/* ===================================================
   Chelsea Blue Academic Theme
   Primary: #034694
   =================================================== */

/* --- Reset / Base --- */
body {
    padding-top: 70px;
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 15px;
    color: #212529;
    background-color: #ffffff;
}

a {
    color: #034694;
}

a:hover, a:focus {
    color: #0258b8;
    text-decoration: underline;
}

/* --- Navbar --- */
.navbar-chelsea {
    background-color: #034694;
    border: none;
    border-radius: 0;
    margin-bottom: 0;
}

.navbar-chelsea .navbar-brand {
    color: #ffffff;
    font-weight: 600;
    font-size: 18px;
    padding: 15px 15px;
}

.navbar-chelsea .navbar-brand:hover {
    color: #cce0ff;
    text-decoration: none;
}

.navbar-chelsea .nav > li > a {
    color: #e0ecff;
    font-size: 14px;
    padding: 22px 15px;
}

.navbar-chelsea .nav > li > a:hover,
.navbar-chelsea .nav > li > a:focus {
    color: #ffffff;
    background-color: #023070;
    text-decoration: none;
}

.navbar-chelsea .nav > li.active > a,
.navbar-chelsea .nav > li.active > a:hover {
    color: #ffffff;
    background-color: #023070;
}

.navbar-chelsea .navbar-toggle {
    border-color: #ffffff;
}

.navbar-chelsea .navbar-toggle .icon-bar {
    background-color: #ffffff;
}

.navbar-chelsea .navbar-toggle:hover,
.navbar-chelsea .navbar-toggle:focus {
    background-color: #023070;
}

/* --- Page sections --- */
.page-section {
    padding: 40px 0 20px;
}

/* --- Hero (index page two-col layout) --- */
.hero-section {
    padding: 40px 0 30px;
    border-bottom: 1px solid #dee2e6;
    margin-bottom: 30px;
}

.hero-photo img {
    width: 100%;
    max-width: 220px;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.hero-info h1 {
    margin-top: 0;
    font-size: 28px;
    font-weight: 700;
    color: #212529;
}

.hero-info .title-line {
    font-size: 16px;
    color: #6c757d;
    margin-bottom: 16px;
}

.hero-info .contact-list {
    list-style: none;
    padding: 0;
    margin: 16px 0;
}

.hero-info .contact-list li {
    margin-bottom: 6px;
    color: #444;
}

.hero-info .contact-list a {
    color: #034694;
}

/* --- Research direction cards --- */
.research-cards {
    margin-top: 30px;
}

.research-card {
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    padding: 20px;
    margin-bottom: 20px;
    height: 100%;
}

.research-card h4 {
    color: #034694;
    font-size: 16px;
    font-weight: 600;
    margin-top: 0;
    margin-bottom: 10px;
}

.research-card p {
    color: #444;
    font-size: 14px;
    margin: 0;
}

/* --- Quick-link cards (Research / Teaching) --- */
.quick-card {
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    padding: 20px;
    margin-bottom: 20px;
}

.quick-card h4 {
    margin-top: 0;
    color: #212529;
}

.quick-card .btn-chelsea {
    background-color: #034694;
    color: #ffffff;
    border: none;
    border-radius: 4px;
    padding: 6px 18px;
    font-size: 14px;
    text-decoration: none;
    display: inline-block;
}

.quick-card .btn-chelsea:hover {
    background-color: #023070;
    color: #ffffff;
    text-decoration: none;
}

/* --- Section headings --- */
.section-heading {
    font-size: 24px;
    font-weight: 700;
    color: #212529;
    border-bottom: 2px solid #034694;
    padding-bottom: 8px;
    margin-bottom: 24px;
}

/* --- Research area intro (rendered from .md file) --- */
.area-intro {
    font-size: 15px;
    color: #444;
    margin-bottom: 20px;
    line-height: 1.7;
}

/* --- Publication entries --- */
.publication-entry {
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    margin-bottom: 16px;
    overflow: hidden;
}

.publication-header {
    padding: 18px 20px;
}

.publication-header h4 {
    margin: 0 0 6px;
    font-size: 16px;
    font-weight: 600;
    color: #212529;
}

.publication-header .pub-authors {
    font-size: 14px;
    color: #555;
    margin-bottom: 4px;
}

.publication-header .pub-venue {
    font-size: 13px;
    color: #6c757d;
    font-style: italic;
    margin-bottom: 10px;
}

