/* Academic Landing Page Styles */
:root {
    --text-color: #333333;
    --background-color: #ffffff;
    --accent-color: #1a75ff;
    --section-margin: 2rem;
    --heading-color: #1a1a1a;
}

body {
    font-family: 'Noto Sans', 'Noto Sans JP', system-ui, -apple-system, sans-serif;
    line-height: 1.8;
    color: var(--text-color);
    background-color: var(--background-color);
    margin: 0;
    padding: 0;
}

/* Language Switch Button */
.language-switch {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 1000;
}

.language-switch button {
    padding: 0.5rem 1rem;
    border: 1px solid #ddd;
    background: white;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
}

/* Main Container */
.main-container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
}

/* Content Sections */
.content-section {
    margin-top: 3rem;
}

.content-section h1 {
    font-size: 2rem;
    color: var(--heading-color);
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 2px solid var(--accent-color);
}

.content-section h2 {
    font-size: 1.5rem;
    color: var(--heading-color);
    margin: 2rem 0 1rem;
}

section {
    margin-bottom: var(--section-margin);
}

/* Publications List */
.publications ol {
    padding-left: 1.5rem;
}

.publications li {
    margin-bottom: 1rem;
    line-height: 1.6;
}

/* Language Toggle */
.content-section.jp {
    display: none;
}

/* Typography */
p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main-container {
        padding: 1rem;
    }

    .content-section h1 {
        font-size: 1.75rem;
    }

    .content-section h2 {
        font-size: 1.25rem;
    }
}

/* Main Container */
.main-container {
    overflow-x: hidden;
}

/* Common Section Styles */
.section {
    padding: var(--section-padding);
}

/* Hero Section */
.hero-section {
    position: relative;
    height: 60vh;
    min-height: 400px;
    background: linear-gradient(135deg, #4a90e2 0%, #2c3e50 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
    margin-bottom: 2rem;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.3);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    padding: 2rem;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.hero-content .lead {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    margin-top: 2rem;
}

.hero-buttons .btn {
    margin: 0 0.5rem;
}

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

.feature-card {
    margin-bottom: 2rem;
}

.feature-card .card {
    border: none;
    border-radius: 15px;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    overflow: hidden;
}

.feature-card .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

/* Research Section */
.research-section {
    padding: 6rem 0;
    background: white;
}

.research-points .point {
    display: flex;
    align-items: center;
    margin-bottom: 1.5rem;
}

.research-points i {
    color: var(--primary-color);
    margin-right: 1rem;
    font-size: 1.5rem;
}

.research-image {
    position: relative;
    padding: 2rem;
}

/* Stats Section */
.stats-section {
    padding: 4rem 0;
    background: var(--secondary-color);
    color: white;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.stat-label {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* CTA Section */
.cta-section {
    padding: 6rem 0;
    background: linear-gradient(135deg, #4a90e2 0%, #2c3e50 100%);
    color: white;
}

.cta-buttons {
    margin-top: 2rem;
}

.cta-buttons .btn {
    margin: 0.5rem;
    padding: 0.8rem 2rem;
}

/* Buttons */
.btn {
    border-radius: 30px;
    padding: 0.8rem 2rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

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

.btn-primary:hover {
    background: darken(var(--primary-color), 10%);
    border-color: darken(var(--primary-color), 10%);
    transform: translateY(-2px);
}

.btn-outline-light {
    border-width: 2px;
}

.btn-outline-light:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

.fade-in {
    animation: fadeIn 1s ease-out;
}

.slide-up {
    animation: slideUp 1s ease-out forwards;
    opacity: 0;
}

.hero-buttons {
    animation: slideUp 1s ease-out 0.5s forwards;
    opacity: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2.5rem;
    }

    .hero-content .lead {
        font-size: 1.2rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .research-image {
        margin-top: 2rem;
    }
}

/* Footer */
footer {
    background: var(--dark-color);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

footer .text-muted {
    color: rgba(255, 255, 255, 0.6) !important;
}