/* 全局样式变量 */
:root {
    --primary-color: #0077cc;
    --secondary-color: #3a9bdc;
    --accent-color: #ff6b6b;
    --dark-color: #333;
    --light-color: #f8f9fa;
    --gray-color: #6c757d;
    --light-gray: #e9ecef;
    --white-color: #fff;
    
    --font-primary: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', Arial, sans-serif;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.12);
    --shadow-lg: 0 8px 16px rgba(0,0,0,0.15);
    
    --transition-fast: 0.2s ease-out;
    --transition-normal: 0.3s ease-out;
    --transition-slow: 0.5s ease-out;
    
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
}

/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--light-color);
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    margin-bottom: 0.5em;
    line-height: 1.2;
    font-weight: 600;
}

p {
    margin-bottom: 1rem;
}

ul, ol {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color var(--transition-fast);
}

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

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

button, .btn {
    cursor: pointer;
    padding: 0.5rem 1.5rem;
    background-color: var(--primary-color);
    color: var(--white-color);
    border: none;
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    transition: background-color var(--transition-fast);
}

button:hover, .btn:hover {
    background-color: var(--secondary-color);
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--white-color);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    display: flex;
    align-items: center;
}

.nav-icon {
    font-size: 1.8rem;
    margin-right: 0.5rem;
}

.nav-menu {
    display: flex;
    gap: 1.5rem;
}

.nav-link {
    font-weight: 500;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width var(--transition-normal);
}

.nav-link:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    cursor: pointer;
}

.bar {
    width: 100%;
    height: 3px;
    background-color: var(--primary-color);
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* 主内容样式 */
.main-content {
    padding-top: 70px; /* 导航栏高度 */
}

/* Hero区域 */
.hero {
    height: 90vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #e0f7ff 0%, #c3e6ff 100%);
    position: relative;
    overflow: hidden;
}

.hero-content {
    max-width: 600px;
    padding: 2rem;
    z-index: 2;
}

.hero-title {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: var(--dark-color);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    color: var(--gray-color);
}

.hero-btn {
    padding: 0.75rem 2rem;
    font-size: 1.1rem;
    border-radius: var(--border-radius-md);
}

.hero-animation {
    position: absolute;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.aircraft-icon {
    font-size: 5rem;
    position: absolute;
    animation: fly 20s linear infinite;
}

@keyframes fly {
    0% {
        left: -10%;
        top: 30%;
        transform: rotate(10deg);
    }
    25% {
        left: 30%;
        top: 20%;
        transform: rotate(-5deg);
    }
    50% {
        left: 70%;
        top: 40%;
        transform: rotate(3deg);
    }
    75% {
        left: 50%;
        top: 65%;
        transform: rotate(-8deg);
    }
    100% {
        left: -10%;
        top: 30%;
        transform: rotate(10deg);
    }
}

/* 内容区域通用样式 */
.content-section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 2.5rem;
    font-size: 2.5rem;
    color: var(--primary-color);
}

.section-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 3rem;
    font-size: 1.2rem;
    color: var(--gray-color);
}

/* 飞机类型介绍样式 */
.classification {
    margin-bottom: 3rem;
}

.classification h3,
.boeing-737 h3,
.b737-specs h3 {
    margin-bottom: 1.5rem;
    font-size: 1.8rem;
    text-align: center;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.card {
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.card-header {
    background-color: var(--primary-color);
    color: var(--white-color);
    padding: 1rem;
}

.card-content {
    padding: 1rem;
}

/* Timeline样式 */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto 3rem;
}

.timeline::before {
    content: '';
    position: absolute;
    width: 4px;
    background-color: var(--light-gray);
    top: 0;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

.timeline-item {
    padding: 10px 40px;
    position: relative;
    width: 50%;
}

.timeline-item:nth-child(odd) {
    left: 0;
}

.timeline-item:nth-child(even) {
    left: 50%;
}

.timeline-date {
    position: absolute;
    width: 40px;
    height: 40px;
    background-color: var(--primary-color);
    color: var(--white-color);
    text-align: center;
    line-height: 40px;
    border-radius: 50%;
    top: 20px;
    z-index: 1;
}

.timeline-item:nth-child(odd) .timeline-date {
    right: -20px;
}

.timeline-item:nth-child(even) .timeline-date {
    left: -20px;
}

.timeline-content {
    padding: 20px;
    background-color: var(--white-color);
    position: relative;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

