:root {
  --ocean: #1b6b93;
  --ocean-dark: #0f4c6e;
  --ocean-mid: #2a8bb0;
  --teal: #2a9d8f;
  --sand: #f4f7fa;
  --foam: #e7f3fa;
  --coral: #e07a5f;
  --ink: #14212b;
  --muted: #5a6b78;
  --white: #ffffff;
  --shadow: 0 18px 50px rgba(15, 76, 110, 0.14);
  --radius: 18px;
  --radius-lg: 28px;
  --max-width: 1120px;
  --font-display: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(42, 157, 143, 0.12), transparent 50%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(27, 107, 147, 0.1), transparent 45%),
    var(--sand);
  font: 16px/1.65 var(--font-body);
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--ocean);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: min(100% - 40px, var(--max-width));
  margin-inline: auto;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(16px);
  background: rgba(244, 247, 250, 0.82);
  border-bottom: 1px solid rgba(27, 107, 147, 0.08);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  text-decoration: none;
}

.brand:hover {
  text-decoration: none;
}

.brand-icon {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  box-shadow: 0 6px 16px rgba(27, 107, 147, 0.2);
}

.brand-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 400;
  color: var(--ocean-dark);
  letter-spacing: 0.04em;
}

.nav {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 10px 18px;
}

.nav a.is-current {
  color: var(--ocean);
  font-weight: 700;
}

.nav a {
  color: var(--muted);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
}

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

.nav-cta {
  padding: 9px 18px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--ocean), var(--teal));
  color: var(--white) !important;
  font-weight: 700;
  box-shadow: 0 8px 20px rgba(27, 107, 147, 0.25);
}

.nav-cta:hover {
  filter: brightness(1.05);
  text-decoration: none;
}

/* Hero */
.hero {
  position: relative;
  overflow: hidden;
  padding: 72px 0 100px;
  min-height: min(88vh, 760px);
  display: flex;
  align-items: center;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, rgba(15, 76, 110, 0.92) 0%, rgba(27, 107, 147, 0.78) 42%, rgba(42, 157, 143, 0.55) 100%),
    url("../assets/images/hero-bottle.png") right 12% center / min(48vw, 520px) no-repeat;
  z-index: 0;
}

.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 70% 40%, rgba(255, 255, 255, 0.12), transparent 35%),
    radial-gradient(circle at 20% 80%, rgba(42, 157, 143, 0.25), transparent 40%);
}

.hero-wave {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 72px;
  background: linear-gradient(180deg, transparent, var(--sand));
  z-index: 1;
}

.hero-inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: center;
  gap: 40px;
}

.hero-copy .eyebrow {
  margin: 0 0 14px;
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.14);
  color: rgba(255, 255, 255, 0.9);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}

.hero-copy h1 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(56px, 8vw, 84px);
  line-height: 1;
  font-weight: 400;
  color: #fff;
  letter-spacing: 0.08em;
  text-shadow: 0 10px 40px rgba(0, 0, 0, 0.18);
}

.hero-copy .tagline {
  margin: 0 0 16px;
  font-size: clamp(18px, 2.4vw, 24px);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.92);
}

.hero-copy .desc {
  margin: 0 0 28px;
  max-width: 440px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 16px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn-primary,
.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 999px;
  font-weight: 700;
  text-decoration: none;
  transition: transform 0.2s, filter 0.2s, background 0.2s;
}

.btn-primary {
  background: #fff;
  color: var(--ocean-dark);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
  transform: translateY(-2px);
  text-decoration: none;
}

.btn-ghost {
  border: 1px solid rgba(255, 255, 255, 0.35);
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.16);
  text-decoration: none;
}

.hero-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-bottle-wrap {
  position: relative;
  width: min(100%, 360px);
  aspect-ratio: 1;
}

.hero-bottle-wrap::before {
  content: "";
  position: absolute;
  inset: 10%;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.28), transparent 70%);
  filter: blur(18px);
}

.hero-bottle {
  position: relative;
  width: 100%;
  height: 100%;
  object-fit: contain;
  filter: drop-shadow(0 28px 50px rgba(0, 0, 0, 0.28));
  animation: float 5.5s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-14px); }
}

