/* ============================================================
   Nanbin Studio - Main stylesheet
   Design language: Liquid Glass (Apple WWDC 2025)
   - Translucent material refracting underlying content in real time
   - Specular highlights, capsule shapes, fluid motion
   - Glass applies to the navigation layer only (floating controls)
   ============================================================ */

:root {
  /* Brand tint color (tint is used only for semantic primary actions) */
  --color-primary: #00BFA5;
  --color-primary-dark: #00897B;
  --color-primary-light: #B2DFDB;
  --color-accent: #26C6DA;

  /* Text */
  --color-text: #1C2430;
  --color-text-secondary: #4A5568;
  --color-text-muted: #7B8794;

  /* ---- Liquid Glass material variables ---- */
  --glass-bg: rgba(255, 255, 255, 0.36);          /* regular glass (high transparency) */
  --glass-bg-strong: rgba(255, 255, 255, 0.58);   /* more solid after scroll for readability */
  --glass-border: rgba(255, 255, 255, 0.65);      /* glass highlight border */
  --glass-edge: rgba(255, 255, 255, 0.9);         /* top specular highlight */
  --glass-shadow: 0 8px 32px rgba(28, 36, 48, 0.10);
  --glass-shadow-sm: 0 4px 16px rgba(28, 36, 48, 0.08);
  --glass-filter: blur(18px) saturate(200%);      /* lensing refraction + saturation boost */
  --glass-tint-bg: rgba(0, 191, 165, 0.16);
  --glass-tint-border: rgba(0, 191, 165, 0.30);

  --radius-sm: 14px;
  --radius-md: 22px;
  --radius-lg: 28px;
  --radius-pill: 999px;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial,
    "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans CJK SC", sans-serif;

  --ease-spring: cubic-bezier(0.34, 1.56, 0.64, 1); /* jelly bounce */
}

/* ----- Reset ----- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; }

/* Page base: soft color gradient so glass refraction stays visible */
body {
  font-family: var(--font-family); font-size: 16px; line-height: 1.6;
  color: var(--color-text);
  background: linear-gradient(135deg, #EAF6F4 0%, #F6F3FC 45%, #FDF1F3 100%) fixed;
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }

/* ============================================================
   Liquid Glass shared material layer
   - Glass applies only to the navigation layer (controls floating above content)
   ============================================================ */
.glass {
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-filter);
  backdrop-filter: var(--glass-filter);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-edge);
}

/* ----- Utilities ----- */
.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }
.section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 48px; }

.section-tag {
  display: inline-block; font-size: 12px; font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--color-primary-dark);
  background: var(--glass-tint-bg);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  border: 1px solid var(--glass-tint-border);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.55);
  padding: 5px 16px; border-radius: var(--radius-pill); margin-bottom: 14px;
}
.section-title { font-size: 30px; font-weight: 700; line-height: 1.3; margin-bottom: 12px; letter-spacing: -0.01em; }
.section-desc { font-size: 16px; color: var(--color-text-secondary); max-width: 560px; margin: 0 auto; }

/* ----- Buttons: capsule glass controls (sheen sweep + touch light + jelly press) ----- */
.btn {
  position: relative; overflow: hidden;
  display: inline-flex; align-items: center; gap: 8px; padding: 12px 28px;
  border-radius: var(--radius-pill); font-size: 15px; font-weight: 600; font-family: inherit;
  border: 1px solid var(--glass-border); cursor: pointer;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  box-shadow: var(--glass-shadow-sm), inset 0 1px 0 var(--glass-edge);
  color: var(--color-text);
  transition: transform 0.35s var(--ease-spring), box-shadow 0.25s, background 0.25s, color 0.25s;
}
/* Specular sheen: a light streak flows across on hover */
.btn::before {
  content: ''; position: absolute; top: -20%; bottom: -20%; left: -70%; width: 45%;
  background: linear-gradient(105deg, transparent, rgba(255,255,255,0.65), transparent);
  transform: skewX(-20deg); opacity: 0; pointer-events: none;
}
.btn:hover::before { left: 130%; opacity: 1; transition: left 0.65s ease, opacity 0.2s; }
/* Touch-point illumination: radial highlight follows the mouse */
.btn::after {
  content: ''; position: absolute; inset: 0; border-radius: inherit; opacity: 0;
  background: radial-gradient(70px circle at var(--mx, 50%) var(--my, 50%), rgba(255,255,255,0.45), transparent 75%);
  transition: opacity 0.3s; pointer-events: none;
}
.btn:hover::after { opacity: 1; }
.btn:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(28,36,48,0.14), inset 0 1px 0 var(--glass-edge); }
.btn:active { animation: glassJelly 0.5s var(--ease-spring); }

