/* ========== PAGE TRANSITION ========== */
.w-page-transition {
  position: fixed;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  z-index: -9999;
}

/* --- Dark layer --- */
.w-page-transition-dark {
  position: absolute;
  height: 100vh;
  inset: 0;
  background: var(--bg-dark, #000);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  opacity: 0;
  transition: opacity 0.8s cubic-bezier(0.77, 0, 0.175, 1);
   z-index: 1;
}

.w-page-transition-dark.active {
  opacity: 1;
}

/* --- Dark - Logo wrapper --- */
.w-page-transition-dark__logo-wrapper {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) translateY(50%);
  display: flex;
  flex-direction: row;
  justify-content: center;
  gap: 20px;
  opacity: 0;
  transition: transform 0.8s ease, opacity 0.8s ease;
  z-index: 2;
}

.w-page-transition-dark__logo-wrapper.active {
  transform: translate(-50%, -50%) translateY(0);
  opacity: 1;
}

.w-page-transition-dark__text {
  color: var(--text-title-contrast, #fff);
  font-size: clamp(32px, 4vw, 100px);
}

.w-page-transition-dark__favicon {
  opacity: 0;
  width: 80px;
  height: 80px;
}

/* --- Light layer --- */
.w-page-transition-light {
  position: absolute;
  height: 100vh;
  inset: 0;
  background: var(--bg-body, #fff);
  display: flex;
  align-items: center;
  justify-content: center;
  transform: translateY(100%);
  transition: transform 1s cubic-bezier(0.77, 0, 0.175, 1);
  z-index: 3;
}

.w-page-transition-light.active {
  transform: translateY(0);
}

/* --- Light - Logo wrapper --- */
.w-page-transition-light__logo-wrapper {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) translateY(0);
  display: flex;
  flex-direction: row;
  justify-content: center;
  gap: 20px;
  opacity: 0;
  transition: opacity 0.6s ease 0.3s, transform 0.6s ease 0.3s;
  z-index: 4;
}

.w-page-transition-light__logo-wrapper.active {
  opacity: 1;
  transform: translate(-50%, -50%) translateY(0);
}

.w-page-transition-light__text {
  color: var(--text-title, #000);
  font-size: clamp(32px, 4vw, 100px);
}

.w-page-transition-light__favicon {
  width: 80px;
  height: 80px;
  opacity: 0;
  transform: scale(0) rotate(-90deg);
  transition: all 0.6s ease 0.3s;
}

.w-page-transition-light__favicon.appear {
  opacity: 1;
  transform: scale(1) rotate(0);
}

document.addEventListener("DOMContentLoaded", () => {
  const dark = document.querySelector(".w-page-transition-dark");
  const darkWrapper = document.querySelector(".w-page-transition-dark__logo-wrapper");
  const light = document.querySelector(".w-page-transition-light");
  const lightWrapper = document.querySelector(".w-page-transition-light__logo-wrapper");
  const favicon = document.querySelector(".w-page-transition-light__favicon");
  const pageTransition = document.querySelector(".w-page-transition");

  if (!dark || !light || !pageTransition) return;

  /** Helper delay */
  function wait(ms) {
    return new Promise((res) => setTimeout(res, ms));
  }

  /** PAGE LEAVE (trước khi chuyển trang) **/
  function startLeave() {
    pageTransition.style.zIndex = "9999";
    dark.classList.add("active");
  }

  /** PAGE ENTER (hiệu ứng khi vào trang) **/
  async function startEnter() {
    // Luôn đảm bảo z-index cao khi bắt đầu
    pageTransition.style.zIndex = "9999";

    // Step 1: Dark layer fade in
    dark.classList.add("active");
    await wait(600);

    // Step 2: Logo/text dark xuất hiện
    darkWrapper.classList.add("active");
    await wait(800);

    // Step 3: Light layer trượt lên
    light.classList.add("active");
    lightWrapper.classList.add("active");
    await wait(1000);

    // Step 4: Logo favicon hiện ra
    favicon.classList.add("appear");
    await wait(1200);

    // Step 5: Toàn bộ transition fade out nhanh
    pageTransition.style.transition = "opacity 0.6s ease";
    pageTransition.style.opacity = "0";
    await wait(1200);

    // Step 6: Reset trạng thái cho lần sau
    dark.classList.remove("active");
    darkWrapper.classList.remove("active");
    light.classList.remove("active");
    lightWrapper.classList.remove("active");
    favicon.classList.remove("appear");

    // Reset style sau khi đã ẩn hẳn
    pageTransition.style.opacity = "";
    pageTransition.style.transition = "";

    // Đưa z-index xuống thấp để không che nội dung
    pageTransition.style.zIndex = "-9999";
  }

  /** Run on initial load **/
  startEnter();

  /** Trigger transition khi click link **/
  document.querySelectorAll("a[href]").forEach((link) => {
    link.addEventListener("click", (e) => {
      const url = link.href;
      if (
        url.includes("#") ||
        url.startsWith("mailto:") ||
        url.startsWith("tel:") ||
        link.target === "_blank"
      )
        return;

      e.preventDefault();
      startLeave();
      setTimeout(() => {
        window.location.href = url;
      }, 600);
    });
  });
});