/* SiYuan Technology — Apple-inspired Design System */

:root {
  --color-black: #1D1D1F;
  --color-gray1: #424245;
  --color-gray2: #86868B;
  --color-gray3: #D2D2D7;
  --color-gray4: #F5F5F7;
  --color-white: #FFFFFF;
  --color-blue: #0071E3;
  --color-blue-hover: #0077ED;
  --font-heading: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Noto Sans SC', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

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

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

body {
  font-family: var(--font-body);
  color: var(--color-black);
  background: var(--color-white);
  line-height: 1.6;
  font-size: 17px;
  overflow-x: hidden;
}

/* --- Navigation --- */
#site-header {
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
}

#site-header.nav-dark {
  background: rgba(29, 29, 31, 0.8);
  color: #F5F5F7;
}

#site-header.nav-light {
  background: rgba(255, 255, 255, 0.8);
  color: #1D1D1F;
  border-bottom: 1px solid rgba(0, 0, 0, 0.04);
}

/* --- Mobile nav drawer (design system: 200ms ease; panel 300ms cubic-bezier; prefers-reduced-motion) --- */
.mobile-menu-icon {
  transition: opacity 200ms ease, transform 200ms ease;
  will-change: opacity, transform;
}

.mobile-menu-icon--close {
  opacity: 0;
  transform: scale(0.88) rotate(90deg);
  pointer-events: none;
}

#site-header.mobile-menu-is-open .mobile-menu-icon--hamburger {
  opacity: 0;
  transform: scale(0.88);
  pointer-events: none;
}

#site-header.mobile-menu-is-open .mobile-menu-icon--close {
  opacity: 1;
  transform: scale(1) rotate(0deg);
  pointer-events: auto;
}

@media (prefers-reduced-motion: reduce) {
  .mobile-menu-icon {
    transition: none;
  }

  .mobile-menu-dropdown {
    transition: none !important;
  }

  #site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

.mobile-menu-dropdown {
  grid-template-rows: 0fr;
  transition: grid-template-rows 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

#site-header.mobile-menu-is-open .mobile-menu-dropdown {
  grid-template-rows: 1fr;
}

.mobile-menu-dropdown__inner {
  min-height: 0;
  pointer-events: none;
}

#site-header.mobile-menu-is-open .mobile-menu-dropdown__inner {
  pointer-events: auto;
}

#site-header.nav-light .mobile-menu-dropdown-border {
  border-color: rgba(0, 0, 0, 0.08);
}

#site-header.nav-dark .mobile-menu-dropdown-border {
  border-color: rgba(255, 255, 255, 0.12);
}

#site-header.nav-light .mobile-menu-link-border {
  border-color: rgba(0, 0, 0, 0.08);
}

#site-header.nav-dark .mobile-menu-link-border {
  border-color: rgba(255, 255, 255, 0.1);
}

/* 展开时链接轻微错开淡入（MASTER：交互 200ms；动效减弱时关闭） */
#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link {
  animation: mobile-menu-link-in 220ms ease-out forwards;
  opacity: 0;
}

#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link:nth-child(1) { animation-delay: 35ms; }
#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link:nth-child(2) { animation-delay: 55ms; }
#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link:nth-child(3) { animation-delay: 75ms; }
#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link:nth-child(4) { animation-delay: 95ms; }
#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link:nth-child(5) { animation-delay: 115ms; }
#site-header.mobile-menu-is-open .mobile-menu-dropdown__panel .mobile-menu-link:nth-child(6) { animation-delay: 135ms; }

@keyframes mobile-menu-link-in {
  from {
    opacity: 0;
    transform: translateY(-6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

#site-header.nav-light #mobile-menu-btn:focus-visible {
  outline-color: var(--color-blue);
}

#site-header.nav-dark #mobile-menu-btn:focus-visible {
  outline-color: rgba(255, 255, 255, 0.85);
}

body.mobile-menu-scroll-lock {
  overflow: hidden;
}

/* --- Hero Titles --- */
.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 3.5vw, 3rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.015em;
  color: var(--color-black);
}

.section-subtitle {
  font-size: 21px;
  color: var(--color-gray2);
  line-height: 1.5;
  max-width: 600px;
}

/* --- Buttons (Apple style) --- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background: var(--color-blue);
  color: #fff;
  font-size: 17px;
  font-weight: 400;
  border-radius: 980px;
  border: none;
  cursor: pointer;
  transition: background 200ms ease;
  text-decoration: none;
}

.btn-primary:hover {
  background: var(--color-blue-hover);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background: transparent;
  color: var(--color-blue);
  font-size: 17px;
  font-weight: 400;
  border-radius: 980px;
  border: 2px solid var(--color-blue);
  cursor: pointer;
  transition: all 200ms ease;
  text-decoration: none;
}

.btn-secondary:hover {
  background: var(--color-blue);
  color: #fff;
}

.btn-ghost-white {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  background: transparent;
  color: #fff;
  font-size: 17px;
  font-weight: 400;
  border-radius: 980px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  cursor: pointer;
  transition: all 200ms ease;
  text-decoration: none;
}

.btn-ghost-white:hover {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.5);
}

/* --- Apple-style link arrow --- */
.link-arrow {
  color: var(--color-blue);
  font-size: 17px;
  text-decoration: none;
  cursor: pointer;
  transition: opacity 200ms ease;
}

.link-arrow::after {
  content: ' >';
  font-size: 14px;
}

.link-arrow:hover {
  opacity: 0.7;
}

/* --- Scroll reveal animation --- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }
.reveal-delay-5 { transition-delay: 0.5s; }
.reveal-delay-6 { transition-delay: 0.6s; }

/* --- Counter animation --- */
.counter-value {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 4vw, 4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
}

/* --- Card hover --- */
.card-hover {
  transition: transform 200ms ease, box-shadow 200ms ease;
}

.card-hover:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

/* --- Image cover --- */
.img-cover {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --- Section spacing (Apple-style generous whitespace) --- */
.section-padding {
  padding-top: 100px;
  padding-bottom: 100px;
}

@media (max-width: 768px) {
  .section-padding {
    padding-top: 64px;
    padding-bottom: 64px;
  }
}

/* --- Respect reduced motion --- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

/* --- Marquee (logo scroll) --- */
.marquee-track {
  display: flex;
  gap: 80px;
  animation: marquee 30s linear infinite;
}

@keyframes marquee {
  0% { transform: translateX(0); }
  100% { transform: translateX(-50%); }
}

@media (prefers-reduced-motion: reduce) {
  .marquee-track {
    animation: none;
  }
}