/* ========================================
   どこでもホワイトニング - メインスタイルシート
   ======================================== */

/* リセット & 基本設定 */
:root {
    --primary-color: #4A90E2;
    --secondary-color: #F5A623;
    --accent-color: #FFD700;
    --text-dark: #333333;
    --text-light: #666666;
    --bg-light: #F8F9FA;
    --bg-white: #FFFFFF;
    --border-color: #E0E0E0;
    --success-color: #4CAF50;
    --error-color: #F44336;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--text-dark);
    line-height: 1.8;
    background-color: var(--bg-white);
    overflow-x: hidden;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

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

.pc-only {
    display: inline;
}

.sp-only {
    display: none;
}

/* ========================================
   ヘッダー
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 0;
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1.2;
}

.logo-subtitle {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-top: 2px;
}

.nav-list {
    display: flex;
    gap: 30px;
}

.nav-list a {
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-dark);
    padding: 8px 0;
    position: relative;
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

.nav-list a:hover::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
}

.mobile-menu-toggle span {
    display: block;
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    margin: 5px 0;
    transition: var(--transition);
}

/* ========================================
   ボタンスタイル
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 30px;
    border-radius: 50px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #357ABD);
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-large {
    padding: 18px 40px;
    font-size: 1.1rem;
}

.btn-block {
    width: 100%;
}

.btn-header {
    padding: 10px 25px;
    font-size: 0.95rem;
}

/* ========================================
   ヒーローセクション
   ======================================== */
.hero {
    position: relative;
    padding: 150px 0 80px;
    background: linear-gradient(135deg, #E3F2FD 0%, #FFFFFF 100%);
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(74, 144, 226, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(245, 166, 35, 0.1) 0%, transparent 50%);
    z-index: 0;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-block;
    background: var(--secondary-color);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
    animation: fadeInDown 0.6s ease;
}

.hero-title {
    font-size: 3rem;
    font-weight: 900;
    line-height: 1.3;
    margin-bottom: 20px;
    animation: fadeInUp 0.6s ease 0.2s both;
}

.highlight {
    color: var(--primary-color);
    position: relative;
    display: inline-block;
}

.hero-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 40px;
    animation: fadeInUp 0.6s ease 0.4s both;
}

.hero-price {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 30px;
    margin-bottom: 40px;
    animation: fadeInUp 0.6s ease 0.6s both;
}

.price-box {
    background: white;
    padding: 30px;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

.price-label {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 10px;
}

.price-amount {
    display: flex;
    align-items: baseline;
    justify-content: center;
    margin-bottom: 10px;
}

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

.price-value {
    font-size: 3.5rem;
    font-weight: 900;
    color: var(--primary-color);
    line-height: 1;
}

.price-period {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-left: 5px;
}

.price-note {
    font-size: 0.85rem;
    color: var(--text-light);
}

.price-arrow {
    font-size: 2rem;
    color: var(--primary-color);
}

.hero-cta {
    animation: fadeInUp 0.6s ease 0.8s both;
}

.hero-cta-note {
    margin-top: 15px;
    font-size: 0.9rem;
    color: var(--text-light);
}

/* ========================================
   セクション共通スタイル
   ======================================== */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 15px;
    line-height: 1.4;
}

.section-description {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 700px;
    margin: 0 auto;
}

/* ========================================
   3つの特徴
   ======================================== */
.features {
    background: var(--bg-light);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 20px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), #357ABD);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
}

.feature-icon i {
    font-size: 2rem;
    color: white;
}

.feature-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 15px;
    line-height: 1.5;
}

.feature-description {
    color: var(--text-light);
    line-height: 1.8;
}

/* ========================================
   比較セクション
   ======================================== */
.comparison {
    background: white;
}

.comparison-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    max-width: 900px;
    margin: 0 auto;
}

.comparison-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-md);
    position: relative;
    transition: var(--transition);
    border: 3px solid #D32F2F;
}

.comparison-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(211, 47, 47, 0.15);
}

.comparison-card.featured {
    border: 4px solid var(--primary-color);
    transform: scale(1.05);
    box-shadow: 0 10px 40px rgba(74, 144, 226, 0.2);
}

.comparison-card.featured:hover {
    transform: scale(1.08);
    box-shadow: 0 15px 50px rgba(74, 144, 226, 0.3);
}