/* Features */
.features {
  padding: 88px 0;
  background: var(--white);
}

.section-head {
  text-align: center;
  margin-bottom: 48px;
}

.section-head h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(30px, 4vw, 40px);
  font-weight: 400;
  color: var(--ocean-dark);
  letter-spacing: 0.06em;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
}

.feature-card {
  padding: 28px 22px;
  border-radius: var(--radius);
  background: linear-gradient(180deg, #fff, #f7fafc);
  border: 1px solid rgba(27, 107, 147, 0.08);
  box-shadow: 0 10px 28px rgba(20, 33, 43, 0.04);
  transition: transform 0.25s, box-shadow 0.25s;
  color: inherit;
  text-decoration: none;
}

a.feature-card:hover {
  text-decoration: none;
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
}

.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  font-size: 22px;
  margin-bottom: 16px;
}

.feature-icon.teal { background: linear-gradient(135deg, #1b6b93, #4ecdc4); }
.feature-icon.coral { background: linear-gradient(135deg, #e07a5f, #ffb347); }
.feature-icon.sand { background: linear-gradient(135deg, #8ecae6, #219ebc); }
.feature-icon.foam { background: linear-gradient(135deg, #2a9d8f, #8ecae6); }

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
}

.feature-card p {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

/* Showcase */
.showcase {
  padding: 80px 0 96px;
  background:
    radial-gradient(circle at 50% 0%, rgba(42, 157, 143, 0.1), transparent 45%),
    linear-gradient(180deg, #fff 0%, var(--foam) 100%);
}

.showcase-carousel {
  position: relative;
  max-width: 560px;
  margin: 0 auto;
}

.carousel-track-wrap {
  overflow: hidden;
  border-radius: var(--radius-lg);
}

.carousel-track {
  display: flex;
  transition: transform 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

.carousel-slide {
  flex: 0 0 100%;
  display: flex;
  justify-content: center;
  padding: 8px 12px 20px;
}

.carousel-slide img {
  width: min(100%, 320px);
  border-radius: 28px;
  box-shadow: 0 24px 60px rgba(15, 76, 110, 0.22);
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border: none;
  border-radius: 50%;
  background: var(--white);
  color: var(--ocean-dark);
  font-size: 20px;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: background 0.2s;
  z-index: 2;
}

.carousel-btn:hover {
  background: var(--foam);
}

.carousel-btn.prev { left: -8px; }
.carousel-btn.next { right: -8px; }

.carousel-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 8px;
}

.carousel-dot {
  width: 8px;
  height: 8px;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: rgba(27, 107, 147, 0.2);
  cursor: pointer;
  transition: all 0.2s;
}

.carousel-dot.active {
  width: 24px;
  border-radius: 4px;
  background: var(--ocean);
}

/* Download */
.download {
  padding: 40px 0 100px;
  background: transparent;
}

.download-inner {
  display: flex;
  justify-content: center;
}

.download-card {
  width: min(100%, 520px);
  padding: 40px 32px;
  border-radius: 28px;
  text-align: center;
  color: #fff;
  background:
    linear-gradient(145deg, rgba(15, 76, 110, 0.98), rgba(42, 157, 143, 0.92));
  box-shadow: 0 24px 60px rgba(15, 76, 110, 0.28);
}

.download-card h2 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 400;
  letter-spacing: 0.06em;
}

.download-card .sub {
  margin: 0 0 28px;
  opacity: 0.85;
  font-size: 15px;
}

.download-cta {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  min-width: 240px;
  padding: 14px 22px;
  border-radius: 18px;
  background: #fff;
  color: var(--ocean-dark);
  text-decoration: none;
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.16);
  transition: transform 0.2s, filter 0.2s;
}

.download-cta:hover {
  transform: translateY(-2px);
  text-decoration: none;
  filter: brightness(1.02);
}

.download-cta-icon {
  width: 42px;
  height: 42px;
  border-radius: 14px;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--ocean), var(--teal));
  color: #fff;
  font-size: 20px;
  font-weight: 700;
}

.download-cta strong {
  display: block;
  font-size: 16px;
}

.download-cta small {
  display: block;
  margin-top: 2px;
  font-size: 12px;
  color: var(--muted);
  font-weight: 500;
}

.download-note {
  margin: 18px 0 0;
  font-size: 12px;
  opacity: 0.7;
}

/* Footer */
.site-footer {
  padding: 48px 0 32px;
  background: #0b2a3a;
  color: rgba(255, 255, 255, 0.75);
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.footer-brand img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
}

