/* 
 * CSS Variables (Modern Vanilla CSS)
 */
:root {
    /* Color Palette (Premium Navy Base) */
    --color-primary: #0F172A;
    /* Rich Dark Navy */
    --color-primary-light: #1E293B;
    /* Slightly Lighter Navy */
    --color-secondary: #2563EB;
    /* Vibrant Royal Blue */
    --color-secondary-light: #3B82F6;
    --color-accent: #EA580C;
    /* Refined Orange for CTA */
    --color-accent-hover: #C2410C;
    --color-text-main: #334155;
    /* Slate 700 */
    --color-text-muted: #64748B;
    /* Slate 500 */
    --color-bg-light: #F8FAFC;
    /* Slate 50 */
    --color-white: #FFFFFF;

    /* Typography */
    --font-family-main: 'Inter', 'Noto Sans JP', sans-serif;

    /* Spacing & Layout */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1.25rem;
    --spacing-md: 2.5rem;
    --spacing-lg: 5rem;
    --spacing-xl: 7.5rem;

    /* Effects (Premium Soft Shadows) */
    --shadow-sm: 0 2px 4px rgba(15, 23, 42, 0.04);
    --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
    --shadow-lg: 0 25px 50px -12px rgba(15, 23, 42, 0.15);

    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-main);
    color: var(--color-text-main);
    background-color: var(--color-bg-light);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    text-decoration: none;
    color: inherit;
}

/* Utility Classes */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

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

/* Buttons */
.btn-cta {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, var(--color-accent) 0%, #F97316 100%);
    color: var(--color-white);
    padding: 1.25rem 3rem;
    font-size: 1.25rem;
    font-weight: 700;
    border-radius: 9999px;
    box-shadow: 0 10px 20px -5px rgba(234, 88, 12, 0.4);
    transition: all var(--transition-normal);
    cursor: pointer;
    border: none;
    text-align: center;
    line-height: 1.5;
    letter-spacing: 0.025em;
    position: relative;
    overflow: hidden;
}

.btn-cta::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(to right, rgba(255, 255, 255, 0) 0%, rgba(255, 255, 255, 0.3) 50%, rgba(255, 255, 255, 0) 100%);
    transform: skewX(-25deg);
    animation: shine 4s infinite;
}

@keyframes shine {
    0% {
        left: -100%;
    }

    20% {
        left: 200%;
    }

    100% {
        left: 200%;
    }
}

.btn-cta:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 25px -5px rgba(234, 88, 12, 0.5);
    background: linear-gradient(135deg, var(--color-accent-hover) 0%, var(--color-accent) 100%);
}

/* Microcopy */
.microcopy {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-top: var(--spacing-xs);
}

/* =========================================
   Sections General
   ========================================= */
section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    text-align: center;
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--color-secondary);
    margin: 1rem auto 0;
    border-radius: 2px;
}

/* =========================================
   Hero Section
   ========================================= */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--spacing-xl) 0;
    overflow: hidden;
    color: var(--color-white);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -2;
}

.hero-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: 70% center;
    /* Shift focus to right */
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    /* テキスト側の視認性を確保するため左側のグラデーションをより濃く、滑らかに調整 */
    background: linear-gradient(90deg,
            rgba(15, 23, 42, 0.98) 0%,
            rgba(15, 23, 42, 0.85) 40%,
            rgba(15, 23, 42, 0.4) 60%,
            rgba(15, 23, 42, 0) 100%);
    z-index: -1;
}

.hero-container-flex {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    gap: var(--spacing-md);
}

.hero-content {
    flex: 1;
    max-width: 700px;
    text-align: left;
    animation: fadeIn 1s ease-out;
}

.hero-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--color-secondary) 0%, #3B82F6 100%);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
    /* バッジの中の文字を白くくっきりさせる */
    color: var(--color-white);
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
    /* 背景から文字を浮かび上がらせる上品なシャドウ */
    text-shadow: 0 4px 12px rgba(0, 0, 0, 0.5), 0 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-title .highlight {
    background: linear-gradient(120deg, #FDE047 0%, #F59E0B 100%);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
    /* text-fill-color: transparentを使用するとtext-shadowが文字の上に重なってぼやけるため、親要素のシャドウを無効化し、代わりにfilter: drop-shadowを使用する */
    text-shadow: none;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.4));
}

.hero-subtitle {
    font-size: clamp(1.1rem, 2vw, 1.35rem);
    font-weight: 500;
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
    /* さらに暗いグレーに変更 */
    color: #475569;
    /* 暗めの文字を背景から浮き上がらせるため、白色のシャドウ（発光・縁取りのような効果）に変更 */
    text-shadow: 0 0 8px rgba(255, 255, 255, 0.9), 0 0 16px rgba(255, 255, 255, 0.6), 0 1px 2px rgba(255, 255, 255, 0.8);
}

