feat: 添加页面加载动画并优化首屏入场效果

- 在页面加载时添加加载进度条动画
- 重构首屏入场动画逻辑，分离加载层和品牌展示层
- 优化滚动控制逻辑，避免 class 和 inline style 冲突
- 添加动画状态管理变量，防止重复触发

app/layouts/default.vue

@@ -10,6 +10,8 @@ import ArcticNewOneHeader from '~/components/layouts/ArcticNewOneHeader.vue';
     <ArcticNewOneHeader />
     <slot />
     <ArcticNewOneFooter />
-    <ArcticNewOneCursor />
+    <ClientOnly>
+      <ArcticNewOneCursor />
+    </ClientOnly>
   </div>
 </template>

app/pages/index.vue

@@ -50,7 +50,11 @@ const heroGalleryColumns = [
   },
 ] as const
 const pageRef = ref<HTMLElement | null>(null)
+const loaderRef = ref<HTMLElement | null>(null)
+const loaderBarRef = ref<HTMLElement | null>(null)
 const introRef = ref<HTMLElement | null>(null)
+const introTitleRef = ref<HTMLElement | null>(null)
+const introCharRefs = ref<HTMLElement[]>([])
 const heroStageRef = ref<HTMLElement | null>(null)
 const heroRef = ref<HTMLElement | null>(null)
 const heroPanelRef = ref<HTMLElement | null>(null)
@@ -58,9 +62,42 @@ let heroAnimationContext: gsap.Context | null = null
 let removeLoadListener: (() => void) | null = null
 let restorePageScroll: (() => void) | null = null
 let cleanupHeroScroll: (() => void) | null = null
+let hasIntroStarted = false
+let loaderTween: gsap.core.Tween | null = null
+let introTimeline: gsap.core.Timeline | null = null
+let introStartTimer: ReturnType<typeof window.setTimeout> | null = null
+
+const setHomeIntroActive = (active: boolean) => {
+  isIntroActive.value = active
+  document.documentElement.classList.toggle('is-home-intro-active', active)
+}
 
 onMounted(() => {
-  if (!pageRef.value || !introRef.value || !heroStageRef.value || !heroRef.value || !heroPanelRef.value) {
+  const pageElement = pageRef.value
+  const loaderElement = loaderRef.value
+  const loaderBarElement = loaderBarRef.value
+  const introElement = introRef.value
+  const introTitleElement = introTitleRef.value
+  const heroStageElement = heroStageRef.value
+  const heroElement = heroRef.value
+  const heroPanelElement = heroPanelRef.value
+
+  if (
+    !pageElement
+    || !loaderElement
+    || !loaderBarElement
+    || !introElement
+    || !introTitleElement
+    || !heroStageElement
+    || !heroElement
+    || !heroPanelElement
+  ) {
+    return
+  }
+
+  const introCharElements = gsap.utils.toArray('.hero-intro-char', introElement)
+
+  if (introCharElements.length === 0) {
     return
   }
 
@@ -75,29 +112,29 @@ onMounted(() => {
     const setupHeroScroll = () => {
       cleanupHeroScroll?.()
 
-      gsap.set(heroPanelRef.value, {
+      gsap.set(heroPanelElement, {
         scale: 1,
         force3D: true,
         transformOrigin: 'center center',
       })
 
+      let renderedScale = -1
+
       const setHeroPanelScale = (scale: number) => {
-        if (!heroPanelRef.value) {
+        if (Math.abs(renderedScale - scale) < 0.001) {
           return
         }
 
-        heroPanelRef.value.style.transform = `scale(${scale})`
+        renderedScale = scale
+        gsap.set(heroPanelElement, { scale })
       }
 
       const updateHeroPanelScale = () => {
-        if (!heroStageRef.value) {
-          return
-        }
-
         const exitDistance = getExitDistance()
         const totalDistance = heroPinDistance + exitDistance
-        const currentScroll = Math.max(window.scrollY, $lenis?.scroll ?? 0)
-        const currentDistance = gsap.utils.clamp(0, totalDistance, currentScroll - heroStageRef.value.offsetTop)
+        // Lenis 存在时只读 Lenis 的平滑滚动值，避免向上滚时 window.scrollY 和 Lenis 值互相打架。
+        const currentScroll = $lenis ? $lenis.scroll : window.scrollY
+        const currentDistance = gsap.utils.clamp(0, totalDistance, currentScroll - heroStageElement.offsetTop)
 
         if (currentDistance <= heroPinDistance) {
           setHeroPanelScale(gsap.utils.interpolate(1, pinEndScale, currentDistance / heroPinDistance))
@@ -123,38 +160,85 @@ onMounted(() => {
     }
 
     const playIntro = () => {
+      if (hasIntroStarted) {
+        return
+      }
+
+      hasIntroStarted = true
       removeLoadListener?.()
       removeLoadListener = null
+      if (introStartTimer) {
+        window.clearTimeout(introStartTimer)
+        introStartTimer = null
+      }
+      loaderTween?.kill()
+      loaderTween = null
+      introTimeline?.kill()
 
