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

:root {
    --color-primary: #E85D04;
    --color-primary-dark: #C94A00;
    --color-primary-light: #FFF0E5;
    --color-accent: #F9C74F;
    --color-accent-green: #2A9D8F;
    --color-bg: #FDF8F5;
    --color-card: #FFFFFF;
    --color-text: #2D1B0E;
    --color-text-secondary: #5A4030;
    --color-text-light: #A48F7A;
    --color-border: #F0E3D8;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.07), 0 2px 6px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 12px 48px rgba(0, 0, 0, 0.10), 0 4px 12px rgba(0, 0, 0, 0.04);
    --radius: 16px;
    --transition: 0.30s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --nav-height: 72px;
}

html { scroll-behavior: smooth; }

[id] { scroll-margin-top: calc(var(--nav-height) + 12px); }

body {
    font-family: var(--font);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-primary-dark); }

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

/* ===== 双语切换（经典 display 切换：当前语言显示、另一语言隐藏，布局由内容天然决定；激活语言淡入过渡） ===== */
.i18n { display: inline; }
.i18n > [data-lang] { display: none; }
html:not(.lang-zh) .i18n > [data-lang="en"],
html.lang-zh .i18n > [data-lang="zh"] { display: inline; animation: i18n-fade 0.7s ease-out; }
@keyframes i18n-fade { from { opacity: 0; } to { opacity: 1; } }

/* ===== 导航栏 ===== */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    height: var(--nav-height);
    display: flex;
    align-items: center;
    background: rgba(255, 252, 248, 0.78);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border-bottom: 1px solid rgba(240, 227, 216, 0.5);
    transition: background var(--transition), box-shadow var(--transition);
}
.navbar.scrolled { background: rgba(255, 252, 248, 0.92); box-shadow: var(--shadow-sm); }
.navbar .container { display: flex; align-items: center; justify-content: space-between; width: 100%; gap: 12px; }
.navbar-brand {
    display: flex; align-items: center; gap: 10px;
    font-weight: 700; font-size: 1.25rem; color: var(--color-text);
    letter-spacing: -0.02em; white-space: nowrap;
}
.navbar-brand img.navbar-logo { height: 24px; width: auto; }
.navbar-brand .logo-text { color: var(--color-primary); }
.navbar-brand .sustech {
    font-weight: 500; font-size: 0.85rem; color: var(--color-text-secondary);
    background: var(--color-bg); padding: 2px 12px; border-radius: 40px;
    border: 1px solid var(--color-border);
}
.nav-links { display: flex; align-items: center; gap: 8px; list-style: none; }
.nav-links li a {
    display: flex; align-items: center; justify-content: center; text-align: center; padding: 8px 18px; font-weight: 500; font-size: 0.95rem;
    color: var(--color-text-secondary); border-radius: 40px; position: relative;
    transition: color var(--transition), background var(--transition);
}
.nav-links li a::after {
    content: ''; position: absolute; bottom: 4px; left: 50%;
    transform: translateX(-50%) scaleX(0); width: 70%; height: 2.5px;
    background: var(--color-primary); border-radius: 4px;
    transition: transform var(--transition), opacity var(--transition); opacity: 0;
}
.nav-links li a:hover { color: var(--color-primary); background: var(--color-primary-light); }
.nav-links li a:hover::after { transform: translateX(-50%) scaleX(1); opacity: 1; }
.nav-links li a.active { color: var(--color-primary); background: var(--color-primary-light); font-weight: 600; }
.nav-links li a.active::after { transform: translateX(-50%) scaleX(1); opacity: 1; }

.lang-toggle {
    display: inline-flex; align-items: center; justify-content: center; text-align: center; gap: 4px; padding: 6px 16px;
    border-radius: 40px; border: 1px solid var(--color-border);
    background: var(--color-card); color: var(--color-primary);
    font-weight: 600; font-size: 0.85rem; font-family: var(--font);
    cursor: pointer; white-space: nowrap;
    transition: background var(--transition), border-color var(--transition), transform var(--transition);
}
.lang-toggle:hover { background: var(--color-primary-light); border-color: var(--color-primary); transform: scale(1.03); }

.hamburger {
    display: none; flex-direction: column; gap: 5px; background: none; border: none;
    cursor: pointer; padding: 6px; border-radius: 8px; transition: background var(--transition);
}
.hamburger span { display: block; width: 24px; height: 2.5px; background: var(--color-text); border-radius: 4px; transition: transform var(--transition), opacity var(--transition); }
.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ===== 面包屑 ===== */
.breadcrumb {
    background: var(--color-card);
    border-bottom: 1px solid var(--color-border);
    padding: 14px 0;
    font-size: 0.9rem;
}
.breadcrumb a { font-weight: 500; }

/* ===== 个人档案区 ===== */
.profile {
    background: linear-gradient(165deg, #FFF0E5 0%, #FDE5D0 60%, #F9C74F 100%);
    padding: 56px 0;
    border-bottom: 1px solid var(--color-border);
}
.profile-grid { display: grid; grid-template-columns: 300px 1fr; gap: 48px; align-items: center; }
.profile-photo img {
    width: 100%; max-width: 300px; aspect-ratio: 1/1; object-fit: cover;
    border-radius: var(--radius); box-shadow: var(--shadow-md);
    border: 4px solid var(--color-primary-light);
    transition: transform var(--transition), box-shadow var(--transition);
}
.profile-photo img:hover { transform: scale(1.02); box-shadow: var(--shadow-lg); }
.profile-info h1 { font-size: 2.4rem; font-weight: 700; letter-spacing: -0.02em; }
.profile-info .role { font-size: 1.1rem; font-weight: 600; color: var(--color-primary); margin-top: 6px; }
.profile-meta { margin-top: 18px; display: flex; flex-direction: column; gap: 8px; font-size: 0.95rem; }
.profile-meta .meta-item { color: var(--color-text-secondary); }
.profile-meta a { color: var(--color-primary); text-decoration: underline; word-break: break-all; }

