8s ease-out forwards;
}

.hero-title {
    animation-delay: 0.1s;
    letter-spacing: 1px;
}

.hero-subtitle {
    animation-delay: 0.3s;
}

.hero-cta {
    animation-delay: 0.5s;
}

.hero-device {
    animation-delay: 0.5s;
}

.feature-card:nth-child(1) {
    transition-delay: 0.1s;
}

.feature-card:nth-child(2) {
    transition-delay: 0.2s;
}

.feature-card:nth-child(3) {
    transition-delay: 0.3s;
}

.feature-card:nth-child(4) {
    transition-delay: 0.4s;
}

.usecase-item:nth-child(1) {
    transition-delay: 0.1s;
}

.usecase-item:nth-child(2) {
    transition-delay: 0.2s;
}

.usecase-item:nth-child(3) {
    transition-delay: 0.3s;
}


/* ===== よくある質問セクション ===== */
.faq {
    background: var(--background-accent);
    padding: 80px 0;
    position: relative;
}

.faq-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 1;
}

/* faq-headerは.section-header--compactを使用 */

/* ===== CTAセクション ===== */
.cta {
    background: var(--brand-primary);
    padding: 80px 0;
    position: relative;
    overflow: hidden;
}

.cta-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
    position: relative;
    z-index: 10;
}

.cta-title {
    color: var(--text-white);
    margin-bottom: 1.5rem;
}

.cta-subtitle {
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2.5rem;
    line-height: 1.8;
}

.cta-button {
    display: flex;
    justify-content: center;
    margin-bottom: 24px;
}

.cta-app-store-btn {
    transform: scale(1.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    height: 60px;
}

.cta-app-store-btn:hover {
    transform: scale(1.15) translateY(-3px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.cta-app-store-btn.click-effect {
    transform: scale(1.05);
}

.cta-illustration {
    display: flex;
    justify-content: center;
    align-items: center;
}

.family-illustration {
    position: relative;
    width: 100%;
    max-width: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.family-image {
    width: 100%;
    height: auto;
    max-width: 100%;
}


/* 背景装飾 */
.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.9;
}

.cta::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -20%;
    width: 140%;
    height: 200%;
    transform: rotate(-15deg);
    pointer-events: none;
}

/* ===== フッター ===== */
.footer {
    background: var(--brand-primary);
    padding: 30px 0;
    position: relative;
}


.footer-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.footer-copyright {
    color: var(--text-white);
    font-size: 0.9rem;
    font-weight: 400;
    margin: 0;
    opacity: 0.9;
    letter-spacing: 0.02em;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    text-align: left;
}

.faq-item {
    background: var(--background-white);
    border-radius: 8px;
    border: 1px solid var(--border-light);
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.faq-item:hover {
    box-shadow: 0 6px 25px rgba(0, 0, 0, 0.12);
    transform: translateY(-2px);
}

.faq-question {
    padding: 16px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.3s ease;
    user-select: none;
}

.faq-question:hover {
    background: var(--brand-secondary);
}

.faq-question-text {
    font-size: 1rem;
    color: var(--text-primary);
    line-height: 1.5;
    flex: 1;
}

.faq-toggle {
    font-size: 0.9rem;
    color: var(--brand-primary);
    font-weight: 600;
    transition: transform 0.3s ease;
    margin-left: 16px;
    flex-shrink: 0;
}

.faq-item.open .faq-toggle {
    transform: rotate(180deg);
}

.faq-answer {
    display: none;
    background: var(--background-white);
    padding: 16px;
}

.faq-item.open .faq-answer {
    display: block;
}

.faq-answer p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin: 0;
}

.faq-answer strong {
    color: var(--text-accent);
    font-weight: 600;
}

.faq-answer ul {
    margin: 10px 0 0 0;
    padding-left: 20px;
}

.faq-answer li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 5px;
}

/* セクション間の視覚的分離 */
.features::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(to bottom, var(--brand-secondary), var(--background-white));
    opacity: 1;
    z-index: 0;
}

.usecase::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(to bottom, var(--background-white), var(--brand-secondary));
    opacity: 1;
    z-index: 0;
}


.faq::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(to bottom, var(--brand-tertiary), var(--background-accent));
    opacity: 1;
    z-index: 0;
}