/* 全局重置与变量 */
:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --text-color: #1f2937;
    --bg-light: #f3f4f6;
    --white: #ffffff;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    color: var(--text-color);
    line-height: 1.6;
}

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

/* 导航栏 */
.navbar {
    background: var(--white);
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo-icon {
    background: var(--primary-color);
    color: var(--white);
    width: 32px;
    height: 32px;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
}

nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: var(--transition);
}

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

.btn-primary {
    background: var(--primary-color);
    color: var(--white) !important;
    padding: 8px 20px;
    border-radius: 6px;
}

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

/* 主视觉区域 */
.hero {
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    padding: 180px 0 100px;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    color: #1e3a8a;
}

.hero p {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 40px;
    color: #4b5563;
}

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

.btn-large {
    padding: 14px 32px;
    font-size: 1.1rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--bg-light);
}

/* 核心功能区域 */
.features {
    padding: 100px 0;
    background: var(--white);
}

.features h2 {
    text-align: center;
    font-size: 2.2rem;
    margin-bottom: 60px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
}

.feature-card {
    background: var(--bg-light);
    padding: 40px 30px;
    border-radius: 12px;
    transition: var(--transition);
    border: 1px solid transparent;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.05);
    border-color: var(--primary-color);
    background: var(--white);
}

.feature-card .icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.2rem;
    margin-bottom: 12px;
}

.feature-card p {
    color: #6b7280;
    font-size: 0.95rem;
}

/* 页脚 */
footer {
    background: #111827;
    color: #9ca3af;
    padding: 40px 0;
    text-align: center;
    font-size: 0.9rem;
}

footer p {
    margin-bottom: 8px;
}

/* 响应式调整 */
@media (max-width: 768px) {
    .hero h1 { font-size: 2rem; }
    .hero-buttons { flex-direction: column; align-items: center; }
    nav a:not(.btn-primary) { display: none; } /* 移动端隐藏普通链接 */
    .navbar .container { justify-content: space-between; }
}