/* ===== 内容区块 ===== */
.section { padding: 48px 0; border-bottom: 1px solid var(--color-border); background: var(--color-card); }
.section:nth-of-type(even) { background: var(--color-bg); }
.section h2 {
    font-size: 1.5rem; font-weight: 700; margin-bottom: 18px;
    display: flex; align-items: center; gap: 10px;
}
.section h2 .sec-icon { font-size: 1.6rem; }
.section p { color: var(--color-text-secondary); font-size: 1.02rem; line-height: 1.75; }
.section ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
.section ul li {
    color: var(--color-text-secondary); font-size: 1rem; line-height: 1.6;
    padding-left: 22px; position: relative;
}
.section ul li::before {
    content: '▸'; position: absolute; left: 4px; color: var(--color-primary); font-weight: 700;
}
.pub-item {
    background: var(--color-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    padding: 18px 20px;
    box-shadow: var(--shadow-sm);
    margin-bottom: 14px;
}
.pub-item .pub-title { font-weight: 700; color: var(--color-text); margin-bottom: 4px; }
.pub-item .pub-venue { font-size: 0.88rem; color: var(--color-text-light); font-style: italic; }
.badge {
    display: inline-flex; align-items: center; justify-content: center; text-align: center; font-size: 0.72rem; font-weight: 600; color: var(--color-primary);
    background: var(--color-primary-light); border-radius: 40px; padding: 2px 12px; margin-left: 8px;
    vertical-align: middle;
}

/* ===== 页脚 ===== */
.footer {
    background: var(--color-text); color: rgba(255, 255, 255, 0.75);
    padding: 40px 0 28px; border-top: 1px solid rgba(255, 255, 255, 0.06);
}
.footer .container { display: flex; flex-direction: column; gap: 20px; }
.footer-top { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 16px; }
.footer-brand { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; font-weight: 700; font-size: 1.2rem; color: #FFFFFF; }
.footer-brand img.footer-logo { height: 40px; width: auto; background: #FFFFFF; border-radius: 8px; padding: 4px 10px; }
.footer-brand .logo-text { color: #F9C74F; }
.footer-brand small { font-weight: 400; font-size: 0.82rem; color: rgba(255, 255, 255, 0.5); margin-left: 8px; }
.footer-links { display: flex; gap: 22px; flex-wrap: wrap; }
.footer-links a { color: rgba(255, 255, 255, 0.60); font-size: 0.92rem; text-align: center; transition: color var(--transition); }
.footer-links a:hover { color: #FFFFFF; }
.footer-bottom { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 10px; padding-top: 16px; border-top: 1px solid rgba(255, 255, 255, 0.06); font-size: 0.82rem; color: rgba(255, 255, 255, 0.40); }

/* ===== 滚动动画 ===== */
.reveal { opacity: 0; transform: translateY(30px); transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.25, 0.46, 0.45, 0.94); }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    :root { --nav-height: 64px; }
    .profile { padding: 40px 0; }
    .profile-grid { grid-template-columns: 1fr; gap: 28px; text-align: center; }
    .profile-photo img { max-width: 220px; margin: 0 auto; }
    .profile-meta { align-items: center; }
    .section { padding: 36px 0; }
    .navbar-brand .sustech { display: none; }
    .nav-links {
        position: fixed; top: var(--nav-height); left: 0; right: 0;
        background: rgba(255, 252, 248, 0.96); backdrop-filter: blur(16px);
        -webkit-backdrop-filter: blur(16px); flex-direction: column;
        padding: 20px 24px 28px; gap: 4px; border-bottom: 1px solid var(--color-border);
        transform: translateY(-120%); opacity: 0;
        transition: transform 0.35s ease, opacity 0.35s ease;
        box-shadow: var(--shadow-md); border-radius: 0 0 var(--radius) var(--radius);
        pointer-events: none;
    }
    .nav-links.open { transform: translateY(0); opacity: 1; pointer-events: auto; }
    .nav-links li a { padding: 12px 16px; width: 100%; text-align: center; font-size: 1.05rem; }
    .nav-links li a::after { display: none; }
    .hamburger { display: flex; }
    .footer-top { flex-direction: column; align-items: flex-start; }
    .footer-bottom { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 480px) {
    .container { padding: 0 16px; }
}

.footer-bottom .social a.social-link { color: rgba(255, 255, 255, 0.6); font-size: 0.9rem; }

/* 小红书二维码模态框 */
.qr-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.25s ease, visibility 0s linear 0.25s;
}
.qr-modal.open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transition: opacity 0.3s ease;
}
.qr-modal-content {
    background: #FFFFFF;
    padding: 20px;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    transform: translateY(10px);
    transition: transform 0.3s ease;
}
.qr-modal.open .qr-modal-content { transform: translateY(0); }
.qr-modal-content img {
    display: block;
    max-width: 260px;
    width: 100%;
    height: auto;
    border-radius: 8px;
}
.footer-bottom .social { display: flex; gap: 16px; }