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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8fafc;
}

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: bold;
    color: #00a896;
}

.logo-icon {
    width: 40px;
    height: 40px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: #00a896;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #00a896;
    transition: width 0.3s ease;
}

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

.sidebar {
    position: fixed;
    right: 2rem;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.9);
    padding: 1rem;
    border-radius: 10px;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    z-index: 999;
}

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

.sidebar a {
    display: block;
    padding: 0.5rem 1rem;
    text-decoration: none;
    color: #333;
    font-size: 0.9rem;
    border-radius: 5px;
    transition: all 0.3s ease;
}

.sidebar a:hover {
    background: #00a896;
    color: white;
}

.hero {
    height: 100vh;
    position: relative;
    overflow: hidden;
}

.carousel {
    height: 100%;
    position: relative;
}

.carousel-slide {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1s ease;
    display: flex;
    justify-content: center;
    align-items: center;
}

.carousel-slide.active {
    opacity: 1;
}

.slide-content {
    text-align: center;
    color: white;
    z-index: 10;
}

.slide-content h1 {
    font-size: 4rem;
    margin-bottom: 1rem;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    animation: fadeInUp 1s ease;
}

.slide-content p {
    font-size: 1.5rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.3s;
    animation-fill-mode: both;
}

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

.floating-elements {
    position: absolute;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.light-spot {
    position: absolute;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.3) 0%, transparent 70%);
    border-radius: 50%;
    animation: float 4s ease-in-out infinite;
}

.spot-1 {
    width: 200px;
    height: 200px;
    top: 20%;
    left: 20%;
    animation-delay: 0s;
}

.spot-2 {
    width: 150px;
    height: 150px;
    top: 60%;
    right: 25%;
    animation-delay: 1.5s;
}

.spot-3 {
    width: 180px;
    height: 180px;
    top: 40%;
    left: 60%;
    animation-delay: 3s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) scale(1);
        opacity: 0.5;
    }
    50% {
        transform: translateY(-20px) scale(1.1);
        opacity: 0.8;
    }
}

.carousel-prev,
.carousel-next {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 2rem;
    padding: 1rem;
    cursor: pointer;
    border-radius: 50%;
    transition: all 0.3s ease;
    z-index: 20;
}

.carousel-prev:hover,
.carousel-next:hover {
    background: rgba(255, 255, 255, 0.4);
    transform: translateY(-50%) scale(1.1);
}

.carousel-prev {
    left: 2rem;
}

.carousel-next {
    right: 2rem;
}

.carousel-dots {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 1rem;
    z-index: 20;
}

.dot {
    width: 12px;
    height: 12px;
    background: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
}

.dot.active,
.dot:hover {
    background: white;
    transform: scale(1.2);
}

.section-title {
    text-align: center;
    margin-bottom: 2rem;
    position: relative;
}

.section-title h2 {
    font-size: 2.5rem;
    color: #0077b6;
    position: relative;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #00a896, #0077b6);
    border-radius: 2px;
}

.overview {
    padding: 5rem 2rem;
    background: white;
}

.overview-text {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    font-size: 1.1rem;
    color: #555;
    line-height: 1.8;
}

.data-section {
    padding: 5rem 2rem;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
}

.chart-container {
    max-width: 1000px;
    margin: 0 auto;
}

.chart {
    display: flex;
    justify-content: center;
    align-items: flex-end;
    height: 400px;
    gap: 2rem;
    padding: 2rem;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    position: relative;
}

.bar-group {
    display: flex;
    align-items: flex-end;
    gap: 2rem;
    height: 100%;
}

.bar {
    width: 80px;
    background: linear-gradient(180deg, #00a896, #0077b6);
    border-radius: 8px 8px 0 0;
    position: relative;
    cursor: pointer;
    transition: all 0.3s ease;
    animation: slideUp 0.8s ease backwards;
}

