/* FCL — B 沉浸首屏 + A 工具站内容区 · 晴空青绿 + 钻石青 */
:root {
  --grass: #3d9a6a;
  --grass-deep: #1f4d3a;
  --grass-soft: #6fbf8f;
  --diamond: #5ec8d8;
  --diamond-deep: #2a9aad;
  --ink: #14261c;
  --ink-soft: #3d5348;
  --paper: #eef7f1;
  --panel: rgba(248, 252, 249, 0.94);
  --line: rgba(31, 77, 58, 0.14);
  --white: #ffffff;
  --shadow: 0 20px 48px rgba(20, 38, 28, 0.16);
  --font-display: "Outfit", "Noto Sans SC", sans-serif;
  --font-body: "Noto Sans SC", "Segoe UI", sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --shell: 1080px;
  --bar-h: 3.75rem;
  --mob-bar-h: 3.75rem;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.7;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

@media (max-width: 760px) {
  body {
    padding-bottom: calc(var(--mob-bar-h) + 0.5rem);
  }
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

ul,
ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin: 0;
}

.shell {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 1.35rem;
}

.sky-wash {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(ellipse 70% 45% at 12% -5%, rgba(94, 200, 216, 0.22), transparent 55%),
    radial-gradient(ellipse 55% 40% at 95% 8%, rgba(61, 154, 106, 0.16), transparent 50%),
    linear-gradient(180deg, #e6f5ec 0%, #f3faf6 40%, #e8f3ec 100%);
}

/* Top bar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 40;
  height: var(--bar-h);
  backdrop-filter: blur(12px);
  background: rgba(238, 247, 241, 0.88);
  border-bottom: 1px solid var(--line);
}

.topbar-inner {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  margin-right: auto;
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  background: #0a0a0a;
  object-fit: cover;
}

.anchors {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.anchors a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--ink-soft);
  transition: color 0.2s var(--ease);
}

.anchors a:hover {
  color: var(--grass-deep);
}

.top-dl {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--white);
  background: var(--grass);
  padding: 0.45rem 0.95rem;
  border-radius: 8px;
  transition: background 0.2s var(--ease);
}

.top-dl:hover {
  background: var(--grass-deep);
}

.menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  background: transparent;
  border-radius: 8px;
  padding: 0;
  cursor: pointer;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
}

.menu-btn span {
  display: block;
  width: 16px;
  height: 2px;
  background: var(--grass-deep);
  transition: transform 0.25s var(--ease), opacity 0.25s;
}

.menu-btn[aria-expanded="true"] span:first-child {
  transform: translateY(3.5px) rotate(45deg);
}

.menu-btn[aria-expanded="true"] span:last-child {
  transform: translateY(-3.5px) rotate(-45deg);
}

/* ========== B：沉浸首屏 ========== */
.world {
  position: relative;
  min-height: calc(100vh - var(--bar-h));
  min-height: calc(100dvh - var(--bar-h));
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  overflow: hidden;
}

.world-media {
  position: absolute;
  inset: 0;
}

.world-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 40%;
  transform: scale(1.08);
  animation: worldDrift 36s ease-in-out infinite alternate;
}

.world-veil {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 55% 50% at 50% 42%, rgba(14, 26, 20, 0.12) 0%, rgba(14, 26, 20, 0.5) 70%),
    linear-gradient(180deg, rgba(14, 26, 20, 0.3) 0%, rgba(14, 26, 20, 0.18) 40%, rgba(14, 26, 20, 0.72) 100%);
}

.world-core {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 4rem 1.5rem 3.5rem;
  max-width: 36rem;
}

.world-logo {
  width: 120px;
  height: 120px;
  margin: 0 auto 1.15rem;
  border-radius: 26px;
  background: #0a0a0a;
  object-fit: cover;
  box-shadow:
    0 16px 40px rgba(0, 0, 0, 0.45),
    0 0 0 1px rgba(94, 200, 216, 0.25);
}

.world-brand {
  font-size: clamp(2.6rem, 9vw, 4.2rem);
  margin-bottom: 0.65rem;
  text-shadow: 0 8px 32px rgba(0, 0, 0, 0.45);
}

.world-line {
  margin: 0 0 1.75rem;
  font-size: clamp(1.05rem, 2.4vw, 1.25rem);
  color: rgba(255, 255, 255, 0.88);
  text-shadow: 0 4px 16px rgba(0, 0, 0, 0.35);
}

.world-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

.dl-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 10.5rem;
  padding: 0.95rem 1.7rem;
  font-family: var(--font-body);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--white);
  background: linear-gradient(180deg, var(--grass-soft), var(--grass));
  border-radius: 12px;
  box-shadow: 0 12px 28px rgba(61, 154, 106, 0.4);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.dl-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 36px rgba(31, 77, 58, 0.45);
}

