[add] Hero Carousel component with Aurora Gradient style in Home page

components/Activity/HeroCarousel.module.less

@@ -0,0 +1,170 @@
+.heroCarousel {
+  --hero-carousel-offset: 4.125rem;
+  background: #050816;
+  min-height: calc(100vh - var(--hero-carousel-offset) - 2.5rem);
+}
+
+.carousel,
+.item,
+.slideCard {
+  min-height: inherit;
+}
+
+.carousel {
+  :global(.carousel-inner) {
+    min-height: inherit;
+  }
+
+  :global(.carousel-item) {
+    min-height: inherit;
+  }
+
+  :global(.carousel-indicators) {
+    right: auto;
+    bottom: 2rem;
+    left: 1rem;
+    justify-content: flex-start;
+    margin: 0;
+  }
+
+  :global(.carousel-indicators button) {
+    opacity: 0.9;
+    margin: 0 0.45rem 0 0;
+    border: 0;
+    border-radius: 999px;
+    background-color: rgb(255 255 255 / 65%);
+    width: 2.25rem;
+    height: 0.32rem;
+  }
+
+  :global(.carousel-control-prev),
+  :global(.carousel-control-next) {
+    opacity: 0.95;
+    width: 6rem;
+  }
+
+  :global(.carousel-control-prev-icon),
+  :global(.carousel-control-next-icon) {
+    filter: drop-shadow(0 12px 24px rgb(0 0 0 / 50%));
+  }
+}
+
+.slideCard {
+  background: linear-gradient(
+    90deg,
+    rgb(5 8 22 / 96%) 0%,
+    rgb(5 8 22 / 88%) 28%,
+    rgb(5 8 22 / 46%) 58%,
+    rgb(5 8 22 / 16%) 100%
+  );
+}
+
+.mediaPane {
+  min-height: 19rem;
+}
+
+.mediaPane::after {
+  position: absolute;
+  inset: 0;
+  background:
+    linear-gradient(180deg, rgb(5 8 22 / 18%) 0%, rgb(5 8 22 / 48%) 58%, rgb(5 8 22 / 82%) 100%),
+    linear-gradient(90deg, rgb(5 8 22 / 10%) 0%, rgb(5 8 22 / 24%) 32%, rgb(5 8 22 / 72%) 100%);
+  pointer-events: none;
+  content: '';
+}
+
+.description {
+  display: -webkit-box;
+  max-width: 40rem;
+  overflow: hidden;
+  font-size: clamp(1rem, 1.6vw, 1.28rem);
+  line-height: 1.55;
+  -webkit-box-orient: vertical;
+  -webkit-line-clamp: 3;
+  line-clamp: 3;
+}
+
+.actionButton {
+  transition:
+    transform 180ms ease,
+    box-shadow 180ms ease,
+    background 180ms ease,
+    border-color 180ms ease;
+  box-shadow: 0 12px 28px rgb(14 165 233 / 18%);
+  border: 1px solid rgb(255 255 255 / 20%);
+  border-radius: 0.9rem;
+  background: linear-gradient(135deg, rgb(255 255 255 / 92%) 0%, rgb(224 242 254 / 96%) 100%);
+  color: #0f172a;
+  letter-spacing: 0.02em;
+}
+
+.actionButton:hover,
+.actionButton:focus,
+.actionButton:active {
+  transform: translateY(-2px);
+  box-shadow: 0 18px 40px rgb(14 165 233 / 22%);
+  border-color: rgb(255 255 255 / 34%);
+  background: linear-gradient(135deg, #ffffff 0%, #e0f2fe 100%);
+  color: #0f172a;
+}
+
+@media (max-width: 991.98px) {
+  .heroCarousel {
+    min-height: calc(100vh - var(--hero-carousel-offset) - 2rem);
+  }
+}
+
+@media (max-width: 767.98px) {
+  .heroCarousel {
+    min-height: calc(100svh - var(--hero-carousel-offset) - 1.25rem);
+  }
+
+  .carousel {
+    :global(.carousel-indicators) {
+      right: 1rem;
+      bottom: 1rem;
+      left: 1rem;
+      justify-content: center;
+    }
+
+    :global(.carousel-indicators button) {
+      margin: 0 0.3rem;
+      width: 1.4rem;
+      height: 0.26rem;
+    }
+
+    :global(.carousel-control-prev),
+    :global(.carousel-control-next) {
+      display: none;
+    }
+  }
+
+  .slideCard {
+    background: linear-gradient(
+      180deg,
+      rgb(5 8 22 / 18%) 0%,
+      rgb(5 8 22 / 54%) 44%,
+      rgb(5 8 22 / 92%) 100%
+    );
+  }
+
+  .mediaPane {
+    min-height: 14rem;
+  }
+
+  .mediaPane::after {
+    background:
+      linear-gradient(180deg, rgb(5 8 22 / 16%) 0%, rgb(5 8 22 / 42%) 42%, rgb(5 8 22 / 88%) 100%),
+      linear-gradient(90deg, rgb(5 8 22 / 18%) 0%, rgb(5 8 22 / 16%) 100%);
+  }
+
+  .description {
+    max-width: none;
+    -webkit-line-clamp: 4;
+    line-clamp: 4;
+  }
+
+  .actionButton {
+    border-radius: 0.8rem;
+  }
+}

components/Activity/HeroCarousel.tsx

@@ -0,0 +1,211 @@
