/* ===== Reset & Variables ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

:root {
  --bg: #F8F4F0;
  --text: #1A1714;
  --muted: #8A8580;
  --accent: #C4A882;
  --green: #8BA888;
  --border: #E8E2DB;
  --font-title: 'Cormorant Garamond', Georgia, serif;
  --font-body: 'DM Sans', sans-serif;
  --font-script: 'Dancing Script', cursive;
  --color-exploration: #5B8FAD;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.7;
}

a { text-decoration: none; color: inherit; }

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 3rem;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}

.logo { display: flex; align-items: center; }

.logo-img { height: 44px; width: auto; max-width: 140px; }

.nav-links {
  display: flex;
  gap: 2.5rem;
}

.nav-links a {
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--muted);
  transition: color 0.2s;
  padding-bottom: 2px;
}

.nav-links a.active {
  color: var(--text);
  border-bottom: 1px solid var(--text);
}

.nav-links a:hover { color: var(--text); }

.nav-icons {
  display: flex;
  gap: 1rem;
  font-size: 0.95rem;
}

.nav-icons a,
.nav-icons button {
  color: var(--text);
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.95rem;
  padding: 0;
  transition: opacity 0.2s;
}
.nav-icons a:hover,
.nav-icons button:hover { opacity: 0.5; }



/* ===== Hero ===== */
.hero {
  position: relative;
  height: 70vh;
  min-height: 460px;
  overflow: hidden;
  display: flex;
  align-items: flex-end;
  justify-content: flex-start;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: #000;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: right center;
  transform: scale(1.5);
  transform-origin: right center;
  display: block;
}

/* 底部漸層遮罩，讓文字清楚浮出 */
.hero-bg::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    to top,
    rgba(10, 8, 6, 0.62) 0%,
    rgba(10, 8, 6, 0.18) 45%,
    transparent 100%
  );
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: left;
  padding: 3rem 3.5rem;
  color: #fff;
}

.hero-title {
  font-family: var(--font-title);
  font-size: clamp(4rem, 10vw, 8.5rem);
  font-weight: 300;
  font-style: italic;
  line-height: 0.95;
  margin-bottom: 0;
  text-shadow: 0 2px 48px rgba(0,0,0,0.15);
  letter-spacing: -0.01em;
}

.hero-tagline {
  font-size: 0.78rem;
  letter-spacing: 0.2em;
  line-height: 2;
  color: rgba(255, 252, 248, 0.72);
  font-weight: 300;
  margin-top: 1.8rem;
  text-transform: lowercase;
}

/* ===== Recent Trips ===== */
.trips-section {
  padding: 5rem 3rem;
}

.trips-header {
  display: flex;
  align-items: center;
  gap: 2rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.section-heading {
  font-family: var(--font-title);
  font-size: 1.8rem;
  font-weight: 400;
  white-space: nowrap;
}

.trip-filter-tags {
  display: flex;
  gap: 1.5rem;
  flex: 1;
}

.filter-tag {
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.filter-tag.exploration { color: var(--color-exploration); }
.filter-tag.inner-journey { color: var(--green); }
.filter-tag.aesthetic { color: var(--accent); }

.view-all-link {
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--muted);
  white-space: nowrap;
  transition: color 0.2s;
}
.view-all-link:hover { color: var(--text); }

/* 輪播 + 時間軸版面 */
.trips-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
}

/* 輪播 */
.trips-carousel {
  position: relative;
  aspect-ratio: 3/4;
  overflow: hidden;
  background: #E4DDD5;
  width: 65%;
  margin: 0 auto;
}

.carousel-track { position: absolute; inset: 0; }

.carousel-slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  transition: opacity 0.7s ease;
}
.carousel-slide.active { opacity: 1; }

.carousel-slide a { display: block; width: 100%; height: 100%; }

.carousel-slide img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
  background: none;
  border: none;
  color: rgba(255,255,255,0.75);
  font-size: 3rem;
  line-height: 1;
  cursor: pointer;
  padding: 0 1rem;
  transition: color 0.2s;
  font-weight: 300;
}
.carousel-btn:hover { color: #fff; }
.carousel-prev { left: 0; }
.carousel-next { right: 0; }

