/* ===== CSS Variables: 蓝色学术配色 ===== */
:root {
    --color-deep-blue: #003366;
    --color-brand-blue: #0066CC;
    --color-light-blue: #E8F4FD;
    --color-accent-gold: #C49B2A;
    --color-white: #FFFFFF;
    --color-bg: #F5F8FC;
    --color-text: #333333;
    --color-text-light: #666666;
    --color-border: #D0DCE8;
    --font-primary: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --shadow: 0 2px 12px rgba(0, 51, 102, 0.10);
    --shadow-hover: 0 8px 28px rgba(0, 51, 102, 0.18);
    --radius: 12px;
    --transition: 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    color: var(--color-brand-blue);
    text-decoration: none;
    transition: color var(--transition);
}
a:hover {
    color: var(--color-deep-blue);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header/Nav ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--color-deep-blue);
    font-weight: 700;
    font-size: 1.25rem;
}
.logo:hover {
    color: var(--color-deep-blue);
}
.logo-icon {
    font-size: 1.6rem;
}

.nav {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 8px 18px;
    border-radius: 6px;
    color: var(--color-text);
    font-size: 0.95rem;
    font-weight: 500;
    transition: background var(--transition), color var(--transition);
}
.nav-link:hover,
.nav-link.active {
    background: var(--color-light-blue);
    color: var(--color-brand-blue);
}

/* ===== Hero ===== */
.hero {
    position: relative;
    height: 420px;
    margin-top: 70px;
    background: linear-gradient(135deg, var(--color-deep-blue) 0%, var(--color-brand-blue) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: url('data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iNDAiIGhlaWdodD0iNDAiIHZpZXdCb3g9IjAgMCA0MCA0MCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj48Y2lyY2xlIGN4PSIyMCIgY3k9IjIwIiByPSIxLjUiIGZpbGw9InJnYmEoMjU1LDI1NSwyNTUsMC4wNSkiLz48L3N2Zz4=') repeat;
    opacity: 0.5;
}

.hero-content {
    position: relative;
    text-align: center;
    z-index: 1;
}

.hero-title {
    font-size: 2.8rem;
    font-weight: 800;
    color: var(--color-white);
    letter-spacing: 6px;
    margin-bottom: 16px;
    text-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.hero-subtitle {
    font-size: 1.15rem;
    color: rgba(255,255,255,0.85);
    letter-spacing: 3px;
    font-weight: 300;
}

/* ===== Section common ===== */
.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-deep-blue);
    position: relative;
    display: inline-block;
    padding-bottom: 14px;
}
.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--color-accent-gold);
    border-radius: 2px;
}

.section-desc {
    color: var(--color-text-light);
    margin-top: 12px;
    font-size: 1rem;
}

/* ===== Species / About Section ===== */
.species,
.about {
    padding: 80px 0;
    scroll-margin-top: 80px;
}

#footer {
    scroll-margin-top: 80px;
}

/* ===== Species Grid ===== */
.species-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
    gap: 28px;
}

/* ===== Filter Bar ===== */
.filter-bar {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-bottom: 36px;
}

.filter-btn {
    padding: 8px 22px;
    border: 2px solid var(--color-brand-blue);
    background: var(--color-white);
    color: var(--color-brand-blue);
    border-radius: 24px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition), color var(--transition), transform var(--transition);
    font-family: var(--font-primary);
}

.filter-btn:hover {
    background: var(--color-light-blue);
    transform: translateY(-1px);
}

.filter-btn.active {
    background: var(--color-brand-blue);
    color: var(--color-white);
}

/* ===== Card ===== */
.species-card {
    background: var(--color-white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    cursor: pointer;
    transition: transform var(--transition), box-shadow var(--transition);
}
.species-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-hover);
}

.card-img-wrap {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--color-light-blue);
}
.card-img-wrap img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition);
}
.species-card:hover .card-img-wrap img {
    transform: scale(1.08);
}

.card-body {
    padding: 18px 20px 22px;
}

.card-name {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--color-deep-blue);
    margin-bottom: 4px;
}

