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

/* ─── Tokens ──────────────────────────────────────────────── */
:root {
  --bg:          #ffffff;
  --bg-2:        #f7f7f7;
  --bg-3:        #f0f0f0;
  --text:        #0a0a0a;
  --text-2:      #525252;
  --text-3:      #a3a3a3;
  --border:      #e5e5e5;
  --radius-sm:   8px;
  --radius-md:   14px;
  --radius-lg:   20px;
  --ease:        cubic-bezier(0.4, 0, 0.2, 1);
  --t:           0.28s;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', -apple-system, 'PingFang SC', 'Microsoft YaHei',
               'Helvetica Neue', sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ─── Layout helpers ──────────────────────────────────────── */
.wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 48px;
}
@media (max-width: 700px) { .wrap { padding: 0 24px; } }

.divider { width: 100%; height: 1px; background: var(--border); }

/* ─── Keyframes ───────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(20px); }
  to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}
@keyframes tickDown {
  0%, 100% { transform: translateY(0);   opacity: 1; }
  50%       { transform: translateY(6px); opacity: 0.35; }
}

/* ─── Scroll-reveal ───────────────────────────────────────── */
.sr {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.65s var(--ease), transform 0.65s var(--ease);
}
.sr.vis { opacity: 1; transform: none; }

/* ─── Nav ─────────────────────────────────────────────────── */
#nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  height: 60px;
  background: rgba(255,255,255,0.82);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t) var(--ease);
}
#nav.scrolled { border-color: var(--border); }

.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 14px; font-weight: 700; letter-spacing: -0.02em;
  color: var(--text); text-decoration: none;
}
.nav-logo em { font-style: normal; color: var(--text-3); font-weight: 400; }

.nav-links {
  display: flex; gap: 36px; list-style: none;
}
.nav-links a {
  font-size: 13px; font-weight: 500; color: var(--text-2);
  text-decoration: none; letter-spacing: 0.01em;
  transition: color var(--t);
}
.nav-links a:hover { color: var(--text); }

@media (max-width: 500px) { .nav-links { gap: 20px; } }

/* ─── Hero ────────────────────────────────────────────────── */
#hero {
  min-height: 100svh;
  display: flex; flex-direction: column;
  justify-content: center;
  padding-top: 60px;
  position: relative;
}

/* subtle grid bg */
#hero::before {
  content: '';
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black 0%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, black 0%, transparent 100%);
  opacity: 0.4;
  pointer-events: none;
}

.hero-content { position: relative; max-width: 720px; }

.hero-eyebrow {
  display: inline-block;
  font-size: 11px; font-weight: 600;
  letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--text-3); margin-bottom: 28px;
  animation: fadeIn 0.8s var(--ease) both;
}

.hero-title {
  font-size: clamp(38px, 6.5vw, 80px);
  font-weight: 800;
  letter-spacing: -0.045em;
  line-height: 1.05;
  color: var(--text);
  margin-bottom: 24px;
  animation: fadeUp 0.75s var(--ease) 0.08s both;
}

.hero-title .sub {
  display: block;
  font-size: clamp(13px, 1.5vw, 17px);
  font-weight: 400;
  letter-spacing: 0.005em;
  color: var(--text-3);
  margin-top: 16px;
  line-height: 1.6;
}

.hero-desc {
  font-size: 17px; font-weight: 400;
  color: var(--text-2); line-height: 1.75; max-width: 500px;
  margin-bottom: 44px;
  animation: fadeUp 0.75s var(--ease) 0.16s both;
}

.hero-cta {
  display: flex; gap: 12px; flex-wrap: wrap;
  animation: fadeUp 0.75s var(--ease) 0.24s both;
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 7px;
  font-family: inherit; font-size: 13.5px; font-weight: 600;
  text-decoration: none; padding: 11px 22px;
  border-radius: var(--radius-sm); cursor: pointer;
  transition: opacity var(--t), transform var(--t), background var(--t), border-color var(--t);
  letter-spacing: 0.01em; white-space: nowrap;
}
.btn-dark {
  background: var(--text); color: #fff; border: 1.5px solid var(--text);
}
.btn-dark:hover { opacity: 0.82; transform: translateY(-1px); }

.btn-ghost {
  background: transparent; color: var(--text-2);
  border: 1.5px solid var(--border);
}
.btn-ghost:hover { color: var(--text); border-color: var(--text-2); }

/* scroll indicator */
.hero-scroll {
  position: absolute; bottom: 36px; left: 50%;
  transform: translateX(-50%);
  display: flex; flex-direction: column; align-items: center; gap: 6px;
  font-size: 10px; letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--text-3);
  animation: fadeIn 1.2s var(--ease) 0.6s both;
}
.hero-scroll-line {
  width: 1px; height: 36px;
  background: var(--border);
  animation: tickDown 2.4s ease-in-out infinite;
}

/* ─── Products ────────────────────────────────────────────── */
#products { padding: 112px 0; }

.section-head { margin-bottom: 64px; }
.section-tag {
  font-size: 11px; font-weight: 600; letter-spacing: 0.15em;
  text-transform: uppercase; color: var(--text-3); margin-bottom: 14px;
}
.section-title {
  font-size: clamp(26px, 4vw, 42px);
  font-weight: 800; letter-spacing: -0.035em;
  line-height: 1.12; color: var(--text); margin-bottom: 14px;
}
.section-lead {
  font-size: 15.5px; color: var(--text-2);
  max-width: 440px; line-height: 1.72;
}