/* 時間軸捲動容器 */
.timeline-scroll-wrapper {
  display: flex;
  gap: 1rem;
  overflow: hidden;
}

/* 時間軸 */
.trips-timeline {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding-top: 1.2rem;
  padding-left: 6px;
  overflow-y: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.trips-timeline::-webkit-scrollbar { display: none; }

/* 飛機捲軸 */
.plane-track {
  width: 26px;
  flex-shrink: 0;
  position: relative;
}

.plane-track::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--border);
  transform: translateX(-50%);
}

.plane-thumb {
  position: absolute;
  left: 50%;
  top: 0;
  transform: translateX(-50%);
  font-size: 1.4rem;
  color: var(--muted);
  line-height: 1;
}

.plane-thumb i {
  display: block;
  transform: rotate(180deg); /* 飛機朝左 */
}

.tl-item {
  display: flex;
  gap: 1.2rem;
}

.tl-dot-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  padding-top: 5px;
}

.tl-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  flex-shrink: 0;
  transition: transform 0.25s;
}
.tl-item.active .tl-dot { transform: scale(1.25); }

.tl-line {
  width: 1px;
  flex: 1;
  background: var(--border);
  margin-top: 6px;
  min-height: 40px;
}

.tl-body { padding-bottom: 2.2rem; }

.tl-date {
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}

.tl-name {
  font-family: var(--font-title);
  font-size: 1.45rem;
  font-weight: 400;
  font-style: italic;
  line-height: 1.2;
  margin-bottom: 0.5rem;
}

.tl-desc {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.9;
  margin-bottom: 0.7rem;
  white-space: pre-line;
}

.tl-link {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--accent);
  transition: opacity 0.2s;
}
.tl-link:hover { opacity: 0.65; text-decoration: underline; }

/* 舊卡片樣式保留（explore 頁使用） */
.trips-cards {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 1.2rem;
}

.trip-card { cursor: pointer; display: block; }

.trip-card-img {
  width: 100%;
  aspect-ratio: 3/4;
  object-fit: cover;
  display: block;
  margin-bottom: 0.9rem;
  transition: filter 0.3s;
}

.trip-card:hover .trip-card-img { filter: brightness(0.88); }

.trip-card-flag { font-size: 0.85rem; margin-bottom: 0.2rem; }

.trip-card-location {
  font-size: 0.82rem;
  font-weight: 400;
  line-height: 1.4;
  margin-bottom: 0.2rem;
}

.trip-card-date {
  font-size: 0.75rem;
  color: var(--muted);
  margin-bottom: 0.7rem;
}

.trip-card-desc {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.7;
  margin-bottom: 0.8rem;
  white-space: pre-line;
}

.trip-card-tag { font-size: 0.75rem; letter-spacing: 0.08em; }
.trip-card-tag.exploration { color: var(--color-exploration); }
.trip-card-tag.inner-journey { color: var(--green); }
.trip-card-tag.aesthetic { color: var(--accent); }

/* ===== Map Section ===== */
.map-section {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 0;
  background: #F0EBE3;
  padding: 0;
  align-items: stretch;
}

.map-left {
  padding: 4rem 2rem 4rem 3rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.map-heading {
  font-family: var(--font-title);
  font-size: 2rem;
  font-weight: 400;
  line-height: 1.25;
  margin-bottom: 0.8rem;
  white-space: nowrap;
}

.map-sub {
  font-size: 0.78rem;
  color: var(--muted);
  line-height: 1.9;
  margin-bottom: 2rem;
}

.map-legend {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-top: 2rem;
}

.legend-title {
  font-size: 0.78rem;
  color: var(--text);
  letter-spacing: 0.02em;
  margin-bottom: 0.4rem;
  font-style: italic;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.75rem;
  color: var(--muted);
  letter-spacing: 0.04em;
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  flex-shrink: 0;
}

.exploration-dot { background: var(--color-exploration); }
.inner-dot { background: var(--green); }
.aesthetic-dot { background: var(--accent); }

/* Vertical timeline */
.destinations-timeline { display: flex; flex-direction: column; }

.dest-item {
  display: flex;
  gap: 1rem;
  padding-bottom: 1.5rem;
}

.dest-dot-col {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: 4px;
  flex-shrink: 0;
}

