/* Variables & Custom Properties */
:root {
    --primary-color: #0d254c; /* 深みのある紺色 */
    --secondary-color: #1a365d; /* やや明るい紺色 */
    --accent-color: #d4af37; /* ゴールド */
    --accent-glow: #ffdf7a; /* 明るいゴールド */
    --text-color: #2d3748; /* ダークグレー */
    --text-muted: #718096; /* ミディアムグレー */
    --bg-light: #f7fafc; /* ライトグレー背景 */
    --bg-dark: #0b132b; /* ダークネイビー */
    --white: #ffffff;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --border-radius: 12px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.15), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

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

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

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

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

/* Typography Utility */
.gradient-text {
    background: linear-gradient(135deg, var(--accent-color) 0%, #ffffff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 900;
}

/* Reusable Components */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.85rem 2rem;
    font-weight: 700;
    font-size: 1rem;
    border-radius: 50px;
    border: none;
    cursor: pointer;
    transition: var(--transition-smooth);
    text-align: center;
    letter-spacing: 0.05em;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-color) 0%, #b8901c 100%);
    color: var(--primary-color);
    box-shadow: 0 4px 15px rgba(212, 175, 55, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(212, 175, 55, 0.6);
    background: linear-gradient(135deg, #e5be49 0%, var(--accent-color) 100%);
}

.btn-gold {
    background: linear-gradient(135deg, var(--accent-color) 0%, #ffdf7a 100%);
    color: #000000;
    box-shadow: 0 4px 20px rgba(212, 175, 55, 0.4);
    font-size: 1.15rem;
    font-weight: 800;
    padding: 1.2rem 3rem;
}

.btn-gold:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(212, 175, 55, 0.7);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid rgba(255, 255, 255, 0.3);
    color: var(--white);
}

.btn-outline:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: var(--white);
}

.btn-lg {
    padding: 1rem 2.5rem;
    font-size: 1.1rem;
}

.badge {
    display: inline-block;
    padding: 0.4rem 1rem;
    background-color: rgba(212, 175, 55, 0.15);
    border: 1px solid var(--accent-color);
    color: var(--accent-glow);
    font-weight: 700;
    font-size: 0.85rem;
    border-radius: 50px;
    letter-spacing: 0.1em;
    margin-bottom: 1.5rem;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-subtitle {
    display: block;
    font-size: 0.9rem;
    font-weight: 800;
    color: var(--accent-color);
    letter-spacing: 0.15em;
    margin-bottom: 0.5rem;
}

.section-title {
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--primary-color);
    position: relative;
    padding-bottom: 1rem;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--accent-color);
    border-radius: 2px;
}

.section-desc {
    margin-top: 1rem;
    color: var(--text-muted);
}

/* Header */
.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background-color: rgba(13, 37, 76, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition-smooth);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0.8rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    flex-direction: column;
}

.logo-sub {
    font-size: 0.65rem;
    font-weight: 700;
    color: var(--accent-color);
    letter-spacing: 0.15em;
    line-height: 1.2;
}

.logo-main {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--white);
    letter-spacing: 0.02em;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: rgba(255, 255, 255, 0.8);
    font-weight: 500;
    font-size: 0.95rem;
}

.nav-link:hover {
    color: var(--accent-color);
}

.header-cta {
    background-color: var(--accent-color);
    color: var(--primary-color);
    padding: 0.5rem 1.2rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: 0 4px 10px rgba(212, 175, 55, 0.2);
}

.header-cta:hover {
    background-color: var(--white);
    transform: translateY(-1px);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--white);
    transition: var(--transition-smooth);
}

/* Hero Section */
.hero-section {
    position: relative;
    padding: 10rem 0 6rem;
    background-color: var(--bg-dark);
    color: var(--white);
    min-height: 90vh;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.hero-bg-wrapper {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.hero-bg-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.25;
    filter: brightness(0.6) contrast(1.1);
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 60% 30%, rgba(13, 37, 76, 0.6) 0%, var(--bg-dark) 90%);
    z-index: 2;
}

.hero-container {
    position: relative;
    z-index: 10;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    width: 100%;
}

.hero-content {
    max-width: 750px;
}

.hero-title {
    font-size: 3rem;
    line-height: 1.25;
    font-weight: 900;
    letter-spacing: -0.02em;
    margin-bottom: 1.5rem;
}

.hero-title .sub-title {
    display: block;
    font-size: 1.8rem;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.9);
    margin-top: 0.75rem;
}

.hero-description {
    font-size: 1.15rem;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 2.5rem;
    line-height: 1.7;
}

.hero-meta {
    background: rgba(255, 255, 255, 0.03);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 2.5rem;
}

.meta-item {
    flex: 1 1 200px;
    display: flex;
    flex-direction: column;
}

.meta-label {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--accent-color);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.25rem;
}