/* Jelly press: non-uniform x/y scaling for a liquid feel */
@keyframes glassJelly {
  0% { transform: scale(1, 1); }
  30% { transform: scale(0.94, 0.88); }
  60% { transform: scale(1.06, 1.1); }
  100% { transform: scale(1, 1); }
}

/* Tinted glass: color reserved for primary actions only (tint semantics) */
.btn-primary {
  background: linear-gradient(180deg, rgba(0,191,165,0.85), rgba(0,150,136,0.85));
  border-color: rgba(255,255,255,0.55); color: #fff;
  box-shadow: 0 8px 24px rgba(0,150,136,0.35), inset 0 1px 0 rgba(255,255,255,0.5);
}
.btn-primary:hover { background: linear-gradient(180deg, rgba(0,178,156,0.9), rgba(0,137,123,0.9)); }

/* ----- Clear glass variant (colorless and transparent) ----- */
.btn-outline { background: rgba(255,255,255,0.28); }

/* ============================================================
   Navbar - floating Liquid Glass capsule (collapses on scroll, like a tab bar)
   ============================================================ */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  padding: 14px 0; pointer-events: none;
  transition: padding 0.35s var(--ease-spring);
}
/* Glass capsule backplate (highly transparent: content and colors show through) */
.navbar::before {
  content: ''; position: absolute; top: 10px; bottom: 10px;
  left: 50%; transform: translateX(-50%);
  width: min(1140px, calc(100% - 24px));
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.26);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-edge);
  transition: all 0.35s var(--ease-spring);
}
/* Collapse after scroll: dynamic toolbar behavior (slightly more solid for readability) */
.navbar.scrolled { padding: 8px 0; }
.navbar.scrolled::before {
  top: 6px; bottom: 6px;
  background: rgba(255, 255, 255, 0.5);
  box-shadow: 0 6px 24px rgba(28,36,48,0.12), inset 0 1px 0 var(--glass-edge);
}
/* Stacking lift: keep content painted above the glass backplate;
   align with the capsule and inset so links never overflow it */
.navbar .container {
  position: relative; display: flex; align-items: center; justify-content: center;
  pointer-events: auto;
  width: min(1140px, calc(100% - 56px)); max-width: none; padding: 0;
}

.navbar-logo { display: flex; align-items: center; gap: 10px; font-size: 17px; font-weight: 600; letter-spacing: 0.01em; color: var(--color-text); }
/* Icon + name */
.navbar-logo .logo-icon {
  width: 34px; height: 34px; border-radius: 10px; overflow: hidden; flex: none;
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.55), 0 4px 12px rgba(28,36,48,0.25);
  display: flex; align-items: center; justify-content: center;
}
.navbar-logo .logo-icon img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* Nav links: small Liquid Glass capsule controls (hover lifts a glass base + touch light + jelly press) */
.navbar-links { position: absolute; right: 0; top: 50%; transform: translateY(-50%); display: flex; align-items: center; gap: 10px; }
.navbar-links a {
  position: relative; overflow: hidden;
  font-size: 14px; font-weight: 600; color: var(--color-text-secondary);
  padding: 8px 20px; border-radius: var(--radius-pill);
  border: 1px solid transparent;
  transition: transform 0.35s var(--ease-spring), color 0.2s, background 0.25s, border-color 0.25s, box-shadow 0.25s;
}
.navbar-links a::after {
  content: ''; position: absolute; inset: 0; border-radius: inherit; opacity: 0;
  background: radial-gradient(40px circle at var(--mx, 50%) var(--my, 50%), rgba(255,255,255,0.6), transparent 75%);
  transition: opacity 0.3s; pointer-events: none;
}
.navbar-links a:hover {
  color: var(--color-primary-dark);
  background: rgba(255,255,255,0.5);
  border-color: var(--glass-border);
  box-shadow: var(--glass-shadow-sm), inset 0 1px 0 var(--glass-edge);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
}
.navbar-links a:hover::after { opacity: 1; }
.navbar-links a:active { animation: glassJelly 0.5s var(--ease-spring); }
.navbar-cta { padding: 8px 22px; font-size: 14px; }

