:root {
    /* Colors */
    --primary-yellow: #F5C518;
    --dark-yellow: #E0B000;
    --light-yellow: #FFF8DC;
    --navy: #2C3E50;
    --text-dark: #333333;
    --text-light: #666666;
    --white: #FFFFFF;
    --gray-light: #F5F5F5;
    --shadow: rgba(0, 0, 0, 0.1);
    --line-green: #06C755;

    /* Typography */
    --font-main: 'Zen Maru Gothic', 'Noto Sans JP', sans-serif;
    --font-accent: 'Zen Maru Gothic', sans-serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;

    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 50%;

    /* Transitions */
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-main);
    color: var(--text-dark);
    line-height: 1.7;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===========================
   Hero Section
   =========================== */
.hero {
    background: linear-gradient(135deg, #FFF8DC 0%, #F5C518 50%, #E0B000 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: var(--spacing-xl) var(--spacing-md);
    padding-bottom: 120px;
}

.hero-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
}

.hero-text {
    flex: 1;
}

.hero-image {
    flex: 0 0 auto;
    position: relative;
}

.hero-profile-img {
    width: 320px;
    height: auto;
    border-radius: var(--radius-lg);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.12);
    animation: heroFloat 4s ease-in-out infinite;
}

@keyframes heroFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-15px); }
}

.kindle-badge {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: var(--primary-yellow);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: 0 4px 16px rgba(245, 197, 24, 0.4);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-weight: 700;
    color: var(--navy);
    animation: float 3s ease-in-out infinite;
    z-index: 10;
}

.kindle-badge i {
    font-size: 1.3rem;
    color: var(--dark-yellow);
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.hero-subtitle {
    display: block;
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--navy);
    margin-bottom: var(--spacing-xs);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-md);
    line-height: 1.3;
}

.hero-description {
    font-size: 1.5rem;
    color: var(--navy);
    margin-bottom: var(--spacing-lg);
    font-weight: 500;
}

.hero-transformation {
    display: inline-block;
    background: rgba(255, 255, 255, 0.85);
    padding: 0.6rem 1.5rem;
    border-radius: var(--radius-lg);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-lg);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    letter-spacing: 0.02em;
}

.hero-note {
    margin-top: var(--spacing-md);
    color: var(--navy);
    font-size: 0.95rem;
}

/* Wave dividers */
.hero-wave,
.section-wave {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    line-height: 0;
}

.hero-wave svg,
.section-wave svg {
    width: 100%;
    height: 80px;
    display: block;
}

/* ===========================
   Buttons
   =========================== */
.cta-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 1rem 2.5rem;
    border-radius: var(--radius-lg);
    font-size: 1.1rem;
    font-weight: 700;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-family: var(--font-main);
}

.cta-button i {
    font-size: 1.3rem;
}

.cta-button.primary {
    background: var(--navy);
    color: var(--white);
    box-shadow: 0 4px 12px rgba(44, 62, 80, 0.3);
}

.cta-button.primary:hover {
    background: #1a252f;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(44, 62, 80, 0.4);
}

.cta-button.secondary {
    background: var(--white);
    color: var(--navy);
    border: 2px solid var(--navy);
}

.cta-button.secondary:hover {
    background: var(--navy);
    color: var(--white);
    transform: translateY(-2px);
}

.cta-button.outline {
    background: transparent;
    color: var(--navy);
    border: 2px solid var(--navy);
}

.cta-button.outline:hover {
    background: var(--navy);
    color: var(--white);
    transform: translateY(-2px);
}

.cta-button.large {
    padding: 1.25rem 3rem;
    font-size: 1.25rem;
}

/* ===========================
   Section Styles
   =========================== */
section {
    padding: var(--spacing-xl) 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-sm);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--primary-yellow);
    border-radius: 2px;
}

.section-description {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-top: var(--spacing-sm);
}

