/* 全局变量与重置 */
:root {
    --primary-color: #0077be; /* 海洋蓝 */
    --secondary-color: #00a8cc; /* 浅海蓝 */
    --accent-color: #ff6b6b; /* 珊瑚红 */
    --text-dark: #1a1a1a;
    --text-light: #f0f0f0;
    --bg-white: #ffffff;
    --bg-dark: #0f172a; /* 深海黑蓝 */
    --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    padding: 1rem 5%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: white;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.logo span {
    color: var(--secondary-color);
}

.navbar nav a {
    margin-left: 2rem;
    font-weight: 500;
    color: white;
    text-shadow: 0 1px 2px rgba(0,0,0,0.2);
}

.navbar nav a:hover {
    color: var(--secondary-color);
}

.btn-dive {
    padding: 0.5rem 1.2rem;
    background: var(--secondary-color);
    color: white;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: 0 4px 10px rgba(0, 168, 204, 0.3);
}

.btn-dive:hover {
    background: #008cba;
    transform: translateY(-2px);
}

/* 英雄区域 */
.hero {
    height: 100vh;
    background: linear-gradient(to bottom, #006994, #001d3d);
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    color: white;
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, transparent 0%, rgba(0,0,0,0.4) 100%);
}

/* 气泡动画 */
.bubbles span {
    position: absolute;
    bottom: -50px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    animation: rise 10s infinite ease-in;
    z-index: 1;
}

.bubbles span:nth-child(1) { width: 40px; height: 40px; left: 10%; animation-duration: 8s; }
.bubbles span:nth-child(2) { width: 20px; height: 20px; left: 20%; animation-duration: 5s; animation-delay: 1s; }
.bubbles span:nth-child(3) { width: 50px; height: 50px; left: 35%; animation-duration: 10s; animation-delay: 2s; }
.bubbles span:nth-child(4) { width: 80px; height: 80px; left: 50%; animation-duration: 11s; animation-delay: 0s; }
.bubbles span:nth-child(5) { width: 35px; height: 35px; left: 55%; animation-duration: 6s; animation-delay: 1s; }

@keyframes rise {
    0% { bottom: -100px; transform: translateX(0); }
    50% { transform: translateX(100px); }
    100% { bottom: 1080px; transform: translateX(-200px); }
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 0 20px;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 3px;
    text-shadow: 0 4px 10px rgba(0,0,0,0.5);
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
    line-height: 1.8;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    margin-bottom: 3rem;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-item strong {
    font-size: 2rem;
    color: var(--secondary-color);
}

.stat-item span {
    font-size: 0.9rem;
    opacity: 0.8;
}

.btn-primary {
    display: inline-block;
    padding: 1rem 3rem;
    background: white;
    color: var(--primary-color);
    border-radius: 50px;
    font-weight: bold;
    font-size: 1.1rem;
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
}

.btn-primary:hover {
    background: var(--secondary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 15px 25px rgba(0,0,0,0.3);
}

.scroll-hint {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    font-size: 0.9rem;
    opacity: 0.8;
    z-index: 2;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {transform: translateX(-50%) translateY(0);}
    40% {transform: translateX(-50%) translateY(-10px);}
    60% {transform: translateX(-50%) translateY(-5px);}
}

/* 通用部分样式 */
.section-container {
    padding: 5rem 5%;
}

.bg-dark {
    background-color: var(--bg-dark);
    color: white;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2.2rem;
    margin-bottom: 0.5rem;
    color: inherit;
}

.section-header p {
    color: #666;
}

.bg-dark .section-header p {
    color: #aaa;
}

/* 海域分层时间轴 */
.zone-timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.zone-timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(to bottom, #0077be, #000);
    transform: translateX(-50%);
}

.zone-card {
    background: white;
    margin-bottom: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    position: relative;
    width: 45%;
    padding: 1.5rem;
}

.zone-card.sunlit {
    margin-left: 0;
    background: linear-gradient(135deg, #e0f7fa 0%, #ffffff 100%);
}

