/* ======================= General Styles ======================= */
.about-header { padding: 3rem 0; position: relative; color: #ffffff; background-color: #343a40; background-image: linear-gradient(rgba(33, 37, 41, 0.7), rgba(33, 37, 41, 0.7)), url("https://a-lab.material.nagoya-u.ac.jp/wp-content/uploads/2025/05/back2.jpg"); background-size: cover; background-position: center; }
.about-header h1 { font-size: 1.5rem; }

.user-content-section .card-title { font-weight: 700; color: #0d6efd; font-size: 1rem; }
.user-content-section .card-body p { font-size: 0.85rem; line-height: 1.4; }

/* ======================= Hero Section ======================= */
.hero-container { display: flex; align-items: center; justify-content: center; gap: 0.75rem; text-align: left; }
.team-img { width: 90px; height: 90px; border-radius: 50%; object-fit: cover; border: 2px solid #fff; box-shadow: 0 0 5px rgba(0,0,0,0.1); flex-shrink: 0; }
.team-social { margin-top: 0.25rem; display: flex; flex-wrap: wrap; gap: 0.5rem; }
.team-social a { color: #ffffff !important; font-size: 1rem; text-decoration: none !important; opacity: 0.8; transition: all 0.2s ease-in-out; }
.team-social a:hover { opacity: 1; transform: translateY(-1px); }

/* ======================= Publications Sidebar ======================= */
.publication-item { padding: 0.4rem 0; border-bottom: 1px solid #e9ecef; }
.publication-item a { color: #212529; text-decoration: none; font-weight: 500; font-size: 0.85rem; }
.publication-item a:hover { color: #0d6efd; }
.publication-item .authors { font-style: italic; color: #6c757d; font-size: 0.7rem; }

/* ======================= Seminar Selection Cards ======================= */
.project-card { border: 1px solid #dee2e6; border-radius: 0.5rem; padding: 0.5rem 0.4rem; text-align: center; cursor: pointer; transition: all 0.2s ease-in-out; background-color: #fff; }
.project-card:not(.disabled):hover { transform: translateY(-1px); box-shadow: 0 0.125rem 0.25rem rgba(0,0,0,0.1); }
.project-card.active { border-color: #0d6efd; background-color: #e7f1ff; }
.project-card.disabled { cursor: not-allowed; background-color: #f8f9fa; opacity: 0.6; }
.project-card-icon { font-size: 1rem; color: #0d6efd; margin-bottom: 0.25rem; }
.project-card-title { font-weight: 600; color: #212529; font-size: 0.85rem; }
#project-details-container { padding-top: 0.5rem; margin-top: 0.5rem; border-top: 2px solid #0d6efd; }

/* ================== Main Seminar Accordion ================== */
.seminar-part-card {
    border: none;
    border-radius: 0.5rem !important;
    margin-bottom: 0.5rem;
    overflow: hidden;
    box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
    border: 1px solid #dee2e6;
}
.seminar-part-card .accordion-header .accordion-button {
    background-color: #f8f9fa;
    color: #212529;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    font-weight: 500;
    transition: background-color 0.3s ease;
}

/* ================== Interactive Exercise Cards (Part 2 & others) ================== */
.interactive-exercise-wrapper .card {
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
    border-width: 1px;
}
.interactive-exercise-wrapper .card:hover {
    transform: translateY(-1px);
    box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.1);
}
.interactive-exercise-wrapper .card.option-notebook {
    background-color: #f8f9fa;
    border-color: #dee2e6;
}
.interactive-exercise-wrapper .card-title {
    font-weight: 600;
    color: #0d6efd;
    font-size: 0.9rem;
}
.interactive-exercise-wrapper #credentials-display {
    padding: 0.4rem;
    margin-top: 0.4rem;
    margin-bottom: 0.4rem;
    font-size: 0.75rem;
}
.seminar-part-card .accordion-header .accordion-button:not(.collapsed) {
    background-color: #0d6efd;
    color: #ffffff;
    box-shadow: inset 0 -1px 0 rgba(0, 0, 0, 0.125);
}
.seminar-part-card .accordion-header .accordion-button:focus {
    box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
}
.seminar-part-card .accordion-button::after {
    width: 0.9rem;
    height: 0.9rem;
    background-size: 0.9rem;
}
.seminar-part-card .accordion-button:not(.collapsed)::after {
     background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='white'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708 .708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e");
     transform: rotate(-180deg);
}
.seminar-part-title { font-weight: 700; }
.seminar-part-subtitle { font-size: 0.7rem; font-weight: 400; color: #6c757d; }
.seminar-part-card .accordion-header .accordion-button:not(.collapsed) .seminar-part-subtitle { color: rgba(255, 255, 255, 0.8); }

/* ============ Inner Interactive Accordion (Part 1) ============ */
.nlp-topic-card.accordion-item { border: 1px solid #dee2e6; border-radius: 0.5rem !important; margin-bottom: 0.4rem; overflow: hidden; }
.nlp-topic-card .accordion-button { font-weight: bold; font-size: 0.9rem; background-color: #f8f9fa; }
.nlp-topic-card .accordion-button:not(.collapsed) { background-color: #0d6efd; color: white; }
.nlp-topic-card .accordion-button:not(.collapsed)::after { background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16' fill='white'%3e%3cpath fill-rule='evenodd' d='M1.646 4.646a.5.5 0 0 1 .708 0L8 10.293l5.646-5.647a.5.5 0 0 1 .708 .708l-6 6a.5.5 0 0 1-.708 0l-6-6a.5.5 0 0 1 0-.708z'/%3e%3c/svg%3e"); }
.nlp-topic-card .accordion-button:focus { box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25); }