/* ===========================
   Stats Section
   =========================== */
.stats {
    background: var(--gray-light);
    padding: var(--spacing-lg) 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.stat-item {
    padding: var(--spacing-md);
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--navy);
    line-height: 1;
}

.stat-suffix {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--navy);
}

.stat-label {
    display: block;
    font-size: 0.95rem;
    color: var(--text-light);
    margin-top: var(--spacing-xs);
}

/* ===========================
   Profile Section
   =========================== */
.profile {
    background: var(--gray-light);
    padding-bottom: 120px;
}

.profile-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: var(--spacing-lg);
    align-items: start;
}

.profile-info {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 12px var(--shadow);
    text-align: center;
}

.profile-avatar {
    width: 160px;
    height: 160px;
    margin: 0 auto var(--spacing-md);
    border-radius: var(--radius-full);
    overflow: hidden;
    border: 4px solid var(--primary-yellow);
    box-shadow: 0 4px 16px rgba(245, 197, 24, 0.3);
    background: var(--light-yellow);
    display: flex;
    align-items: center;
    justify-content: center;
}

.profile-img {
    width: 140%;
    height: auto;
    object-fit: cover;
    margin-top: 20px;
}

.profile-name {
    font-size: 2rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-xs);
}

.profile-role {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.profile-book {
    background: var(--light-yellow);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin-top: var(--spacing-md);
}

.book-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-xs);
}

.book-title i {
    color: var(--dark-yellow);
}

.profile-story {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 12px var(--shadow);
}

.profile-story p {
    margin-bottom: var(--spacing-md);
}

.profile-story p:last-child {
    margin-bottom: 0;
}

.profile-mission {
    background: var(--light-yellow);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    font-weight: 500;
    color: var(--navy);
    border-left: 4px solid var(--primary-yellow);
}

.profile-works {
    background: var(--gray-light);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin: var(--spacing-sm) 0;
}

.works-title {
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-sm);
    font-size: 0.95rem;
}

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

.works-list li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--text-dark);
}

.works-list li::before {
    content: "\f00c";
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    position: absolute;
    left: 0;
    color: var(--primary-yellow);
}

/* ===========================
   Kindle Coming Soon
   =========================== */
.kindle-coming-soon {
    background: linear-gradient(180deg, var(--light-yellow) 0%, var(--white) 100%);
    padding-bottom: 120px;
}

.kindle-showcase {
    text-align: center;
}

.kindle-cover {
    position: relative;
    display: inline-block;
    animation: heroFloat 4s ease-in-out infinite;
}

.kindle-cover-img {
    max-width: 400px;
    width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
}

.release-badge {
    position: absolute;
    top: -16px;
    right: -16px;
    width: 90px;
    height: 90px;
    background: var(--primary-yellow);
    border-radius: var(--radius-full);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 16px rgba(245, 197, 24, 0.4);
    transform: rotate(12deg);
    border: 3px solid var(--white);
}

.release-date {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--navy);
    line-height: 1;
}

.release-label {
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--navy);
    line-height: 1;
}

.kindle-note {
    margin-top: var(--spacing-lg);
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-light);
    letter-spacing: 0.1em;
}

/* ===========================
   Target Audience
   =========================== */
.target-audience {
    background: var(--white);
    padding-bottom: 120px;
}

.audience-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
    max-width: 900px;
    margin: 0 auto;
}

.audience-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--gray-light);
    border-radius: var(--radius-md);
    transition: var(--transition);
    border-left: 4px solid transparent;
}

.audience-item:hover {
    background: var(--light-yellow);
    transform: translateX(5px);
    border-left-color: var(--primary-yellow);
}

.item-icon {
    font-size: 1.3rem;
    flex-shrink: 0;
    color: var(--primary-yellow);
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--white);
    border-radius: var(--radius-full);
    box-shadow: 0 2px 8px var(--shadow);
}

.item-text {
    font-size: 1rem;
    color: var(--text-dark);
}

/* ===========================
   First Step
   =========================== */
.first-step {
    background: var(--light-yellow);
    padding-bottom: 120px;
}

