/* CSS Variables for requested colors */
:root {
    --bg-color: #252525;
    --text-color: #f3f3f3;
    --subtext-color: #DDDDDD;
    --accent-color: #56a3fe;

    /* Additional structural colors derived from base */
    --card-bg: rgba(255, 255, 255, 0.05);
    --card-hover: rgba(86, 163, 254, 0.1);
    --border-color: rgba(221, 221, 221, 0.1);
}

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

body {
    font-family: 'Noto Sans JP', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
}

h1,
h2,
h3,
.h1,
.h2,
.h3 {
    font-family: 'Outfit', 'Noto Sans JP', sans-serif;
    color: var(--text-color);
}

p {
    color: var(--subtext-color);
    margin-bottom: 1rem;
}

a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: lighten(var(--accent-color), 10%);
    text-decoration: underline;
}

.container {
    width: 90%;
    max-width: 1100px;
    margin: 0 auto;
}

/* Sections */
.section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    display: block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background-color: var(--accent-color);
}

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

/* Navigation Header */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(37, 37, 37, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-family: 'Outfit', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-color) !important;
    text-decoration: none !important;
    letter-spacing: 0.05em;
}

.nav-logo:hover {
    color: var(--accent-color) !important;
    text-decoration: none !important;
}

.nav-logo-img {
    height: 32px;
    width: auto;
    display: block;
    filter: drop-shadow(0 2px 4px rgba(0,0,0,0.4));
    transition: opacity 0.3s ease;
}

.nav-logo:hover .nav-logo-img {
    opacity: 0.8;
}

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

.nav-links a {
    color: var(--subtext-color);
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: var(--accent-color);
    text-decoration: none;
}

@media (max-width: 600px) {
    .nav-links {
        gap: 1rem;
    }
    .nav-links a {
        font-size: 0.8rem;
    }
}

/* Hero Section */
.hero {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, rgba(37, 37, 37, 1) 0%, rgba(20, 20, 20, 1) 100%);
    position: relative;
    overflow: hidden;
}

.hero h1 {
    margin-bottom: 1rem;
    text-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
}

.brand-logo {
    max-width: 400px;
    width: 90%;
    height: auto;
    filter: drop-shadow(0 4px 10px rgba(0, 0, 0, 0.5));
}

.hero .subtitle {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 0 auto;
    font-weight: 300;
}

/* Cards & Grid */
.grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2rem;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    transition: transform 0.3s ease, background-color 0.3s ease, box-shadow 0.3s ease;
    backdrop-filter: blur(10px);
}

.project-card {
    display: block;
    text-align: center;
    text-decoration: none;
    flex: 1 1 300px;
    max-width: 350px;
}

.project-card:hover {
    transform: translateY(-5px);
    background-color: var(--card-hover);
    border-color: rgba(86, 163, 254, 0.3);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.3);
    text-decoration: none;
}

.project-card .icon-wrapper {
    font-size: 3rem;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
}

.project-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.project-card.highlight {
    border: 1px solid rgba(86, 163, 254, 0.5);
    background: linear-gradient(180deg, rgba(86, 163, 254, 0.05) 0%, transparent 100%);
}

#about .card {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

/* Social Links */
.social-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    font-size: 2rem;
}

.social-links a {
    color: var(--text-color);
    transition: color 0.3s ease, transform 0.3s ease;
}

.social-links a:hover {
    color: var(--accent-color);
    transform: scale(1.1);
}

/* Footer */
footer {
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
    color: var(--subtext-color);
    font-size: 0.9rem;
}

footer .legal-links {
    margin-top: 1rem;
}

footer .legal-links a {
    color: var(--subtext-color);
    margin: 0 10px;
}

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

/* Animations */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.fade-in.appear {
    opacity: 1;
    transform: translateY(0);
}

.delay-1 {
    transition-delay: 0.2s;
}

.delay-2 {
    transition-delay: 0.4s;
}

.delay-3 {
    transition-delay: 0.6s;
}

.delay-4 {
    transition-delay: 0.8s;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 3rem;
    }

    .section {
        padding: 3rem 0;
    }

    .card {
        padding: 1.5rem;
    }
}