.card-desc {
    font-size: 0.9rem;
    color: var(--color-text-light);
    line-height: 1.5;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ===== About section ===== */
.about {
    background: var(--color-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 48px;
    align-items: center;
}

.about-text p {
    margin-bottom: 14px;
    color: var(--color-text-light);
    line-height: 1.8;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.stat-item {
    text-align: center;
    background: var(--color-light-blue);
    border-radius: var(--radius);
    padding: 28px 12px;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    color: var(--color-brand-blue);
}

.stat-label {
    display: block;
    margin-top: 6px;
    font-size: 0.85rem;
    color: var(--color-text-light);
}

/* ===== Footer ===== */
.footer {
    background: var(--color-deep-blue);
    color: rgba(255,255,255,0.8);
    padding: 56px 0 0;
}

.footer-inner {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    padding-bottom: 40px;
}

.footer-col h4 {
    color: var(--color-white);
    font-size: 1.05rem;
    margin-bottom: 14px;
    position: relative;
    padding-bottom: 8px;
}
.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 36px;
    height: 2px;
    background: var(--color-accent-gold);
}

.footer-col p {
    font-size: 0.9rem;
    margin-bottom: 6px;
    line-height: 1.7;
}

.footer-col a {
    color: rgba(255,255,255,0.7);
}
.footer-col a:hover {
    color: var(--color-white);
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 18px 0;
    text-align: center;
    font-size: 0.85rem;
}

/* ===== Modal ===== */
.modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 2000;
    justify-content: center;
    align-items: center;
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background: var(--color-white);
    border-radius: var(--radius);
    max-width: 720px;
    width: 90%;
    max-height: 85vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    animation: modalIn 0.3s ease;
}

@keyframes modalIn {
    from {
        opacity: 0;
        transform: scale(0.92) translateY(20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.modal-close {
    position: absolute;
    top: 12px;
    right: 16px;
    width: 36px;
    height: 36px;
    border: none;
    background: var(--color-light-blue);
    border-radius: 50%;
    font-size: 1.4rem;
    color: var(--color-text);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition);
    z-index: 10;
}
.modal-close:hover {
    background: var(--color-border);
}

.modal-body {
    padding: 0;
}

.modal-img {
    width: 100%;
    max-height: 400px;
    object-fit: cover;
    border-radius: var(--radius) var(--radius) 0 0;
}

.modal-info {
    padding: 28px 32px 32px;
}

.modal-info h2 {
    font-size: 1.5rem;
    color: var(--color-deep-blue);
    margin-bottom: 4px;
}

.modal-info .detail-row {
    display: flex;
    margin-bottom: 10px;
    font-size: 0.95rem;
}

.modal-info .detail-label {
    width: 80px;
    flex-shrink: 0;
    color: var(--color-text-light);
    font-weight: 500;
}

.modal-info .detail-value {
    color: var(--color-text);
    flex: 1;
}

.modal-info .detail-desc {
    margin-top: 14px;
    padding-top: 14px;
    border-top: 1px solid var(--color-border);
    line-height: 1.8;
    color: var(--color-text-light);
}

/* ===== Scrollbar ===== */
.modal-content::-webkit-scrollbar {
    width: 6px;
}
.modal-content::-webkit-scrollbar-track {
    background: transparent;
}
.modal-content::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 3px;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
    .hero-title {
        font-size: 2rem;
    }
    .hero {
        height: 320px;
    }
    .about-content {
        grid-template-columns: 1fr;
    }
    .footer-inner {
        grid-template-columns: 1fr;
        gap: 28px;
    }
}

@media (max-width: 600px) {
    .header-inner {
        flex-direction: column;
        height: auto;
        padding: 12px 0;
        gap: 8px;
    }
    .hero {
        margin-top: 110px;
        height: 260px;
    }
    .hero-title {
        font-size: 1.5rem;
    }
    .hero-subtitle {
        font-size: 0.9rem;
    }
    .species-grid {
        grid-template-columns: 1fr;
    }
    .about-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 12px;
    }
    .stat-number {
        font-size: 1.4rem;
    }
    .modal-info {
        padding: 20px;
    }
}