:root {
  --bg: #0a0a0f;
  --bg-soft: #12121a;
  --surface: rgba(255, 255, 255, 0.05);
  --surface-hover: rgba(255, 255, 255, 0.1);
  --text: #ffffff;
  --text-muted: rgba(255, 255, 255, 0.65);
  --text-dim: rgba(255, 255, 255, 0.4);
  --brand: #2b6579;
  --brand-light: #a0d8ef;
  --accent: #ffb7c5;
  --accent-2: #b8eaff;
  --glow: rgba(160, 216, 239, 0.35);
  --radius: 20px;
  --radius-sm: 12px;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
  --max-width: 1200px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

/* Loader */
.loader {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at 50% 40%, #151520 0%, #07070a 70%);
  transition: opacity 0.6s ease, visibility 0.6s;
}

.loader--hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loader__content {
  text-align: center;
  width: min(320px, 80vw);
}

.loader__icon {
  font-size: 48px;
  margin-bottom: 16px;
  animation: pulse 1.6s ease-in-out infinite;
}

.loader__title {
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.loader__bar {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 100px;
  overflow: hidden;
  margin-bottom: 12px;
}

.loader__bar span {
  display: block;
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--brand-light), var(--accent));
  border-radius: 100px;
  transition: width 0.3s ease;
}

.loader__hint {
  font-size: 0.8rem;
  color: var(--text-dim);
}

@keyframes pulse {
  0%, 100% { opacity: 0.7; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.1); }
}

.loader__actions {
  margin-top: 20px;
  min-height: 40px;
}

.loader__skip {
  appearance: none;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: var(--text-muted);
  padding: 10px 18px;
  border-radius: 100px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.25s ease;
}

.loader__skip:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.4);
  color: var(--text);
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s;
}

.modal--open {
  opacity: 1;
  visibility: visible;
}

.modal__backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(6px);
}

.modal__card {
  position: relative;
  width: min(420px, 100%);
  background: linear-gradient(145deg, #1a1a28, #13131c);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  box-shadow: var(--shadow);
  transform: translateY(20px);
  transition: transform 0.3s ease;
}

.modal--open .modal__card {
  transform: translateY(0);
}

.modal__close {
  position: absolute;
  top: 14px;
  right: 18px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.8rem;
  cursor: pointer;
  line-height: 1;
}

.modal__icon {
  width: 72px;
  height: 72px;
  border-radius: 22px;
  margin: 0 auto 18px;
  box-shadow: 0 12px 30px rgba(43, 101, 121, 0.25);
}

.modal__title {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.modal__desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 24px;
}

.modal__actions {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 16px;
}

.modal__note {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: 100px;
  padding: 14px 28px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
  color: #fff;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn--primary {
  background: linear-gradient(135deg, var(--brand), var(--brand-light));
  color: #071015;
  box-shadow: 0 8px 24px rgba(43, 101, 121, 0.35);
}

.btn--primary:hover {
  box-shadow: 0 12px 32px rgba(43, 101, 121, 0.5);
}

.btn--secondary {
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: var(--text);
}

.btn--secondary:hover {
  background: var(--surface-hover);
}

.btn--ghost {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: var(--text);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.06);
}

.btn--install {
  background: linear-gradient(135deg, #3a8fbf, #6ec4e6);
  color: #fff;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.25);
  box-shadow: 0 6px 18px rgba(58, 143, 191, 0.35);
}

.btn--install:hover {
  box-shadow: 0 10px 26px rgba(58, 143, 191, 0.5);
}

.btn--small {
  padding: 10px 20px;
  font-size: 0.9rem;
}

.btn--large {
  padding: 18px 36px;
  font-size: 1.1rem;
}

.btn--block {
  width: 100%;
}

.btn--glow {
  position: relative;
}

.btn--glow::after {
  content: "";
  position: absolute;
  inset: -2px;
  border-radius: 100px;
  background: linear-gradient(135deg, var(--brand-light), var(--accent));
  filter: blur(16px);
  opacity: 0.45;
  z-index: -1;
  transition: opacity 0.3s;
}