/* Language switcher: glass dropdown */
.lang-select { position: relative; }
.lang-switch {
  position: relative; overflow: hidden;
  font-family: inherit; font-size: 14px; font-weight: 600; color: var(--color-primary-dark);
  padding: 8px 20px; border-radius: var(--radius-pill); cursor: pointer;
  background: var(--glass-tint-bg);
  border: 1px solid var(--glass-tint-border);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.55);
  transition: transform 0.35s var(--ease-spring), box-shadow 0.25s, background 0.25s;
}
.lang-switch:hover {
  transform: translateY(-2px);
  background: rgba(0, 191, 165, 0.24);
  box-shadow: 0 6px 18px rgba(0,150,136,0.22), inset 0 1px 0 rgba(255,255,255,0.55);
}
.lang-switch:active { animation: glassJelly 0.5s var(--ease-spring); }
.lang-menu {
  display: none; position: absolute; top: calc(100% + 8px); right: 0;
  min-width: 160px; max-height: 320px; overflow-y: auto; z-index: 100;
  flex-direction: column; padding: 8px; gap: 2px;
  background: var(--glass-bg-strong);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  border: 1px solid var(--glass-border); border-radius: var(--radius-sm);
  box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-edge);
}
.lang-menu.open { display: flex; }
.lang-menu button {
  font-family: inherit; font-size: 14px; font-weight: 500; text-align: left;
  color: var(--color-text-secondary); background: transparent; border: none;
  border-radius: 10px; padding: 8px 14px; cursor: pointer; transition: background 0.2s, color 0.2s;
}
.lang-menu button:hover { background: rgba(255,255,255,0.6); color: var(--color-primary-dark); }
.lang-menu button.active { background: var(--glass-tint-bg); color: var(--color-primary-dark); font-weight: 600; }

.navbar-toggle { position: absolute; right: 0; top: 50%; transform: translateY(-50%); display: none; flex-direction: column; gap: 5px; background: rgba(255,255,255,0.35); border: 1px solid var(--glass-border); border-radius: 10px; cursor: pointer; padding: 8px 6px; -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter); }
.navbar-toggle span { width: 22px; height: 2px; background: var(--color-text); border-radius: 2px; transition: all 0.25s; }
.navbar-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px,5px); }
.navbar-toggle.active span:nth-child(2) { opacity: 0; }
.navbar-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px,-5px); }

