:root {
    --primary: #0284C7; /* 调整为一个更偏向专业的蓝色 */
    --primary-hover: #0369A1;
    --bg: #F8FAFC;
    --text-main: #0F172A;
    --text-muted: #64748B;
    --card-bg: #FFFFFF;
    --border: #E2E8F0;
    --success: #10B981;
    --warning: #F59E0B;
    --vip: #8B5CF6;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
header {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--border);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

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

.logo-icon {
    width: 34px;
    height: 34px;
    background: linear-gradient(135deg, #38BDF8, var(--primary));
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.25);
}

.logo h1 {
    font-size: 22px;
    font-weight: 700;
    letter-spacing: -0.5px;
    color: #0F172A;
}

.logo span {
    font-weight: 500;
    color: var(--text-muted);
    font-size: 16px;
    margin-left: 6px;
}

nav {
    display: flex;
    align-items: center;
    gap: 28px;
}

nav a {
    font-weight: 500;
    font-size: 15px;
    color: var(--text-muted);
    transition: color 0.2s ease;
}

nav a:hover {
    color: var(--primary);
}

nav .btn {
    background-color: var(--primary);
    color: white;
    padding: 8px 24px;
    border-radius: 100px;
    font-weight: 600;
    transition: all 0.2s ease;
}

nav .btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.2);
}

/* Hero Section */
.hero {
    padding: 100px 0 120px;
    overflow: hidden;
    background: radial-gradient(circle at top right, rgba(2, 132, 199, 0.05), transparent 40%);
}

.hero-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
}

.hero-text {
    flex: 1;
    max-width: 520px;
}

.hero-text h2 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
    letter-spacing: -1px;
    color: #0F172A;
}

.hero-text p {
    font-size: 17px;
    color: #475569;
    margin-bottom: 48px;
    line-height: 1.7;
}

.hero-text strong {
    color: var(--primary);
    font-weight: 600;
}

/* App Store Button */
.store-btn {
    display: inline-flex;
    align-items: center;
    background-color: #0F172A;
    color: #fff;
    padding: 12px 24px;
    border-radius: 14px;
    gap: 14px;
    transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.store-btn:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(15, 23, 42, 0.2);
}

.store-btn .icon {
    font-size: 28px;
}

.store-btn .btn-text {
    display: flex;
    flex-direction: column;
}

.store-btn .small {
    font-size: 11px;
    line-height: 1;
    opacity: 0.8;
    margin-bottom: 2px;
}

.store-btn .large {
    font-size: 20px;
    font-weight: 500;
    line-height: 1.1;
    letter-spacing: -0.5px;
}

/* App Visual Mockup (CSS Drawing) */
.hero-visual {
    flex: 1;
    display: flex;
    justify-content: center;
    perspective: 1200px;
}

.app-mockup {
    width: 320px;
    height: 650px;
    background-color: #000;
    border-radius: 44px;
    padding: 10px;
    box-shadow: 
        0 24px 80px rgba(15, 23, 42, 0.15), 
        0 0 0 1px rgba(0,0,0,0.05),
        inset 0 0 0 2px rgba(255,255,255,0.1);
    transform: rotateY(-12deg) rotateX(4deg);
    transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.app-mockup:hover {
    transform: rotateY(-4deg) rotateX(2deg) translateY(-10px);
}

.app-screen {
    width: 100%;
    height: 100%;
    background-color: #F1F5F9;
    border-radius: 34px;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
}

.app-header {
    background-color: var(--primary);
    color: white;
    padding: 48px 20px 16px;
    font-weight: 600;
    font-size: 18px;
    text-align: center;
    letter-spacing: 0.5px;
}

.app-search {
    margin: 16px;
    background-color: #fff;
    padding: 12px 16px;
    border-radius: 12px;
    font-size: 13px;
    color: #94A3B8;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
    border: 1px solid var(--border);
}

.app-cards {
    padding: 0 16px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow-y: hidden;
}