.pub-notation {
    font-size: 12px;
    color: #888;
    margin-bottom: 10px;
}

.pub-year-badge {
    display: inline-block;
    background-color: #034694;
    color: #ffffff;
    font-size: 12px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 3px;
    margin-right: 8px;
    vertical-align: middle;
}

.pub-links a {
    font-size: 13px;
    color: #034694;
    margin-right: 12px;
    text-decoration: none;
    font-weight: 500;
}

.pub-links a:hover {
    color: #0258b8;
    text-decoration: underline;
}

.pub-abstract {
    border-top: 1px solid #dee2e6;
    padding: 14px 20px;
    background: #ffffff;
    font-size: 14px;
    color: #444;
    display: none;
}

.pub-abstract.show {
    display: block;
}

/* --- Teaching two-column grid --- */
.teaching-grid > [class*="col-"] {
    display: flex;
    flex-direction: column;
    margin-bottom: 0;
}

.teaching-grid .teaching-entry {
    flex: 1;
}

/* --- Teaching entries --- */
.teaching-entry {
    background: #f8f9fa;
    border: 1px solid #dee2e6;
    border-radius: 6px;
    margin-bottom: 14px;
    overflow: hidden;
}

.teaching-header {
    padding: 18px 22px;
}

.teaching-header h4 {
    margin: 0 0 6px;
    font-size: 18px;
    line-height: 1.4;
}

.teaching-header h4 a {
    color: #034694;
    text-decoration: none;
    font-weight: 600;
}

.teaching-header h4 a:hover {
    color: #0258b8;
    text-decoration: underline;
}

.course-num-inline {
    font-size: 13px;
    color: #6c757d;
    font-weight: normal;
    margin-left: 8px;
    vertical-align: middle;
}

.teaching-header .semester-badge {
    display: inline-block;
    background-color: #034694;
    color: #ffffff;
    font-size: 12px;
    padding: 2px 9px;
    border-radius: 3px;
    margin-bottom: 8px;
}

.teaching-toggle {
    font-size: 14px;
    color: #034694;
    cursor: pointer;
    font-weight: 500;
    background: none;
    border: none;
    padding: 0;
    text-decoration: none;
}

.teaching-toggle:hover {
    color: #0258b8;
    text-decoration: underline;
}

.teaching-intro {
    border-top: 1px solid #dee2e6;
    padding: 14px 22px;
    background: #ffffff;
    font-size: 15px;
    color: #444;
    display: none;
    line-height: 1.7;
}

.teaching-intro.show {
    display: block;
}

/* --- About page --- */
.about-photo img {
    width: 100%;
    max-width: 200px;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.12);
}

.about-content h2 {
    font-size: 20px;
    font-weight: 700;
    color: #034694;
    border-bottom: 1px solid #dee2e6;
    padding-bottom: 6px;
    margin-top: 32px;
    margin-bottom: 12px;
}

.about-content h3 {
    font-size: 16px;
    font-weight: 700;
    color: #212529;
    margin-top: 24px;
    margin-bottom: 8px;
}

.about-content h4 {
    font-size: 14px;
    font-weight: 600;
    color: #444;
    margin-top: 18px;
    margin-bottom: 6px;
}

.about-content ul {
    padding-left: 20px;
}

.about-content p, .about-content li {
    font-size: 15px;
    color: #333;
    line-height: 1.7;
}

/* --- Footer --- */
.site-footer {
    background-color: #f8f9fa;
    border-top: 1px solid #dee2e6;
    padding: 20px 0;
    margin-top: 50px;
    color: #6c757d;
    font-size: 13px;
    text-align: center;
}

.site-footer a {
    color: #6c757d;
}

.site-footer img {
    vertical-align: middle;
    opacity: 0.7;
}

/* --- 404 page --- */
.not-found-section {
    padding: 80px 0;
    text-align: center;
}

.not-found-section h1 {
    font-size: 80px;
    color: #034694;
    font-weight: 700;
    margin-bottom: 0;
}

.not-found-section h2 {
    font-size: 28px;
    color: #444;
    margin-top: 10px;
}

/* --- Utility --- */
.divider {
    border: none;
    border-top: 2px solid #dee2e6;
    margin: 24px 0;
}

@media (max-width: 767px) {
    .hero-photo {
        text-align: center;
        margin-bottom: 20px;
    }

    .hero-photo img {
        max-width: 160px;
    }
}