:root {
    --bg-dark: #0a0a0c;
    --bg-light-dark: #121216;
    --text-main: #f4f4f5;
    --text-muted: #a1a1aa;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --border: #27272a;
    --card-bg: rgba(255, 255, 255, 0.03);

    --font-sans: 'Inter', 'Noto Sans JP', sans-serif;

    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 4rem;
    --space-2xl: 8rem;
}

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

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s ease;
}

ul {
    list-style: none;
}

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

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 500;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 300;
    margin-bottom: var(--space-xl);
    text-transform: none;
    letter-spacing: 0.02em;
    position: relative;
    display: inline-block;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-muted);
    margin-left: 0.5rem;
    font-weight: 300;
    letter-spacing: 0.05em;
}

.method-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
    text-transform: none;
    letter-spacing: 0.05em;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 40px;
    height: 1px;
    background-color: var(--accent);
}

.mb-4 {
    margin-bottom: var(--space-md);
}

.mb-6 {
    margin-bottom: 1.5rem;
}

/* Buttons */
.btn-primary {
    display: inline-block;
    background-color: var(--accent);
    color: #fff;
    padding: 1rem 2.5rem;
    border-radius: 4px;
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: background-color 0.3s ease, transform 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
}

.btn-secondary {
    display: inline-block;
    background-color: transparent;
    color: var(--text-main);
    padding: 1rem 2.5rem;
    border-radius: 4px;
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: background-color 0.3s ease, border-color 0.3s ease, transform 0.3s ease;
    border: 1px solid var(--border);
    cursor: pointer;
    font-size: 1rem;
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.btn-primary-small {
    display: inline-block;
    background-color: var(--accent);
    color: #fff;
    padding: 0.5rem 1.25rem;
    border-radius: 4px;
    font-size: 0.875rem;
    font-weight: 500;
}

.btn-primary-small:hover {
    background-color: var(--accent-hover);
}

/* Header & Nav */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: rgba(10, 10, 12, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    transition: all 0.3s ease;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    display: flex;
    align-items: center;
}

.logo-text {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.1em;
}

.logo-dot {
    color: var(--accent);
}

.nav-menu ul {
    display: flex;
    align-items: center;
    gap: 2.5rem;
}

.nav-menu a:not(.btn-primary-small) {
    font-size: 0.875rem;
    letter-spacing: 0.05em;
    color: var(--text-muted);
}

.nav-menu a:not(.btn-primary-small):hover {
    color: var(--text-main);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    width: 30px;
    height: 20px;
    position: relative;
    z-index: 1001;
}

.hamburger span {
    position: absolute;
    width: 100%;
    height: 2px;
    background-color: var(--text-main);
    transition: all 0.3s ease;
    left: 0;
}

.hamburger span:nth-child(1) {
    top: 0;
}

.hamburger span:nth-child(2) {
    top: 50%;
    transform: translateY(-50%);
}

.hamburger span:nth-child(3) {
    bottom: 0;
}

.hamburger.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 70% 50%, rgba(59, 130, 246, 0.15) 0%, transparent 50%);
    z-index: -1;
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 300;
    line-height: 1.2;
    margin-bottom: var(--space-lg);
}

.hero-subtitle {
    font-size: clamp(1.2rem, 3vw, 1.5rem);
    font-weight: 500;
    margin-bottom: var(--space-md);
    color: var(--text-muted);
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-muted);
    max-width: 600px;
    margin-bottom: var(--space-xl);
}

/* Sections Common */
.section {
    padding: var(--space-2xl) 0;
}

.bg-light-dark {
    background-color: var(--bg-light-dark);
}

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

.service-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    padding: 3rem 2rem;
    border-radius: 4px;
    transition: transform 0.3s ease, border-color 0.3s ease;
}

.service-card:hover {
    transform: translateY(-5px);
    border-color: rgba(59, 130, 246, 0.3);
}

.service-icon {
    font-size: 2rem;
    font-weight: 300;
    color: var(--accent);
    margin-bottom: 1.5rem;
    font-family: var(--font-sans);
}

.service-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.service-card p {
    color: var(--text-muted);
    font-size: 0.9375rem;
}

/* Lectures */
.feature-list {
    margin-top: 2rem;
}

.feature-list li {
    padding: 1rem 0;
    border-bottom: 1px solid var(--border);
    position: relative;
    padding-left: 1.5rem;
}

.feature-list li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--accent);
}

/* Company Profile */
.company-profile {
    display: flex;
    flex-wrap: wrap;
    gap: 4rem;
    align-items: flex-start;
}

.company-info {
    flex: 1;
    min-width: 300px;
    background: var(--card-bg);
    border: 1px solid var(--border);
    padding: 2.5rem;
    border-radius: 4px;
}

.company-role {
    color: var(--accent);
    font-weight: 500;
    font-size: 0.875rem;
    letter-spacing: 0.1em;
    margin-bottom: 0.75rem;
}

.company-name {
    font-size: 1.75rem;
    margin-bottom: 1.25rem;
    display: flex;
    align-items: baseline;
    gap: 1rem;
    flex-wrap: wrap;
}

.company-name-en {
    font-size: 1rem;
    color: var(--text-muted);
    font-weight: 300;
}

.company-credentials {
    margin-bottom: 1.5rem;
}

.credential-badge {
    display: inline-block;
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.875rem;
    color: #e4e4e7;
}

.company-bio {
    color: var(--text-muted);
    line-height: 1.8;
}

/* Contact */
.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.contact-info p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.contact-method {
    margin-bottom: 1rem;
}

.method-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    margin-bottom: 0.25rem;
}

.method-value {
    font-size: 1.25rem;
    font-weight: 300;
    word-break: break-all;
}

.method-value:hover {
    color: var(--accent);
}

.contact-form-container {
    background: var(--card-bg);
    border: 1px solid var(--border);
    padding: 2.5rem;
    border-radius: 4px;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
    color: #e4e4e7;
}

.required {
    color: #ef4444;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    background-color: var(--card-bg);
    border: 1px solid var(--border);
    color: var(--text-main);
    border-radius: 4px;
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    color-scheme: dark;
}

select option {
    background-color: var(--card-bg);
    color: var(--text-main);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

.btn-submit {
    width: 100%;
    margin-top: 1rem;
}

/* Footer */
.footer {
    border-top: 1px solid var(--border);
    padding: 4rem 0 2rem;
    background-color: #050505;
}

.footer-content {
    margin-bottom: 3rem;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    margin-bottom: 0.5rem;
}

.footer-company {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 2rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.75rem;
}

/* Mobile Responsiveness */
@media (max-width: 900px) {
    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

@media (max-width: 768px) {
    :root {
        --space-2xl: 5rem;
        --space-xl: 3rem;
    }

    .hamburger {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        height: 100vh;
        background-color: var(--bg-dark);
        display: flex;
        justify-content: center;
        align-items: center;
        transition: right 0.4s ease;
        z-index: 1000;
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-menu ul {
        flex-direction: column;
        gap: 2rem;
        text-align: center;
        padding: 0;
    }

    .nav-menu a {
        font-size: 1.5rem !important;
    }

    .company-profile {
        gap: 2rem;
    }

    .contact-form-container {
        padding: 1.5rem;
    }
}