/* ============================================================
   Hero - flowing color backdrop that highlights glass refraction
   ============================================================ */
.hero { position: relative; overflow: hidden; padding-top: 96px; }
/* Carousel background layer: active slide lightly blurred as module backdrop,
   white overlay keeps foreground readable */
.carousel-bg { position: absolute; inset: 0; z-index: 0; overflow: hidden; }
.carousel-bg::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(255,255,255,0.62) 0%, rgba(255,255,255,0.38) 45%, rgba(255,255,255,0.66) 100%);
}
.carousel-bg-img {
  position: absolute; inset: 0; width: 100%; height: 100%;
  object-fit: cover; opacity: 0; transform: scale(1.08);
  filter: blur(6px) saturate(1.15);
  transition: opacity 0.8s ease;
}
.carousel-bg-img.active { opacity: 1; }
/* Floating light blobs: ambient colors behind the glass (stacked above the backdrop image) */
.hero::before, .hero::after {
  content: ''; position: absolute; border-radius: 50%; z-index: 1;
  filter: blur(70px); opacity: 0.35; pointer-events: none;
}
.hero::before {
  width: 520px; height: 520px; top: -140px; left: -120px;
  background: radial-gradient(circle, #4DD0C4 0%, rgba(77,208,196,0) 70%);
  animation: blobFloat 12s ease-in-out infinite;
}
.hero::after {
  width: 560px; height: 560px; bottom: -180px; right: -140px;
  background: radial-gradient(circle, #B39DDB 0%, rgba(179,157,219,0) 70%);
  animation: blobFloat 15s ease-in-out infinite reverse;
}
.hero .container { position: relative; z-index: 2; }

@keyframes blobFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(50px, -36px) scale(1.12); }
  66% { transform: translate(-30px, 24px) scale(0.95); }
}

/* ----- Carousel ----- */
.carousel { position: relative; width: 100%; overflow: hidden; }
.carousel-track { display: flex; transition: transform 0.65s cubic-bezier(0.22, 1, 0.36, 1); } /* fluid slide */

.carousel-slide {
  min-width: 100%; display: grid; grid-template-columns: 1fr 1fr; gap: 60px;
  align-items: center; padding: 80px 0 60px;
}

.carousel-badge {
  display: inline-block; font-size: 13px; font-weight: 600; color: var(--color-primary-dark);
  background: var(--glass-tint-bg);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  border: 1px solid var(--glass-tint-border);
  box-shadow: inset 0 1px 0 rgba(255,255,255,0.55);
  padding: 5px 16px; border-radius: var(--radius-pill); margin-bottom: 20px;
}
.carousel-title { font-size: 40px; font-weight: 800; line-height: 1.2; letter-spacing: -0.02em; margin-bottom: 16px; }
.carousel-title .highlight { color: var(--color-primary-dark); }
.carousel-desc { font-size: 17px; color: var(--color-text-secondary); line-height: 1.7; margin-bottom: 28px; max-width: 480px; }
.carousel-actions { display: flex; gap: 12px; flex-wrap: wrap; }

/* Content stays solid: small radius, no border, floating above the blurred backdrop */
.carousel-image { display: flex; align-items: center; justify-content: center; }
.carousel-placeholder {
  width: 100%; max-width: 460px; height: 300px;
  border-radius: 8px; overflow: hidden; position: relative;
  box-shadow: 0 12px 36px rgba(28,36,48,0.18);
}
.carousel-placeholder img {
  width: 100%; height: 100%; object-fit: cover; display: block; border-radius: 8px;
}

/* Carousel controls: glass round buttons (touch light + jelly press) */
.carousel-controls {
  display: flex; justify-content: center; align-items: center; gap: 24px; padding: 20px 0 40px;
}
.carousel-btn {
  position: relative; overflow: hidden;
  width: 42px; height: 42px; border-radius: 50%;
  border: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, 0.32);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  box-shadow: var(--glass-shadow-sm), inset 0 1px 0 var(--glass-edge);
  cursor: pointer; font-size: 16px; display: flex; align-items: center;
  justify-content: center; color: var(--color-text-secondary);
  transition: transform 0.35s var(--ease-spring), color 0.2s, box-shadow 0.2s;
}
.carousel-btn::after {
  content: ''; position: absolute; inset: 0; border-radius: inherit; opacity: 0;
  background: radial-gradient(50px circle at var(--mx, 50%) var(--my, 50%), rgba(255,255,255,0.55), transparent 75%);
  transition: opacity 0.3s; pointer-events: none;
}
.carousel-btn:hover::after { opacity: 1; }
.carousel-btn:hover { color: var(--color-primary-dark); transform: translateY(-2px); }
.carousel-btn:active { animation: glassJelly 0.5s var(--ease-spring); }
.carousel-dots { display: flex; gap: 8px; }
.carousel-dot {
  width: 8px; height: 8px; border-radius: var(--radius-pill);
  background: rgba(28,36,48,0.18); border: 1px solid rgba(255,255,255,0.5);
  cursor: pointer; transition: all 0.3s var(--ease-spring); padding: 0;
}
.carousel-dot.active {
  background: var(--color-primary); width: 24px;
  box-shadow: 0 2px 8px rgba(0,150,136,0.4);
}

