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

html, body {
    height: 100%;
    display: flex;
    flex-direction: column;
}

body {
    font-family: system-ui, -apple-system, 'PingFang TC', 'Microsoft JhengHei', 'Noto Sans TC', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* ===== Language Toggle ===== */
.en { display: none; }
html[lang="en"] .en { display: inline; }
html[lang="en"] .zh { display: none; }

.language-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1001;
    background: #27ae60;
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    cursor: pointer;
    font-weight: 500;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(39,174,96,0.3);
}

.language-toggle:hover {
    background: #219150;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(39,174,96,0.4);
}

/* ===== Layout ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ===== Header ===== */
header {
    background:
        linear-gradient(135deg, rgba(20, 83, 45, 0.85) 0%, rgba(26, 119, 69, 0.85) 100%),
        url('https://images.unsplash.com/photo-1526374965328-7f61d4dc18c5?ixlib=rb-4.0.3&auto=format&fit=crop&w=1920&q=80') center/cover;
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    position: relative;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.header-text {
    text-align: center;
}

.header-text h1 {
    font-size: 2.5rem;
    font-weight: 400;
    margin-bottom: 0.3rem;
}

.header-text .subheadline {
    font-size: 1.5rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    color: hsl(210, 100%, 93%);
    text-shadow: 0 0 2px rgba(255, 255, 255, 0.15);
}

.profile-photo {
    width: 180px;
    height: 180px;
    object-fit: cover;
    border-radius: 50%;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
    margin: 1rem 1rem 0.5rem 1rem;
    display: block;
}

/* ===== Navigation ===== */
nav {
    background: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-container {
    display: flex;
    justify-content: center;
    flex-wrap: nowrap;
    overflow-x: auto;
}

.nav-item {
    background: none;
    border: none;
    padding: 0.5rem 0.7rem;
    font-size: 0.95rem;
    color: #2c3e50;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    white-space: nowrap;
    text-decoration: none;
}

.nav-item:hover, .nav-item.active {
    background: #27ae60;
    color: white;
}

.nav-toggle {
    display: none;
}

/* ===== Main Content ===== */
main {
    flex: 1 0 auto;
    padding-bottom: 80px;
}

.section {
    display: none;
    background: white;
    border-radius: 10px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.section.active {
    display: block;
}

.section h2 {
    color: #2c3e50;
    font-size: 1.75rem;
    font-weight: 500;
    margin-bottom: 1.5rem;
    border-bottom: 3px solid #27ae60;
    padding-bottom: 0.5rem;
}

.section h3 {
    color: #2c3e50;
    font-size: 1.25rem;
    font-weight: 500;
    margin: 1.5rem 0 1rem 0;
    border-left: 4px solid #27ae60;
    padding-left: 1rem;
}

/* ===== Stats Grid ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    background: linear-gradient(135deg, #27ae60 0%, #219150 100%);
    color: white;
    padding: 2rem;
    border-radius: 10px;
    text-align: center;
    border: none;
    box-shadow: 0 4px 8px rgba(39,174,96,0.3);
    outline: none;
    cursor: pointer;
}

.stat-card:focus {
    box-shadow: 0 0 0 3px #27ae60;
}

.stat-card:hover {
    background: linear-gradient(135deg, #1e8449 0%, #186a3b 100%);
}

.stat-number {
    font-size: 1.7rem;
    font-weight: 500;
    display: block;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
    margin-top: 0.5rem;
}

/* ===== Honors ===== */
.honors-highlight {
    color: #2980b9;
}

.honors-list {
    list-style: none;
    padding: 0;
}

.honors-list li {
    margin-bottom: 1rem;
    padding-left: 1rem;
    border-left: 4px solid #27ae60;
}

.honors-image {
    display: block;
    margin: 0 auto;
    width: 900px;
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.honors-caption {
    text-align: center;
    margin-top: 8px;
    font-size: 0.95em;
    color: #555;
}

.honors-paragraph {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 2rem;
    color: #555;
}

figure {
    margin: 2rem 0;
}

/* ===== Footer ===== */
.site-footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background-color: white;
    color: #333;
    padding: 0.3rem 0;
    font-size: 0.8rem;
    text-align: center;
    box-shadow: 0 -2px 6px rgba(0,0,0,0.1);
    border-top: 1px solid #ddd;
    z-index: 1000;
}

.footer-content {
    display: flex;
    justify-content: space-evenly;
    align-items: center;
    gap: 0.3rem;
    flex-wrap: wrap;
    padding: 0.3rem 1rem;
    overflow: visible;
    position: relative;
}

.footer-logo {
    height: 32px;
    max-width: 128px;
    object-fit: contain;
    transition: transform 0.3s ease, opacity 0.3s ease;
    filter: brightness(1.1);
}

.footer-logo:hover {
    transform: scale(2);
    filter: brightness(1.2);
    opacity: 0.85;
    position: relative;
    z-index: 10;
}

/* ===== Lab Page Header ===== */
body.lab-page .header-text h1 {
    font-size: 2rem;
    letter-spacing: -0.02em;
}

/* ===== Animation ===== */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===== Responsive: Mobile ===== */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }

    .header-text h1 {
        font-size: 1.7rem;
        line-height: 1.4;
        margin-bottom: 0.3rem;
    }

    .header-text .subheadline {
        font-size: 1.1rem;
        line-height: 1.4;
    }

    .header-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 0.5rem;
    }

    .profile-photo {
        width: 140px;
        height: 140px;
        margin: 0.5rem;
    }

    .language-toggle {
        top: 10px;
        right: 10px;
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }

    .nav-toggle {
        display: block;
        padding: 1rem;
        font-size: 1.5rem;
        background: none;
        border: none;
        color: #2c3e50;
        cursor: pointer;
    }

    .nav-container {
        display: none;
        flex-direction: column;
        align-items: flex-start;
        padding: 1rem;
    }

    .nav-container.show {
        display: flex;
    }

    .nav-item {
        width: 100%;
        text-align: left;
        padding: 0.8rem 1rem;
    }

    .section {
        padding: 1.5rem;
    }

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

    .site-footer {
        position: static;
        box-shadow: none;
        border-top: 1px solid #ccc;
    }

    main {
        padding-bottom: 2rem;
    }
}

/* ===== Responsive: Tablet ===== */
@media (max-width: 1024px) and (min-width: 769px) {
    .nav-item {
        padding: 0.5rem 0.6rem;
        font-size: 0.9rem;
    }
}