:root {
    --color-bg: #0f172a;
    --color-text: #f8fafc;
    --color-text-muted: #94a3b8;
    --color-primary: #38bdf8;
    --color-primary-hover: #0ea5e9;
    --color-secondary: #1e293b;
    --color-accent: #2dd4bf;

    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Noto Sans JP', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 1.5rem;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: -0.02em;
}

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

.nav a {
    color: var(--color-text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav a:hover {
    color: var(--color-primary);
}

/* Hero */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 10;
}

.hero-title {
    font-family: var(--font-heading);
    font-size: clamp(3rem, 8vw, 6rem);
    line-height: 1.1;
    font-weight: 800;
    margin-bottom: 1.5rem;
    background: linear-gradient(to right, #fff, #94a3b8);
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-title .accent {
    color: var(--color-primary);
    -webkit-text-fill-color: var(--color-primary);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    max-width: 600px;
    margin-bottom: 2.5rem;
}

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

.hero-bg {
    position: absolute;
    top: 50%;
    right: -10%;
    transform: translateY(-50%);
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(56, 189, 248, 0.15) 0%, rgba(15, 23, 42, 0) 70%);
    filter: blur(60px);
    z-index: 1;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary {
    background-color: var(--color-primary);
    color: #0f172a;
}

.btn-primary:hover {
    background-color: var(--color-primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(56, 189, 248, 0.3);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--color-text);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* Sections */
.section {
    padding: 6rem 0;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
    padding-left: 1.5rem;
}

.section-title::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 100%;
    background-color: var(--color-accent);
    border-radius: 2px;
}

/* About */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

@media (max-width: 768px) {
    .about-grid {
        grid-template-columns: 1fr;
    }
}

.about-text p {
    margin-bottom: 1.5rem;
    color: var(--color-text-muted);
    font-size: 1.1rem;
}

.about-stat {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
}

.stat-item {
    background: var(--color-secondary);
    padding: 2rem;
    border-radius: 1rem;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.stat-num {
    display: block;
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 3rem;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Projects */
.section-dark {
    background-color: #0b1120;
}

.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--color-secondary);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: transform 0.3s, border-color 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
    border-color: var(--color-primary);
}

.project-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.project-desc {
    color: var(--color-text-muted);
}

/* Contact */
.contact-container {
    text-align: center;
}

.contact-container p {
    color: var(--color-text-muted);
    font-size: 1.25rem;
    margin-bottom: 2rem;
}

/* Footer */
.footer {
    padding: 3rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--color-text-muted);
}

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

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

.footer-links a {
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.3s;
}

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

.org-details {
    margin-top: 1.5rem;
    list-style: none;
    padding: 0;
}

.org-details li {
    margin-bottom: 0.5rem;
    color: var(--color-text-muted);
}

.org-details strong {
    color: var(--color-text);
    margin-right: 0.5rem;
}

.org-details a {
    color: var(--color-primary);
    text-decoration: none;
}

.org-details a:hover {
    text-decoration: underline;
}