:root {
    --primary-color: #3b82f6;
    --primary-dark: #2563eb;
    --secondary-color: #10b981;
    --accent-color: #f59e0b;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-health: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-calm: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: var(--bg-light);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
.header {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
}

.nav {
    padding: 1rem 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo-icon {
    width: 32px;
    height: 32px;
    stroke-width: 2;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
    background-color: rgba(59, 130, 246, 0.1);
}

/* Hero Section */
.hero {
    margin-top: 80px;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
    z-index: 1;
}

.hero-content {
    text-align: center;
    color: white;
    z-index: 2;
    position: relative;
    padding: 2rem;
}

.hero-title {
    font-family: 'Noto Serif SC', serif;
    font-size: 3.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
}

.btn {
    display: inline-block;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    font-size: 1.1rem;
}

.btn-primary {
    background: white;
    color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

/* Stats Section */
.stats-section {
    padding: 4rem 0;
    background: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    text-align: center;
}

.stat-item {
    padding: 2rem;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* Organs Section */
.organs-section {
    padding: 5rem 0;
    background: var(--bg-light);
}

.section-title {
    font-family: 'Noto Serif SC', serif;
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 3rem;
}

.organs-filter {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 3rem;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 50px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-dark);
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.organs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 2rem;
}

.organ-card {
    background: white;
    border-radius: 1rem;
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    cursor: pointer;
}

.organ-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.organ-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.organ-name {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.organ-brief {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.btn-detail {
    padding: 0.75rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-detail:hover {
    background: var(--primary-dark);
    transform: scale(1.05);
}

/* Tips Section */
.tips-section {
    padding: 5rem 0;
    background: white;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tip-card {
    padding: 2.5rem;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 1rem;
    text-align: center;
    transition: all 0.3s ease;
}

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

.tip-icon {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.tip-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.tip-card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* About Section */
.about-section {
    padding: 5rem 0;
    background: var(--bg-light);
}

.about-content {
    max-width: 800px;
    margin: 2rem auto;
    text-align: center;
    font-size: 1.2rem;
    line-height: 2;
    color: var(--text-light);
}

.about-content p {
    margin-bottom: 1.5rem;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    animation: fadeIn 0.3s ease;
}

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

.modal-content {
    background-color: white;
    margin: 5% auto;
    padding: 0;
    border-radius: 1rem;
    max-width: 900px;
    box-shadow: var(--shadow-xl);
    animation: slideDown 0.3s ease;
    max-height: 85vh;
    overflow-y: auto;
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.close {
    color: #aaa;
    float: right;
    font-size: 32px;
    font-weight: bold;
    padding: 1rem 1.5rem;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close:hover,
.close:focus {
    color: var(--text-dark);
}

.modal-header {
    background: var(--gradient-primary);
    color: white;
    padding: 2.5rem;
    border-radius: 1rem 1rem 0 0;
}

.modal-organ-icon {
    font-size: 5rem;
    margin-bottom: 1rem;
}

.modal-organ-name {
    font-family: 'Noto Serif SC', serif;
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

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

.modal-body {
    padding: 2.5rem;
}

.detail-section {
    margin-bottom: 2.5rem;
}

.detail-section h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.detail-section p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.detail-section ul {
    list-style: none;
    padding-left: 0;
}

.detail-section li {
    padding: 0.75rem 0;
    padding-left: 2rem;
    position: relative;
    color: var(--text-light);
    line-height: 1.7;
}

.detail-section li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
    font-size: 1.2rem;
}

.warning-box {
    background: linear-gradient(135deg, #fff5f5 0%, #fed7d7 100%);
    border-left: 4px solid #f56565;
    padding: 1.5rem;
    border-radius: 0.5rem;
    margin-top: 1.5rem;
}

.warning-box h4 {
    color: #c53030;
    margin-bottom: 0.75rem;
    font-size: 1.2rem;
}

.warning-box ul {
    margin-top: 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
        font-size: 0.9rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

    .section-title {
        font-size: 2rem;
    }

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

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

    .modal-content {
        margin: 10% 5%;
        max-width: 90%;
    }

    .organs-filter {
        gap: 0.5rem;
    }

    .filter-btn {
        padding: 0.5rem 1rem;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
        display: none;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

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

/* Smooth scrolling animations */
@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

.organ-card:hover .organ-icon {
    animation: float 1s ease-in-out infinite;
}

/* Loading animation */
.organs-grid.loading .organ-card {
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
}

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

.organs-grid .organ-card:nth-child(1) { animation-delay: 0.1s; }
.organs-grid .organ-card:nth-child(2) { animation-delay: 0.2s; }
.organs-grid .organ-card:nth-child(3) { animation-delay: 0.3s; }
.organs-grid .organ-card:nth-child(4) { animation-delay: 0.4s; }
.organs-grid .organ-card:nth-child(5) { animation-delay: 0.5s; }
.organs-grid .organ-card:nth-child(6) { animation-delay: 0.6s; }