.bar:nth-child(1) { animation-delay: 0.1s; }
.bar:nth-child(2) { animation-delay: 0.2s; }
.bar:nth-child(3) { animation-delay: 0.3s; }
.bar:nth-child(4) { animation-delay: 0.4s; }
.bar:nth-child(5) { animation-delay: 0.5s; }

@keyframes slideUp {
    from {
        transform: translateY(100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.bar:hover {
    transform: scale(1.1);
    box-shadow: 0 10px 30px rgba(0, 168, 150, 0.4);
}

.bar-label {
    position: absolute;
    bottom: -30px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 0.9rem;
    font-weight: 500;
    color: #333;
    white-space: nowrap;
}

.chart-tooltip {
    position: absolute;
    background: rgba(0, 119, 182, 0.95);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: 10px;
    font-size: 0.9rem;
    pointer-events: none;
    opacity: 0;
    transition: opacity 0.3s ease;
    z-index: 100;
    max-width: 250px;
}

.chart-tooltip.active {
    opacity: 1;
}

.chart-legend {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-top: 2rem;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    color: #555;
}

.legend-color {
    width: 20px;
    height: 15px;
    border-radius: 3px;
}

.types-section {
    padding: 5rem 2rem;
    background: white;
}

.types-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.type-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    text-align: center;
}

.type-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 40px rgba(0, 168, 150, 0.2);
}

.card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
}

.type-card h3 {
    color: #0077b6;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.type-card p {
    color: #666;
    font-size: 0.95rem;
}

.about-section {
    padding: 5rem 2rem;
    background: linear-gradient(135deg, #0077b6 0%, #00a896 100%);
    color: white;
}

.about-section .section-title h2 {
    color: white;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 1.1rem;
    line-height: 1.8;
    opacity: 0.9;
}

.footer {
    text-align: center;
    padding: 2rem;
    background: #1a1a2e;
    color: white;
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: #00a896;
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: 0 4px 15px rgba(0, 168, 150, 0.4);
}

.back-to-top:hover {
    transform: scale(1.1);
    background: #008f82;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.image-modal {
    display: none;
    position: fixed;
    z-index: 2000;
    padding-top: 100px;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.9);
}

.image-modal.show {
    display: block;
}

.modal-content {
    margin: auto;
    display: block;
    max-width: 80%;
    max-height: 80vh;
    animation: zoomIn 0.3s ease;
}

@keyframes zoomIn {
    from {
        transform: scale(0.8);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.modal-close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
}

.modal-close:hover {
    color: #bbb;
}

.page-container {
    padding-top: 80px;
    min-height: 100vh;
}

.page-header {
    background: linear-gradient(135deg, #0077b6 0%, #00a896 100%);
    color: white;
    padding: 4rem 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
}

.content-section {
    padding: 4rem 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.principles-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.principles-card h3 {
    color: #0077b6;
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

.principle-diagram {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.principle-diagram svg {
    width: 200px;
    height: 200px;
}

.principle-content {
    display: none;
    margin-top: 1rem;
    padding: 1.5rem;
    background: #f0f9ff;
    border-radius: 10px;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.principle-content.active {
    display: block;
}

.principle-toggle {
    background: linear-gradient(135deg, #00a896, #0077b6);
    color: white;
    border: none;
    padding: 0.8rem 2rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.principle-toggle:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 20px rgba(0, 168, 150, 0.4);
}

.progress-section {
    margin-top: 2rem;
}

.progress-title {
    font-size: 1.2rem;
    color: #333;
    margin-bottom: 1rem;
}

.progress-bar-container {
    background: #e2e8f0;
    height: 25px;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 1.5rem;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #00a896, #0077b6);
    border-radius: 12px;
    position: relative;
    animation: progressFill 2s ease forwards;
    width: 0;
}

@keyframes progressFill {
    to { width: var(--progress-width); }
}

.progress-bar::after {
    content: attr(data-percent);
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    color: white;
    font-size: 0.8rem;
    font-weight: bold;
}

