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

:root {
    --primary-green: #0F5132;
    --secondary-green: #198754;
    --accent-gold: #FFD700;
    --card-white: #FFFFFF;
    --card-shadow: rgba(0, 0, 0, 0.15);
    --text-dark: #212529;
    --text-light: #6C757D;
    --background-pattern: #1A5E3A;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: linear-gradient(135deg, var(--primary-green) 0%, var(--background-pattern) 100%);
    background-attachment: fixed;
    min-height: 100vh;
}

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

.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 20px var(--card-shadow);
    position: sticky;
    top: 0; 
    z-index: 100;
    border-bottom: 3px solid var(--accent-gold);
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.card-icon {
    width: 40px;
    height: 56px;
    background: linear-gradient(145deg, var(--card-white), #f8f9fa);
    border: 2px solid var(--primary-green);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    font-weight: bold;
    color: var(--primary-green);
    box-shadow: 0 4px 8px var(--card-shadow);
}

.logo-text {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-green);
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.hero {
    background: var(--card-white);
    margin: 2rem 0;
    border-radius: 16px;
    box-shadow: 0 8px 32px var(--card-shadow);
    overflow: hidden;
    height: 80vh;
    min-height: 600px;
}

.hero {
    width: 100vw;
    height: 100vh;
    margin: 0;
    padding: 0;
    border-radius: 0;
    box-shadow: none;
    overflow: hidden;
    /* 移除重复的样式定义，不使用 position: fixed */
}

.hero iframe {
    width: 100%;
    height: 100%;
    border: none;
    border-radius: 0;
}

.hero-content {
    padding: 4rem 3rem;
    text-align: center;
    background: linear-gradient(135deg, #f8f9fa 0%, var(--card-white) 100%);
    border-radius: 16px;
    box-shadow: 0 8px 32px var(--card-shadow);
    margin: 2rem;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--primary-green);
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta-button {
    display: inline-block;
    background: linear-gradient(145deg, var(--secondary-green), var(--primary-green));
    color: white;
    padding: 1rem 2.5rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    box-shadow: 0 4px 16px rgba(25, 135, 84, 0.3);
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(25, 135, 84, 0.4);
}

.content-section {
    background: var(--card-white);
    margin: 2rem 0;
    padding: 3rem;
    border-radius: 16px;
    box-shadow: 0 8px 32px var(--card-shadow);
}

.content-section h2 {
    font-size: 2.5rem;
    color: var(--primary-green);
    margin-bottom: 1.5rem;
    border-bottom: 3px solid var(--accent-gold);
    padding-bottom: 0.5rem;
}

.content-section h3 {
    font-size: 1.8rem;
    color: var(--secondary-green);
    margin: 2rem 0 1rem 0;
}

.content-section h4 {
    font-size: 1.4rem;
    color: var(--primary-green);
    margin: 1.5rem 0 0.8rem 0;
}

.content-section p {
    margin-bottom: 1.2rem;
    color: var(--text-dark);
    line-height: 1.7;
}

.content-section ul, .content-section ol {
    margin: 1rem 0 1.5rem 2rem;
}

.content-section li {
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.difficulty-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.difficulty-card {
    background: linear-gradient(145deg, #f8f9fa, var(--card-white));
    border: 2px solid var(--secondary-green);
    border-radius: 12px;
    padding: 2rem;
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.difficulty-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--card-shadow);
}

.difficulty-card h4 {
    color: var(--primary-green);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.tip-card {
    background: linear-gradient(145deg, #e8f5e8, #f0f8f0);
    border-left: 4px solid var(--secondary-green);
    border-radius: 8px;
    padding: 1.5rem;
}

.tip-card h4 {
    color: var(--primary-green);
    margin-bottom: 0.8rem;
}

.faq-item {
    background: #f8f9fa;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1rem 0;
    border-left: 4px solid var(--accent-gold);
}