.meta-val {
    font-size: 1.2rem;
    font-weight: 700;
}

.meta-val .day {
    font-size: 1rem;
    font-weight: 500;
}

.meta-val .tax {
    font-size: 0.8rem;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.6);
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.8s forwards;
}

.hero-title { animation-delay: 0.2s; }
.hero-description { animation-delay: 0.4s; }
.hero-meta { animation-delay: 0.6s; }
.hero-actions { animation-delay: 0.8s; }

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

/* Concept Banner */
.concept-banner {
    padding: 3rem 0;
    background-color: var(--bg-light);
    margin-top: -3rem;
    position: relative;
    z-index: 20;
}

.concept-card {
    background-color: var(--white);
    border-left: 5px solid var(--accent-color);
    box-shadow: var(--shadow-md);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    padding: 2rem;
}

.concept-badge {
    font-size: 0.8rem;
    font-weight: 800;
    color: var(--accent-color);
    background-color: rgba(212, 175, 55, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    display: inline-block;
    margin-bottom: 1rem;
}

.concept-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    line-height: 1.4;
}

.concept-subtext {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* Features Section */
.features-section {
    padding: 6rem 0;
    background-color: var(--white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.feature-card {
    background-color: var(--white);
    border: 1px solid #edf2f7;
    border-radius: var(--border-radius);
    padding: 2.5rem 2rem;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(212, 175, 55, 0.3);
}

.feature-icon {
    width: 60px;
    height: 60px;
    border-radius: 12px;
    background-color: rgba(13, 37, 76, 0.05);
    color: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    transition: var(--transition-smooth);
}

.feature-icon svg {
    width: 30px;
    height: 30px;
}

.feature-card:hover .feature-icon {
    background-color: var(--primary-color);
    color: var(--accent-color);
    transform: rotate(5deg);
}

.feature-card h3 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature-card p {
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.7;
}

/* Curriculum Section */
.curriculum-section {
    padding: 6rem 0;
    background-color: var(--bg-light);
}

.timeline {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    padding-left: 2rem;
}

.timeline::before {
    content: '';
    position: absolute;
    top: 0;
    left: 7px;
    width: 2px;
    height: 100%;
    background-color: #cbd5e0;
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-item:last-child {
    margin-bottom: 0;
}

.timeline-item::before {
    content: '';
    position: absolute;
    top: 6px;
    left: -29px;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background-color: var(--white);
    border: 4px solid var(--accent-color);
    z-index: 2;
    transition: var(--transition-smooth);
}

.timeline-item:hover::before {
    background-color: var(--accent-color);
    transform: scale(1.2);
}

.time-badge {
    display: inline-block;
    padding: 0.2rem 0.8rem;
    background-color: var(--primary-color);
    color: var(--white);
    font-weight: 700;
    font-size: 0.9rem;
    border-radius: 4px;
    margin-bottom: 0.75rem;
}

.time-badge .duration {
    font-size: 0.75rem;
    color: var(--accent-color);
    margin-left: 0.5rem;
}

.timeline-content {
    background-color: var(--white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    border: 1px solid #e2e8f0;
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.timeline-content p {
    font-size: 0.95rem;
    color: var(--text-muted);
}

.highlight-text {
    color: #e53e3e;
    font-weight: 700;
    font-size: 0.85rem;
    margin-bottom: 0.25rem;
}

/* Instructor Section */
.instructor-section {
    padding: 6rem 0;
    background-color: var(--white);
}

.instructor-card {
    max-width: 900px;
    margin: 0 auto;
    background-color: var(--bg-dark);
    color: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    display: flex;
    box-shadow: var(--shadow-lg);
}

.instructor-image {
    flex: 0 0 350px;
    background-color: #1a202c;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.instructor-avatar {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--accent-color);
    box-shadow: var(--shadow-lg);
    transition: var(--transition-smooth);
}

.instructor-avatar:hover {
    transform: scale(1.05) rotate(2deg);
    border-color: var(--accent-glow);
}

.instructor-info {
    padding: 3rem;
    flex: 1;
}

.info-subtitle {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--accent-color);
    letter-spacing: 0.1em;
}

.instructor-name {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 0.25rem;
}

.instructor-title {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 1.5rem;
}

.divider {
    border: 0;
    height: 1px;
    background-color: rgba(255, 255, 255, 0.15);
    margin-bottom: 1.5rem;
}

.instructor-bio {
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
}

/* Overview Section */
.overview-section {
    padding: 6rem 0;
    background-color: var(--bg-light);
}

.table-responsive {
    max-width: 900px;
    margin: 0 auto;
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    border: 1px solid #e2e8f0;
}

.overview-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

.overview-table th, .overview-table td {
    padding: 1.5rem 2rem;
    border-bottom: 1px solid #edf2f7;
}

.overview-table tr:last-child th, .overview-table tr:last-child td {
    border-bottom: none;
}