.hero-cta-area {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-sm);
}

/* Tablet Mockup in Hero */
.hero-visual {
    flex: 1;
    display: flex;
    justify-content: flex-end;
    animation: slideInRight 1.2s ease-out;
}

.tablet-mockup {
    background: #111;
    padding: 15px;
    border-radius: 20px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    border: 2px solid #333;
    max-width: 500px;
    width: 100%;
    position: relative;
    transform: perspective(1000px) rotateY(-15deg) rotateX(5deg);
    transition: transform 0.5s ease;
}

.tablet-mockup:hover {
    transform: perspective(1000px) rotateY(-5deg) rotateX(2deg) scale(1.05);
}

.tablet-screen {
    background: #000;
    border-radius: 8px;
    overflow: hidden;
    position: relative;
    aspect-ratio: 16/9;
}

.tablet-screen img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.hero-cta-area .microcopy {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.85rem;
    background-color: rgba(0, 0, 0, 0.5);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    max-width: 90%;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* =========================================
   Section 2: Problems
   ========================================= */
.bg-light {
    background-color: var(--color-white);
}

.problem-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.problem-card {
    background-color: var(--color-bg-light);
    border-radius: 12px;
    padding: var(--spacing-md);
    text-align: center;
    box-shadow: var(--shadow-sm);
    border-top: 4px solid var(--color-secondary);
    transition: transform var(--transition-fast);
}

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

.problem-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.problem-text {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--color-text-main);
    line-height: 1.5;
}

.solution-box {
    background: linear-gradient(to right, #e0e7ff, #eff6ff);
    border-radius: 16px;
    padding: var(--spacing-lg) var(--spacing-md);
    text-align: center;
    border: 1px solid #bfdbfe;
    box-shadow: var(--shadow-md);
}

.solution-title {
    font-size: clamp(1.5rem, 3vw, 2rem);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.solution-text {
    font-size: 1.15rem;
    line-height: 1.8;
}

/* =========================================
   Section 3: Video Intro
   ========================================= */
.intro-microcopy {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-muted);
}

.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    /* 16:9 Aspect Ratio */
    height: 0;
    overflow: hidden;
    max-width: 900px;
    margin: 0 auto;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* =========================================
   Section 4: Benefits (with thumbnail grid)
   ========================================= */
.benefits {
    position: relative;
    padding: var(--spacing-xl) 0;
    overflow: hidden;
    color: var(--color-white);
}

.benefits-bg-grid {
    position: absolute;
    top: -5%;
    left: -5%;
    width: 110%;
    height: 110%;
    background-image:
        linear-gradient(rgba(30, 58, 138, 0.95), rgba(30, 58, 138, 0.98)),
        repeating-linear-gradient(45deg, rgba(255, 255, 255, 0.03) 0%, rgba(255, 255, 255, 0.03) 5%, transparent 5%, transparent 10%);
    background-size: cover, 100px 100px;
    z-index: 0;
}

.relative-z {
    position: relative;
    z-index: 1;
}

.benefit-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-md);
}

.benefit-card {
    background-color: var(--color-white);
    color: var(--color-text-main);
    border-radius: 16px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    border-top: 5px solid var(--color-accent);
    transition: transform var(--transition-normal);
}

.benefit-card:hover {
    transform: translateY(-8px);
}

.benefit-title {
    font-size: 1.4rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    font-weight: 700;
}

.benefit-text {
    font-size: 1.05rem;
    line-height: 1.7;
}

/* =========================================
   Section 5: Profile
   ========================================= */
.profile-container {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-lg);
    align-items: stretch;
    /* 説明文と高さを合わせる */
}

.profile-image {
    flex: 1 1 300px;
    position: relative;
    display: flex;
    flex-direction: column;
}

.profile-img-inner {
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    flex-grow: 1;
    /* 高さいっぱいに広げる */
}

.profile-img-inner img {
    width: 100%;
    height: 100%;
    /* 親要素の高さに合わせる */
    object-fit: cover;
    /* 縦横比を維持しながらトリミング不要で埋める */
    display: block;
    /* 人物を120%に拡大し、顔付近が中心になるように調整 */
    transform: scale(1.2);
    transform-origin: center 15%;
}

.profile-image::before {
    content: '';
    position: absolute;
    top: -15px;
    left: -15px;
    width: 100%;
    height: 100%;
    border: 3px solid var(--color-secondary);
    border-radius: 16px;
    z-index: -1;
}