.products-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 24px;
}
@media (max-width: 760px) {
  .products-grid { grid-template-columns: 1fr; }
}

.p-card {
  background: var(--bg-2);
  border-radius: var(--radius-lg);
  padding: 44px;
  transition: transform var(--t) var(--ease), box-shadow var(--t) var(--ease);
}
.p-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 60px rgba(0,0,0,0.07);
}
@media (max-width: 600px) { .p-card { padding: 28px; } }

/* stagger delay for grid children */
.products-grid .sr:nth-child(2) { transition-delay: 0.1s; }

.p-badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 10.5px; font-weight: 600;
  letter-spacing: 0.1em; text-transform: uppercase;
  margin-bottom: 22px;
}
.p-badge-dot {
  width: 5px; height: 5px; border-radius: 50%; background: currentColor;
}
.badge-green { color: #16a34a; }
.badge-purple { color: #7c3aed; }

.p-name {
  font-size: 26px; font-weight: 800; letter-spacing: -0.035em;
  color: var(--text); line-height: 1.1; margin-bottom: 6px;
}
.p-sub {
  font-size: 12px; color: var(--text-3); font-weight: 500;
  margin-bottom: 18px; letter-spacing: 0.01em;
}
.p-desc {
  font-size: 14.5px; color: var(--text-2); line-height: 1.72;
  margin-bottom: 28px;
}

.p-features {
  list-style: none; display: flex; flex-direction: column;
  gap: 9px; margin-bottom: 36px;
}
.p-features li {
  display: flex; align-items: flex-start; gap: 10px;
  font-size: 13.5px; color: var(--text); line-height: 1.5;
}
.p-features li::before {
  content: '';
  width: 3.5px; height: 3.5px; border-radius: 50%;
  background: var(--text-3); margin-top: 7px; flex-shrink: 0;
}

.p-link {
  display: inline-flex; align-items: center; gap: 7px;
  font-size: 13.5px; font-weight: 600; color: var(--text);
  text-decoration: none;
  transition: gap var(--t) var(--ease), opacity var(--t);
}
.p-link:hover { gap: 11px; opacity: 0.7; }

/* arrow icon */
.ico-arr { width: 14px; height: 14px; flex-shrink: 0; }

/* ─── About ───────────────────────────────────────────────── */
#about { padding: 112px 0; background: var(--bg-2); }

.about-grid {
  display: grid; grid-template-columns: 1.1fr 0.9fr;
  gap: 80px; align-items: start;
}
@media (max-width: 760px) {
  .about-grid { grid-template-columns: 1fr; gap: 48px; }
}

.about-body p {
  font-size: 15px; color: var(--text-2); line-height: 1.8;
  margin-bottom: 20px;
}
.about-body p:last-of-type { margin-bottom: 32px; }

.about-meta {
  display: flex; flex-direction: column; gap: 10px;
}
.meta-row {
  display: flex; gap: 14px; align-items: baseline;
  font-size: 13px;
}
.meta-key {
  color: var(--text-3); font-weight: 500; min-width: 72px; flex-shrink: 0;
}
.meta-val { color: var(--text); }

/* stats */
.stats { display: flex; flex-direction: column; gap: 0; }
.stat {
  padding: 24px 0; border-top: 1px solid var(--border);
}
.stat:last-child { border-bottom: 1px solid var(--border); }
.stat-num {
  font-size: 40px; font-weight: 800; letter-spacing: -0.05em;
  color: var(--text); line-height: 1; margin-bottom: 4px;
}
.stat-lbl {
  font-size: 12.5px; color: var(--text-3); font-weight: 500;
}

/* stagger about-grid children */
.about-grid .sr:nth-child(2) { transition-delay: 0.12s; }

/* ─── Contact strip ───────────────────────────────────────── */
#contact {
  padding: 96px 0;
  text-align: center;
}
.contact-center {
  text-align: center;
  max-width: 560px;
  margin: 0 auto;
}
.contact-tag {
  text-align: center;
  margin-bottom: 14px;
}
.contact-title {
  font-size: clamp(24px, 3.5vw, 38px);
  font-weight: 800; letter-spacing: -0.035em;
  color: var(--text); margin-bottom: 16px;
}
.contact-sub {
  font-size: 15px; color: var(--text-2); margin-bottom: 36px;
}
.contact-btns {
  display: flex; justify-content: center; gap: 12px; flex-wrap: wrap;
}

/* ─── Footer ──────────────────────────────────────────────── */
footer {
  padding: 48px 0;
  border-top: 1px solid var(--border);
}
.footer-row {
  display: flex; justify-content: space-between;
  align-items: flex-end; gap: 32px; flex-wrap: wrap;
}
.footer-brand {
  font-size: 13.5px; font-weight: 700; color: var(--text);
  margin-bottom: 6px;
}
.footer-addr {
  font-size: 11.5px; color: var(--text-3); line-height: 1.8;
}
.footer-right {
  text-align: right; font-size: 11.5px; color: var(--text-3);
  line-height: 1.8;
}
.footer-right a {
  color: var(--text-3); text-decoration: none;
  transition: color var(--t);
}
.footer-right a:hover { color: var(--text-2); }
@media (max-width: 600px) {
  .footer-row { flex-direction: column; }
  .footer-right { text-align: left; }
}

/* ─── Utility ─────────────────────────────────────────────── */
::selection { background: var(--text); color: #fff; }
:focus-visible { outline: 2px solid var(--text); outline-offset: 3px; }