.channels-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    max-width: 900px;
    margin: 0 auto;
}

.channel-card {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 12px var(--shadow);
    transition: var(--transition);
}

.channel-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.channel-card.featured {
    border: 3px solid var(--primary-yellow);
    position: relative;
}

.card-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    position: relative;
}

.card-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
}

.channel-card.featured .card-icon {
    color: var(--line-green);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--navy);
}

.recommended-badge {
    position: absolute;
    top: -10px;
    right: 0;
    background: var(--primary-yellow);
    color: var(--navy);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 700;
}

.card-description {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.card-features {
    list-style: none;
    margin-bottom: var(--spacing-md);
}

.card-features li {
    padding: var(--spacing-xs) 0;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.card-features li i {
    color: var(--primary-yellow);
    width: 20px;
    text-align: center;
}

.channel-card .cta-button {
    width: 100%;
}

/* ===========================
   Deep Learning
   =========================== */
.deep-learning {
    background: var(--white);
    padding-bottom: 120px;
}

.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    max-width: 900px;
    margin: 0 auto;
}

.content-card {
    background: var(--gray-light);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    transition: var(--transition);
    text-align: center;
}

.content-card:hover {
    transform: translateY(-5px);
    background: var(--light-yellow);
    box-shadow: 0 8px 24px var(--shadow);
}

.content-card .card-header {
    justify-content: center;
    margin-bottom: var(--spacing-md);
}

.content-card .card-icon {
    color: var(--navy);
}

.content-card .card-description {
    margin-bottom: var(--spacing-md);
}

/* ===========================
   Daily Updates
   =========================== */
.daily-updates {
    background: var(--gray-light);
    padding-bottom: 120px;
}

.social-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    max-width: 700px;
    margin: 0 auto;
}

.social-card {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    text-align: center;
    text-decoration: none;
    color: var(--text-dark);
    transition: var(--transition);
    box-shadow: 0 4px 12px var(--shadow);
}

.social-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    background: var(--light-yellow);
}

.social-icon {
    font-size: 3rem;
    display: block;
    margin-bottom: var(--spacing-sm);
    color: var(--navy);
}

.social-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-xs);
}

.social-description {
    font-size: 0.95rem;
    color: var(--text-light);
}

/* ===========================
   FAQ Section
   =========================== */
.faq {
    background: var(--white);
    padding: var(--spacing-xl) 0;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.faq-item {
    background: var(--gray-light);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: var(--transition);
}

.faq-item[open] {
    background: var(--light-yellow);
    box-shadow: 0 4px 12px var(--shadow);
}

.faq-question {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    cursor: pointer;
    font-weight: 700;
    color: var(--navy);
    font-size: 1.05rem;
    list-style: none;
    user-select: none;
}

.faq-question::-webkit-details-marker {
    display: none;
}

.faq-q-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--primary-yellow);
    color: var(--navy);
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 1rem;
    flex-shrink: 0;
}

.faq-toggle {
    margin-left: auto;
    transition: transform 0.3s ease;
    color: var(--text-light);
    flex-shrink: 0;
}

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

.faq-answer {
    display: flex;
    gap: var(--spacing-sm);
    padding: 0 var(--spacing-md) var(--spacing-md);
    color: var(--text-dark);
    line-height: 1.8;
}

.faq-a-label {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--navy);
    color: var(--white);
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 1rem;
    flex-shrink: 0;
}

/* ===========================
   Final CTA
   =========================== */
.final-cta {
    background: linear-gradient(135deg, #FFF8DC 0%, #F5C518 50%, #E0B000 100%);
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
}

.final-cta-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.final-cta-img {
    width: 180px;
    height: auto;
    margin-bottom: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: 0 6px 24px rgba(0, 0, 0, 0.1);
    animation: heroFloat 4s ease-in-out infinite;
}