.profile-content {
    flex: 2 1 400px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.profile-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: var(--spacing-sm);
}

.profile-tag {
    background-color: rgba(59, 130, 246, 0.1);
    color: var(--color-secondary);
    padding: 0.3rem 0.8rem;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
}

.profile-text {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-sm);
}

.profile-achievements {
    list-style: none;
    margin-top: var(--spacing-sm);
}

.profile-achievements li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.profile-achievements li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: bold;
}

/* =========================================
   Section 6: Books Integration (3D Effect)
   ========================================= */
.integration-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-lg);
    background-color: var(--color-white);
    padding: var(--spacing-xl) var(--spacing-lg);
    border-radius: 24px;
    box-shadow: var(--shadow-xl);
}

.integration-text {
    flex: 1 1 400px;
}

.integration-text p {
    font-size: 1.15rem;
    line-height: 1.9;
    color: var(--color-text-main);
}

.books-showcase {
    flex: 1 1 400px;
    display: flex;
    justify-content: center;
    gap: 2rem;
    perspective: 1200px;
    /* Essential for 3D effect */
}

/* 3D Book CSS */
.book-3d {
    position: relative;
    width: 200px;
    height: 280px;
    transform-style: preserve-3d;
    transform: rotateY(-20deg) rotateX(10deg);
    transition: transform 0.5s ease;
}

.book-3d:hover {
    transform: rotateY(-5deg) rotateX(5deg) translateY(-10px);
}

.book-3d::before {
    /* Book Pages (Side) */
    content: '';
    position: absolute;
    top: 2%;
    left: 100%;
    width: 25px;
    height: 96%;
    background-color: #E2E8F0;
    transform-origin: left top;
    transform: rotateY(90deg);
    border-radius: 0 3px 3px 0;
    box-shadow: inset 0px 0px 5px rgba(0, 0, 0, 0.1);
}

.book-3d::after {
    /* Book Pages (Bottom) */
    content: '';
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    height: 25px;
    background-color: #CBD5E1;
    transform-origin: left top;
    transform: rotateX(-90deg);
    box-shadow: inset 0px 0px 5px rgba(0, 0, 0, 0.1);
}

.book-cover {
    width: 100%;
    height: 100%;
    border-radius: 4px 10px 10px 4px;
    box-shadow:
        inset 4px 0 10px rgba(0, 0, 0, 0.1),
        /* Spine shadow */
        inset -1px 0 2px rgba(255, 255, 255, 0.3);
    /* Edge highlight */
    object-fit: cover;
    position: relative;
    z-index: 10;
}

.book-shadow {
    position: absolute;
    bottom: -15px;
    left: 10px;
    width: 90%;
    height: 20px;
    background: rgba(0, 0, 0, 0.3);
    filter: blur(10px);
    transform: rotateX(80deg) translateZ(-20px);
    z-index: 0;
}

/* =========================================
   Section 7: Testimonials
   ========================================= */
.testimonial-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.testimonial-card {
    background-color: white;
    padding: var(--spacing-lg);
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    position: relative;
}

.testimonial-card::before {
    content: '"';
    position: absolute;
    top: 10px;
    left: 20px;
    font-size: 6rem;
    color: rgba(59, 130, 246, 0.1);
    font-family: serif;
    line-height: 1;
}

.testimonial-stars {
    color: #FFD700;
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.testimonial-text {
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
    font-style: italic;
    position: relative;
    z-index: 1;
}

.testimonial-author {
    font-weight: 700;
    text-align: right;
    color: var(--color-primary);
}

/* =========================================
   Section 8: FAQ & Closing
   ========================================= */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background-color: var(--color-white);
    border-radius: 8px;
    margin-bottom: var(--spacing-sm);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

.faq-question {
    padding: 1.2rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 700;
    font-size: 1.1rem;
    cursor: pointer;
    background-color: var(--color-white);
    transition: background-color var(--transition-fast);
}

.faq-question:hover {
    background-color: var(--color-bg-light);
}

.faq-toggle {
    font-size: 1.5rem;
    color: var(--color-primary);
    transition: transform var(--transition-fast);
}

.faq-item.active .faq-toggle {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
    background-color: var(--color-bg-light);
}

.faq-answer p {
    padding: 1.5rem;
    border-top: 1px solid #e5e7eb;
    color: var(--color-text-main);
}

.final-cta {
    background: linear-gradient(135deg, rgba(30, 58, 138, 0.05), rgba(59, 130, 246, 0.1));
    padding: var(--spacing-xl) var(--spacing-md);
    border-radius: 24px;
    border: 1px solid rgba(59, 130, 246, 0.2);
}