+import { CSSProperties, FC, useContext, useEffect, useState } from 'react';
+import { TableCellLocation } from 'mobx-lark';
+import { Badge, Button, Card, Carousel, Col, Container, Row, Stack } from 'react-bootstrap';
+
+import { Activity, ActivityModel } from '../../models/Activity';
+import { I18nContext } from '../../models/Translation';
+import { LarkImage } from '../LarkImage';
+import styles from './HeroCarousel.module.less';
+
+const FALLBACK_LINK = '/hackathon/Labor-AI-hackathon-2026';
+const MAX_ITEMS = 5;
+
+const timestampOf = (value: unknown) => {
+  if (typeof value === 'number') return value;
+  if (typeof value === 'string') {
+    const time = new Date(value).getTime();
+
+    return Number.isFinite(time) ? time : 0;
+  }
+
+  return 0;
+};
+
+const formatDateLabel = (value: unknown) => {
+  const timestamp = timestampOf(value);
+
+  if (!timestamp) return '';
+
+  return new Intl.DateTimeFormat('zh-CN', {
+    month: 'short',
+    day: 'numeric',
+  }).format(timestamp);
+};
+
+const locationTextOf = ({ city, location }: Activity) =>
+  [(city as string) || '', (location as TableCellLocation | undefined)?.full_address || '']
+    .filter(Boolean)
+    .join(' · ');
+
+const descriptionOf = (activity: Activity) =>
+  (activity.summary as string) || locationTextOf(activity) || (activity.type as string) || '';
+
+export const HeroCarousel: FC = () => {
+  const { t } = useContext(I18nContext);
+  const [heroStyle, setHeroStyle] = useState<CSSProperties>();
+  const [activities, setActivities] = useState<Activity[]>([]);
+  const infoBodyStyle = { minHeight: 'clamp(0rem, 38vh, 24rem)' } as CSSProperties;
+
+  useEffect(() => {
+    const navbar = document.querySelector('nav');
+    const syncHeroOffset = () => {
+      const navbarHeight = navbar?.getBoundingClientRect().height || 56;
+
+      setHeroStyle({
+        '--hero-carousel-offset': `${navbarHeight}px`,
+      } as CSSProperties);
+    };
+    const observer =
+      typeof ResizeObserver === 'undefined' || !navbar
+        ? undefined
+        : new ResizeObserver(syncHeroOffset);
+
+    syncHeroOffset();
+    if (navbar) observer?.observe(navbar);
+    window.addEventListener('resize', syncHeroOffset);
+
+    return () => {
+      observer?.disconnect();
+      window.removeEventListener('resize', syncHeroOffset);
+    };
+  }, []);
+
+  useEffect(() => {
+    (async () => {
+      try {
+        const model = new ActivityModel();
+        const data = await model.getAll();
+        const latestActivities = data
+          .filter(({ name }) => Boolean(name))
+          .sort(
+            ({ startTime: left }, { startTime: right }) => timestampOf(right) - timestampOf(left),
+          )
+          .slice(0, MAX_ITEMS);
+
+        setActivities(latestActivities);
+      } catch (err) {
+        console.error('Failed to load activities:', err);
+      }
+    })();
+  }, []);
+
+  const slides = activities.length
+    ? activities
+    : [
+        {
+          id: 'fallback',
+          name: 'Labor AI Hackathon 2026',
+          summary: t('home_hackathon_top_bar_description'),
+        } as Activity,
+      ];
+
+  return (
+    <section
+      className={`${styles.heroCarousel} position-relative`}
+      aria-label={t('home_hackathon_top_bar_aria_label')}
+      style={heroStyle}
+    >
+      <Carousel
+        fade
+        touch
+        pause="hover"
+        interval={6500}
+        indicators={slides.length > 1}
+        controls={slides.length > 1}
+        className={`${styles.carousel} h-100`}
+      >
+        {slides.map(activity => {
+          const href =
+            (activity.id as string) === 'fallback'
+              ? FALLBACK_LINK
+              : ActivityModel.getLink(activity);
+          const hosts = ((activity.host as string[]) || []).slice(0, 2);
+          const locationText = locationTextOf(activity);