.comparison-badge {
    position: absolute;
    top: -15px;
    right: 30px;
    background: var(--secondary-color);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.comparison-type {
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 30px;
}

.comparison-type.beauty {
    background: #FFE0E0;
    color: #D32F2F;
    border: 2px solid #FF9999;
}

.comparison-type.medical {
    background: #E3F2FD;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.comparison-feature {
    margin-bottom: 25px;
}

.comparison-feature h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 8px;
}

.comparison-feature p {
    color: var(--text-light);
    line-height: 1.6;
}

/* ========================================
   ビフォーアフター
   ======================================== */
.results {
    background: var(--bg-light);
}

.results-comparison {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 40px;
    max-width: 900px;
    margin: 0 auto 30px;
}

.result-item {
    flex: 1;
    text-align: center;
}

.result-image-wrapper {
    position: relative;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    margin-bottom: 20px;
}

.result-image {
    width: 100%;
    height: auto;
    display: block;
}

.result-label {
    position: absolute;
    top: 20px;
    left: 20px;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 700;
    font-size: 1.1rem;
    color: white;
}

.result-label.before {
    background: #F44336;
}

.result-label.after {
    background: #4CAF50;
}

.result-description {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-dark);
}

.result-arrow {
    font-size: 3rem;
    color: var(--primary-color);
}

.results-note {
    background: white;
    padding: 20px;
    border-radius: 15px;
    border-left: 4px solid var(--primary-color);
    max-width: 900px;
    margin: 0 auto;
}

.results-note i {
    color: var(--primary-color);
    margin-right: 8px;
}

/* ========================================
   よくある悩み
   ======================================== */
.problems-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.problem-card {
    background: white;
    padding: 35px;
    border-radius: 20px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border-left: 5px solid var(--secondary-color);
}

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

.problem-number {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: var(--secondary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 15px;
}

.problem-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.problem-description {
    color: var(--text-light);
    line-height: 1.8;
}

/* ========================================
   利用の流れ
   ======================================== */
.flow {
    background: var(--bg-light);
}

.flow-steps {
    max-width: 700px;
    margin: 0 auto;
}

.flow-step {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    text-align: center;
    position: relative;
}

.flow-step-number {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 20px;
}

.flow-step-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), #357ABD);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.flow-step-icon i {
    font-size: 2rem;
    color: white;
}

.flow-step-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 15px;
}

.flow-step-description {
    color: var(--text-light);
    line-height: 1.8;
}

.flow-arrow {
    text-align: center;
    padding: 20px 0;
    font-size: 2rem;
    color: var(--primary-color);
}

/* ========================================
   初回キット詳細
   ======================================== */
.kit {
    background: white;
}

.kit-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.kit-image {
    position: sticky;
    top: 100px;
}

.kit-img {
    width: 100%;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

.kit-list {
    margin-bottom: 40px;
}

.kit-item {
    display: flex;
    gap: 20px;
    padding: 20px;
    background: var(--bg-light);
    border-radius: 15px;
    margin-bottom: 15px;
    transition: var(--transition);
}

.kit-item:hover {
    background: #E3F2FD;
    transform: translateX(5px);
}

.kit-item-icon {
    flex-shrink: 0;
}

.kit-item-icon i {
    font-size: 1.5rem;
    color: var(--success-color);
}

.kit-item-content h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 5px;
    color: var(--text-dark);
}

.kit-item-content p {
    font-size: 0.95rem;
    color: var(--text-light);
}

.kit-specs {
    background: #FFF9E6;
    padding: 25px;
    border-radius: 15px;
    border-left: 4px solid var(--secondary-color);
}

.kit-specs h4 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.kit-specs ul {
    list-style: none;
}

.kit-specs li {
    padding: 8px 0;
    color: var(--text-light);
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.kit-specs li:last-child {
    border-bottom: none;
}

/* ========================================
   料金プラン
   ======================================== */
.pricing {
    background: linear-gradient(135deg, #E3F2FD 0%, #FFFFFF 100%);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
    max-width: 900px;
    margin: 0 auto;
}

.pricing-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: var(--shadow-lg);
    position: relative;
    transition: var(--transition);
}

.pricing-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.2);
}

.pricing-card.featured {
    border: 3px solid var(--primary-color);
    transform: scale(1.05);
}

.pricing-badge {
    background: var(--secondary-color);
    color: white;
    padding: 10px 15px;
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
    text-align: center;
    line-height: 1.4;
}