.dl-lg {
  min-width: 12rem;
  padding: 1.05rem 2rem;
}

.btn-line {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.95rem 1.4rem;
  font-weight: 600;
  color: var(--white);
  border: 1.5px solid rgba(255, 255, 255, 0.45);
  border-radius: 12px;
  backdrop-filter: blur(6px);
  background: rgba(255, 255, 255, 0.08);
  transition: background 0.25s var(--ease);
}

.btn-line:hover {
  background: rgba(255, 255, 255, 0.16);
}

.scroll-cue {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  width: 28px;
  height: 42px;
  border: 1.5px solid rgba(255, 255, 255, 0.4);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 8px;
}

.scroll-cue span {
  width: 4px;
  height: 8px;
  border-radius: 2px;
  background: var(--diamond);
  animation: cueBounce 1.6s ease-in-out infinite;
}

.rise {
  opacity: 0;
  transform: translateY(24px);
  animation: riseIn 0.85s var(--ease) forwards;
}

.d1 { animation-delay: 0.12s; }
.d2 { animation-delay: 0.22s; }
.d3 { animation-delay: 0.32s; }

@keyframes riseIn {
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes worldDrift {
  from { transform: scale(1.08) translate(0, 0); }
  to { transform: scale(1.14) translate(-1.5%, -1%); }
}

@keyframes cueBounce {
  0%, 100% { transform: translateY(0); opacity: 0.7; }
  50% { transform: translateY(8px); opacity: 1; }
}

/* ========== A：画廊 ========== */
.strip {
  padding: 4.25rem 0 3.5rem;
  background: var(--paper);
}

.strip-head {
  margin-bottom: 1.5rem;
}

.strip-head h2 {
  margin: 0 0 0.35rem;
  font-size: clamp(1.45rem, 2.8vw, 1.85rem);
  color: var(--grass-deep);
}

.strip-head p {
  margin: 0;
  color: var(--ink-soft);
  font-size: 0.98rem;
}

.gallery {
  display: flex;
  gap: 1rem;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding: 0.35rem 0.15rem 1rem;
  -webkit-overflow-scrolling: touch;
  cursor: grab;
}

.gallery:active,
.gallery.dragging {
  cursor: grabbing;
  scroll-snap-type: none;
}

.gallery::-webkit-scrollbar {
  height: 6px;
}

.gallery::-webkit-scrollbar-thumb {
  background: rgba(61, 154, 106, 0.35);
  border-radius: 999px;
}

.shot {
  flex: 0 0 min(78vw, 340px);
  margin: 0;
  scroll-snap-align: start;
  border-radius: 14px;
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--line);
  box-shadow: 0 10px 28px rgba(20, 38, 28, 0.08);
  transition: transform 0.35s var(--ease);
}

.shot:hover {
  transform: translateY(-4px);
}

.shot img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

.shot figcaption {
  padding: 0.7rem 0.9rem 0.85rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--grass-deep);
}

.gallery-tip {
  margin: 0;
  font-size: 0.82rem;
  color: var(--ink-soft);
  opacity: 0.75;
}

/* ========== A：为何下载 ========== */
.why {
  padding: 1rem 0 4rem;
  background: var(--paper);
}

.why h2 {
  margin: 0 0 1.35rem;
  font-size: clamp(1.45rem, 2.8vw, 1.85rem);
  color: var(--grass-deep);
}

.why-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.why-row li {
  border-top: 3px solid var(--diamond);
  padding-top: 0.9rem;
}

.why-row strong {
  display: block;
  margin-bottom: 0.4rem;
  font-family: var(--font-display);
  font-size: 1.05rem;
}

.why-row span {
  font-size: 0.92rem;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* ========== A：安装时间线 ========== */
.install {
  padding: 3.5rem 0;
  background:
    linear-gradient(180deg, transparent 0%, rgba(94, 200, 216, 0.1) 40%, transparent 100%),
    var(--paper);
}

.install h2 {
  margin: 0 0 1.75rem;
  font-size: clamp(1.45rem, 2.8vw, 1.85rem);
  color: var(--grass-deep);
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 1.05rem;
  left: 8%;
  right: 8%;
  height: 2px;
  background: linear-gradient(90deg, var(--grass-soft), var(--diamond));
  opacity: 0.55;
}

.timeline li {
  position: relative;
  padding: 0 0.85rem;
  text-align: center;
}

.tl-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.1rem;
  height: 2.1rem;
  margin-bottom: 0.85rem;
  border-radius: 50%;
  background: var(--grass);
  color: var(--white);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 0.95rem;
  position: relative;
  z-index: 1;
  box-shadow: 0 0 0 4px var(--paper);
}

.timeline h3 {
  margin: 0 0 0.4rem;
  font-size: 1.02rem;
}

.timeline p {
  margin: 0;
  font-size: 0.9rem;
  color: var(--ink-soft);
  line-height: 1.55;
}