.dest-dot { width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0; }

.dest-line {
  width: 1px;
  flex: 1;
  background: var(--border);
  margin-top: 4px;
  min-height: 24px;
}

.dest-year {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 0.1rem;
}

.dest-name {
  font-family: var(--font-title);
  font-size: 1.05rem;
  font-weight: 400;
  font-style: italic;
}

.map-right { position: relative; }

#worldMap { width: 100%; height: auto; display: block; border-radius: 4px; }

.map-stats {
  text-align: center;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-top: 1.5rem;
}

/* ===== About ===== */
.about-section {
  display: grid;
  grid-template-columns: 3fr 2fr;
  align-items: stretch;
  min-height: 400px;
  scroll-margin-top: 65px;
}

.about-photo {
  background: #E4DDD5;
  overflow: hidden;
}

.about-photo-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  height: 100%;
  align-items: stretch;
  gap: 3px;
}

.about-photo-item {
  overflow: hidden;
  transition: transform 0.7s cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.about-photo-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* 各照片裁切焦點 */
#photoInfj img  { object-position: 15% 50%; }
#photoIntp img  { object-position: 15% 55%; transform: scale(1.6); transform-origin: 15% 55%; }
#photoIsfp img  { object-position: 65% 7%; transform: scale(1.2); transform-origin: 65% 7%; }

/* 照片浮動動畫 */
@keyframes float-up-left {
  0%   { transform: translateY(0px); }
  50%  { transform: translateY(-30px); }
  100% { transform: translateY(0px); }
}

@keyframes float-up {
  0%   { transform: translateY(0px); }
  50%  { transform: translateY(-30px); }
  100% { transform: translateY(0px); }
}

@keyframes float-up-mid {
  0%   { transform: translateY(0px); }
  50%  { transform: translateY(-30px); }
  100% { transform: translateY(0px); }
}

.about-photo-item.floating-1 { animation: float-up-left 1.8s ease-in-out forwards; }
.about-photo-item.floating-2 { animation: float-up-mid 1.8s ease-in-out forwards; }
.about-photo-item.floating-3 { animation: float-up 1.8s ease-in-out forwards; }

.about-content { padding: 1.7rem 3rem; }

.about-heading {
  font-family: var(--font-title);
  font-size: 2.5rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  margin-bottom: 0.3rem;
}

.about-sub {
  font-family: var(--font-script);
  font-size: 1rem;
  color: var(--muted);
  margin-bottom: 2rem;
  letter-spacing: 0.02em;
}

.about-desc {
  font-size: 0.82rem;
  line-height: 2;
  color: var(--muted);
  margin-bottom: 1.8rem;
}

/* MBTI Cards */
.mbti-cards {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 0;
  align-items: start;
  margin-bottom: 2rem;
}

.mbti-x {
  font-family: var(--font-title);
  font-size: 3.5rem;
  font-weight: 300;
  color: #444;
  align-self: start;
  padding-top: 1.8rem;
  line-height: 1;
  width: 3rem;
  display: flex;
  justify-content: center;
}

.mbti-card {
  display: flex;
  flex-direction: column;
  cursor: default;
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.mbti-card.visible {
  opacity: 1;
  transform: translateY(0);
}

.mbti-card.visible.infj-card { transition-delay: 0.1s; }
.mbti-card.visible.intp-card { transition-delay: 0.2s; }
.mbti-card.visible.isfp-card { transition-delay: 0.3s; }

.mbti-icon {
  font-size: 1.2rem;
  color: #444;
  opacity: 0.7;
  margin-bottom: 1rem;
  display: inline-block;
  transition: opacity 0.5s ease-out, transform 0.5s ease-out, filter 0.5s ease-out;
}

.mbti-type {
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--muted);
  margin-bottom: 0.3rem;
}

.mbti-title {
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: #444;
  margin-bottom: 0.5rem;
  transition: color 0.4s;
}

.mbti-sub {
  font-size: 0.78rem;
  color: var(--muted);
  opacity: 0.7;
  margin-bottom: 0.6rem;
  transition: opacity 0.4s;
}

.mbti-hover {
  font-size: 0.75rem;
  color: #999;
  opacity: 0;
  line-height: 1.7;
  transition: opacity 0.4s 0.1s;
}

