:root {
    --primary-color: #2E7D32;
    --secondary-color: #81C784;
    --text-color: #333;
    --bg-color: #f9fbf9;
    --white: #ffffff;
    --gray: #666;
    --radius: 8px;
    --shadow: 0 4px 6px rgba(0,0,0,0.1);
}

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

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

/* Language Toggling */
body.lang-en .lang-zh { display: none; }
body.lang-zh .lang-en { display: none; }

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo {
    width: 40px;
    height: 40px;
    border-radius: 8px;
}

.brand-name {
    font-weight: bold;
    font-size: 1.2rem;
    color: var(--primary-color);
}

.divider {
    color: #ccc;
    margin: 0 5px;
}

.btn-outline {
    border: 1px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.3s;
}

.btn-outline:hover {
    background: var(--primary-color);
    color: var(--white);
}

/* Hero */
.hero {
    text-align: center;
    padding: 80px 20px;
    background: linear-gradient(180deg, var(--white) 0%, #e8f5e9 100%);
}

.badge {
    background: #e3f2fd;
    color: #1565c0;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-block;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--gray);
    max-width: 600px;
    margin: 0 auto 30px;
}

.btn-primary {
    background: var(--primary-color);
    color: var(--white);
    text-decoration: none;
    padding: 12px 24px;
    border-radius: 25px;
    font-weight: 600;
    display: inline-block;
    transition: transform 0.2s;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(46, 125, 50, 0.3);
}

/* App Preview Section */
.app-preview-section {
    padding: 0 0 80px 0;
    text-align: center;
    background: linear-gradient(180deg, #e8f5e9 0%, var(--white) 100%);
}

.app-preview-image {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
}

.app-preview-image img {
    width: 100%;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

/* Problem Section */
.problem-section {
    padding: 80px 0;
    background: var(--white);
}

.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.problem-image img {
    width: 100%;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.problem-text h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: #c62828; /* Slight red for problem */
}

/* Mission Section */
.mission-section {
    padding: 80px 0;
    text-align: center;
    background-color: var(--primary-color);
    color: var(--white);
}

.mission-section h2 {
    margin-bottom: 30px;
    font-size: 2rem;
}

.mission-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.2rem;
    font-weight: 300;
}

/* Features Section */
.features-section {
    padding: 80px 0;
}

.features-section h2 {
    text-align: center;
    margin-bottom: 50px;
    font-size: 2rem;
    color: var(--primary-color);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.card {
    background: var(--white);
    padding: 30px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s;
}

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

.icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.card h3 {
    margin-bottom: 15px;
    color: var(--text-color);
}

.card p {
    color: var(--gray);
    font-size: 0.95rem;
}

/* Footer */
footer {
    padding: 40px 0;
    text-align: center;
    color: var(--gray);
    border-top: 1px solid #eee;
}

.icp-info {
    margin-top: 10px;
    font-size: 0.9rem;
}

.icp-info a {
    color: var(--gray);
    text-decoration: none;
}

.icp-info a:hover {
    text-decoration: underline;
}

/* Responsive */
@media (max-width: 768px) {
    .grid-2 {
        grid-template-columns: 1fr;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .navbar {
        flex-direction: column;
        gap: 15px;
    }
}