/* ============================================================
   Showcase cards - floating glass cards
   ============================================================ */
.showcase-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.showcase-card {
  display: block; color: inherit; text-decoration: none;
  border-radius: var(--radius-md); overflow: hidden;
  background: var(--glass-bg);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow-sm), inset 0 1px 0 var(--glass-edge);
  transition: transform 0.35s var(--ease-spring), box-shadow 0.25s;
}
.showcase-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(28,36,48,0.14), inset 0 1px 0 var(--glass-edge);
}
.showcase-image { height: 200px; overflow: hidden; }
.showcase-image img { width: 100%; height: 100%; object-fit: cover; display: block; }
.showcase-body { padding: 24px; }
.showcase-body h3 { font-size: 17px; font-weight: 700; margin-bottom: 6px; }
.showcase-body p { font-size: 14px; color: var(--color-text-secondary); line-height: 1.6; margin-bottom: 12px; }
.showcase-tags { display: flex; gap: 8px; flex-wrap: wrap; }
.showcase-tag {
  font-size: 12px; font-weight: 500; color: var(--color-primary-dark);
  background: var(--glass-tint-bg); border: 1px solid var(--glass-tint-border);
  padding: 3px 12px; border-radius: var(--radius-pill);
}

/* ============================================================
   Footer - glass layer finish
   ============================================================ */
.footer {
  background: rgba(255,255,255,0.5);
  -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
  border-top: 1px solid var(--glass-border);
  box-shadow: 0 -8px 32px rgba(28,36,48,0.06), inset 0 1px 0 var(--glass-edge);
  color: var(--color-text); padding: 48px 0 24px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; padding-bottom: 32px; border-bottom: 1px solid rgba(28,36,48,0.08); margin-bottom: 24px; }
.footer-brand .navbar-logo { color: var(--color-text); margin-bottom: 12px; }
.footer-brand p { font-size: 14px; color: var(--color-text-muted); line-height: 1.7; max-width: 300px; }
.footer-col h4 { font-size: 15px; font-weight: 700; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; color: var(--color-text-muted); padding: 5px 0; transition: color 0.2s; }
.footer-col a:hover { color: var(--color-primary-dark); }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; font-size: 13px; color: var(--color-text-muted); }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .section { padding: 48px 0; }
  .section-title { font-size: 24px; }
  /* Glass dropdown menu panel */
  .navbar-links {
    display: none; position: absolute; top: calc(100% + 6px);
    left: 16px; right: 16px; transform: none;
    background: var(--glass-bg-strong);
    -webkit-backdrop-filter: var(--glass-filter); backdrop-filter: var(--glass-filter);
    border: 1px solid var(--glass-border); border-radius: var(--radius-md);
    box-shadow: var(--glass-shadow), inset 0 1px 0 var(--glass-edge);
    flex-direction: column; padding: 20px; gap: 16px;
  }
  .navbar-links.open { display: flex; }
  .navbar-toggle { display: flex; }
  .carousel-slide { grid-template-columns: 1fr; padding: 40px 0; text-align: center; }
  .carousel-title { font-size: 28px; }
  .carousel-desc { margin: 0 auto 24px; }
  .carousel-actions { justify-content: center; }
  .carousel-image { display: none; }
  .carousel-controls { padding: 12px 0 24px; }
  .showcase-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: 12px; text-align: center; }
}

@media (max-width: 480px) {
  .carousel-title { font-size: 24px; }
}

/* ----- Reduced motion preference ----- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero::before, .hero::after { animation: none; }
  *, *::before, *::after { transition-duration: 0.01ms !important; }
}