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

:root {
    --primary-color: #000000;
    --secondary-color: #333333;
    --accent-color: #ffffff;
    --text-white: #000000;
    --text-gray: #666666;
    --bg-gray: #ffffff;
    --bg-dark: #f5f5f5;
    --border-color: #e5e5e5;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-white);
    background: var(--bg-gray);
}

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

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 1px 0 var(--border-color);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    height: 64px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 24px;
    font-weight: 600;
    background: linear-gradient(90deg, #000000, #333333);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
    align-items: center;
}

.nav-menu a {
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 400;
    font-size: 15px;
    transition: color 0.3s ease;
}

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

.download-btn {
    background: var(--primary-color);
    color: #ffffff;
    padding: 10px 28px;
    border-radius: 4px;
    font-weight: 500;
    font-size: 14px;
    transition: all 0.3s ease;
}

.download-btn:hover {
    background: var(--secondary-color);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--primary-color);
    border-radius: 1px;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-gray);
    position: relative;
    overflow: hidden;
    padding-top: 64px;
}

.hero-bg {
    position: absolute;
    inset: 0;
    opacity: 0.6;
}

.hero-bubble {
    position: absolute;
    border-radius: 50%;
    filter: blur(120px);
}

.bubble-1 {
    top: 100px;
    left: 60px;
    width: 500px;
    height: 500px;
    background: #f8f8f8;
}

.bubble-2 {
    top: 250px;
    right: 80px;
    width: 400px;
    height: 400px;
    background: #f0f0f0;
}

.bubble-3 {
    bottom: 150px;
    left: 50%;
    transform: translateX(-50%);
    width: 450px;
    height: 450px;
    background: #fafafa;
}

.hero-content {
    position: relative;
    z-index: 10;
    text-align: center;
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 8px 20px;
    margin-bottom: 32px;
    font-size: 13px;
    color: var(--text-gray);
    font-weight: 400;
}

.hero-title {
    font-size: 64px;
    font-weight: 300;
    margin-bottom: 24px;
    line-height: 1.1;
    letter-spacing: -2px;
}

.title-gradient {
    background: linear-gradient(90deg, #000000, #333333);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.title-secondary {
    font-size: 42px;
    color: var(--text-gray);
    font-weight: 300;
    letter-spacing: -1px;
}

.hero-description {
    font-size: 18px;
    color: var(--text-gray);
    margin-bottom: 56px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    font-weight: 300;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 64px;
    flex-wrap: wrap;
}

.btn-primary {
    background: var(--primary-color);
    color: #ffffff;
    padding: 16px 48px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: all 0.3s ease;
    border: 2px solid var(--primary-color);
}

.btn-primary:hover {
    background: var(--secondary-color);
    border-color: var(--secondary-color);
}

.btn-secondary {
    background: transparent;
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-color);
    color: var(--text-white);
    padding: 16px 48px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    font-size: 16px;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    border-color: var(--primary-color);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
    max-width: 1000px;
    margin: 0 auto;
}

.stat-item {
    background: var(--bg-gray);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 40px 24px;
    transition: all 0.4s ease;
}

.stat-item:hover {
    border-color: var(--primary-color);
}

.stat-number {
    font-size: 56px;
    font-weight: 300;
    color: var(--primary-color);
    margin-bottom: 8px;
    letter-spacing: -2px;
}

.stat-label {
    font-size: 14px;
    color: var(--text-gray);
    font-weight: 400;
}

.hero-fade {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 128px;
    background: linear-gradient(to top, var(--bg-gray), transparent);
}

/* Features Section */
.features {
    padding: 160px 0;
    background: var(--bg-gray);
}

.section-header {
    text-align: center;
    margin-bottom: 96px;
}

.section-header h2 {
    font-size: 48px;
    font-weight: 300;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

.section-header p {
    font-size: 17px;
    color: var(--text-gray);
    max-width: 600px;
    margin: 0 auto;
    font-weight: 300;
    line-height: 1.8;
}

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

.feature-card {
    background: var(--bg-gray);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 48px 36px;
    transition: all 0.4s ease;
}

.feature-card:hover {
    border-color: var(--primary-color);
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.05);
}

.feature-icon {
    font-size: 36px;
    margin-bottom: 24px;
    color: var(--text-gray);
}

.feature-card h3 {
    font-size: 22px;
    font-weight: 400;
    margin-bottom: 16px;
    color: var(--text-white);
}

.feature-card p {
    color: var(--text-gray);
    line-height: 1.8;
    font-weight: 300;
}

/* How It Works Section */
.how-it-works {
    padding: 160px 0;
    background: var(--bg-dark);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 64px;
}

.step {
    position: relative;
    padding: 0;
    background: transparent;
    border-radius: 0;
    border: none;
}

.step-number {
    font-size: 80px;
    font-weight: 200;
    color: var(--border-color);
    margin-bottom: 24px;
    line-height: 1;
    letter-spacing: -4px;
}

.step-content h3 {
    font-size: 20px;
    font-weight: 400;
    margin-bottom: 16px;
    color: var(--text-white);
}

.step-content p {
    color: var(--text-gray);
    line-height: 1.8;
    font-weight: 300;
}

/* About Section */
.about {
    padding: 160px 0;
    background: var(--bg-gray);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: start;
}

.about-text h2 {
    font-size: 48px;
    font-weight: 300;
    margin-bottom: 32px;
    letter-spacing: -1px;
}

.about-intro {
    font-size: 19px;
    color: var(--text-gray);
    margin-bottom: 40px;
    font-weight: 400;
    line-height: 1.8;
}