-      const introTimeline = gsap.timeline({
+      introTimeline = gsap.timeline({
         defaults: { ease: 'power3.out' },
         onComplete: () => {
-          gsap.set(introRef.value, { display: 'none' })
-          gsap.set(heroRef.value, { clearProps: 'transform' })
+          gsap.set(introElement, { display: 'none' })
+          gsap.set(heroElement, { clearProps: 'transform' })
           restorePageScroll?.()
           restorePageScroll = null
           ScrollTrigger.refresh()
+          introTimeline = null
         },
       })
 
       introTimeline
-        .to('.hero-intro-char', {
+        .to(loaderBarElement, {
+          scaleX: 1,
+          duration: 0.25,
+          ease: 'power2.out',
+        })
+        .to(loaderElement, {
+          yPercent: -100,
+          duration: 0.75,
+          ease: 'power4.inOut',
+        })
+        .set(loaderElement, {
+          display: 'none',
+        })
+        .set(introElement, {
+          display: 'grid',
           yPercent: 0,
+          autoAlpha: 1,
+        })
+        .set(introTitleElement, {
+          y: 0,
+          autoAlpha: 1,
+        })
+        .set('.hero-intro-tm', {
+          autoAlpha: 0,
+        })
+        .fromTo(gsap.utils.toArray('.hero-intro-char', introElement), {
+          yPercent: 110,
+          y: 0,
+        }, {
+          yPercent: 0,
+          y: 0,
           duration: 0.75,
           stagger: 0.055,
         })
+        .to('.hero-intro-tm', {
+          autoAlpha: 1,
+          duration: 0.4,
+          ease: 'power2.out',
+        })
         .addLabel('introOut', '+=0.35')
-        .to('.hero-intro-title', {
+        .to(introTitleElement, {
           autoAlpha: 0,
           duration: 1.05,
           ease: 'power4.inOut',
         }, 'introOut')
-        .to(introRef.value, {
+        .to(introElement, {
           yPercent: -100,
           duration: 1.05,
           ease: 'power4.inOut',
         }, 'introOut')
-        .to(heroRef.value, {
+        .to(heroElement, {
           yPercent: 0,
           duration: 1.05,
           ease: 'power4.inOut',
@@ -169,47 +253,70 @@ onMounted(() => {
       }
     }
 
-    // 首屏入场期间锁住滚动，等 window load 后再开始字母动画，避免资源未就绪时露出 Hero。
-    const previousHtmlOverflow = document.documentElement.style.overflow
-    const previousBodyOverflow = document.body.style.overflow
-
     const releasePageScroll = () => {
-      isIntroActive.value = false
-      document.documentElement.classList.remove('is-home-intro-active')
-      document.documentElement.style.overflow = previousHtmlOverflow
-      document.body.style.overflow = previousBodyOverflow
+      setHomeIntroActive(false)
       $lenis?.start()
     }
 
-    document.documentElement.classList.add('is-home-intro-active')
-    document.documentElement.style.overflow = 'hidden'
-    document.body.style.overflow = 'hidden'
+    // 首屏入场期间只通过 html class 锁滚动，避免 class 和 inline overflow 两套状态互相覆盖。
+    setHomeIntroActive(true)
     $lenis?.scrollTo(0, { immediate: true })
     $lenis?.stop()
     restorePageScroll = releasePageScroll
 
-    // 每次播放前都重置首屏状态，避免热更新或页面返回时残留上一次的 inline style。
-    gsap.set(introRef.value, { display: 'grid', yPercent: 0, autoAlpha: 1 })
-    gsap.set('.hero-intro-title', { y: 0, autoAlpha: 1 })
-    gsap.set('.hero-intro-char', { yPercent: 110 })
-    gsap.set(heroRef.value, { yPercent: 100 })
+    // Loading 层先接管首屏；真正的品牌入场等 window.load 完成后再开始。
+    gsap.set(loaderElement, { display: 'grid', yPercent: 0, autoAlpha: 1 })
+    gsap.set(loaderBarElement, { scaleX: 0.18, transformOrigin: 'left center' })
+    gsap.set(introElement, { display: 'grid', yPercent: 0, autoAlpha: 0 })
+    gsap.set(introTitleElement, { y: 0, autoAlpha: 1 })
+    // 强制清除 CSS 中的 translateY 像素值，避免被 GSAP 解析为固定 y 像素导致一直不可见
+    gsap.set(introCharElements, { y: 0, yPercent: 110 })
+    gsap.set('.hero-intro-tm', { autoAlpha: 0 })
+    gsap.set(heroElement, { yPercent: 100 })
     if (topHeader) {
       gsap.set(topHeader, { yPercent: -140, autoAlpha: 0 })
     }
     setupHeroScroll()
 