.btn--glow:hover::after {
  opacity: 0.7;
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 16px 24px;
  transition: background 0.3s, backdrop-filter 0.3s, box-shadow 0.3s;
}

.nav--scrolled {
  background: rgba(10, 10, 15, 0.75);
  backdrop-filter: blur(16px);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.nav__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  flex-shrink: 0;
  white-space: nowrap;
}

.nav__logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.nav__links {
  display: flex;
  gap: 28px;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.nav__links a {
  transition: color 0.2s;
}

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

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 120px 24px 80px;
}

#three-canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  outline: none;
}

.hero__fallback {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 30%;
  z-index: 0;
  opacity: 0;
  transform: scale(1.05);
  transition: opacity 1s ease, transform 8s ease;
  pointer-events: none;
}

.hero__fallback--visible {
  opacity: 0.55;
  transform: scale(1);
}

.hero__gradient {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: radial-gradient(circle at 50% 50%, transparent 0%, rgba(10, 10, 15, 0.4) 60%, rgba(10, 10, 15, 0.85) 100%);
  pointer-events: none;
}

.hero__content {
  position: relative;
  z-index: 2;
  max-width: var(--max-width);
  width: 100%;
  text-align: center;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 100px;
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 28px;
}

.hero__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 12px var(--accent-2);
}

.hero__title {
  margin-bottom: 20px;
}

.hero__word {
  display: block;
  font-size: clamp(3rem, 10vw, 7rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -2px;
  background: linear-gradient(135deg, #fff 20%, var(--brand-light) 70%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__sub {
  display: block;
  font-size: clamp(1.25rem, 3vw, 2rem);
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 16px;
  letter-spacing: 2px;
}

.hero__lead {
  max-width: 620px;
  margin: 0 auto 36px;
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-muted);
}

.hero__actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 48px;
  flex-wrap: wrap;
}

.hero__stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}

.hero__stat {
  text-align: center;
}

.hero__stat strong {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--text);
}

.hero__stat span {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.scroll-hint {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 0.75rem;
  letter-spacing: 1px;
}

.scroll-hint__line {
  width: 1px;
  height: 36px;
  background: linear-gradient(to bottom, var(--text-dim), transparent);
  animation: scrollLine 1.8s ease-in-out infinite;
}

@keyframes scrollLine {
  0% { transform: scaleY(0); transform-origin: top; }
  50% { transform: scaleY(1); }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* Section commons */
.section__eyebrow {
  font-size: 0.8rem;
  letter-spacing: 3px;
  color: var(--brand-light);
  margin-bottom: 12px;
}

.section__title {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.2;
}

.section__lead {
  max-width: 620px;
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Features */
.features {
  padding: 100px 24px;
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg-soft) 100%);
}

.features__header {
  max-width: var(--max-width);
  margin: 0 auto 48px;
  text-align: center;
}

.features__grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 18px;
}

.feature-card {
  grid-column: span 4;
  background: var(--surface);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  overflow: hidden;
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: rgba(160, 216, 239, 0.25);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.25);
}

.feature-card--wide {
  grid-column: span 8;
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  align-items: center;
}

.feature-card--wide .feature-card__image {
  max-height: 340px;
}

.feature-card--wide .feature-card__image img {
  max-height: 308px;
}

/* 竖版图片卡片：图片完整显示且尽量大 */
.feature-card--tall .feature-card__image {
  max-height: 320px;
  padding: 10px;
}

.feature-card--tall .feature-card__image img {
  max-height: 300px;
}

.feature-card__image {
  overflow: hidden;
  background: radial-gradient(circle at 50% 60%, rgba(160, 216, 239, 0.12), rgba(255, 255, 255, 0.03) 70%);
  display: grid;
  place-items: center;
  max-height: 220px;
  padding: 16px;
}

.feature-card__image img {
  width: 100%;
  height: 100%;
  max-height: 188px;
  object-fit: contain;
  transition: transform 0.5s;
}