.nlp-task-text { background-color: rgba(13, 110, 253, 0.1); border-left: 4px solid #0d6efd; padding: 0.4rem; font-size: 0.8rem; color: #0d6efd;}
.nlp-task-text1 { background-color: rgba(13, 110, 253, 0.1); border-left: 4px solid #f8f9fa; padding: 0.4rem; font-size: 0.8rem; color: #0d6efd;}
.challenge-box, .computer-attempt { 
    border: 1px solid #dee2e6;
    border-radius: 0.5rem; 
    padding: 0.6rem; 
    height: 100%; 
    background-color: #ffffff;
    box-shadow: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
}
.challenge-box h6, .computer-attempt h6 { font-weight: bold; color: #212529; font-size: 0.85rem; }
.challenge-quote { background-color: rgba(13, 110, 253, 0.1);font-style: normal; color: #0d6efd; border-left: 3px solid #0d6efd; padding-left: 0.4rem; font-size: 0.8rem; }
.challenge-quote1 { font-style: normal; color: #0d6efd; border-left: 3px solid #0d6efd; padding-left: 0.4rem; font-size: 0.8rem; }

.form-check-label.text-success, .form-check-label.text-danger, .sentiment-choices label.text-success, .sentiment-choices label.text-danger { font-weight: bold; font-size: 0.8rem; }
.computer-output-box { background-color: #212529; color: #f8f9fa; border: 1px solid #495057; padding: 0.3rem; border-radius: 0.25rem; font-family: 'Courier New', Courier, monospace; font-size: 0.7rem; line-height: 1.3; }
.computer-output-box.thinking { color: #adb5bd; font-style: italic; }

mark.entity-material { background-color: #0d6efd; color: white; padding: 0.1em 0.2em; border-radius: 0.25rem; font-size: 0.8rem; }
.pos-tag { padding: 0.1em 0.2em; border-radius: 0.25rem; color: white; font-size: 0.55rem; vertical-align: super; margin-left: 1px;}
.pos-adj { background-color: #198754; } .pos-noun { background-color: #0d6efd; } .pos-verb { background-color: #dc3545; } .pos-other { background-color: #6c757d; }
.sentiment-positive { background-color: #198754; color: white; padding: 0.1em 0.2em; border-radius: 0.25rem; font-weight: bold; font-size: 0.75rem; }
.sentiment-negative { background-color: #dc3545; color: white; padding: 0.1em 0.2em; border-radius: 0.25rem; font-weight: bold; font-size: 0.75rem; }

/* Styles for Relation Extraction Visualization */
.relation-graph { display: flex; align-items: center; justify-content: center; flex-wrap: wrap; gap: 0.25rem; padding: 0.4rem; background-color: #f8f9fa; border-radius: 0.375rem; }
.entity-node { padding: 0.25rem 0.5rem; border-radius: 50rem; color: white; font-weight: bold; box-shadow: 0 2px 4px rgba(0,0,0,0.1); font-size: 0.75rem; }
.entity-node.material { background-color: #0d6efd; }
.entity-node.property { background-color: #198754; }
.entity-node.value { background-color: #6c757d; }
.relation-arrow { display: flex; flex-direction: column; align-items: center; text-align: center; color: #6c757d; }
.relation-arrow span { font-size: 0.6rem; font-weight: bold; font-family: monospace; }
.relation-arrow i { font-size: 0.9rem; }
#re-with-nlp .relation-graph { opacity: 0; transform: scale(0.9); transition: all 0.5s ease-in-out; }
#re-with-nlp.show .relation-graph { opacity: 1; transform: scale(1); }

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
.fade-in-reveal { animation: fadeIn 0.8s ease-in-out; }

/* ======================= POS Challenge Layout ======================= */
.pos-challenge-row {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    margin-bottom: 0.25rem;
}
.pos-challenge-row > div {
    flex: 1;
    text-align: left;
}

/* ======================= Image and Section Styles ======================= */
#part1-intro { 
    padding: 0.4rem 0;
    background-color: #f8f9fa;
    border-radius: 0.5rem;
    margin-bottom: 0.4rem;
}
#part1-intro h2 { 
    color: #0d6efd; 
    font-weight: 700;
}
.nlp-intro-image {
    display: flex;
    justify-content: center;
    align-items: flex-start;
    margin-top: 0.75rem;
    animation: fadeIn 1.2s ease-in-out;
    gap: 0.75rem;
    flex-wrap: wrap;
}
.nlp-intro-image .intro-figure {
    margin: 0;
    max-width: 45%;
    display: flex;
    flex-direction: column;
}
.nlp-intro-image .intro-figure img {
    width: 100%;
    height: auto;
    border-radius: 0.5rem;
    box-shadow: 0 0.5rem 1rem rgba(0,0,0,0.1);
}
.nlp-intro-image .intro-figure figcaption {
    margin-top: 0.3rem;
    font-size: 0.8rem;
    color: #6c757d;
    font-style: normal;
    line-height: 1.2;
}
.nlp-ner-image {
    display: flex;
    justify-content: center;
    margin-top: 0.75rem;
    animation: fadeIn 1.2s ease-in-out;
}
.nlp-ner-image img {
    max-width: 65%;
    height: auto;
    border-radius: 0.5rem;
    box-shadow: 0 0.5rem 1rem rgba(0,0,0,0.1);
}

/* ======================= Responsive Styles ======================= */
@media (max-width: 767px) { 
    .hero-container { 
        flex-direction: column; 
        text-align: center; 
        gap: 0.5rem; 
    } 
    .team-social { 
        justify-content: center; 
    } 
    .nlp-intro-image {
        flex-direction: column;
        align-items: center;
        gap: 0.5rem;
    }
    .nlp-intro-image img {
        max-width: 90%;
    }
}