:root {
    --bg: #f8f9fb;
    --text: #1a1a1a;
    --muted: #6d6d6d;
    --card: #ffffff;
    --accent1: #6b2cff;
    --accent2: #00a6ff;
    --radius: 14px;
    --container: 1400px;
    /* 改成 90% 屏幕宽度 */
    --shadow: 0 4px 18px rgba(0, 0, 0, 0.05);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: Inter, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
    line-height: 1.7;
}


/* Layout */
header {
    position: sticky;
    top: 0;
    background: #ffffffcc;
    backdrop-filter: blur(12px);
    border-bottom: 1px solid #e8e8e8;
    z-index: 30;
}

.nav {
    max-width: var(--container);
    margin: 0 auto;
    padding: 18px 24px;
    display: flex;
    align-items: center;
    gap: 20px;
}

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

.brand img {
    height: 48px;
}

nav {
    display: flex;
    margin-left: auto;
    gap: 20px;
}

nav a {
    padding: 10px 14px;
    border-radius: 10px;
    color: #444;
    font-weight: 600;
    transition: 0.2s;
}

nav a:not(.cta):hover {
    background: #f0f0f8;
}

/* 🔥 选中状态 */
nav a.active {
    background: #eaeaff;
    color: var(--accent1);
}

.cta {
    background: linear-gradient(90deg, var(--accent1), #9b6bff);
    color: white;
    padding: 10px 18px;
    border-radius: 12px;
    text-decoration: none;
    /* ← 按钮也不带下划线 */
}

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

footer {
    text-align: center;
    margin-top: 60px;
    padding: 20px;
    color: #777;
    font-size: 14px;
}

h1 {
    margin: 0;
    font-size: 32px;
    font-weight: 700;
}