.about-text p {
    margin-bottom: 24px;
    color: var(--text-gray);
    line-height: 1.9;
    font-weight: 300;
}

.about-values {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-top: 64px;
}

.value-item {
    padding: 28px 32px;
    background: var(--bg-dark);
    border-left: 3px solid var(--primary-color);
    border-radius: 0;
}

.value-item strong {
    display: block;
    font-size: 17px;
    margin-bottom: 10px;
    color: var(--text-white);
    font-weight: 500;
}

.value-item span {
    color: var(--text-gray);
    font-weight: 300;
    line-height: 1.8;
}

.about-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.about-card {
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 64px 48px;
    text-align: center;
    max-width: 450px;
}

.about-card-icon {
    font-size: 56px;
    margin-bottom: 32px;
    color: var(--text-gray);
}

.about-card h3 {
    font-size: 24px;
    font-weight: 400;
    margin-bottom: 20px;
    color: var(--text-white);
}

.about-card p {
    color: var(--text-gray);
    line-height: 1.8;
    font-weight: 300;
}

/* Contact Section */
.contact {
    padding: 160px 0;
    background: var(--bg-dark);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 48px;
}

.contact-item {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.contact-icon {
    font-size: 28px;
    background: var(--bg-gray);
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 4px;
    flex-shrink: 0;
    color: var(--text-gray);
}

.contact-item h4 {
    font-size: 19px;
    font-weight: 500;
    margin-bottom: 10px;
    color: var(--text-white);
}

.contact-item p {
    color: var(--text-gray);
    font-weight: 300;
}

.contact-form {
    background: var(--bg-gray);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 48px;
}

.form-group {
    margin-bottom: 28px;
}

.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 14px;
    color: var(--text-white);
    font-size: 15px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 16px 20px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    color: var(--text-white);
    font-size: 16px;
    transition: all 0.3s ease;
    font-weight: 300;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    background: var(--bg-gray);
}

.form-group textarea {
    resize: vertical;
    min-height: 140px;
}

/* Download Section */
.download {
    padding: 160px 0;
    background: var(--primary-color);
}

.download-content {
    text-align: center;
}

.download-content h2 {
    font-size: 48px;
    font-weight: 300;
    margin-bottom: 24px;
    color: #ffffff;
    letter-spacing: -1px;
}

.download-content > p {
    font-size: 19px;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: 64px;
    font-weight: 300;
    line-height: 1.8;
}

.download-buttons {
    display: flex;
    gap: 24px;
    justify-content: center;
    margin-bottom: 64px;
    flex-wrap: wrap;
}

.download-btn-apple,
.download-btn-android {
    display: flex;
    align-items: center;
    gap: 14px;
    background: transparent;
    border: 2px solid #ffffff;
    color: #ffffff;
    padding: 18px 36px;
    border-radius: 4px;
    text-decoration: none;
    transition: all 0.3s ease;
    min-width: 220px;
}

.download-btn-apple:hover,
.download-btn-android:hover {
    background: #ffffff;
    color: var(--primary-color);
}

.download-btn-icon {
    font-size: 32px;
}

.download-btn-small {
    display: block;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.85);
}

.download-btn-large {
    display: block;
    font-size: 19px;
    font-weight: 500;
}

.download-qr {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
    margin-top: 64px;
}

.qr-code {
    width: 200px;
    height: 200px;
    background: white;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #000;
    border-radius: 4px;
    font-weight: 500;
}

.download-qr p {
    color: rgba(255, 255, 255, 0.85);
    font-weight: 300;
}

/* Footer */
.footer {
    padding: 100px 0 60px;
    background: var(--bg-gray);
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 48px;
    margin-bottom: 60px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 28px;
    font-weight: 500;
}

.footer-section p {
    color: var(--text-gray);
    font-weight: 300;
    line-height: 1.8;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 12px;
}

.footer-section ul a {
    color: var(--text-gray);
    text-decoration: none;
    transition: color 0.3s ease;
    font-weight: 300;
}

.footer-section ul a:hover {
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 12px;
}

.social-links a {
    background: var(--bg-dark);
    padding: 12px 24px;
    border-radius: 4px;
    color: var(--text-gray);
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 300;
}

.social-links a:hover {
    background: var(--primary-color);
    color: #ffffff;
}

.footer-bottom {
    text-align: center;
    padding-top: 56px;
    border-top: 1px solid var(--border-color);
}

.footer-bottom p {
    color: var(--text-gray);
    font-weight: 300;
}

/* Responsive */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 56px;
    }

    .title-secondary {
        font-size: 36px;
    }

    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }

    .about-content,
    .contact-content {
        gap: 48px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-menu.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: var(--bg-gray);
        padding: 28px;
        box-shadow: 0 8px 40px rgba(0, 0, 0, 0.08);
    }

    .hero-title {
        font-size: 42px;
    }

    .title-secondary {
        font-size: 28px;
    }

    .hero-description {
        font-size: 16px;
    }

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

    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
    }

    .download-buttons {
        flex-direction: column;
        align-items: center;
    }

    .section-header h2 {
        font-size: 36px;
    }

    .features {
        padding: 120px 0;
    }

    .how-it-works,
    .about,
    .contact,
    .download {
        padding: 120px 0;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
    }

    .hero-stats {
        grid-template-columns: 1fr;
    }

    .section-header h2 {
        font-size: 32px;
    }

    .stat-number {
        font-size: 40px;
    }

    .hero-title {
        font-size: 36px;
    }

    .title-secondary {
        font-size: 24px;
    }
}