/* === Base Reset & Typography === */
*,
*::before,
*::after {
    box-sizing: border-box;
}

:root {
    --navy: #1B2A4A;
    --navy-light: #243656;
    --accent: #2E5090;
    --accent-hover: #3A65B0;
    --text-primary: #2D3748;
    --text-secondary: #4A5568;
    --text-light: #718096;
    --bg-page: #F7F8FA;
    --bg-card: #FFFFFF;
    --bg-subtle: #F1F3F7;
    --border: #E2E8F0;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 4px 12px rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.07), 0 10px 24px rgba(0, 0, 0, 0.06);
    --radius: 6px;
    --max-width: 900px;
}

body {
    font-family: 'Source Sans 3', 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.75;
    color: var(--text-primary);
    margin: 0;
    padding: 0;
    background-color: var(--bg-page);
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
    font-family: 'Crimson Text', Georgia, 'Times New Roman', serif;
    font-weight: 600;
    line-height: 1.3;
    color: var(--navy);
}

a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--accent-hover);
}

/* === Header === */
header {
    background: var(--navy);
    color: #fff;
    padding: 0;
    text-align: center;
    border-bottom: 3px solid var(--accent);
}

.header-content {
    padding: 2rem 1.5rem 0.75rem;
    max-width: var(--max-width);
    margin: 0 auto;
}

header h1 {
    font-family: 'Crimson Text', Georgia, 'Times New Roman', serif;
    font-size: 2rem;
    font-weight: 700;
    color: #fff;
    margin: 0 0 0.15rem;
    letter-spacing: 0.5px;
}

header .subtitle {
    font-family: 'Source Sans 3', 'Segoe UI', sans-serif;
    font-size: 0.95rem;
    font-weight: 400;
    color: rgba(255, 255, 255, 0.7);
    margin: 0;
    letter-spacing: 0.3px;
}

/* === Navigation === */
nav {
    background: var(--navy-light);
    margin-top: 0.75rem;
}

nav ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    justify-content: center;
    max-width: var(--max-width);
    margin: 0 auto;
}

nav ul li {
    position: relative;
}

nav ul li a {
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    font-family: 'Source Sans 3', 'Segoe UI', sans-serif;
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.75rem 1.25rem;
    display: block;
    transition: color 0.2s ease, background-color 0.2s ease;
    letter-spacing: 0.3px;
    text-transform: uppercase;
}

nav ul li a:hover,
nav ul li a:focus {
    color: #fff;
    background-color: rgba(255, 255, 255, 0.08);
}

nav ul li a:visited {
    color: rgba(255, 255, 255, 0.85);
}

nav ul li a:visited:hover {
    color: #fff;
}

nav ul li a.active {
    color: #fff;
    border-bottom: 2px solid var(--accent);
}

/* Dropdown */
nav ul li ul {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--navy-light);
    padding: 0.25rem 0;
    list-style: none;
    min-width: 220px;
    box-shadow: var(--shadow-lg);
    border-radius: 0 0 var(--radius) var(--radius);
    z-index: 100;
}

nav ul li:hover ul {
    display: block;
}

nav ul li ul li {
    display: block;
    margin: 0;
}

nav ul li ul li a {
    color: rgba(255, 255, 255, 0.85);
    padding: 0.6rem 1.25rem;
    display: block;
    text-decoration: none;
    font-size: 0.85rem;
    text-transform: none;
    border-bottom: none;
}

nav ul li ul li a:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: #fff;
}

/* === Main Content === */
.container {
    width: 90%;
    max-width: var(--max-width);
    margin: 2.5rem auto;
    background-color: var(--bg-card);
    padding: 2.5rem 3rem;
    box-shadow: var(--shadow);
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.container h2 {
    font-size: 1.65rem;
    margin-top: 0;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--bg-subtle);
}

.container h3 {
    font-size: 1.25rem;
    margin-top: 1.75rem;
    margin-bottom: 0.75rem;
    color: var(--accent);
}

.container p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

/* === Home Page Profile === */
.profile-section {
    display: flex;
    gap: 2rem;
    align-items: flex-start;
    margin-bottom: 1.5rem;
}

.portrait {
    width: 180px;
    height: auto;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    flex-shrink: 0;
    border: 3px solid var(--bg-subtle);
}

.profile-text {
    flex: 1;
}

.profile-text h2 {
    margin-top: 0;
}

/* === Research Page === */
.research-area {
    padding: 1.25rem 1.5rem;
    margin-bottom: 1rem;
    background: var(--bg-subtle);
    border-radius: var(--radius);
    border-left: 3px solid var(--accent);
}

.research-area h3 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.research-area p {
    margin-bottom: 0;
    font-size: 0.95rem;
}

/* === Contact Page === */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.contact-item {
    padding: 1.25rem 1.5rem;
    background: var(--bg-subtle);
    border-radius: var(--radius);
}

.contact-item h3 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--accent);
}

.contact-item p {
    margin: 0;
    color: var(--text-secondary);
}

.contact-item a {
    color: var(--accent);
    font-weight: 500;
}

/* === Teaching & Applet === */
.course-list {
    list-style: none;
    padding: 0;
}

.course-list li {
    padding: 0.75rem 1rem;
    margin-bottom: 0.5rem;
    background: var(--bg-subtle);
    border-radius: var(--radius);
    border-left: 3px solid var(--accent);
}

.course-list li a {
    font-weight: 500;
}

.applet {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: var(--bg-subtle);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    text-align: center;
}

.applet h3 {
    margin-top: 0;
}

.applet iframe {
    width: 100%;
    height: 600px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: #fff;
}

.applet-full iframe {
    height: 2400px;
}

/* === Publications === */
.bibbase-readmore {
    color: var(--accent);
    cursor: pointer;
    font-weight: 500;
}

.bibbase-entry {
    margin: 0.75em 0;
    padding: 1em 1.25em;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-subtle);
}

.bibbase-author {
    font-weight: 600;
}

.bibbase-title {
    font-style: italic;
}

.bibbase-journal,
.bibbase-year {
    font-style: italic;
    color: var(--text-light);
    font-size: 0.9em;
}

/* === Footer === */
footer {
    background: var(--navy);
    color: rgba(255, 255, 255, 0.6);
    text-align: center;
    padding: 1.25rem 1rem;
    margin-top: 1rem;
    font-size: 0.85rem;
    border-top: 3px solid var(--accent);
}

footer p {
    margin: 0;
}

/* === Responsive === */
@media (max-width: 768px) {
    .container {
        width: 95%;
        padding: 1.5rem;
    }

    header h1 {
        font-size: 1.5rem;
    }

    nav ul {
        flex-wrap: wrap;
    }

    nav ul li a {
        padding: 0.6rem 0.75rem;
        font-size: 0.8rem;
    }

    .profile-section {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .portrait {
        width: 150px;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }
}