.cta-title {
    font-size: 3rem;
    font-weight: 700;
    color: var(--navy);
    margin-bottom: var(--spacing-md);
    line-height: 1.3;
}

.cta-description {
    font-size: 1.25rem;
    color: var(--navy);
    margin-bottom: var(--spacing-lg);
}

.cta-note {
    margin-top: var(--spacing-md);
    color: var(--navy);
    font-size: 0.95rem;
}

/* ===========================
   Sticky CTA (Mobile)
   =========================== */
.sticky-cta {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    padding: 12px 16px;
    padding-bottom: calc(12px + env(safe-area-inset-bottom, 0px));
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.1);
    transform: translateY(100%);
    transition: transform 0.4s ease;
    display: none;
}

.sticky-cta.visible {
    transform: translateY(0);
}

.sticky-cta-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding: 14px 20px;
    background: var(--line-green);
    color: var(--white);
    border-radius: var(--radius-md);
    font-size: 1.05rem;
    font-weight: 700;
    text-decoration: none;
    font-family: var(--font-main);
    box-shadow: 0 4px 12px rgba(6, 199, 85, 0.3);
    transition: var(--transition);
}

.sticky-cta-button:hover {
    background: #05b34d;
}

.sticky-cta-button i {
    font-size: 1.3rem;
}

/* ===========================
   Footer
   =========================== */
.footer {
    background: var(--navy);
    color: var(--white);
    text-align: center;
    padding: var(--spacing-lg) var(--spacing-md);
}

.sticky-cta.visible ~ .footer,
body:has(.sticky-cta.visible) .footer {
    padding-bottom: calc(var(--spacing-lg) + 70px);
}

.footer-text {
    font-size: 0.9rem;
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 768px) {
    .hero {
        min-height: auto;
        padding-top: 80px;
        padding-bottom: 100px;
    }

    .hero-inner {
        flex-direction: column-reverse;
        text-align: center;
    }

    .hero-text {
        display: flex;
        flex-direction: column;
        align-items: center;
    }

    .hero-profile-img {
        width: 220px;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .hero-description {
        font-size: 1.2rem;
    }

    .kindle-badge {
        top: var(--spacing-sm);
        right: var(--spacing-sm);
        padding: var(--spacing-xs) var(--spacing-sm);
    }

    .badge-text {
        font-size: 0.85rem;
    }

    .section-title {
        font-size: 1.8rem;
    }

    .stats-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--spacing-sm);
    }

    .stat-number {
        font-size: 2.2rem;
    }

    .stat-suffix {
        font-size: 1rem;
    }

    .stat-label {
        font-size: 0.8rem;
    }

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

    .kindle-cover-img {
        max-width: 280px;
    }

    .release-badge {
        width: 76px;
        height: 76px;
        top: -12px;
        right: -12px;
    }

    .release-date {
        font-size: 1.5rem;
    }

    .release-label {
        font-size: 0.8rem;
    }

    .cta-title {
        font-size: 2rem;
    }

    .cta-button {
        padding: 0.875rem 2rem;
        font-size: 1rem;
    }

    .cta-button.large {
        padding: 1rem 2rem;
        font-size: 1.1rem;
    }

    .sticky-cta {
        display: block;
    }

    .footer {
        padding-bottom: calc(var(--spacing-lg) + 80px);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-profile-img {
        width: 180px;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .kindle-cover-img {
        max-width: 240px;
    }

    .release-badge {
        width: 64px;
        height: 64px;
        top: -10px;
        right: -10px;
    }

    .release-date {
        font-size: 1.3rem;
    }

    .release-label {
        font-size: 0.75rem;
    }

    .audience-list {
        grid-template-columns: 1fr;
    }

    .channels-grid,
    .content-grid {
        grid-template-columns: 1fr;
    }

    .stat-item {
        padding: var(--spacing-sm);
    }

    .stat-number {
        font-size: 1.8rem;
    }

    .final-cta-img {
        width: 140px;
    }
}