/* INFJ：glow + scale */
.infj-card:hover .mbti-icon {
  opacity: 1;
  transform: scale(1.08);
  filter: drop-shadow(0 0 5px rgba(0,0,0,0.18));
}

/* INTP：旋轉 */
.intp-card:hover .mbti-icon {
  opacity: 1;
  transform: rotate(5deg);
  transition-duration: 0.6s;
}

/* ISFP：左右漂移 loop */
.isfp-card:hover .mbti-icon {
  opacity: 1;
  animation: wave-drift 0.8s ease-in-out infinite alternate;
}

@keyframes wave-drift {
  from { transform: translateX(0); }
  to   { transform: translateX(5px); }
}

@keyframes infj-pulse {
  0%, 100% { transform: scale(1.06); filter: drop-shadow(0 0 3px rgba(0,0,0,0.12)); }
  50%       { transform: scale(1.14); filter: drop-shadow(0 0 8px rgba(0,0,0,0.28)); }
}

@keyframes intp-think {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-6px); }
}

/* 共用 hover 文字 */
.mbti-card:hover .mbti-title,
.mbti-card.active .mbti-title { color: #111; }

.mbti-card:hover .mbti-sub,
.mbti-card.active .mbti-sub   { opacity: 1; }

.mbti-card:hover .mbti-hover,
.mbti-card.active .mbti-hover { opacity: 1; }

/* INFJ active */
.infj-card.active .mbti-icon {
  opacity: 1;
  animation: infj-pulse 2.2s ease-in-out infinite;
}

/* INTP active */
.intp-card.active .mbti-icon {
  opacity: 1;
  animation: intp-think 1.8s ease-in-out infinite;
}

/* ISFP active */
.isfp-card.active .mbti-icon {
  opacity: 1;
  animation: wave-drift 0.8s ease-in-out infinite alternate;
}

.about-quote {
  font-size: 0.82rem;
  color: var(--muted);
  font-style: italic;
  line-height: 2;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 4rem 2rem;
  border-top: 1px solid var(--border);
}

.footer-logo img {
  height: 100px;
  width: auto;
  opacity: 0.6;
  margin-bottom: 1.5rem;
  transition: opacity 0.2s;
}
.footer-logo:hover img { opacity: 1; }

.footer-icons {
  display: flex;
  justify-content: center;
  gap: 1.2rem;
  margin-top: 1.5rem;
  color: var(--muted);
  font-size: 0.9rem;
}
.footer-icons a { color: var(--muted); font-size: 1.1rem; }
.footer-icons a:hover { color: var(--text); }

/* ===== Responsive ===== */
/* ===== Hamburger ===== */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
  width: 28px;
}
.hamburger span {
  display: block;
  height: 1.5px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(6.5px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-6.5px) rotate(-45deg); }

/* 手機選單 — 右側 drawer */
.menu-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.25);
  z-index: 298;
  cursor: pointer;
}
.menu-overlay.open { display: block; }

.mobile-menu {
  position: fixed;
  top: 0;
  right: 0;
  width: 72%;
  max-width: 280px;
  height: 100vh;
  background: var(--bg);
  z-index: 300;
  display: block;
  padding-top: 5rem;
  overflow: hidden;
  transform: translateX(110%);
  transition: transform 0.35s ease;
  box-shadow: -8px 0 32px rgba(0,0,0,0.08);
  pointer-events: none;
}
.mobile-menu.open {
  transform: translateX(0);
  pointer-events: auto;
}
.menu-close {
  position: absolute;
  top: 1.2rem;
  right: 1.2rem;
  background: none;
  border: none;
  font-size: 1.2rem;
  color: var(--muted);
  cursor: pointer;
  padding: 0.4rem;
  line-height: 1;
}
.mobile-menu a {
  display: block;
  padding: 1.1rem 2rem;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--muted);
  border-bottom: 1px solid var(--border);
  transition: color 0.2s;
}
.mobile-menu a.active,
.mobile-menu a:hover { color: var(--text); }
.menu-social {
  display: flex;
  gap: 1.4rem;
  padding: 1.5rem 2rem;
}
.mobile-menu .menu-social a {
  padding: 0;
  border-bottom: none;
  font-size: 1rem;
  letter-spacing: 0;
}