.pricing-label {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary-color);
    color: white;
    padding: 8px 25px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.pricing-header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 2px solid var(--border-color);
}

.pricing-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-dark);
}

.pricing-price {
    display: flex;
    align-items: baseline;
    justify-content: center;
    margin-bottom: 10px;
}

.pricing-currency {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
}

.pricing-amount {
    font-size: 4rem;
    font-weight: 900;
    color: var(--primary-color);
    line-height: 1;
}

.pricing-period {
    font-size: 1rem;
    color: var(--text-light);
    margin-top: 5px;
}

.pricing-features {
    margin-bottom: 30px;
}

.pricing-features li {
    padding: 12px 0;
    color: var(--text-dark);
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 12px;
}

.pricing-features i {
    color: var(--success-color);
    font-size: 1.2rem;
}

/* ========================================
   医師紹介
   ======================================== */
.doctor {
    background: var(--bg-light);
}

.doctor-profile {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    max-width: 1000px;
    margin: 0 auto;
    background: white;
    padding: 50px;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
}

.doctor-image img {
    width: 100%;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
}

.doctor-name {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.doctor-title {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 30px;
}

.doctor-credentials h4 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.doctor-credentials ul {
    list-style: none;
}

.doctor-credentials li {
    padding: 10px 0;
    color: var(--text-light);
    border-bottom: 1px solid var(--border-color);
}

.doctor-credentials li:last-child {
    border-bottom: none;
}

.doctor-note {
    margin-top: 20px;
    padding: 15px;
    background: #E3F2FD;
    border-radius: 10px;
    color: var(--primary-color);
    font-weight: 600;
}

/* ========================================
   お客様の声
   ======================================== */
.testimonials {
    background: white;
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.testimonial-card {
    background: var(--bg-light);
    padding: 35px;
    border-radius: 20px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.testimonial-rating {
    margin-bottom: 20px;
}

.testimonial-rating i {
    color: var(--secondary-color);
    font-size: 1.2rem;
    margin-right: 3px;
}

.testimonial-text {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-dark);
    margin-bottom: 20px;
}

.testimonial-name {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-light);
}

/* ========================================
   FAQ（アコーディオン）
   ======================================== */
.faq {
    background: var(--bg-light);
    padding: 80px 0;
}

.faq .container {
    max-width: 900px;
}

.faq-category {
    background: white;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: var(--shadow-sm);
}

.faq-category-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 12px;
    padding-bottom: 15px;
    border-bottom: 2px solid #E3F2FD;
}

.faq-category-title i {
    font-size: 1.3rem;
}

.faq-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.faq-item {
    background: #FAFBFC;
    border-radius: 10px;
    border: 1px solid #E8EBED;
    overflow: hidden;
    transition: all 0.3s ease;
}

.faq-item:hover {
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(74, 144, 226, 0.1);
}

.faq-item.active {
    background: #F0F7FF;
    border-color: var(--primary-color);
    box-shadow: 0 2px 12px rgba(74, 144, 226, 0.15);
}

.faq-question {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    padding: 18px 20px;
    cursor: pointer;
    transition: var(--transition);
}

.faq-question:hover {
    background: rgba(74, 144, 226, 0.03);
}

.faq-q {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    margin-top: 2px;
}

.faq-question h4 {
    flex: 1;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-dark);
    line-height: 1.6;
}

.faq-question i {
    color: var(--primary-color);
    font-size: 1rem;
    transition: transform 0.3s ease;
    margin-top: 4px;
    flex-shrink: 0;
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

.faq-item.active .faq-answer {
    max-height: 2000px;
}

.faq-answer-wrapper {
    display: flex;
    gap: 15px;
    padding: 0 20px 18px 20px;
}

.faq-a {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    background: var(--secondary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.faq-answer-content {
    flex: 1;
    color: var(--text-light);
    line-height: 1.7;
    font-size: 0.95rem;
}

.faq-answer-content p {
    margin-bottom: 12px;
}

.faq-answer-content p:last-child {
    margin-bottom: 0;
}

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

/* ========================================
   CTA
   ======================================== */
.cta {
    background: linear-gradient(135deg, var(--primary-color), #357ABD);
    color: white;
    text-align: center;
    padding: 100px 0;
}

