:root {
    --primary: #e74c3c; --paper-bg: #fffbf0; --envelope-bg: #fdf5e6; --flap-bg: #faebd7;
    --font-base: -apple-system, BlinkMacSystemFont, "Microsoft YaHei", "PingFang SC", sans-serif;
    --font-hand: "KaiTi", "STKaiti", "楷体", serif;
}

.about_us-plugin-container {
    min-height: 100vh; padding: 60px 0; font-family: var(--font-base); color: #444; 
    background-size: cover; background-attachment: fixed; position: relative;
}
.about_us-mask { position: absolute; top: 0; left: 0; right: 0; bottom: 0; background: rgba(255, 255, 255, 0.85); z-index: 1; }
.about_us-container { position: relative; z-index: 2; max-width: 1000px; margin: 0 auto; padding: 0 20px; }
.empty-tip { text-align: center; padding: 50px; color: #888; font-size: 16px; }
.page-not-found { text-align: center; padding: 100px 20px; }
.page-not-found h2 { font-size: 32px; color: #333; margin-bottom: 20px; }

/* 头部 */
.about_us-header { text-align: center; margin-bottom: 60px; }
.about_us-title { font-family: var(--font-hand); font-size: 3.5rem; color: #333; margin-bottom: 10px; font-weight: bold; }
.about_us-subtitle { font-size: 1rem; color: #666; border-top: 1px solid #ddd; border-bottom: 1px solid #ddd; display: inline-block; padding: 8px 30px; letter-spacing: 2px; }

/* 顶部导航菜单 */
.top-nav-menu { display: flex; justify-content: center; gap: 15px; margin: 25px 0; flex-wrap: wrap; }
.top-nav-item { padding: 8px 20px; background: #fff; border: 1px solid #e2e8f0; border-radius: 6px; color: #475569; text-decoration: none; transition: 0.2s; font-size: 0.9rem; }
.top-nav-item:hover { background: #6366f1; color: #fff; border-color: #6366f1; }

/* 页面导航 */
.page-header { margin-bottom: 40px; }
.page-nav { display: flex; align-items: center; gap: 10px; margin-bottom: 20px; color: #666; font-size: 0.9rem; }
.nav-home { color: #6366f1; text-decoration: none; }
.nav-home:hover { text-decoration: underline; }
.nav-separator { color: #ccc; }
.nav-current { color: #333; font-weight: 500; }
.page-title { font-size: 2.5rem; color: #333; margin: 0; }

/* 页面内容 */
.page-content { background: #fff; padding: 40px; border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.05); }
.default-template { max-width: 800px; margin: 0 auto; }
.wide-template { max-width: 100%; }
.simple-template { background: none; box-shadow: none; padding: 20px 0; }

/* 筛选 */
.about_us-filter { margin-top: 25px; display: flex; justify-content: center; gap: 10px; flex-wrap: wrap; }
.filter-btn { padding: 6px 20px; background: #fff; border: 1px dashed #ccc; border-radius: 4px; color: #666; cursor: pointer; transition: 0.2s; text-decoration: none; }
.filter-btn.active, .filter-btn:hover { background: var(--primary); color: #fff; border-color: var(--primary); border-style: solid; }

/* 时间轴 */
.about_us { position: relative; padding: 20px 0; }
.about_us::before { content: ''; position: absolute; top: 0; bottom: 0; left: 50%; width: 2px; background: linear-gradient(to bottom, #ccc 50%, transparent 50%); background-size: 2px 20px; margin-left: -1px; }

.about_us-event { position: relative; margin-bottom: 80px; display: flex; justify-content: center; width: 100%; transition: 0.5s; opacity: 1; }
.about_us-event.js-ready { opacity: 0; transform: translateY(50px); }
.about_us-event.js-visible { opacity: 1; transform: translateY(0); }

.about_us-content { width: 45%; position: relative; }
.about_us-event:nth-child(odd) { justify-content: flex-start; }
.about_us-event:nth-child(odd) .about_us-content { margin-left: auto; padding-right: 50px; }
.about_us-event:nth-child(even) { justify-content: flex-end; }
.about_us-event:nth-child(even) .about_us-content { margin-right: auto; padding-left: 50px; }

/* 日历 */
.calendar-flip { position: absolute; top: 20px; width: 60px; height: 66px; z-index: 10; box-shadow: 0 4px 10px rgba(0,0,0,0.1); background: #fff; border-radius: 4px; border: 1px solid #eee; }
.calendar-flip::before { content: ''; position: absolute; top: -5px; left: 50%; margin-left: -20px; width: 40px; height: 10px; border-radius: 10px; background: rgba(0,0,0,0.1); z-index: 1; }
.about_us-event:nth-child(odd) .calendar-flip { right: -30px; }
.about_us-event:nth-child(even) .calendar-flip { left: -30px; }
.calendar-top { background: #ff7675; color: white; height: 24px; line-height: 24px; text-align: center; font-size: 12px; font-weight: bold; }
.calendar-bottom { display: flex; flex-direction: column; align-items: center; justify-content: center; height: 42px; }
.calendar-bottom .day { font-size: 24px; font-weight: 800; color: #333; line-height: 1; }
.calendar-bottom .weekday { font-size: 10px; color: #999; margin-top: 2px; }