.overview-table th {
    background-color: rgba(13, 37, 76, 0.02);
    color: var(--primary-color);
    font-weight: 700;
    width: 250px;
    vertical-align: top;
    border-right: 1px solid #edf2f7;
}

.overview-table td {
    color: var(--text-color);
}

.overview-table td strong {
    color: var(--primary-color);
    font-size: 1.25rem;
}

/* FAQ Section */
.faq-section {
    padding: 6rem 0;
    background-color: var(--white);
}

.faq-accordion {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid #e2e8f0;
    padding: 1rem 0;
}

.faq-item:first-child {
    border-top: 1px solid #e2e8f0;
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    text-align: left;
    background: none;
    border: none;
    padding: 1rem 0;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--primary-color);
    cursor: pointer;
    transition: var(--transition-smooth);
}

.faq-question:hover {
    color: var(--accent-color);
}

.faq-icon-arrow {
    position: relative;
    width: 16px;
    height: 16px;
}

.faq-icon-arrow::before, .faq-icon-arrow::after {
    content: '';
    position: absolute;
    background-color: var(--primary-color);
    transition: var(--transition-smooth);
}

.faq-icon-arrow::before {
    top: 7px;
    left: 0;
    width: 16px;
    height: 2px;
}

.faq-icon-arrow::after {
    top: 0;
    left: 7px;
    width: 2px;
    height: 16px;
}

.faq-item.active .faq-icon-arrow::after {
    transform: rotate(90deg);
    opacity: 0;
}

.faq-item.active .faq-question {
    color: var(--accent-color);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
}

.faq-answer p {
    padding: 0.5rem 0 1.5rem;
    font-size: 0.95rem;
    color: var(--text-muted);
    line-height: 1.7;
}

.faq-item.active .faq-answer {
    max-height: 1000px;
    transition: max-height 0.5s ease-in-out;
}

/* CTA Section */
.cta-section {
    padding: 8rem 0;
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.cta-section::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(212,175,55,0.08) 0%, transparent 60%);
    pointer-events: none;
}

.cta-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 1.5rem;
    position: relative;
    z-index: 10;
}

.cta-badge {
    background-color: rgba(229, 62, 62, 0.2);
    border: 1px solid #e53e3e;
    color: #feb2b2;
    padding: 0.4rem 1rem;
    border-radius: 50px;
    font-weight: 700;
    font-size: 0.85rem;
    display: inline-block;
    margin-bottom: 2rem;
    letter-spacing: 0.05em;
}

.cta-section h2 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.35;
}

.cta-section p {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 3rem;
}

.cta-btn {
    margin-bottom: 1.5rem;
}

.cta-note {
    font-size: 0.85rem !important;
    color: rgba(255, 255, 255, 0.5) !important;
}

/* Footer */
.main-footer {
    background-color: #081730;
    color: rgba(255, 255, 255, 0.6);
    padding: 3rem 0;
    font-size: 0.85rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.5rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}

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

/* Intersection Observer Animations */
.scroll-reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.scroll-reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive Styles */
@media (max-width: 991px) {
    .hero-title {
        font-size: 2.5rem;
    }
    .hero-title .sub-title {
        font-size: 1.5rem;
    }
    .instructor-card {
        flex-direction: column;
    }
    .instructor-image {
        flex: 0 0 auto;
        padding: 4rem 2rem 2rem;
    }
    .instructor-info {
        padding: 2rem;
        text-align: center;
    }
    .divider {
        margin: 1.5rem auto;
        max-width: 200px;
    }
    .overview-table th {
        width: 200px;
    }
}

@media (max-width: 768px) {
    .header-cta, .nav-menu {
        display: none;
    }
    .menu-toggle {
        display: flex;
    }
    
    /* Mobile Menu Open State */
    .nav-menu.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 100%;
        left: 0;
        width: 100%;
        background-color: var(--primary-color);
        padding: 2rem;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
        box-shadow: var(--shadow-lg);
    }
    
    .hero-section {
        padding-top: 8rem;
    }
    .hero-title {
        font-size: 2rem;
    }
    .hero-title .sub-title {
        font-size: 1.3rem;
    }
    .hero-meta {
        flex-direction: column;
        gap: 1rem;
    }
    .meta-item {
        flex: 1 1 auto;
    }
    .overview-table th, .overview-table td {
        display: block;
        width: 100%;
        padding: 1rem 1.5rem;
    }
    .overview-table th {
        border-right: none;
        border-bottom: none;
        padding-bottom: 0;
        background-color: transparent;
    }
    .overview-table td {
        padding-top: 0.5rem;
    }
    .overview-table tr {
        border-bottom: 1px solid #edf2f7;
    }
    .overview-table tr:last-child {
        border-bottom: none;
    }
    .cta-section h2 {
        font-size: 1.8rem;
    }
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
}