/* =============================================================
   Tinfant.China · 科子
   Style: clean editorial × brand blue gradient signature
   ============================================================= */

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

html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; scroll-behavior: smooth; }

/* ---------- Local: GetVoIP Grotesque (Tinfant brand) ---------- */
@font-face {
  font-family: 'GetVoIP Grotesque';
  src: url('fonts/GetVoIP-Grotesque.otf') format('opentype');
  font-weight: 400 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: 'GetVoIP Grotesque';
  src: url('fonts/GetVoIP-Grotesque-Italic.otf') format('opentype');
  font-weight: 400 800;
  font-style: italic;
  font-display: swap;
}

:root {
  /* surface */
  --bg:          #FAFBFD;
  --bg-2:        #F2F5FA;
  --ink:         #0E1A2E;
  --ink-soft:    #1E2A3F;
  --muted:       #6B7488;
  --muted-2:     #9AA1B2;
  --hairline:    rgba(14, 26, 46, 0.10);
  --hairline-s:  rgba(14, 26, 46, 0.18);

  /* brand */
  --blue-1:      #5DA8E8;
  --blue-2:      #2575C6;
  --blue-deep:   #1A5A9E;
  --blue-soft:   rgba(93, 168, 232, 0.08);
  --blue-soft-2: rgba(37, 117, 198, 0.04);

  /* product chip accents (subtle differentiation only) */
  --warm:        #E07A38;   /* druumen */
  --cool:        #5DADAA;   /* prism */

  /* type */
  --f-logo:      'GetVoIP Grotesque', sans-serif;                /* brand wordmark ONLY */
  --f-display:   'Poppins', system-ui, sans-serif;               /* other display headings */
  --f-body:      'DM Sans', 'PingFang SC', system-ui, sans-serif;
  --f-mono:      'JetBrains Mono', ui-monospace, monospace;
  --f-cn:        'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;

  /* layout */
  --max:         1320px;
  --pad-x:       clamp(24px, 5vw, 80px);
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--f-body);
  font-weight: 400;
  font-size: 16px;
  line-height: 1.55;
  overflow-x: hidden;
  font-feature-settings: "ss01" 1, "cv11" 1;
}

::selection { background: var(--blue-2); color: white; }
a { color: inherit; }

/* utility */
.mono {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
}

.dot {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--blue-2);
  margin-right: 8px;
  vertical-align: middle;
  transform: translateY(-1px);
  box-shadow: 0 0 0 3px rgba(37, 117, 198, 0.12);
}
.dot--warm { background: var(--warm); box-shadow: 0 0 0 3px rgba(224, 122, 56, 0.14); }
.dot--cool { background: var(--cool); box-shadow: 0 0 0 3px rgba(93, 173, 170, 0.14); }

.arr { display: inline-block; margin-left: 4px; transition: transform .35s cubic-bezier(.6,.1,.2,1); }

/* =========================================================
   NAV
   ========================================================= */
.nav {
  position: sticky;
  top: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--hairline);
}
.nav__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px var(--pad-x);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.nav__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
}
.nav__logo { display: inline-flex; transition: transform .4s cubic-bezier(.6,.1,.2,1); }
.nav__brand:hover .nav__logo { transform: rotate(-4deg) scale(1.05); }
.nav__wordmark {
  font-family: var(--f-logo);
  font-weight: 500;
  font-size: 20px;
  letter-spacing: -0.012em;
  line-height: 1;
  background: linear-gradient(180deg, var(--blue-1) 0%, var(--blue-2) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(1px 1.5px 0 rgba(26, 90, 158, 0.22));
}
.nav__cn {
  font-family: var(--f-cn);
  font-weight: 500;
  font-size: 13px;
  color: var(--muted);
  padding-left: 10px;
  border-left: 1px solid var(--hairline-s);
  margin-left: 2px;
}
.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 28px);
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.nav__link {
  position: relative;
  color: var(--ink);
  text-decoration: none;
  padding: 6px 0;
  transition: color .25s ease;
}
.nav__link::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: 2px;
  height: 1px;
  background: var(--blue-2);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .4s cubic-bezier(.6,.1,.2,1);
}
.nav__link:hover { color: var(--blue-2); }
.nav__link:hover::after { transform: scaleX(1); }
.nav__cta {
  font-family: var(--f-body);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0;
  text-transform: none;
  text-decoration: none;
  color: white;
  background: linear-gradient(180deg, var(--blue-1) 0%, var(--blue-2) 100%);
  padding: 8px 16px;
  border-radius: 999px;
  transition: transform .25s, box-shadow .25s;
  box-shadow: 0 1px 0 rgba(37, 117, 198, 0.4), 0 8px 24px -8px rgba(37, 117, 198, 0.45);
}
.nav__cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 1px 0 rgba(37, 117, 198, 0.5), 0 14px 30px -10px rgba(37, 117, 198, 0.55);
}