.faq-item h4 {
    color: var(--primary-green);
    margin-bottom: 0.8rem;
}

.shortcuts-table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    background: var(--card-white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 4px 16px var(--card-shadow);
}

.shortcuts-table th, .shortcuts-table td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid #e9ecef;
}

.shortcuts-table th {
    background: var(--primary-green);
    color: white;
    font-weight: 600;
}

.shortcuts-table td:first-child {
    font-family: 'Courier New', monospace;
    background: #f8f9fa;
    font-weight: bold;
    color: var(--primary-green);
}

.footer {
    background: var(--primary-green);
    color: white;
    text-align: center;
    padding: 3rem 0;
    margin-top: 4rem;
}

.footer-content {
    max-width: 800px;
    margin: 0 auto;
}

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

.footer-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 2rem 0;
    flex-wrap: wrap;
}

.footer-links a {
    color: white;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--accent-gold);
}

/* 汉堡菜单样式 */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 8px;
    background: none;
    border: none;
    z-index: 101;
}

.mobile-menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary-green);
    margin: 3px 0;
    transition: 0.3s;
    border-radius: 2px;
}

.mobile-menu-toggle.active span:nth-child(1) {
    transform: rotate(-45deg) translate(-5px, 6px);
}

.mobile-menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active span:nth-child(3) {
    transform: rotate(45deg) translate(-5px, -6px);
}

/* 移动端导航菜单 */
.mobile-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 20px var(--card-shadow);
    border-top: 1px solid #e9ecef;
    z-index: 100;
}

.mobile-nav.active {
    display: block;
}

.mobile-nav ul {
    list-style: none;
    padding: 1rem 0;
    margin: 0;
}

.mobile-nav li {
    border-bottom: 1px solid #f1f3f4;
}

.mobile-nav li:last-child {
    border-bottom: none;
}

.mobile-nav a {
    display: block;
    padding: 1rem 2rem;
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: all 0.3s ease;
}

.mobile-nav a:hover {
    background: #f8f9fa;
    color: var(--secondary-green);
}

.mobile-nav .language-selector {
    padding: 1rem 2rem;
    border-bottom: none;
}

.mobile-nav .language-selector select {
    width: 100%;
    margin-top: 0.5rem;
}

@media (max-width: 768px) {
    .hero {
        height: 70vh;
        min-height: 500px;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .hero-content {
        padding: 2rem 1.5rem;
    }
    
    .content-section {
        padding: 2rem 1.5rem;
    }
    
    .content-section h2 {
        font-size: 2rem;
    }
    
    .header-content {
        position: relative;
    }
    
    .nav-links {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .difficulty-grid {
        grid-template-columns: 1fr;
    }
    
    .container {
        padding: 0 15px;
    }
}

.highlight {
    background: linear-gradient(120deg, var(--accent-gold) 0%, var(--accent-gold) 100%);
    background-repeat: no-repeat;
    background-size: 100% 0.2em;
    background-position: 0 88%;
    font-weight: 600;
}

.card-suite {
    display: inline-block;
    font-size: 1.2em;
    margin: 0 0.2em;
}

.spade { color: #000; }
.heart { color: #dc3545; }
.diamond { color: #dc3545; }
.club { color: #000; }

/* 语言选择器样式 */
.language-selector {
    position: relative;
    display: flex;
    align-items: center;
}

.language-selector select {
    background: var(--card-white);
    border: 2px solid var(--secondary-green);
    border-radius: 8px;
    padding: 8px 12px;
    font-size: 14px;
    color: var(--text-dark);
    cursor: pointer;
    outline: none;
    transition: all 0.3s ease;
    font-weight: 500;
}

.language-selector select:hover {
    border-color: var(--accent-gold);
    box-shadow: 0 2px 8px var(--card-shadow);
}

.language-selector select:focus {
    border-color: var(--accent-gold);
    box-shadow: 0 0 0 3px rgba(255, 215, 0, 0.2);
}