.card {
    background-color: #fff;
    padding: 16px;
    border-radius: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    border: 1px solid var(--border);
}

.alert-card {
    border-left: 4px solid var(--warning);
}

.card-title {
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 8px;
    color: #1E293B;
    display: flex;
    align-items: center;
    gap: 6px;
}

.card-desc {
    font-size: 12px;
    color: #64748B;
    margin-bottom: 12px;
    line-height: 1.5;
}

.info-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 4px;
    border-bottom: 1px dashed #F1F5F9;
    padding-bottom: 4px;
}

.info-row:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.price {
    color: #EF4444;
}

.optometry-data {
    font-family: monospace;
    background: #F8FAFC;
    padding: 8px;
    border-radius: 6px;
    color: #334155;
}

.card-tags {
    display: flex;
    gap: 8px;
}

.card-tag {
    display: inline-block;
    padding: 4px 8px;
    background-color: #F1F5F9;
    color: #475569;
    font-size: 10px;
    font-weight: 600;
    border-radius: 6px;
}

.tag-success {
    background-color: #D1FAE5;
    color: #059669;
}

.tag-warning {
    background-color: #FEF3C7;
    color: #D97706;
}

.tag-vip {
    background-color: #EDE9FE;
    color: #7C3AED;
}

/* App Tab Bar */
.app-tabbar {
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-top: 1px solid var(--border);
    padding: 12px 20px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.tab {
    font-size: 10px;
    color: #94A3B8;
    font-weight: 500;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.tab::before {
    content: '';
    display: block;
    width: 20px;
    height: 20px;
    background-color: currentColor;
    border-radius: 4px;
    opacity: 0.5;
}

.tab.active {
    color: var(--primary);
}

.tab.active::before {
    opacity: 1;
}

.tab-fab {
    width: 44px;
    height: 44px;
    background: var(--primary);
    border-radius: 22px;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 24px;
    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.3);
    margin-top: -24px;
    border: 4px solid #F1F5F9;
}

/* Features Section */
.features {
    padding: 120px 0;
    background-color: #fff;
    border-top: 1px solid var(--border);
}

.section-title {
    text-align: center;
    font-size: 32px;
    font-weight: 800;
    margin-bottom: 72px;
    letter-spacing: -0.5px;
    color: #0F172A;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.feature-card {
    padding: 40px;
    border-radius: 24px;
    background-color: var(--bg);
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 16px 32px rgba(15, 23, 42, 0.04);
    background-color: #fff;
    border-color: var(--border);
}

.feature-icon {
    font-size: 28px;
    margin-bottom: 24px;
    background-color: #fff;
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(15, 23, 42, 0.04);
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 16px;
    color: #1E293B;
}

.feature-card p {
    color: #475569;
    line-height: 1.7;
    font-size: 15px;
}

/* Footer */
footer {
    background-color: #0F172A;
    color: #94A3B8;
    padding: 48px 0;
    text-align: center;
}

.footer-bottom {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    font-size: 14px;
}

.footer-bottom a {
    transition: color 0.2s, text-decoration-color 0.2s;
    text-decoration: underline;
    text-decoration-color: rgba(148, 163, 184, 0.6);
}

.footer-bottom a:hover {
    color: #fff;
    text-decoration-color: #fff;
}

/* Responsive */
@media (max-width: 900px) {
    .hero-content {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-text {
        max-width: 100%;
        display: flex;
        flex-direction: column;
        align-items: center;
    }
    
    .hero-text h2 {
        font-size: 36px;
    }
    
    .app-mockup {
        transform: rotateY(0) rotateX(0);
        margin-top: 20px;
    }
    
    .app-mockup:hover {
        transform: translateY(-4px);
    }
}

@media (max-width: 600px) {
    header .container {
        height: 60px;
    }
    nav {
        display: none;
    }
    .hero {
        padding: 40px 0;
    }
    .hero-text h2 {
        font-size: 28px;
    }
}