.zone-card.twilight {
    margin-left: 55%;
    background: linear-gradient(135deg, #cfd8dc 0%, #ffffff 100%);
}

.zone-card.midnight {
    margin-left: 0;
    background: linear-gradient(135deg, #263238 0%, #37474f 100%);
    color: white;
}

.zone-depth {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: var(--primary-color);
    color: white;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    white-space: nowrap;
}

.sunlit .zone-depth { right: -130px; }
.twilight .zone-depth { left: -130px; }
.midnight .zone-depth { right: -130px; background: #000; }

.zone-content h3 {
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.zone-content p {
    font-size: 0.9rem;
    margin-bottom: 1rem;
    opacity: 0.8;
}

.zone-species {
    display: flex;
    gap: 10px;
}

.zone-species img {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid white;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

/* 生物图鉴网格 */
.creature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.creature-card {
    background: #1e293b;
    border-radius: 12px;
    overflow: hidden;
    transition: transform 0.3s ease;
    border: 1px solid #334155;
}

.creature-card:hover {
    transform: translateY(-10px);
    border-color: var(--secondary-color);
}

.card-img {
    height: 200px;
    background-size: cover;
    background-position: center;
    position: relative;
}

.badge {
    position: absolute;
    top: 15px;
    right: 15px;
    padding: 0.3rem 0.8rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    color: white;
}

.badge.rare { background: #9b59b6; }
.badge.dangerous { background: #e74c3c; }
.badge.cute { background: #f1c40f; color: #333; }
.badge.giant { background: #3498db; }

.card-body {
    padding: 1.5rem;
}

.card-body h3 {
    font-size: 1.3rem;
    margin-bottom: 0.2rem;
    color: white;
}

.latin-name {
    font-style: italic;
    color: #94a3b8;
    font-size: 0.9rem;
    margin-bottom: 0.8rem;
}

.desc {
    color: #cbd5e1;
    font-size: 0.9rem;
    margin-bottom: 1rem;
    line-height: 1.5;
}

.specs {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: #64748b;
    border-top: 1px solid #334155;
    padding-top: 1rem;
}

/* 行动网格 */
.action-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
}

.action-item {
    text-align: center;
    padding: 2rem;
    background: #f8fafc;
    border-radius: 12px;
    transition: all 0.3s;
    border: 1px solid #e2e8f0;
}

.action-item:hover {
    background: white;
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
    border-color: var(--primary-color);
}

.action-item .icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.action-item h3 {
    margin-bottom: 0.8rem;
    color: var(--text-dark);
}

.action-item p {
    font-size: 0.9rem;
    color: #64748b;
}

/* 页脚 */
footer {
    background: #0f172a;
    color: white;
    padding: 4rem 5% 2rem;
    border-top: 1px solid #1e293b;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 2rem;
    margin-bottom: 3rem;
}

.footer-col h3 {
    color: var(--secondary-color);
    margin-bottom: 1rem;
}

.footer-col h4 {
    margin-bottom: 1rem;
    color: #e2e8f0;
}

.footer-col ul li {
    margin-bottom: 0.5rem;
}

.footer-col ul li a {
    color: #94a3b8;
    font-size: 0.9rem;
}

.footer-col ul li a:hover {
    color: white;
}

.newsletter-form {
    display: flex;
    gap: 0.5rem;
}

.newsletter-form input {
    padding: 0.5rem;
    border-radius: 4px;
    border: 1px solid #334155;
    background: #1e293b;
    color: white;
}

.newsletter-form button {
    padding: 0.5rem 1rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}

.copyright {
    text-align: center;
    border-top: 1px solid #1e293b;
    padding-top: 2rem;
    color: #64748b;
    font-size: 0.8rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero h1 { font-size: 2.5rem; }
    .hero-stats { flex-direction: column; gap: 1rem; }
    .navbar nav { display: none; }
    
    .zone-timeline::before { left: 20px; }
    .zone-card { width: 100%; margin-left: 0 !important; padding-left: 50px; }
    .zone-depth { left: 0 !important; right: auto !important; transform: translate(-50%, -50%); top: 20px; }
}