/* =========================================================
   HERO
   ========================================================= */
.hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--hairline);
}
.hero__inner {
  position: relative;
  z-index: 2;
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(72px, 11vw, 160px) var(--pad-x) clamp(64px, 9vw, 130px);
  display: grid;
  gap: clamp(28px, 4vw, 52px);
}

/* diagonal brand-signature accents (echo logo composition) */
.hero__accent {
  position: absolute;
  z-index: 1;
  pointer-events: none;
  filter: blur(4px);
}
.hero__accent--tr {
  top: -8%;
  right: -4%;
  width: min(54vw, 720px);
  height: min(54vw, 720px);
  background: linear-gradient(135deg,
    rgba(93, 168, 232, 0.32) 0%,
    rgba(37, 117, 198, 0.22) 40%,
    rgba(37, 117, 198, 0.06) 70%,
    transparent 100%);
  clip-path: polygon(38% 0, 100% 0, 100% 62%, 0 100%);
}
.hero__accent--bl {
  bottom: -10%;
  left: -6%;
  width: min(46vw, 600px);
  height: min(46vw, 600px);
  background: linear-gradient(315deg,
    rgba(93, 168, 232, 0.26) 0%,
    rgba(37, 117, 198, 0.16) 40%,
    rgba(37, 117, 198, 0.04) 70%,
    transparent 100%);
  clip-path: polygon(0 38%, 62% 100%, 0 100%);
}

.hero__pretitle { display: inline-flex; }
.hero__pretitle .mono { color: var(--ink); }

.hero__wordmark {
  font-family: var(--f-logo);
  font-weight: 500;
  font-size: clamp(72px, 14.4vw, 220px);
  line-height: 0.95;
  letter-spacing: -0.028em;
  background: linear-gradient(180deg, var(--blue-1) 0%, var(--blue-2) 65%, var(--blue-deep) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  display: inline-block;
  /* bottom-right directional shadow — extruded 3D feel */
  filter:
    drop-shadow(6px 8px 0 rgba(26, 90, 158, 0.18))
    drop-shadow(3px 4px 2px rgba(26, 90, 158, 0.22));
}

.hero__lede {
  max-width: 680px;
  border-top: 1px solid var(--hairline-s);
  padding-top: 22px;
}
.hero__zh {
  font-family: var(--f-body);
  font-size: clamp(22px, 2.6vw, 32px);
  font-weight: 400;
  line-height: 1.35;
  letter-spacing: -0.005em;
  color: var(--ink);
  margin-bottom: 10px;
}
.hero__zh em {
  font-style: normal;
  font-weight: 500;
  background: linear-gradient(180deg, var(--blue-1), var(--blue-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero__en {
  font-family: var(--f-body);
  font-size: clamp(15px, 1.4vw, 17px);
  color: var(--muted);
  line-height: 1.55;
}

.hero__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 32px;
  padding-top: 22px;
  border-top: 1px solid var(--hairline);
}
.hero__meta-item.mono { color: var(--ink); }
.hero__scroll {
  text-decoration: none;
  color: var(--blue-2) !important;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-left: auto;
  transition: opacity .2s;
}
.hero__scroll .arr { transition: transform .35s cubic-bezier(.6,.1,.2,1); }
.hero__scroll:hover .arr { transform: translateY(3px); }

/* =========================================================
   SECTION HEADER
   ========================================================= */
.section__header {
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(64px, 8vw, 110px) var(--pad-x) clamp(36px, 4.5vw, 56px);
  display: flex;
  align-items: baseline;
  gap: 18px;
  border-top: 1px solid var(--hairline);
}
.section__num { color: var(--blue-2); font-weight: 500; }
.section__cn {
  font-family: var(--f-body);
  font-weight: 500;
  font-size: clamp(20px, 1.9vw, 26px);
  letter-spacing: -0.01em;
  color: var(--ink);
}
.section__en {
  color: var(--muted);
  margin-left: auto;
}

