:root {
    --bg-color: #252626;
    --card-bg: #303030;
    --text-primary: #E7DDB7;
    --text-accent: #D5A45D;
    --nav-text: #E7DDB7;
    --nav-bg: rgba(37, 38, 38, 0.78);
    --font-main: 'JetBrains Mono', Courier, monospace;
    --container-width: 650px;
    --border-rad: 12px;
    --padding-sm: 1rem;
    --padding-md: 2rem;
    --padding-lg: 4rem;
    --card-border: #695B4B;
}

body.light-mode {
    --bg-color: #F7EEC5;
    --card-bg: #E7DDB7;
    --text-primary: #473A33;
    --text-accent: #966C2D;
    --nav-text: #473A33;
    --nav-bg: rgba(247, 238, 197, 0.62);
    --card-border: #C4B18D;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.4s ease, color 0.4s ease;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 1.5rem;
    left: 0;
    right: 0;
    margin: 0 auto;
    width: calc(100% - 3rem);
    max-width: var(--container-width);
    z-index: 100;
    padding: 1rem 1.5rem;
    border-radius: var(--border-rad);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.15);
    border: 1px solid var(--card-border);
    background-color: var(--nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: background-color 0.4s ease;
}

.nav-container {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-logo img {
    height: 32px;
    width: auto;
    display: block;
    transition: transform 0.2s ease;
}

.nav-logo:hover img {
    transform: scale(1.1);
}

.nav-links {
    display: flex;
    gap: 3rem;
}

.nav-container a {
    color: var(--nav-text);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

.nav-container a:hover,
.nav-container a.active {
    color: var(--text-accent);
}

/* Main Container Layout */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--padding-sm);
    /* Pad top for fixed navbar */
    padding-top: 8rem;
    padding-bottom: 4rem;
}

/* Sections */
.section {
    margin-bottom: var(--padding-lg);
    scroll-margin-top: 8rem;
    /* Account for navbar when scrolling */
}

/* Typography */
.page-title {
    font-size: 1.35rem;
    font-weight: 500;
    color: var(--text-accent);
    margin-bottom: 0.2rem;
    margin-top: 0.5rem;
}

.japanese-name {
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: var(--padding-sm);
    opacity: 0.8;
}

.section-title {
    font-size: 1.35rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: var(--padding-md);
}

/* About Section */
.banner-container {
    width: 100%;
    margin-bottom: var(--padding-sm);
    border-radius: 15px;
    overflow: hidden;
}

.banner {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
}

.about-text p {
    font-size: 0.95rem;
}

/* Tech Stack */
.tech-stack {
    margin-top: 0.5rem;
}

.tech-stack-grid {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.tech-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--border-rad);
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
    font-weight: 500;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.tech-item:hover {
    transform: translateY(-2px);
    border-color: var(--text-accent);
}

.tech-icon {
    width: 18px;
    height: 18px;
    color: var(--text-accent);
    flex-shrink: 0;
}

/* Education Section */
.edu-item {
    margin-bottom: var(--padding-md);
}

.edu-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 0.5rem;
}

.edu-name {
    font-weight: bold;
    font-size: 0.95rem;
}

.edu-date {
    color: var(--text-accent);
    font-size: 0.9rem;
    font-weight: bold;
}

.edu-desc {
    font-size: 0.95rem;
}

/* Projects Section */
.projects-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--padding-sm);
}

.project-card {
    background-color: var(--card-bg);
    padding: var(--padding-sm);
    border-radius: var(--border-rad);
    transition: transform 0.2s ease, border-color 0.2s ease;
    border: 1px solid var(--card-border);
    position: relative;
    text-decoration: none;
    display: flex;
    flex-direction: column;
    color: inherit;
}

.project-card:hover {
    transform: translateY(-2px);
    border-color: var(--text-accent);
}

.project-link-icon {
    position: absolute;
    top: 1.15rem;
    right: 1rem;
    color: var(--text-accent);
    opacity: 0;
    transition: opacity 0.2s ease, transform 0.2s ease;
    transform: scale(0.8) translateX(-5px);
}

.project-card:hover .project-link-icon {
    opacity: 1;
    transform: scale(1) translateX(0);
}

.project-title {
    color: var(--text-accent);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    transition: transform 0.2s ease;
}

.project-desc {
    font-size: 0.85rem;
    line-height: 1.4;
    margin-bottom: 0.75rem;
}