+    loaderTween = gsap.to(loaderBarElement, {
+      scaleX: 0.82,
+      duration: 1.2,
+      ease: 'power1.inOut',
+      repeat: -1,
+      yoyo: true,
+    })
+
+    const loaderStartedAt = window.performance.now()
+    const minLoaderDuration = 1200
+    const queueIntro = () => {
+      const remainingTime = Math.max(0, minLoaderDuration - (window.performance.now() - loaderStartedAt))
+
+      introStartTimer = window.setTimeout(() => {
+        window.requestAnimationFrame(playIntro)
+      }, remainingTime)
+    }
+
     if (document.readyState === 'complete') {
-      requestAnimationFrame(playIntro)
+      queueIntro()
       return
     }
 
-    window.addEventListener('load', playIntro, { once: true })
-    removeLoadListener = () => window.removeEventListener('load', playIntro)
-  }, pageRef.value)
+    window.addEventListener('load', queueIntro, { once: true })
+    removeLoadListener = () => window.removeEventListener('load', queueIntro)
+  }, pageElement)
 })
 
 onBeforeUnmount(() => {
-  isIntroActive.value = false
+  setHomeIntroActive(false)
+  hasIntroStarted = false
+  if (introStartTimer) {
+    window.clearTimeout(introStartTimer)
+    introStartTimer = null
+  }
+  loaderTween?.kill()
+  loaderTween = null
+  introTimeline?.kill()
+  introTimeline = null
   cleanupHeroScroll?.()
   cleanupHeroScroll = null
   removeLoadListener?.()
@@ -229,15 +336,26 @@ onBeforeUnmount(() => {
     :data-demo-user="demoUserName"
     :data-demo-user-role="demoUserRole"
   >
+    <div ref="loaderRef" class="page-loader" aria-hidden="true">
+      <div class="page-loader-content">
+        <p>Loading</p>
+        <span class="page-loader-line">
+          <span ref="loaderBarRef" class="page-loader-line-inner" />
+        </span>
+      </div>
+    </div>
+
     <div ref="introRef" class="hero-intro" aria-hidden="true">
-      <h1 class="hero-intro-title" :aria-label="introTitle">
-        <span
-          v-for="(letter, index) in introLetters"
-          :key="`${letter}-${index}`"
-          class="hero-intro-char-wrap"
-        >
-          <span class="hero-intro-char">{{ letter }}</span>
-          <span v-if="index === introLetters.length - 1" class="hero-intro-tm">TM</span>
+      <h1 ref="introTitleRef" class="hero-intro-title" :aria-label="introTitle">
+        <span class="hero-intro-word">
+          <span
+            v-for="(letter, index) in introLetters"
+            :key="`${letter}-${index}`"
+            class="hero-intro-char-wrap"
+          >
+            <span ref="introCharRefs" class="hero-intro-char">{{ letter }}</span>
+          </span>
+          <span class="hero-intro-tm">TM</span>
         </span>
       </h1>
     </div>
@@ -289,6 +407,45 @@ onBeforeUnmount(() => {
 </template>
 
 <style scoped>
+.page-loader {
+  position: fixed;
+  inset: 0;
+  z-index: 90;
+  display: grid;
+  place-items: center;
+  color: #fff;
+  background: #000;
+  will-change: transform;
+}
+
+.page-loader-content {
+  width: min(220px, calc(100vw - 48px));
+  font-size: 12px;
+  letter-spacing: 0.18em;
+  text-transform: uppercase;
+}
+
+.page-loader-content p {
+  margin: 0 0 14px;
+}
+
+.page-loader-line {
+  display: block;
+  width: 100%;
+  height: 1px;
+  overflow: hidden;
+  background: rgb(255 255 255 / 20%);
+}
+
+.page-loader-line-inner {
+  display: block;
+  width: 100%;
+  height: 100%;
+  background: #fff;
+  transform: scaleX(0);
+  transform-origin: left center;
+}
+
 .hero-intro {
   position: fixed;
   inset: 0;
@@ -304,7 +461,6 @@ onBeforeUnmount(() => {
 .hero-intro-title {
   display: flex;
   margin: 0;
-  overflow: hidden;
   font-size: clamp(36px, 6.2vw, 104px);
   font-weight: 700;
   line-height: 0.9;
@@ -312,6 +468,11 @@ onBeforeUnmount(() => {
   white-space: nowrap;
 }
 
+.hero-intro-word {
+  position: relative;
+  display: inline-flex;
+}
+
 .hero-intro-char-wrap,
 .hero-intro-char {
   display: inline-block;