/* 技术参数表格 */
.specs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.spec-card {
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
}

.spec-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    text-align: center;
}

.spec-card table {
    width: 100%;
    border-collapse: collapse;
}

.spec-card td {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--light-gray);
}

.spec-card td:first-child {
    font-weight: 500;
}

.spec-card td:last-child {
    text-align: right;
}

/* 飞机结构样式 */
.aircraft-interactive {
    margin-top: 3rem;
}

.aircraft-interactive h3 {
    text-align: center;
    margin-bottom: 1rem;
}

.aircraft-interactive p {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--gray-color);
}

.aircraft-diagram {
    max-width: 800px;
    margin: 0 auto 3rem;
    position: relative;
    height: 250px;
    background-color: var(--light-gray);
    border-radius: var(--border-radius-lg);
}

.aircraft-body {
    position: relative;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 700px;
    height: 150px;
    background-color: var(--light-color);
    border-radius: 150px 50px 20px 20px;
    box-shadow: var(--shadow-sm);
}

.aircraft-part {
    position: absolute;
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.part-label {
    position: absolute;
    background-color: rgba(0, 0, 0, 0.7);
    color: var(--white-color);
    padding: 0.25rem 0.5rem;
    border-radius: var(--border-radius-sm);
    font-size: 0.8rem;
    opacity: 0;
    transition: opacity var(--transition-fast);
    pointer-events: none;
    z-index: 10;
    white-space: nowrap;
}

.aircraft-part:hover {
    background-color: rgba(58, 155, 220, 0.3);
}

.aircraft-part:hover .part-label {
    opacity: 1;
}

.cockpit {
    width: 100px;
    height: 150px;
    border-radius: 50% 0 0 50%;
    left: 0;
}

.cabin {
    width: 400px;
    height: 150px;
    left: 100px;
}

.galley {
    width: 80px;
    height: 150px;
    right: 120px;
}

.cargo {
    width: 100%;
    height: 50px;
    bottom: 0;
    left: 0;
    border-radius: 0 0 50px 50px;
}

.wings-left, .wings-right {
    width: 150px;
    height: 20px;
    top: 50%;
    background-color: var(--light-color);
}

.wings-left {
    left: -130px;
    transform: rotate(-5deg);
}

.wings-right {
    right: -130px;
    transform: rotate(5deg);
}

.tail {
    width: 50px;
    height: 70px;
    right: 20px;
    top: -60px;
    border-radius: 5px;
    transform: rotate(5deg);
}

.part-info {
    margin-top: 2rem;
}

.info-card {
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
    margin-bottom: 1rem;
}

.info-card h4 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

/* 飞行结构样式 */
.flight-systems {
    margin-top: 3rem;
}

.system-category {
    margin-bottom: 3rem;
}

.system-category h3 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.system-details {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    justify-content: center;
}

.detail-card {
    flex: 1;
    min-width: 250px;
    max-width: 400px;
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

.detail-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* 飞行控制样式 */
.flight-control-demo {
    margin-bottom: 3rem;
}

.flight-control-demo h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.control-axes {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2rem;
}

.axis-demo {
    flex: 1;
    min-width: 300px;
    max-width: 350px;
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
}

.axis-info h4 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.control-details {
    margin-bottom: 1.5rem;
}

.demo-animation {
    text-align: center;
    padding: 2rem 0;
}

.aircraft-icon.roll-demo, 
.aircraft-icon.pitch-demo, 
.aircraft-icon.yaw-demo {
    position: relative;
    font-size: 3rem;
    display: inline-block;
    transition: transform var(--transition-slow);
}

.control-systems h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.system-evolution {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 1.5rem;
}

.evolution-item {
    flex: 1;
    min-width: 250px;
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

.evolution-item h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.flight-operations h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.operations-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.operation-card {
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

.operation-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
}

.operation-card ol {
    padding-left: 1.5rem;
}

.operation-card li {
    margin-bottom: 0.5rem;
}

/* 自动驾驶样式 */
.components-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.component-card {
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: transform var(--transition-normal);
}

.component-card:hover {
    transform: translateY(-5px);
}

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

.component-card h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.autopilot-functions h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.functions-container {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 3rem;
}

.function-category {
    flex: 1;
    min-width: 300px;
    max-width: 450px;
}

.function-category h4 {
    text-align: center;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

