/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* 头部样式 */
header {
    text-align: center;
    margin-bottom: 30px;
    color: white;
    animation: fadeInDown 1s ease-in;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 导航菜单样式 */
.system-nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 30px;
    animation: fadeInUp 1s ease-in 0.3s both;
}

.nav-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 15px 20px;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    min-width: 100px;
}

.nav-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.2);
    background: white;
}

.nav-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    transform: scale(1.05);
}

.nav-btn .icon {
    font-size: 2rem;
    margin-bottom: 8px;
}

.nav-btn span {
    font-size: 0.9rem;
    font-weight: 500;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 主内容区域 */
.main-content {
    animation: fadeIn 1s ease-in 0.6s both;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* 系统展示容器 */
.system-container {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

.system-display {
    padding: 30px;
}

.system-display h2 {
    text-align: center;
    color: #667eea;
    margin-bottom: 20px;
    font-size: 2rem;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.1);
}

/* 动画包装器 */
.animation-wrapper {
    background: linear-gradient(to bottom, #f8f9fa, #e9ecef);
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 30px;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 350px;
}

.system-svg {
    max-width: 100%;
    height: auto;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
}

/* 系统信息区域 */
.system-info {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.system-info h3 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.5rem;
}

.system-info p {
    margin-bottom: 15px;
    font-size: 1.1rem;
    color: #495057;
}

.system-info ul {
    list-style: none;
    padding: 0;
}

.system-info li {
    padding: 10px 0;
    padding-left: 30px;
    position: relative;
    border-bottom: 1px solid #dee2e6;
}

.system-info li:last-child {
    border-bottom: none;
}

.system-info li:before {
    content: "▸";
    position: absolute;
    left: 10px;
    color: #667eea;
    font-size: 1.2rem;
}

.system-info strong {
    color: #667eea;
    font-weight: 600;
}

/* SVG动画效果 */

/* 循环系统 */
.heart-group {
    animation: heartbeat 1.5s ease-in-out infinite;
    transform-origin: center;
}

@keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.blood-dot {
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.3));
}

.artery {
    stroke-dasharray: 200;
    animation: pulse-flow 2s ease-in-out infinite;
}

@keyframes pulse-flow {
    0%, 100% { stroke-width: 8; }
    50% { stroke-width: 10; }
}

/* 呼吸系统 */
.lung-outer {
    animation: breathe 4s ease-in-out infinite;
    transform-origin: bottom;
}

.lung-inner {
    animation: breathe 4s ease-in-out infinite;
    transform-origin: bottom;
}

.diaphragm {
    animation: diaphragm-move 4s ease-in-out infinite;
}

@keyframes breathe {
    0%, 100% {
        transform: scaleX(1);
    }
    50% {
        transform: scaleX(1.1);
    }
}

@keyframes diaphragm-move {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-15px);
    }
}

.oxygen {
    animation: oxygen-move 2s ease-in-out infinite;
}

@keyframes oxygen-move {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(30px);
    }
}

.airflow line {
    animation: airflow-move 2s ease-in-out infinite;
}

@keyframes airflow-move {
    0%, 100% {
        transform: translateY(0);
        opacity: 1;
    }
    50% {
        transform: translateY(10px);
        opacity: 0.5;
    }
}

/* 消化系统 */
.food-particle {
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.digestion-fluid {
    animation: fluid-pulse 1.5s ease-in-out infinite;
}

@keyframes fluid-pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 0.7;
    }
    50% {
        transform: scale(1.3);
        opacity: 0.4;
    }
}

/* 神经系统 */
.nerve-signal {
    filter: drop-shadow(0 0 8px #f1c40f);
    animation: signal-pulse 0.5s ease-in-out infinite;
}

@keyframes signal-pulse {
    0%, 100% {
        r: 6;
        opacity: 1;
    }
    50% {
        r: 8;
        opacity: 0.7;
    }
}

.brain {
    animation: brain-pulse 3s ease-in-out infinite;
}

@keyframes brain-pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.02);
    }
}

/* 骨骼系统 */
.skull {
    animation: skull-tilt 4s ease-in-out infinite;
    transform-origin: center;
}

@keyframes skull-tilt {
    0%, 100% {
        transform: rotate(-5deg);
    }
    50% {
        transform: rotate(5deg);
    }
}

/* 肌肉系统 */
.contract {
    animation: muscle-contract 2s ease-in-out infinite;
}

@keyframes muscle-contract {
    0%, 100% {
        transform: scaleX(1);
    }
    50% {
        transform: scaleX(1.1);
    }
}

.biceps {
    animation: bicep-flex 3s ease-in-out infinite;
}

@keyframes bicep-flex {
    0%, 100% {
        transform: scaleY(1);
    }
    50% {
        transform: scaleY(1.1);
    }
}