/* =========================================================
   ABOUT
   ========================================================= */
.about__stack {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--pad-x) clamp(40px, 6vw, 80px);
  display: flex;
  flex-direction: column;
  gap: clamp(28px, 4vw, 56px);
}
.about__pull {
  font-family: var(--f-display);
  font-weight: 600;
  font-size: clamp(28px, 4vw, 56px);
  line-height: 1.18;
  letter-spacing: -0.022em;
  color: var(--ink);
  max-width: 22ch;
}
.about__pull em {
  font-style: italic;
  font-weight: 600;
  background: linear-gradient(180deg, var(--blue-1) 0%, var(--blue-2) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.about__body {
  max-width: 62ch;
  padding-left: clamp(0px, 3vw, 56px);
  border-left: 1px solid var(--hairline);
}
.about__body p {
  font-size: 16px;
  line-height: 1.75;
  margin-bottom: 1.1em;
  color: var(--ink-soft);
}
.about__body p:last-child { margin-bottom: 0; }
.about__body strong {
  font-weight: 600;
  color: var(--ink);
}

/* =========================================================
   PILLARS — Deep Tech × Lean Innovation × VC + Hub
   ========================================================= */
.pillars {
  max-width: var(--max);
  margin: 0 auto;
  padding: clamp(36px, 5vw, 64px) var(--pad-x) 0;
}
.pillars__grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  border-top: 1px solid var(--hairline-s);
  border-bottom: 1px solid var(--hairline-s);
}
.pillar {
  position: relative;
  padding: clamp(24px, 3vw, 40px) clamp(18px, 2.4vw, 32px);
  border-right: 1px solid var(--hairline-s);
  display: flex;
  flex-direction: column;
  gap: 4px;
  transition: background .35s ease;
}
.pillar:last-child { border-right: none; }
.pillar:hover { background: var(--blue-soft); }
.pillar__num { color: var(--blue-2); font-weight: 500; }
.pillar__en {
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(22px, 2.4vw, 30px);
  letter-spacing: -0.018em;
  line-height: 1.05;
  color: var(--ink);
  margin-top: 6px;
}
.pillar__cn {
  font-family: var(--f-cn);
  font-size: 14px;
  color: var(--muted);
  margin-top: -2px;
}
.pillar__note {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--muted-2);
  margin-top: 14px;
  line-height: 1.5;
}
.pillars__hub {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding-top: 26px;
  padding-bottom: clamp(20px, 3vw, 36px);
}
.pillars__arrow {
  font-family: var(--f-mono);
  color: var(--muted);
  font-size: 16px;
}
.pillars__hub-box {
  text-align: center;
  padding: 18px 32px 20px;
  border: 1px solid var(--hairline-s);
  background: linear-gradient(180deg, var(--blue-soft) 0%, transparent 100%);
}
.pillars__hub-label { display: block; color: var(--blue-2); margin-bottom: 6px; }
.pillars__hub-name {
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(22px, 2.6vw, 30px);
  letter-spacing: -0.018em;
  background: linear-gradient(180deg, var(--blue-1) 0%, var(--blue-2) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.pillars__hub-cn {
  font-family: var(--f-cn);
  font-size: 13px;
  color: var(--muted);
  margin-top: 4px;
}

/* =========================================================
   PRODUCTS
   ========================================================= */
.products__grid {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--pad-x);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
  border-top: 1px solid var(--hairline-s);
  border-bottom: 1px solid var(--hairline-s);
}
.product {
  position: relative;
  padding: clamp(28px, 4vw, 56px);
  display: flex;
  flex-direction: column;
  gap: 16px;
  border-right: 1px solid var(--hairline-s);
  transition: background .35s ease;
}
.product:last-child { border-right: none; }
.product::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--blue-1), var(--blue-2));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .55s cubic-bezier(.6,.1,.2,1);
}
.product:hover {
  background: linear-gradient(180deg, rgba(93, 168, 232, 0.04) 0%, transparent 80%);
}
.product:hover::before { transform: scaleX(1); }
.product__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px;
}
.product__idx { color: var(--ink); font-weight: 500; }
.product__name {
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(44px, 5.2vw, 74px);
  letter-spacing: -0.022em;
  line-height: 1;
  margin-top: 8px;
  color: var(--ink);
}
.product__name-cn {
  font-family: var(--f-cn);
  font-weight: 500;
  font-size: 0.42em;
  letter-spacing: -0.005em;
  color: var(--muted);
  margin-left: 14px;
  vertical-align: 0.16em;
}
.product__tagline {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  line-height: 1.5;
}
.product__tagline em {
  font-style: italic;
  font-family: var(--f-body);
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
  color: var(--ink-soft);
  font-size: 13px;
}
.product__dot {
  margin: 0 8px;
  color: var(--hairline-s);
}
.product__desc {
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-soft);
  max-width: 56ch;
  flex: 1;
  margin-top: 4px;
}
.product__link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--ink);
  font-family: var(--f-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  margin-top: 14px;
  padding-top: 18px;
  border-top: 1px solid var(--hairline);
  width: max-content;
  transition: color .25s;
}
.product__url { position: relative; }
.product__url::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -3px;
  height: 1px;
  background: var(--blue-2);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .4s cubic-bezier(.6,.1,.2,1);
}
.product__link:hover { color: var(--blue-2); }
.product__link:hover .product__url::after { transform: scaleX(1); }
.product__arrow {
  display: inline-block;
  transition: transform .4s cubic-bezier(.6,.1,.2,1);
}
.product__link:hover .product__arrow {
  transform: translate(6px, -6px);
  color: var(--blue-2);
}