+          const dateText = formatDateLabel(activity.startTime);
+          const title = (activity.name as string) || 'Activity';
+          const description = descriptionOf(activity);
+          const image = activity.cardImage || activity.image;
+
+          return (
+            <Carousel.Item key={activity.id as string} className={`${styles.item} h-100`}>
+              <Card
+                className={`${styles.slideCard} h-100 rounded-0 border-0 bg-transparent text-white`}
+              >
+                <Row className="g-0 h-100 flex-column-reverse flex-md-row">
+                  <Col
+                    xs={12}
+                    md={6}
+                    lg={5}
+                    className="d-flex align-items-center position-relative z-1"
+                  >
+                    <Container fluid="md" className="px-3 px-md-4 px-xl-5 py-5">
+                      <Card.Body
+                        className="p-0 d-flex flex-column justify-content-center"
+                        style={infoBodyStyle}
+                      >
+                        <Stack direction="horizontal" gap={2} className="flex-wrap mb-3 mb-md-4">
+                          {(hosts.length
+                            ? hosts
+                            : [(activity.type as string) || t('hackathon')]
+                          ).map(item => (
+                            <Badge
+                              key={item}
+                              pill
+                              bg="info"
+                              text="dark"
+                              className="px-3 py-2 fw-semibold"
+                            >
+                              {item}
+                            </Badge>
+                          ))}
+                          {(dateText || t('event_duration')) && (
+                            <Badge pill bg="light" text="dark" className="px-3 py-2 fw-semibold">
+                              {dateText || t('event_duration')}
+                            </Badge>
+                          )}
+                        </Stack>
+
+                        <Card.Title
+                          as="h1"
+                          className="display-3 fw-bold lh-1 mb-3 mb-md-4"
+                          style={{ textWrap: 'balance' }}
+                        >
+                          {title}
+                        </Card.Title>
+
+                        <Card.Text className={`${styles.description} text-white-50 mb-4`}>
+                          {description}
+                        </Card.Text>
+
+                        <Stack
+                          direction="horizontal"
+                          gap={3}
+                          className="flex-wrap align-items-start align-items-md-center"
+                        >
+                          <Card.Text className="mb-0 fs-6 text-info-emphasis fw-semibold">
+                            {locationText || 'Open Source Bazaar'}
+                          </Card.Text>
+                          <Button
+                            href={href}
+                            variant="light"
+                            className={`${styles.actionButton} px-4 py-2 fw-semibold text-uppercase`}
+                          >
+                            {t('home_hackathon_top_bar_action')}
+                          </Button>
+                        </Stack>
+                      </Card.Body>
+                    </Container>
+                  </Col>
+
+                  <Col xs={12} md={6} lg={7} className={`${styles.mediaPane} position-relative`}>
+                    <LarkImage src={image} alt={title} className="w-100 h-100 object-fit-cover" />
+                  </Col>
+                </Row>
+              </Card>
+            </Carousel.Item>
+          );
+        })}
+      </Carousel>
+    </section>
+  );
+};