:root {
    --primary: #4f46e5;
    --secondary: #8b5cf6;
    --text: #1f2937;
    --text-light: #4b5563;
    --text-muted: #9ca3af;
    --bg: #ffffff;
    --bg-light: #f9fafb;
    --border: #e5e7eb;
    --border-light: #f3f4f6;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
}

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

html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.8;
}

/* ===== 顶部导航 ===== */
.about-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.about-header-inner {
    max-width: 860px;
    margin: 0 auto;
    padding: 0 24px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.about-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--text);
}

.about-brand img { width: 34px; height: 34px; border-radius: 8px; }
.about-brand-text { font-weight: 700; font-size: 1.05rem; }
.about-brand-text em {
    font-style: normal;
    font-weight: 500;
    color: var(--text-muted);
    margin-left: 6px;
    font-size: 0.9rem;
}

.about-link {
    color: var(--text-light);
    text-decoration: none;
    font-size: 0.9rem;
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    transition: all 0.2s;
}

.about-link:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: #f5f3ff;
}

/* ===== 页头 ===== */
.about-hero {
    text-align: center;
    padding: 48px 24px 32px;
    background:
        radial-gradient(600px 220px at 50% -40px, rgba(99, 102, 241, 0.15), transparent),
        var(--bg-light);
    border-bottom: 1px solid var(--border);
}

.about-hero h1 { font-size: 2rem; font-weight: 800; letter-spacing: -0.02em; }
.about-hero p { margin-top: 10px; color: var(--text-light); font-size: 0.95rem; }

/* ===== 左侧边栏 + 内容区 ===== */
.about-layout {
    max-width: 1080px;
    margin: 0 auto;
    padding: 32px 24px 72px;
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: 40px;
    align-items: start;
}

.about-sidebar {
    position: sticky;
    top: 88px;
    display: flex;
    flex-direction: column;
    gap: 4px;
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: 14px;
    padding: 10px;
}

.about-side-item {
    display: block;
    padding: 11px 16px;
    color: var(--text-light);
    text-decoration: none;
    font-size: 0.95rem;
    border-radius: 9px;
    transition: all 0.2s;
}

.about-side-item:hover { color: var(--primary); }

.about-side-item.active {
    color: var(--primary);
    background: #eef2ff;
    font-weight: 600;
}

.about-content { min-width: 0; }

.about-card { display: none; padding: 8px 4px; }
.about-card.active { display: block; }

.about-card h2 {
    font-size: 1.5rem;
    font-weight: 800;
    margin-bottom: 8px;
}

.about-card .subtitle {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 24px;
}

.about-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin: 28px 0 8px;
}

.about-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 10px;
}

.about-card ul {
    padding-left: 20px;
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 10px;
}

.about-card li { margin: 4px 0; }

/* 理念卡片 */
.values-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 16px;
}

.value-card {
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: 14px;
    padding: 20px;
    text-align: center;
}

.value-card .icon {
    width: 44px;
    height: 44px;
    margin: 0 auto 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    background: var(--gradient);
    color: #fff;
}

.value-card h4 { font-size: 1rem; margin-bottom: 4px; }
.value-card p { font-size: 0.85rem; color: var(--text-muted); margin: 0; }

/* 联系卡片 */
.contact-list { display: flex; flex-direction: column; gap: 12px; margin-top: 16px; }

.contact-item {
    display: flex;
    align-items: center;
    gap: 14px;
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 14px 18px;
}

.contact-item .icon {
    width: 38px;
    height: 38px;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    background: var(--gradient);
    color: #fff;
}

.contact-item .label { font-size: 0.82rem; color: var(--text-muted); }
.contact-item .value { font-size: 0.95rem; font-weight: 600; color: var(--text); }

/* 加入我们：职位卡片 */
.jobs-list { display: flex; flex-direction: column; gap: 12px; margin-top: 16px; }

.job-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    background: var(--bg-light);
    border: 1px solid var(--border-light);
    border-radius: 12px;
    padding: 16px 20px;
    transition: border-color 0.2s;
    flex-wrap: wrap;
}

.job-card:hover { border-color: var(--primary); }

.job-card h4 { font-size: 1rem; margin-bottom: 2px; }
.job-card .meta { font-size: 0.82rem; color: var(--text-muted); }
.job-tag {
    font-size: 0.78rem;
    color: var(--primary);
    background: #eef2ff;
    border-radius: 999px;
    padding: 4px 12px;
    white-space: nowrap;
}

/* ===== 响应式 ===== */
@media (max-width: 720px) {
    .about-hero h1 { font-size: 1.6rem; }
    .about-layout { grid-template-columns: 1fr; gap: 24px; }
    .about-sidebar {
        position: static;
        flex-direction: row;
        overflow-x: auto;
        top: auto;
    }
    .about-side-item { white-space: nowrap; }
    .values-grid { grid-template-columns: 1fr; }
    .job-card { flex-direction: column; align-items: flex-start; }
}