.navigation-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 3rem;
}

.nav-btn {
    background: linear-gradient(135deg, #0077b6, #00a896);
    color: white;
    border: none;
    padding: 1rem 2rem;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 20px rgba(0, 119, 182, 0.4);
}

.detail-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.detail-card {
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.detail-card h3 {
    color: #0077b6;
    margin-bottom: 1rem;
    font-size: 1.3rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.detail-card h3::before {
    content: '';
    width: 4px;
    height: 20px;
    background: linear-gradient(180deg, #00a896, #0077b6);
    border-radius: 2px;
}

.expandable-content {
    display: none;
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px solid #e2e8f0;
    animation: slideDown 0.3s ease;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.expandable-content.active {
    display: block;
}

.expand-btn {
    background: none;
    border: 2px solid #00a896;
    color: #00a896;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    margin-top: 1rem;
}

.expand-btn:hover {
    background: #00a896;
    color: white;
}

.compare-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.compare-table th,
.compare-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

.compare-table th {
    background: #f0f9ff;
    color: #0077b6;
    font-weight: 600;
}

.compare-table tr:hover {
    background: #f8fafc;
}

.wind-game-container {
    background: linear-gradient(135deg, #e0f2fe 0%, #f0f9ff 100%);
    border-radius: 15px;
    padding: 2rem;
    margin-top: 2rem;
}

.wind-game-title {
    text-align: center;
    color: #0077b6;
    margin-bottom: 2rem;
    font-size: 1.5rem;
}

.wind-game-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.windmill-display svg {
    width: 150px;
    height: 150px;
}

.wind-slider {
    width: 100%;
    max-width: 400px;
}

.wind-slider input {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    appearance: none;
    background: #e2e8f0;
    border-radius: 4px;
    outline: none;
}

.wind-slider input::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    background: linear-gradient(135deg, #00a896, #0077b6);
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.wind-slider input::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.wind-value {
    font-size: 1.2rem;
    color: #0077b6;
    font-weight: bold;
}

.efficiency-tip {
    background: rgba(0, 168, 150, 0.1);
    border-left: 4px solid #00a896;
    padding: 1rem;
    margin-top: 1rem;
    border-radius: 0 5px 5px 0;
}

.battery-game-container {
    background: linear-gradient(135deg, #dcfce7 0%, #f0fdf4 100%);
    border-radius: 15px;
    padding: 2rem;
    margin-top: 2rem;
}

.battery-game-title {
    text-align: center;
    color: #0077b6;
    margin-bottom: 2rem;
    font-size: 1.5rem;
}

.battery-game-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2rem;
}

.battery-display svg {
    width: 120px;
    height: 180px;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.battery-display svg:hover {
    transform: scale(1.05);
}

.battery-status {
    font-size: 1.1rem;
    color: #333;
}

.battery-controls {
    display: flex;
    gap: 1rem;
}

.battery-btn {
    padding: 0.8rem 2rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s ease;
}

.battery-btn.charge {
    background: linear-gradient(135deg, #059669, #047857);
    color: white;
}

.battery-btn.discharge {
    background: linear-gradient(135deg, #dc2626, #b91c1c);
    color: white;
}

.battery-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.2);
}

.page-nav-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 3rem;
    padding: 1rem;
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.08);
}

.page-nav-btn {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.8rem 1.5rem;
    background: linear-gradient(135deg, #0077b6, #00a896);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.3s ease;
}

.page-nav-btn:hover {
    transform: scale(1.05);
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-links {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }

    .sidebar {
        display: none;
    }

    .slide-content h1 {
        font-size: 2.5rem;
    }

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

    .chart {
        height: 300px;
        gap: 1rem;
    }

    .bar {
        width: 50px;
    }

    .page-nav-buttons {
        flex-direction: column;
        gap: 1rem;
    }
}