* {
    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: #333;
    background-color: #fff;
}

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

header {
    height: 70px;
    display: flex;
    align-items: center;
    background: #fff;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid #f0f0f0;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo img {
    height: 30px;
}

nav a {
    margin: 0 15px;
    text-decoration: none;
    color: #333;
    font-size: 14px;
}

.header-btns a {
    margin-left: 15px;
    text-decoration: none;
    padding: 8px 20px;
    border-radius: 4px;
    font-size: 14px;
}

.btn-download-top {
    background-color: #0052d9;
    color: #fff;
}

.btn-login {
    border: 1px solid #0052d9;
    color: #0052d9;
}

.hero {
    padding: 100px 0;
    background: linear-gradient(135deg, #f5f7fa 0%, #fff 100%);
}

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

.hero-text {
    flex: 1;
}

.hero-text h1 {
    font-size: 48px;
    color: #0052d9;
    margin-bottom: 10px;
}

.hero-text h2 {
    font-size: 36px;
    margin-bottom: 20px;
    color: #333;
}

.hero-text p {
    font-size: 18px;
    color: #666;
    margin-bottom: 40px;
    max-width: 500px;
}

.hero-btns {
    display: flex;
    gap: 20px;
}

.btn-primary {
    background-color: #0052d9;
    color: #fff;
    padding: 12px 40px;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
}

.btn-secondary {
    background-color: #fff;
    color: #0052d9;
    border: 1px solid #0052d9;
    padding: 12px 40px;
    border-radius: 4px;
    text-decoration: none;
}

.hero-image {
    flex: 1;
    text-align: right;
}

.hero-image img {
    max-width: 100%;
    height: auto;
}

.apps {
    padding: 80px 0;
    text-align: center;
}

.apps h3 {
    font-size: 32px;
    margin-bottom: 50px;
}

.app-grid {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 60px;
}

.app-item {
    width: 120px;
}

.app-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
    background-color: #f0f0f0;
    border-radius: 12px;
}

.app-icon.doc { background-color: #4a90e2; }
.app-icon.sheet { background-color: #7ed321; }
.app-icon.ppt { background-color: #f5a623; }
.app-icon.pdf { background-color: #d0021b; }
.app-icon.form { background-color: #f8e71c; }

.app-item h4 {
    font-size: 16px;
    margin-bottom: 5px;
}

.app-item p {
    font-size: 12px;
    color: #999;
}

.center-btn {
    margin-top: 40px;
}

.btn-primary.large {
    padding: 15px 60px;
    font-size: 18px;
}

.features {
    padding: 80px 0;
    background-color: #f9f9f9;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    background: #fff;
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.03);
}

.feature-card h4 {
    font-size: 20px;
    margin-bottom: 15px;
    color: #0052d9;
}

.feature-card p {
    font-size: 14px;
    color: #666;
}

footer {
    padding: 60px 0;
    text-align: center;
    border-top: 1px solid #eee;
}

.footer-links {
    margin-top: 20px;
}

.footer-links a {
    margin: 0 10px;
    color: #999;
    text-decoration: none;
    font-size: 14px;
}