/* 内分泌系统 */
.pulse-small {
    animation: gland-pulse 2s ease-in-out infinite;
}

@keyframes gland-pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 0.5;
    }
    50% {
        transform: scale(1.2);
        opacity: 0.3;
    }
}

.hormone-dot {
    filter: drop-shadow(0 0 4px rgba(231, 76, 60, 0.5));
}

.hormone-dot-small {
    filter: drop-shadow(0 0 4px rgba(155, 89, 182, 0.5));
}

/* 免疫系统 */
.white-blood-cell {
    filter: drop-shadow(0 0 8px rgba(155, 89, 182, 0.5));
}

.macrophage {
    filter: drop-shadow(0 0 8px rgba(243, 156, 18, 0.5));
}

.lymphocyte {
    filter: drop-shadow(0 0 8px rgba(26, 188, 156, 0.5));
}

/* 页脚 */
footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: white;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    header h1 {
        font-size: 1.8rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .system-nav {
        gap: 10px;
    }

    .nav-btn {
        padding: 12px 15px;
        min-width: 80px;
    }

    .nav-btn .icon {
        font-size: 1.5rem;
    }

    .nav-btn span {
        font-size: 0.8rem;
    }

    .system-display h2 {
        font-size: 1.5rem;
    }

    .animation-wrapper {
        min-height: 280px;
    }

    .system-info {
        padding: 20px;
    }

    .system-info h3 {
        font-size: 1.2rem;
    }

    .system-info p {
        font-size: 1rem;
    }

    .system-info li {
        font-size: 0.9rem;
        padding: 8px 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    .nav-btn {
        padding: 10px 12px;
        min-width: 70px;
    }

    .nav-btn .icon {
        font-size: 1.2rem;
    }

    .animation-wrapper {
        min-height: 240px;
        padding: 10px;
    }

    .system-display {
        padding: 20px;
    }
}

/* 加载动画 */
.loading {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 300px;
}

.loading::after {
    content: "";
    width: 40px;
    height: 40px;
    border: 4px solid #667eea;
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* 悬浮效果 */
.system-display {
    transition: transform 0.3s ease;
}

.system-display:hover {
    transform: scale(1.01);
}

/* 平滑过渡 */
.system-display {
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.system-display.fade-in {
    opacity: 1;
    transform: translateY(0);
}

.system-display.fade-out {
    opacity: 0;
    transform: translateY(10px);
}

/* Sidebar Navigation */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 250px;
    height: 100vh;
    background: #2c3e50;
    overflow-y: auto;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
}

.sidebar-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px 20px;
    text-align: center;
}

.sidebar-header h2 {
    font-size: 1.5em;
    margin: 0;
    font-weight: 700;
}

.sidebar-nav {
    padding: 10px 0;
}

.sidebar-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.sidebar-nav li {
    margin: 0;
}

.sidebar-nav a {
    display: block;
    padding: 12px 25px;
    color: #ecf0f1;
    text-decoration: none;
    transition: all 0.3s ease;
    font-size: 0.95em;
    border-left: 3px solid transparent;
}

.sidebar-nav a::before {
    content: '-';
    margin-right: 8px;
    font-weight: bold;
    color: #667eea;
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background-color: #34495e;
    color: #3498db;
    border-left-color: #3498db;
}

.menu-category {
    padding: 15px 25px 8px 25px;
    color: #95a5a6;
    font-size: 0.85em;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 15px;
}

.menu-category::before {
    content: '+';
    margin-right: 8px;
    font-weight: bold;
    color: #667eea;
}

.menu-category:first-of-type {
    margin-top: 10px;
}

/* Main Content */
.main-content {
    margin-left: 250px;
    padding: 40px;
    min-height: 100vh;
    background-color: #f5f5f5;
}

/* Sidebar Toggle Button */
.sidebar-toggle {
    display: none;
    position: fixed;
    left: 10px;
    top: 10px;
    z-index: 1001;
    background: #3498db;
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1.2em;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    transition: background 0.3s ease;
}

.sidebar-toggle:hover {
    background: #2980b9;
}

/* Body Systems Content Adjustment */
.body-systems-content {
    margin-left: 250px; /* 为侧边栏留出空间 */
    width: calc(100% - 250px); /* 减去侧边栏宽度 */
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
}

.body-systems-content > header,
.body-systems-content > nav,
.body-systems-content > main {
    width: 100%;
    max-width: 1200px; /* 设置最大宽度以保持居中 */
    margin: 0 auto; /* 居中对齐 */
}

/* 专门针对 main-content 的样式调整 */
.body-systems-content .main-content {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -250px;
        transition: left 0.3s ease;
    }

    .sidebar.open {
        left: 0;
    }

    .body-systems-content {
        margin-left: 0;
        width: 100%;
    }

    .main-content {
        margin-left: 0;
        padding: 20px;
    }

    .sidebar-toggle {
        display: block;
        position: fixed;
        left: 10px;
        top: 10px;
        z-index: 1001;
    }
}