.feature-card:hover .feature-card__image img {
  transform: scale(1.05);
}

.feature-card__text {
  padding: 22px;
}

.feature-card__text h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
}

.feature-card__text p {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
}

.feature-card--accent {
  padding: 24px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.feature-card__icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

/* Showcase */
.showcase {
  padding: 140px 24px;
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.showcase__content {
  max-width: 520px;
}

.showcase__list {
  list-style: none;
  margin-top: 28px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.showcase__list li {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-muted);
}

.showcase__list span {
  color: var(--brand-light);
  font-size: 1.2rem;
}

.showcase__visual {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  overflow: visible;
}

.showcase__visual::before {
  content: "";
  position: absolute;
  width: 90%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(160, 216, 239, 0.18) 0%, rgba(160, 216, 239, 0.05) 50%, transparent 70%);
  z-index: 0;
  pointer-events: none;
}

.showcase__ring {
  position: absolute;
  width: 80%;
  aspect-ratio: 1;
  border-radius: 50%;
  border: 1px solid rgba(160, 216, 239, 0.2);
  animation: ringExpand 3s ease-out infinite;
  z-index: 0;
}

.showcase__ring--delay {
  animation-delay: 1.5s;
}

@keyframes ringExpand {
  0% { transform: scale(0.8); opacity: 0.6; }
  100% { transform: scale(1.25); opacity: 0; }
}

.showcase__canvas {
  position: relative;
  z-index: 3;
  width: 120%;
  height: 120%;
}

.showcase__fallback-img {
  display: none;
  position: relative;
  z-index: 3;
  width: 55%;
  height: auto;
  object-fit: contain;
  border-radius: 0;
  filter: drop-shadow(0 24px 50px rgba(0, 0, 0, 0.3));
}

.showcase__visual--fallback .showcase__canvas {
  display: none;
}

.showcase__visual--fallback .showcase__fallback-img {
  display: block;
}

/* Download */
.download {
  padding: 140px 24px;
  background: radial-gradient(circle at 50% 50%, rgba(43, 101, 121, 0.18) 0%, transparent 60%);
  text-align: center;
}

.download__inner {
  max-width: 600px;
  margin: 0 auto;
}

.download__logo {
  width: 88px;
  height: 88px;
  border-radius: 26px;
  margin: 0 auto 24px;
  box-shadow: 0 16px 40px rgba(43, 101, 121, 0.25);
}

.download__title {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  margin-bottom: 12px;
}

.download__lead {
  color: var(--text-muted);
  font-size: 1.1rem;
  margin-bottom: 32px;
}

.download__note {
  position: relative;
  z-index: 2;
  margin-top: 40px;
  font-size: 0.85rem;
  color: var(--text-dim);
}

.download .btn--glow {
  position: relative;
  z-index: 2;
}

.download .btn--glow::after {
  filter: blur(12px);
  opacity: 0.35;
}

/* Footer */
.footer {
  padding: 40px 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  flex-wrap: wrap;
}

.footer__brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
}

.footer__brand img {
  width: 28px;
  height: 28px;
  border-radius: 8px;
}

.footer__copy {
  color: var(--text-dim);
  font-size: 0.85rem;
}

/* Responsive */
@media (max-width: 900px) {
  .nav__links {
    display: none;
  }

  .features__grid {
    grid-template-columns: 1fr;
  }

  .feature-card,
  .feature-card--wide {
    grid-column: span 1;
  }

  .feature-card--wide {
    grid-template-columns: 1fr;
  }

  .showcase {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .showcase__list {
    align-items: center;
  }

  .showcase__fallback-img {
    width: 55%;
  }

  .hero__stats {
    gap: 32px;
  }
}

@media (max-width: 520px) {
  .hero {
    padding: 110px 20px 70px;
  }

  .hero__actions {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
    margin-left: auto;
    margin-right: auto;
  }

  .btn {
    width: 100%;
  }

  .nav .btn {
    width: auto;
  }

  .features,
  .showcase,
  .download {
    padding: 80px 20px;
  }

  .feature-card__text {
    padding: 22px;
  }

  .footer__inner {
    flex-direction: column;
    text-align: center;
  }
}