/* 信封 */
.envelope { background: var(--envelope-bg); border-radius: 4px; padding: 25px; box-shadow: 0 10px 25px rgba(0,0,0,0.08); position: relative; border: 1px solid rgba(0,0,0,0.03); transition: 0.3s; }
.about_us-event:hover .envelope { transform: scale(1.02); z-index: 20; }
.envelope-flap { position: absolute; top: 0; left: 0; width: 100%; height: 40px; background: var(--flap-bg); clip-path: polygon(0 0, 50% 100%, 100% 0); z-index: 2; filter: drop-shadow(0 2px 2px rgba(0,0,0,0.1)); transition: 0.5s; transform-origin: top; }
.about_us-event:hover .envelope-flap { transform: rotateX(180deg); opacity: 0.2; }

/* 装饰 */
.css-pin { position: absolute; top: -10px; left: 50%; width: 14px; height: 14px; background: radial-gradient(circle at 30% 30%, #e74c3c, #c0392b); border-radius: 50%; margin-left: -7px; z-index: 20; box-shadow: 2px 2px 4px rgba(0,0,0,0.3); }
.wax-seal { position: absolute; top: 20px; left: 50%; transform: translateX(-50%); width: 28px; height: 28px; background: radial-gradient(circle at 30% 30%, #ff7675, #d63031); border-radius: 50%; z-index: 3; box-shadow: 0 2px 4px rgba(0,0,0,0.2); }
.stamp-container { position: relative; height: 60px; }
.post-stamp { position: absolute; top: 15px; right: 15px; z-index: 5; background: #fff; padding: 4px; box-shadow: 0 2px 4px rgba(0,0,0,0.2); transform: rotate(5deg); background-image: radial-gradient(transparent 0px, transparent 3px, #fff 3px, #fff); background-size: 10px 10px; background-position: -5px -5px; }
.post-mark { position: absolute; top: -5px; left: -20px; width: 60px; height: 60px; border: 2px solid rgba(0,0,0,0.2); border-radius: 50%; transform: rotate(-20deg); display: flex; align-items: center; justify-content: center; font-size: 10px; color: rgba(0,0,0,0.4); pointer-events: none; }
.stamp-text { display: block; padding: 2px 4px; font-size: 12px; font-weight: bold; color: #333; }

/* 信纸 */
.letter { background: var(--paper-bg); padding: 25px; box-shadow: 0 1px 3px rgba(0,0,0,0.1); position: relative; z-index: 1; background-image: linear-gradient(#f0f0f0 1px, transparent 1px); background-size: 100% 30px; }
.letter-header { margin-bottom: 20px; border-bottom: 2px solid #333; padding-bottom: 8px; display: flex; justify-content: space-between; align-items: baseline; }
.event-title { margin: 0; font-size: 1.4rem; color: #222; font-weight: bold; }
.event-title a.event-link { color: #222; text-decoration: none; }
.event-title a.event-link:hover { color: #e74c3c; }
.event-year { color: #888; font-style: italic; }
.event-image-wrap { position: relative; margin: 15px auto; width: 95%; background: #fff; border: 5px solid #fff; box-shadow: 0 3px 8px rgba(0,0,0,0.15); transform: rotate(-1deg); }
.css-paperclip { position: absolute; top: -12px; right: 15px; width: 10px; height: 30px; border-radius: 10px; border: 3px solid #bdc3c7; z-index: 10; }
.event-image { width: 100%; display: block; cursor: zoom-in; }
.event-description { font-size: 15px; color: #444; line-height: 30px; text-align: justify; }
.event-description img { max-width: 100%; height: auto; }
.event-description p { margin: 0 0 15px 0; }
.event-description a { color: #e74c3c; text-decoration: none; }
.event-description a:hover { text-decoration: underline; }
.letter-footer { margin-top: 20px; padding-top: 10px; border-top: 1px dashed #ddd; display: flex; justify-content: space-between; align-items: center; }
.category-link { display: inline-block; padding: 4px 12px; background: #f1f5f9; border-radius: 4px; color: #475569; text-decoration: none; font-size: 12px; }
.category-link:hover { background: #e2e8f0; }

/* 特殊事件 */
.about_us-event.special .calendar-top { background: #e74c3c; }
.about_us-event.special .wax-seal { background: radial-gradient(circle at 30% 30%, #e74c3c, #c0392b); }

@media (max-width: 768px) {
    .about_us::before { left: 20px; }
    .about_us-event { justify-content: flex-start !important; }
    .about_us-content { width: 100%; padding-left: 50px !important; padding-right: 0 !important; }
    .about_us-event:nth-child(odd) .calendar-flip, 
    .about_us-event:nth-child(even) .calendar-flip { left: -10px !important; right: auto !important; }
    .about_us-title { font-size: 2.5rem; }
    .page-title { font-size: 2rem; }
    .page-content { padding: 20px; }
    .top-nav-menu { gap: 8px; }
    .top-nav-item { padding: 6px 12px; font-size: 0.8rem; }
}