/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #2c3e50;
    --text-secondary: #34495e;
    --text-tertiary: #7f8c8d;
    --border-color: #e0e0e0;
    --footer-bg: #2c3e50;
    --footer-text: #bdc3c7;
}

body.dark-mode {
    --bg-primary: #1a1a1a;
    --bg-secondary: #242424;
    --text-primary: #e8e8e8;
    --text-secondary: #d0d0d0;
    --text-tertiary: #a0a0a0;
    --border-color: #3a3a3a;
    --footer-bg: #0f0f0f;
    --footer-text: #888888;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    font-size: 16px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Header */
.header {
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--bg-primary);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-link {
    display: block;
    text-decoration: none;
}

.logo {
    height: 2.5rem;
    width: 2.5rem;
    border-radius: 50%;
    object-fit: cover;
    display: block;
}

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

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

.nav-link:hover {
    color: var(--text-secondary);
}

.nav-separator {
    color: #95a5a6;
    font-size: 0.95rem;
}

.dark-mode-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    transition: color 0.3s ease, opacity 0.2s ease;
    margin-left: 1rem;
}

.dark-mode-toggle:hover {
    opacity: 0.7;
}

.dark-mode-toggle:focus {
    outline: 2px solid var(--text-primary);
    outline-offset: 4px;
    border-radius: 4px;
}

.dark-mode-icon {
    width: 20px;
    height: 20px;
    stroke-width: 2;
}

.sun-icon {
    display: none;
}

/* Hero section */
.hero {
    padding: 4rem 0 6rem;
    background-color: var(--bg-primary);
    transition: background-color 0.3s ease;
}

.hero-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.hero-headline {
    font-size: 3.5rem;
    font-weight: 300;
    color: var(--text-primary);
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
    transition: color 0.3s ease;
}

.hero-subheadline {
    font-size: 1.5rem;
    color: var(--text-tertiary);
    font-weight: 300;
    margin-bottom: 2rem;
    transition: color 0.3s ease;
}

.hero-intro {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    max-width: 600px;
    margin: 0 auto;
    text-align: justify;
    transition: color 0.3s ease;
}

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

.section-alt {
    background-color: var(--bg-secondary);
    transition: background-color 0.3s ease;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 300;
    color: var(--text-primary);
    margin-bottom: 2rem;
    letter-spacing: -0.01em;
    transition: color 0.3s ease;
}

.section-text {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    max-width: 700px;
    text-align: justify;
    transition: color 0.3s ease;
}

/* Focus list */
.focus-list {
    list-style: none;
    max-width: 700px;
}

.focus-list li {
    font-size: 1.1rem;
    color: var(--text-secondary);
    padding: 0.75rem 0;
    padding-left: 1.5rem;
    position: relative;
    line-height: 1.7;
    transition: color 0.3s ease;
}

.focus-list li::before {
    content: '—';
    position: absolute;
    left: 0;
    color: #95a5a6;
}

/* People section */
.people-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 3rem;
    margin-top: 2rem;
}

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

.person-link {
    text-decoration: none;
    color: inherit;
    display: inline-block;
    transition: opacity 0.2s ease;
}

.person-link:hover {
    opacity: 0.8;
}

.person-link:focus {
    outline: 2px solid #2c3e50;
    outline-offset: 4px;
    border-radius: 4px;
}

.person-link .person-name {
    text-decoration: none;
}

.person-photo {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 1.5rem;
    display: block;
    border: 2px solid var(--border-color);
    transition: border-color 0.3s ease;
}

.person-name {
    font-size: 1.5rem;
    font-weight: 400;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    transition: color 0.3s ease;
}

.person-role {
    font-size: 1rem;
    color: var(--text-tertiary);
    margin-bottom: 1rem;
    font-weight: 500;
    transition: color 0.3s ease;
}

.person-description {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.7;
    transition: color 0.3s ease;
}

/* Contact section */
.contact-info {
    margin-top: 2rem;
    display: flex;
    gap: 2rem;
    justify-content: center;
    align-items: center;
}

.contact-icon-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    text-decoration: none;
    transition: color 0.2s ease, transform 0.2s ease;
}

.contact-icon-link:hover {
    color: var(--text-secondary);
    transform: translateY(-2px);
}

.contact-icon-link:focus {
    outline: 2px solid #2c3e50;
    outline-offset: 4px;
    border-radius: 4px;
}

.contact-icon {
    width: 32px;
    height: 32px;
    stroke-width: 2;
}

/* Footer */
.footer {
    padding: 3rem 0;
    background-color: var(--footer-bg);
    color: #ecf0f1;
    text-align: center;
    transition: background-color 0.3s ease;
}

.footer-text {
    font-size: 0.95rem;
    line-height: 1.8;
    color: var(--footer-text);
    transition: color 0.3s ease;
}

/* Responsive design */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
        padding: 0 1.5rem;
    }

    .logo {
        height: 2rem;
        width: 2rem;
    }

    .nav {
        justify-content: center;
    }

    .hero {
        padding: 3rem 0 4rem;
    }

    .hero-headline {
        font-size: 2.5rem;
    }

    .hero-subheadline {
        font-size: 1.25rem;
    }

    .hero-intro {
        font-size: 1rem;
    }

    .section {
        padding: 3rem 0;
    }

    .section-title {
        font-size: 2rem;
    }

    .container {
        padding: 0 1.5rem;
    }

    .people-grid {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }

    .person-photo {
        width: 120px;
        height: 120px;
    }

    .focus-list li {
        font-size: 1rem;
    }

    .section-text {
        font-size: 1rem;
    }

    .contact-info {
        gap: 1.5rem;
    }

    .contact-icon {
        width: 28px;
        height: 28px;
    }
}

@media (max-width: 480px) {
    .hero-headline {
        font-size: 2rem;
    }

    .hero-subheadline {
        font-size: 1.1rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .nav-link {
        font-size: 0.9rem;
    }
}