/* ===== Tablet（≤ 900px）===== */
@media (max-width: 900px) {
  /* Navbar */
  .navbar { padding: 1rem 1.5rem; }
  .nav-links { display: none; }
  .nav-icons a { display: none; }
  .hamburger { display: flex; }

  /* Hero */
  .hero-tagline { font-size: 0.82rem; }

  /* Trips */
  .trips-section { padding: 3rem 1.5rem; }
  .trips-header { flex-direction: column; align-items: flex-start; gap: 0.8rem; }
  .trip-filter-tags { flex-wrap: wrap; gap: 0.5rem 1.2rem; }
  .filter-tag { white-space: nowrap; }
  .trips-layout { grid-template-columns: 1fr; gap: 2rem; }
  .trips-carousel { aspect-ratio: 4/3; width: 100%; }
  .timeline-scroll-wrapper { max-height: 320px; }

  /* Chapter Break */
  .ch-break { flex-direction: column; align-items: flex-start; gap: 1.2rem; padding: 3rem 1.5rem; }
  .ch-break-num { font-size: 64px; }
  .ch-break-sep { display: none; }
  .ch-break-sub { max-width: 100%; }

  /* Map */
  .map-section { grid-template-columns: 1fr; }
  .map-left { padding: 2.5rem 1.5rem 1.5rem; }
  .map-heading { white-space: normal; font-size: 1.6rem; }

  /* About */
  .about-section { grid-template-columns: 1fr; }
  .about-photo { height: 234px; overflow: hidden; }
  .about-photo-grid { height: 234px; }
  .about-photo img { height: 234px; object-fit: cover; width: 100%; }
  .about-content { padding: 3rem 1.5rem; }
  .mbti-cards { gap: 1rem; }
}

/* ===== Mobile（≤ 480px）===== */
@media (max-width: 480px) {
  /* Hero */
  .hero-title { font-size: clamp(3rem, 16vw, 6rem); }
  .hero-tagline { font-size: 0.78rem; }
  .hero-bg img { object-fit: cover; object-position: center center; transform: none; }

  /* Trips */
  .section-heading { font-size: 1.4rem; }
  .trip-filter-tags { gap: 0.6rem; flex-wrap: wrap; }
  .trips-carousel { aspect-ratio: 1/1; }

  /* Map */
  .map-heading { font-size: 1.4rem; }
  .map-sub { font-size: 0.75rem; }
  .map-legend { margin-top: 1rem; }

  /* About */
  .about-heading { font-size: 1.8rem; margin-bottom: 0; }
  .about-sub { margin-top: 0.2rem; margin-bottom: 0.8rem; }
  .about-content { padding: 2rem 1rem; }
  .mbti-cards { grid-template-columns: 1fr; gap: 1.2rem; }
  .mbti-x { display: none; }
  .mbti-card { display: flex; flex-direction: row; align-items: flex-start; gap: 0.4rem; }
  .mbti-icon { flex-shrink: 0; width: 1.2rem; text-align: center; margin-bottom: 0; font-size: 0.9rem; }
  .mbti-text-block { display: grid; grid-template-columns: 2rem 6rem 5rem 1fr; column-gap: 0.3rem; row-gap: 0; flex: 1; min-width: 0; }
  .mbti-desc-row { display: contents; }
  .mbti-type, .mbti-title, .mbti-sub { margin-bottom: 0; align-self: baseline; }
  .mbti-title { white-space: nowrap; }
  .mbti-sub { opacity: 1; }
  .mbti-hover { display: block; opacity: 0; margin-bottom: 0; align-self: baseline; transition: opacity 0.5s; }
  .mbti-card.active .mbti-hover { opacity: 1; }

  /* Footer */
  .footer-tagline { font-size: 1.2rem; }
}

/* ===== Scroll to Top ===== */
.scroll-top-btn {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 2.6rem;
  height: 2.6rem;
  border-radius: 50%;
  border: 1px solid rgba(0,0,0,0.25);
  background: rgba(255,255,255,0.55);
  backdrop-filter: blur(6px);
  color: #555;
  font-size: 0.78rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 0.3s, transform 0.3s, border-color 0.2s, color 0.2s;
  z-index: 400;
}
.scroll-top-btn.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
.scroll-top-btn:hover {
  border-color: rgba(0,0,0,0.55);
  color: #222;
}