/* Reset and Base Styles */
:root {
    --primary-color: #4A90E2;
    --secondary-color: #34495E;
    --text-color: #2C3E50;
    --light-text: #FFFFFF;
    --background-color: #F5F6FA;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --transition-speed: 0.3s;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    overflow-x: hidden;
}

/* Hero Section */
.hero {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: lightskyblue;
    z-index: -2;
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: linear-gradient(135deg, rgba(0,0,0,0.7) 0%, rgba(0,0,0,0.1) 100%);
    z-index: -1;
}

/* Main Content */
.content-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    text-align: center;
    position: relative;
}

.app-container {
    background: rgba(255, 255, 255, 0.95);
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    backdrop-filter: blur(10px);
    max-width: 600px;
    width: 100%;
    margin: 0 auto;
}

.app-icon {
    width: 120px;
    height: 120px;
    border-radius: 22px;
    margin-bottom: 1.5rem;
    box-shadow: 0 8px 20px var(--shadow-color);
}

.app-title {
    color: var(--text-color);
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    font-weight: 700;
}

.subtitle {
    display: block;
    font-size: 1.2rem;
    color: var(--secondary-color);
    margin-top: 0.5rem;
    font-weight: 400;
}

/* Download Section */
.download-section {
    margin-top: 2rem;
}

.download-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.download-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all var(--transition-speed) ease;
    min-width: 200px;
    position: relative;
    margin-bottom: 35px;
}

.ios-button {
    background-color: var(--primary-color);
    color: var(--light-text);
}

.android-button {
    background-color: var(--secondary-color);
    color: var(--light-text);
}

.download-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--shadow-color);
}

.download-button i {
    font-size: 1.2rem;
}

/* Version Label */
.version-label {
    position: absolute;
    bottom: -30px;
    left: 0;
    width: 100%;
    text-align: center;
    font-size: 12px;
    color: var(--secondary-color);
    font-weight: 400;
}

/* Features Section */
.features-section {
    background: white;
    padding: 4rem 2rem;
}

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

.features-section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-color);
    font-size: 2rem;
}

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

.feature-item {
    text-align: center;
    padding: 2rem;
    border-radius: 15px;
    background: var(--background-color);
    transition: transform var(--transition-speed) ease;
}

.feature-item:hover {
    transform: translateY(-5px);
}

.feature-item i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.feature-item h3 {
    color: var(--text-color);
    margin-bottom: 0.5rem;
}

.feature-item p {
    color: var(--secondary-color);
}

/* Scroll Prompt */
.scroll-prompt {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    color: var(--light-text);
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-20px);
    }
    60% {
        transform: translateY(-10px);
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .app-title {
        font-size: 2rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .download-button {
        width: 100%;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    .scroll-prompt {
        animation: none;
    }
    
    .download-button:hover {
        transform: none;
    }
}

/* High Contrast Mode */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #0066CC;
        --secondary-color: #003366;
    }
}

/* Browser Guide Overlay 浏览器引导遮罩层 */
.browser-guide-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    padding: 10vh 0.5rem 0.5rem;
    animation: fadeIn 0.3s ease-out;
}

.overlay-backdrop {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(2px);
}

.guide-steps {
    position: relative;
    width: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
}

.step-item {
    margin-bottom: 0.5rem;
    padding: 1rem;
}

.step-item p {
    color: white;
    font-size: 1rem;
    text-align: center;
}

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

/* 响应式设计 */
@media (max-width: 480px) {
    .browser-guide-overlay {
        padding: 20vh 1.5rem 1.5rem;
    }
    
    .guide-header h3 {
        font-size: 1.5rem;
    }
    
    .step-item {
        padding: 0.8rem;
    }
}