.cta-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.4;
}

.cta-description {
    font-size: 1.2rem;
    margin-bottom: 40px;
    opacity: 0.95;
}

.cta .btn-primary {
    background: white;
    color: var(--primary-color);
}

.cta .btn-primary:hover {
    background: var(--bg-light);
}

/* ========================================
   フッター
   ======================================== */
.footer {
    background: #2C3E50;
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 15px;
}

.footer-description {
    opacity: 0.8;
    line-height: 1.8;
}

.footer-heading {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a {
    opacity: 0.8;
    transition: var(--transition);
}

.footer-links a:hover {
    opacity: 1;
    color: var(--accent-color);
}

.footer-info li {
    margin-bottom: 12px;
    font-size: 0.9rem;
    opacity: 0.8;
    line-height: 1.6;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    opacity: 0.7;
    font-size: 0.9rem;
}

/* ========================================
   トップへ戻るボタン
   ======================================== */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-lg);
    z-index: 999;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-5px);
    background: #357ABD;
}

.scroll-to-top i {
    font-size: 1.2rem;
}

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

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ========================================
   レスポンシブデザイン
   ======================================== */

/* タブレット（1024px以下） */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .testimonials-grid {
        grid-template-columns: 1fr;
    }
    
    .kit-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .kit-image {
        position: static;
    }
    
    .doctor-profile {
        grid-template-columns: 1fr;
        gap: 30px;
        padding: 30px;
    }
}

/* タブレット（768px以下） */
@media (max-width: 768px) {
    .pc-only {
        display: none;
    }
    
    .sp-only {
        display: inline;
    }
    
    .nav {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 80%;
        height: calc(100vh - 70px);
        background: white;
        box-shadow: var(--shadow-lg);
        transition: left 0.3s ease;
        z-index: 999;
    }
    
    .nav.active {
        left: 0;
    }
    
    .nav-list {
        flex-direction: column;
        padding: 30px;
        gap: 0;
    }
    
    .nav-list li {
        border-bottom: 1px solid var(--border-color);
    }
    
    .nav-list a {
        display: block;
        padding: 20px 0;
    }
    
    .btn-header {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    .hero {
        padding: 120px 0 60px;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-price {
        flex-direction: column;
        gap: 20px;
    }
    
    .price-box {
        padding: 20px;
    }
    
    .price-value {
        font-size: 2.5rem;
    }
    
    .price-arrow {
        transform: rotate(90deg);
    }
    
    section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .section-description {
        font-size: 1rem;
    }
    
    .comparison-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .comparison-card.featured {
        transform: scale(1);
    }
    
    .results-comparison {
        flex-direction: column;
        gap: 20px;
    }
    
    .result-arrow {
        transform: rotate(90deg);
    }
    
    .problems-grid {
        grid-template-columns: 1fr;
    }
    
    .pricing-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .pricing-card.featured {
        transform: scale(1);
    }
    
    .pricing-amount {
        font-size: 3rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .cta-title {
        font-size: 2rem;
    }
    
    .cta-description {
        font-size: 1rem;
    }
}

/* スマートフォン（480px以下） */
@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-title {
        font-size: 1.6rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .feature-card {
        padding: 30px 20px;
    }
    
    .comparison-card {
        padding: 25px;
    }
    
    .flow-step {
        padding: 30px 20px;
    }
    
    .faq-category {
        padding: 20px 15px;
    }
    
    .faq-category-title {
        font-size: 1.2rem;
        gap: 8px;
    }
    
    .faq-category-title i {
        font-size: 1.1rem;
    }
    
    .faq-question {
        padding: 15px;
        gap: 12px;
    }
    
    .faq-q {
        width: 26px;
        height: 26px;
        font-size: 0.85rem;
    }
    
    .faq-question h4 {
        font-size: 0.9rem;
        line-height: 1.5;
    }
    
    .faq-question i {
        font-size: 0.9rem;
    }
    
    .faq-answer-wrapper {
        padding: 0 15px 15px 15px;
        gap: 12px;
    }
    
    .faq-a {
        width: 26px;
        height: 26px;
        font-size: 0.85rem;
    }
    
    .faq-answer-content {
        font-size: 0.875rem;
        line-height: 1.6;
    }
    
    .pricing-card {
        padding: 30px 20px;
    }
    
    .scroll-to-top {
        width: 45px;
        height: 45px;
        bottom: 20px;
        right: 20px;
    }
}