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

:root {
    --primary-color: #0a0a0a;
    --secondary-color: #2a2a2a;
    --accent-color: #0066cc;
    --text-color: #1a1a1a;
    --text-light: #666;
    --bg-color: #ffffff;
    --section-bg: #fafafa;
    --border-color: #e5e5e5;
    --max-width: 1200px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.7;
    color: var(--text-color);
    background-color: var(--bg-color);
    font-size: 16px;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

/* Logo Container - Centered at top */
.logo-container {
    padding: 2.5rem 0 2rem;
    text-align: center;
    background: var(--bg-color);
}

.main-logo {
    max-width: 400px;
    width: 100%;
    height: auto;
    display: block;
    margin: 0 auto;
}

/* Introduction Section */
.intro-section {
    padding: 1.5rem 0 2rem;
    background: var(--bg-color);
    text-align: center;
}

.intro-text {
    font-size: 1.2rem;
    line-height: 1.9;
    color: var(--text-light);
    max-width: 900px;
    margin: 0 auto;
    font-weight: 400;
}

/* Tabs Section */
.tabs-section {
    padding: 2rem 0 2.5rem;
    background: var(--bg-color);
}

.tabs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
    margin-top: 2rem;
}

.tab-card {
    background: var(--section-bg);
    padding: 2.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.tab-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.12);
    border-color: var(--accent-color);
}

.tab-card h2 {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    letter-spacing: -0.5px;
}

.tab-card p {
    color: var(--text-light);
    line-height: 1.9;
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.tab-card a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.tab-card a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.tab-link {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.tab-link a {
    font-size: 1rem;
    font-weight: 600;
}

.expertise-list {
    list-style: none;
    margin: 1.5rem 0;
    padding: 0;
}

.expertise-list li {
    color: var(--text-light);
    line-height: 1.9;
    margin-bottom: 1.5rem;
    padding-left: 1.5rem;
    position: relative;
}

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

.expertise-list li strong {
    color: var(--primary-color);
    font-weight: 600;
}

/* QR Code Section */
.qr-section {
    padding: 2rem 0 2.5rem;
    background: var(--section-bg);
}

.qr-container {
    text-align: center;
    max-width: 300px;
    margin: 0 auto;
}

.qr-code {
    width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    display: block;
}

/* Footer */
.footer {
    background-color: var(--primary-color);
    color: #ffffff;
    padding: 2rem 0;
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.footer-left {
    text-align: left;
}

.footer-right {
    text-align: right;
}

.footer p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.footer-email {
    margin-top: 0.5rem;
}

.footer-email a {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.footer-email a:hover {
    color: #ffffff;
    text-decoration: underline;
}

/* Responsive Design */
@media (max-width: 968px) {
    .tabs-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .main-logo {
        max-width: 300px;
    }

    .logo-container {
        padding: 2rem 0 1.5rem;
    }

    .footer .container {
        flex-direction: column;
        gap: 1.5rem;
    }

    .footer-left,
    .footer-right {
        text-align: center;
    }
}

@media (max-width: 768px) {
    .container {
        padding: 0 1.5rem;
    }

    .tab-card {
        padding: 2rem;
    }

    .tab-card h2 {
        font-size: 1.5rem;
    }

    .main-logo {
        max-width: 250px;
    }

    .logo-container {
        padding: 2rem 0 1.5rem;
    }

    .footer .container {
        flex-direction: column;
        gap: 1rem;
    }

    .footer-left,
    .footer-right {
        text-align: center;
    }

    .qr-container {
        max-width: 250px;
    }
}

@media (max-width: 480px) {
    .tab-card {
        padding: 1.5rem;
    }

    .main-logo {
        max-width: 200px;
    }

    .qr-container {
        max-width: 200px;
    }
}