.footer-brand span {
  font-family: var(--font-display);
  font-size: 18px;
  color: var(--white);
  letter-spacing: 0.04em;
}

.footer-desc {
  margin: 0;
  line-height: 1.7;
  opacity: 0.75;
  max-width: 360px;
}

.footer-col h4 {
  margin: 0 0 14px;
  font-size: 14px;
  font-weight: 700;
  color: var(--white);
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-links li {
  margin-bottom: 8px;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.72);
  text-decoration: none;
}

.footer-links a:hover {
  color: var(--white);
  text-decoration: underline;
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 13px;
  opacity: 0.6;
}

.footer-bottom a {
  color: rgba(255, 255, 255, 0.72);
}

.footer-company {
  margin: 10px 0 0;
  font-size: 13px;
  opacity: 0.8;
}

/* Inner pages */
.page-main {
  padding: 36px 0 72px;
}

.breadcrumb {
  margin: 0 0 18px;
  font-size: 13px;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--ocean);
}

.page-title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 400;
  color: var(--ocean-dark);
  letter-spacing: 0.06em;
}

.page-lead {
  margin: 0 0 28px;
  max-width: 720px;
  color: var(--muted);
  font-size: 16px;
}

.prose {
  max-width: 760px;
  color: var(--ink);
}

.prose h2 {
  margin: 32px 0 12px;
  font-size: 22px;
  color: var(--ocean-dark);
}

.prose h3 {
  margin: 22px 0 8px;
  font-size: 17px;
}

.prose p,
.prose li {
  margin: 0 0 12px;
  line-height: 1.8;
  color: #3a4a55;
}

.prose ul {
  padding-left: 1.2em;
}

.intro {
  padding: 8px 0 72px;
}

.intro-card {
  max-width: 760px;
  margin: 0 auto;
  padding: 32px 28px;
  border-radius: var(--radius-lg);
  background: var(--white);
  border: 1px solid rgba(27, 107, 147, 0.08);
  box-shadow: 0 10px 28px rgba(20, 33, 43, 0.04);
}

.intro-card h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 400;
  color: var(--ocean-dark);
}

.intro-card p {
  margin: 0 0 12px;
  color: #3a4a55;
  line-height: 1.8;
}

.intro-card p:last-child {
  margin-bottom: 0;
}

.faq-list {
  display: grid;
  gap: 14px;
  max-width: 760px;
}

.faq-item {
  padding: 20px 22px;
  border-radius: var(--radius);
  background: var(--white);
  border: 1px solid rgba(27, 107, 147, 0.08);
}

.faq-item h2 {
  margin: 0 0 8px;
  font-size: 17px;
  color: var(--ocean-dark);
}

.faq-item p {
  margin: 0;
  color: #3a4a55;
  line-height: 1.8;
}

.install-steps {
  display: grid;
  gap: 12px;
  margin: 0 0 28px;
  padding: 0;
  list-style: none;
  max-width: 760px;
}

.install-steps li {
  padding: 16px 18px;
  border-radius: 14px;
  background: var(--white);
  border: 1px solid rgba(27, 107, 147, 0.08);
}

.install-steps strong {
  display: block;
  margin-bottom: 4px;
  color: var(--ocean-dark);
}

/* Responsive */
@media (max-width: 960px) {
  .hero {
    min-height: auto;
    padding: 56px 0 80px;
  }

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

  .hero-copy .desc {
    margin-inline: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .hero-bg {
    background:
      linear-gradient(160deg, rgba(15, 76, 110, 0.94), rgba(42, 157, 143, 0.7));
  }

  .hero-bottle-wrap {
    width: min(68vw, 260px);
  }

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .footer-brand,
  .footer-desc {
    margin-inline: auto;
  }

  .footer-brand {
    justify-content: center;
  }

  .carousel-btn.prev { left: 4px; }
  .carousel-btn.next { right: 4px; }
}

@media (max-width: 600px) {
  .nav {
    gap: 8px 12px;
  }

  .nav a {
    font-size: 13px;
  }

  .nav-cta {
    padding: 7px 12px;
  }

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

  .features,
  .showcase {
    padding: 56px 0;
  }

  .download {
    padding: 24px 0 72px;
  }

  .download-card {
    padding: 32px 20px;
  }
}