.function-list {
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

.function-item {
    display: flex;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--light-gray);
}

.function-item:last-child {
    border-bottom: none;
}

.function-name {
    font-weight: 500;
}

.function-desc {
    color: var(--gray-color);
    text-align: right;
    font-size: 0.9rem;
}

.autopilot-demo h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.demo-container {
    max-width: 600px;
    margin: 0 auto;
}

.demo-scenario {
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    margin-bottom: 1.5rem;
}

.scenario-step {
    display: flex;
    padding: 1rem;
    border-bottom: 1px solid var(--light-gray);
}

.scenario-step:last-child {
    border-bottom: none;
}

.step-number {
    width: 30px;
    height: 30px;
    background-color: var(--primary-color);
    color: var(--white-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 1rem;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-content h5 {
    margin-bottom: 0.25rem;
    color: var(--dark-color);
}

.step-content p {
    margin-bottom: 0;
    color: var(--gray-color);
}

#altitude-demo-btn {
    display: block;
    margin: 0 auto 1.5rem;
}

.demo-result {
    background-color: var(--light-gray);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    text-align: center;
}

.altitude-display {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.altitude-display #current-altitude {
    color: var(--primary-color);
    font-weight: 600;
}

.target-display {
    color: var(--gray-color);
}

.pilot-cooperation h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.cooperation-points {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.point-card {
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal);
}

.point-card:hover {
    transform: translateY(-5px);
}

.point-card h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

/* 航线飞行样式 */
.phase-timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto 3rem;
}

.phase-item {
    display: flex;
    margin-bottom: 2rem;
    align-items: flex-start;
}

.phase-icon {
    font-size: 2rem;
    margin-right: 1.5rem;
    flex-shrink: 0;
}

.phase-info {
    background-color: var(--white-color);
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
    flex: 1;
}

.phase-info h4 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.phase-info ul {
    margin-bottom: 0;
}

.planning-factors h4 {
    text-align: center;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.factors-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.factor-item {
    background-color: var(--white-color);
    padding: 1rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
}

.factor-icon {
    font-size: 1.5rem;
    margin-right: 1rem;
}

.factor-content h5 {
    margin-bottom: 0.25rem;
    color: var(--dark-color);
}

.factor-content p {
    margin-bottom: 0;
    color: var(--gray-color);
    font-size: 0.9rem;
}

.fms-system h3,
.atc-system h3,
.special-situations h3 {
    text-align: center;
    margin-bottom: 2rem;
}

.fms-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.fms-card {
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

.fms-card h4 {
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.atc-stages {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 3rem;
}

.atc-stage {
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.atc-stage h4 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.situations-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.situation-card {
    background-color: var(--white-color);
    padding: 1.5rem;
    border-radius: var(--border-radius-md);
    box-shadow: var(--shadow-sm);
}

.situation-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.situation-card ul {
    margin-bottom: 0;
}

/* 页脚样式 */
.footer {
    background-color: var(--dark-color);
    color: var(--white-color);
    padding: 3rem 0;
}

.footer-content {
    text-align: center;
}

/* 响应式样式 */
@media (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .aircraft-body {
        width: 90%;
        max-width: 500px;
    }
    
    .aircraft-part .part-label {
        font-size: 0.7rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background-color: var(--white-color);
        flex-direction: column;
        align-items: center;
        padding: 1rem 0;
        box-shadow: var(--shadow-sm);
        clip-path: polygon(0 0, 100% 0, 100% 0, 0 0);
        transition: clip-path var(--transition-normal);
    }
    
    .nav-menu.active {
        clip-path: polygon(0 0, 100% 0, 100% 100%, 0 100%);
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-content {
        padding: 1.5rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .timeline::before {
        left: 31px;
    }
    
    .timeline-item {
        width: 100%;
        padding-left: 70px;
        padding-right: 25px;
    }
    
    .timeline-item:nth-child(even) {
        left: 0;
    }
    
    .timeline-date {
        left: 11px !important;
    }
    
    .phase-item {
        flex-direction: column;
    }
    
    .phase-icon {
        margin-bottom: 1rem;
        text-align: center;
        width: 100%;
    }
}

@media (max-width: 576px) {
    .hero {
        height: 70vh;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .section-intro {
        font-size: 1rem;
    }
    
    .content-section {
        padding: 3rem 0;
    }
    
    .aircraft-interactive .info-card {
        padding: 1rem;
    }
}