/* =========================================================
   CONTACT
   ========================================================= */
.contact__grid {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--pad-x) clamp(60px, 8vw, 120px);
  display: flex;
  flex-direction: row;
  justify-content: space-between;
  align-items: flex-end;
  gap: clamp(24px, 4vw, 64px);
}
.contact__mail {
  font-family: var(--f-display);
  font-weight: 500;
  font-size: clamp(36px, 5.6vw, 80px);
  letter-spacing: -0.025em;
  line-height: 1;
  text-decoration: none;
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  background: linear-gradient(180deg, var(--blue-1) 0%, var(--blue-2) 65%, var(--blue-deep) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.contact__mail .arr {
  font-family: var(--f-mono);
  font-size: 0.36em;
  -webkit-text-fill-color: var(--blue-2);
  transform: translateY(-0.6em);
  display: inline-block;
}
.contact__mail:hover .arr {
  transform: translate(10px, calc(-0.6em - 8px));
}
.contact__meta {
  text-align: right;
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex-shrink: 0;
}
.contact__where { color: var(--ink); margin-bottom: 4px; }
.contact__note {
  font-size: 14px;
  color: var(--muted);
  font-weight: 400;
}
.contact__note--en {
  font-family: var(--f-display);
  font-style: italic;
  font-weight: 500;
  font-size: 13px;
  color: var(--muted-2);
}

/* =========================================================
   FOOTER
   ========================================================= */
.foot {
  border-top: 1px solid var(--hairline-s);
  background: var(--bg-2);
}
.foot__inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 22px var(--pad-x);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
}
.foot__brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.foot__right { color: var(--muted); }

/* =========================================================
   ANIMATIONS
   ========================================================= */
@keyframes rise {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fade {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes diagDrift {
  0%   { transform: translate(0, 0) rotate(0); }
  50%  { transform: translate(-1.2%, 1.6%) rotate(-0.4deg); }
  100% { transform: translate(0, 0) rotate(0); }
}

.hero__pretitle,
.hero__wordmark,
.hero__lede,
.hero__meta {
  animation: rise .95s cubic-bezier(.2,.6,.2,1) both;
}
.hero__pretitle { animation-delay: 0.05s; }
.hero__wordmark { animation-delay: 0.18s; }
.hero__lede     { animation-delay: 0.42s; }
.hero__meta     { animation-delay: 0.60s; }

.hero__accent {
  animation: fade 1.4s ease both, diagDrift 22s ease-in-out 1s infinite;
}
.hero__accent--tr { animation-delay: 0.05s, 1s; }
.hero__accent--bl { animation-delay: 0.25s, 1s; }

/* =========================================================
   RESPONSIVE
   ========================================================= */
@media (max-width: 720px) {
  .about__body { padding-left: 0; border-left: none; border-top: 1px solid var(--hairline); padding-top: 24px; }

  .nav__cn { display: none; }
  .nav__links { gap: 14px; }
  .nav__link:not([href^="#"]):not([href^="mailto"]) { display: none; }
  .nav__cta { padding: 7px 14px; font-size: 12px; }

  .products__grid { grid-template-columns: 1fr; }
  .product { border-right: none; border-bottom: 1px solid var(--hairline-s); }
  .product:last-child { border-bottom: none; }

  .pillars__grid { grid-template-columns: 1fr; }
  .pillar { border-right: none; border-bottom: 1px solid var(--hairline); }
  .pillar:last-child { border-bottom: none; }

  .hero__meta { gap: 10px 20px; }
  .hero__scroll { margin-left: 0; }

  .contact__grid { flex-direction: column; align-items: flex-start; }
  .contact__meta {
    text-align: left;
    width: 100%;
    max-width: 480px;
    padding-top: 12px;
    border-top: 1px solid var(--hairline);
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}