.project-badges {
    display: flex;
    gap: 0.4rem;
    flex-wrap: wrap;
    margin-top: auto;
}

.badge {
    font-size: 0.7rem;
    padding: 0.15rem 0.4rem;
    border-radius: 4px;
    background-color: var(--text-accent);
    color: var(--bg-color);
    font-weight: 600;
}

/* Projects Expand/Collapse */
.projects-wrapper {
    position: relative;
    overflow: hidden;
    padding-top: 10px;
    padding-bottom: 10px;
    margin-top: -10px;
    transition: max-height 0.4s ease-out;
}

.projects-fade {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 120px;
    background: linear-gradient(to bottom, transparent, var(--bg-color) 90%);
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.projects-wrapper.expanded .projects-fade {
    opacity: 0;
    pointer-events: none;
}

.show-more-btn {
    display: inline-block;
    padding: 0.6rem 1.5rem;
    background-color: transparent;
    border: 1px solid var(--text-accent);
    color: var(--text-accent);
    border-radius: var(--border-rad);
    cursor: pointer;
    font-family: inherit;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.show-more-btn:hover {
    background-color: var(--text-accent);
    color: var(--bg-color);
}

/* Private Project Card */
.private-card {
    cursor: default;
}

.private-card .project-link-icon {
    display: none;
}

.private-overlay {
    position: absolute;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    border-radius: var(--border-rad);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 1.5rem;
    text-align: center;
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 10;
    color: var(--text-primary);
}

body.light-mode .private-overlay {
    background-color: rgba(0, 0, 0, 0.4);
    color: #F7EEC5; /* light mode text override for dark overlay */
}

.private-card:hover .private-overlay {
    opacity: 1;
}

.private-card:hover .project-title {
    transform: none;
}

.private-overlay span {
    font-size: 0.95rem;
    font-weight: 600;
    transform: translateY(10px);
    transition: transform 0.3s ease;
}

.private-card:hover .private-overlay span {
    transform: translateY(0);
}

/* Contact Section */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--padding-sm);
}

.contact-card {
    background-color: var(--card-bg);
    padding: 1.5rem var(--padding-sm);
    border-radius: var(--border-rad);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    text-decoration: none;
    color: var(--text-primary);
    transition: transform 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
    border: 1px solid var(--card-border);
}

.contact-card:hover {
    transform: translateY(-2px);
    border-color: var(--text-accent);
}

.contact-label {
    font-size: 0.85rem;
    margin-bottom: 1rem;
}

.contact-icon {
    color: var(--text-accent);
    margin-bottom: 1rem;
}

.contact-value {
    font-size: 0.75rem;
    line-height: 1.3;
}

/* Burger Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 101;
}

.menu-toggle .bar {
    width: 100%;
    height: 2px;
    background-color: var(--text-accent);
    transition: all 0.3s ease;
}

.menu-toggle.active .bar:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.menu-toggle.active .bar:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active .bar:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* Theme Toggle Button */
.theme-toggle {
    background: transparent;
    border: none;
    color: var(--text-accent);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    transition: transform 0.2s ease, color 0.3s ease;
}

.theme-toggle:hover {
    transform: scale(1.1);
}

/* Media Queries */
@media (max-width: 768px) {
    .nav-container {
        flex-wrap: wrap;
    }

    .nav-links {
        position: static;
        width: 100%;
        max-width: 100%;
        background-color: transparent;
        backdrop-filter: none;
        -webkit-backdrop-filter: none;
        flex-direction: column;
        align-items: center;
        gap: 1.5rem;
        padding: 0;
        box-shadow: none;
        
        /* Expand animation inside the navbar */
        max-height: 0;
        opacity: 0;
        margin-top: 0;
        pointer-events: none;
        transform: none;
        order: 3;
        transition: max-height 0.4s ease, opacity 0.3s ease, margin-top 0.4s ease;
    }

    .nav-links.active {
        max-height: 300px;
        opacity: 1;
        margin-top: 1.5rem;
        pointer-events: auto;
        transform: none;
    }

    .nav-links a {
        font-size: 1.2rem;
        letter-spacing: 0.05em;
    }

    .menu-toggle {
        display: flex;
    }



    .projects-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .edu-header {
        flex-direction: column;
        align-items: flex-start;
    }
}