/* ========== A：FAQ ========== */
.faq {
  padding: 2.5rem 0 3.5rem;
  background: var(--paper);
}

.faq-shell {
  max-width: 720px;
}

.faq h2 {
  margin: 0 0 1.25rem;
  font-size: clamp(1.45rem, 2.8vw, 1.85rem);
  color: var(--grass-deep);
}

.faq-doc details {
  border-bottom: 1px solid var(--line);
}

.faq-doc summary {
  cursor: pointer;
  list-style: none;
  padding: 1.05rem 1.75rem 1.05rem 0;
  font-weight: 600;
  position: relative;
}

.faq-doc summary::-webkit-details-marker {
  display: none;
}

.faq-doc summary::after {
  content: "+";
  position: absolute;
  right: 0;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-display);
  font-size: 1.25rem;
  color: var(--diamond-deep);
  font-weight: 600;
}

.faq-doc details[open] summary::after {
  content: "–";
}

.faq-doc p {
  margin: 0 0 1.1rem;
  padding-right: 1rem;
  color: var(--ink-soft);
  font-size: 0.96rem;
}

.faq-doc em {
  font-style: normal;
  font-weight: 600;
  color: var(--grass-deep);
}

/* ========== A：下载面板 ========== */
.download {
  padding: 0 0 5rem;
  background: var(--paper);
}

.download-panel {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 2rem;
  align-items: center;
  padding: 2.25rem;
  border-radius: 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.download-copy h2 {
  margin-bottom: 0.65rem;
  font-size: clamp(1.4rem, 2.6vw, 1.85rem);
  color: var(--grass-deep);
}

.download-copy p {
  margin: 0 0 1.5rem;
  color: var(--ink-soft);
}

.download-visual {
  margin: 0;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 12px 32px rgba(20, 38, 28, 0.12);
}

.download-visual img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}

/* Footer */
.foot {
  padding: 2.25rem 0 2.75rem;
  background: var(--grass-deep);
  color: rgba(255, 255, 255, 0.72);
  font-size: 0.9rem;
}

.foot-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  margin-bottom: 0.75rem;
  color: var(--white);
  font-family: var(--font-display);
  font-weight: 600;
}

.foot-brand img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  background: #0a0a0a;
  object-fit: cover;
}

.foot p {
  margin: 0 0 0.55rem;
  max-width: 40rem;
  line-height: 1.65;
}

.foot-copy {
  opacity: 0.5;
  margin-bottom: 0 !important;
}

.mob-bar {
  display: none;
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 45;
  height: var(--mob-bar-h);
  padding: 0 1rem;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  background: rgba(31, 77, 58, 0.96);
  backdrop-filter: blur(10px);
  border-top: 1px solid rgba(94, 200, 216, 0.25);
  color: rgba(255, 255, 255, 0.85);
  font-size: 0.88rem;
  font-weight: 500;
}

.mob-bar a {
  flex-shrink: 0;
  padding: 0.55rem 1.1rem;
  border-radius: 9px;
  background: var(--diamond);
  color: var(--grass-deep);
  font-weight: 700;
}

@media (prefers-reduced-motion: reduce) {
  .rise,
  .world-media img,
  .scroll-cue span,
  .shot {
    animation: none !important;
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

@media (max-width: 900px) {
  .why-row {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.35rem 1.5rem;
  }

  .timeline {
    grid-template-columns: 1fr 1fr;
    gap: 1.75rem 1rem;
  }

  .timeline::before {
    display: none;
  }

  .download-panel {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .menu-btn {
    display: inline-flex;
  }

  .top-dl {
    display: none;
  }

  .anchors {
    position: absolute;
    top: var(--bar-h);
    left: 0;
    right: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 0.5rem 1.25rem 1rem;
    background: rgba(238, 247, 241, 0.97);
    border-bottom: 1px solid var(--line);
  }

  .anchors.open {
    display: flex;
  }

  .anchors a {
    padding: 0.8rem 0.25rem;
    border-bottom: 1px solid var(--line);
  }

  .world-logo {
    width: 96px;
    height: 96px;
    border-radius: 22px;
  }

  .why-row {
    grid-template-columns: 1fr;
  }

  .timeline {
    grid-template-columns: 1fr;
    gap: 1.25rem;
  }

  .timeline li {
    text-align: left;
    display: grid;
    grid-template-columns: auto 1fr;
    grid-template-rows: auto auto;
    column-gap: 0.85rem;
    padding: 0;
  }

  .tl-num {
    grid-row: 1 / span 2;
    margin-bottom: 0;
    align-self: start;
  }

  .download-panel {
    padding: 1.5rem;
  }

  .mob-bar {
    display: flex;
  }
}