/* ============================================
   华为 Kirin 9040 · 韬（τ）定律 产品展示页
   Style: Dark Mode / Split-Screen / Premium Tech
   ============================================ */

/* --- RESET & BASE --- */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: auto;
}

body {
  font-family: 'Noto Sans SC', 'Inter', sans-serif;
  background: #000;
  color: var(--text-primary);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- CSS VARIABLES --- */
:root {
  --bg-primary: #000000;
  --bg-secondary: #050505;
  --bg-tertiary: #0a0a0a;
  --text-primary: #f0ede8;
  --text-secondary: #b0b0b0;
  --text-muted: #6a6a6a;
  --accent-gold: #c8a65e;
  --accent-gold-dim: rgba(200, 166, 94, 0.15);
  --accent-blue: #4a7cf7;
  --accent-blue-dim: rgba(74, 124, 247, 0.1);
  --border-subtle: rgba(255, 255, 255, 0.06);
  --font-display: 'Noto Serif SC', serif;
  --font-body: 'Noto Sans SC', 'Inter', sans-serif;
  --font-en: 'Inter', sans-serif;

  /* Layout */
  --left-width: 33.33vw;
  --right-width: 66.67vw;
}

/* --- LOADER --- */
#loader {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: #000;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.8s ease, visibility 0.8s ease;
}

#loader.loaded {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loader-content {
  text-align: center;
}

.loader-brand {
  font-family: var(--font-en);
  font-size: 1.4rem;
  font-weight: 300;
  letter-spacing: 0.4em;
  color: var(--text-primary);
  margin-bottom: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.8rem;
}

.loader-brand-en {
  font-weight: 200;
  text-transform: uppercase;
}

.loader-brand-divider {
  color: var(--accent-gold);
  font-weight: 100;
  opacity: 0.5;
}

.loader-brand-cn {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: 1.1rem;
  letter-spacing: 0.3em;
}

.loader-bar-track {
  width: 200px;
  height: 1px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 2px;
  overflow: hidden;
  margin: 0 auto;
}

#loader-bar {
  width: 0%;
  height: 100%;
  background: var(--accent-gold);
  border-radius: 2px;
  transition: width 0.3s ease;
}

#loader-percent {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 300;
  color: var(--text-muted);
  margin-top: 0.8rem;
  letter-spacing: 0.1em;
}

/* --- HEADER --- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 1.8rem 2.5rem;
  mix-blend-mode: difference;
  pointer-events: none;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 100%;
}

.header-logo {
  display: flex;
  align-items: baseline;
  gap: 0.3rem;
  pointer-events: auto;
}

.logo-kirin {
  font-family: var(--font-en);
  font-size: 1rem;
  font-weight: 400;
  letter-spacing: 0.25em;
  color: var(--text-primary);
  text-transform: uppercase;
}

.logo-tau {
  font-family: var(--font-en);
  font-size: 1.2rem;
  font-weight: 300;
  color: var(--accent-gold);
}

.header-nav {
  display: flex;
  gap: 2rem;
  pointer-events: auto;
}

.nav-link {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.15em;
  color: var(--text-secondary);
  text-decoration: none;
  text-transform: uppercase;
  transition: color 0.3s ease;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--accent-gold);
  transition: width 0.3s ease;
}

.nav-link:hover {
  color: var(--text-primary);
}

.nav-link:hover::after {
  width: 100%;
}

/* --- HERO --- */
#hero {
  position: relative;
  height: 100vh;
  width: 100%;
  background: #000;
  display: flex;
  align-items: center;
  z-index: 50;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 70% 50%, rgba(200, 166, 94, 0.04) 0%, transparent 60%),
    radial-gradient(ellipse at 30% 30%, rgba(74, 124, 247, 0.03) 0%, transparent 50%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  padding-left: 5vw;
  max-width: 55%;
}

.hero-label {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
}

.label-line {
  width: 2rem;
  height: 1px;
  background: var(--accent-gold);
  opacity: 0.6;
}

.label-text {
  font-family: var(--font-en);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.2em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3.5rem, 8vw, 7rem);
  font-weight: 900;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
}

.title-tau {
  display: inline-block;
  background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-en);
  font-size: clamp(0.9rem, 1.2vw, 1.15rem);
  font-weight: 300;
  letter-spacing: 0.15em;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.sub-chip {
  font-weight: 500;
  color: var(--accent-blue);
}

.sub-dot {
  opacity: 0.4;
}

.hero-desc {
  font-size: clamp(0.9rem, 1.1vw, 1.05rem);
  font-weight: 300;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

.scroll-indicator {
  position: absolute;
  bottom: 3rem;
  left: 5vw;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.4rem;
  opacity: 0.4;
  animation: float-down 2s ease-in-out infinite;
}

.scroll-text {
  font-family: var(--font-en);
  font-size: 0.65rem;
  font-weight: 300;
  letter-spacing: 0.2em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.scroll-arrow {
  font-size: 1rem;
  color: var(--text-secondary);
}

@keyframes float-down {
  0%, 100% { transform: translateY(0); opacity: 0.4; }
  50% { transform: translateY(6px); opacity: 0.8; }
}

/* --- RIGHT PANEL --- */
#right-panel {
  position: fixed;
  top: 0;
  left: var(--left-width);
  width: var(--right-width);
  height: 100vh;
  z-index: 1;
  clip-path: circle(0% at 50% 50%);
  background: #000;
}

.canvas-wrap {
  width: 100%;
  height: 100%;
  overflow: hidden;
}

#product-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* Panel divider line */
#right-panel::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  width: 1px;
  height: 100%;
  background: linear-gradient(
    to bottom,
    transparent 0%,
    rgba(255, 255, 255, 0.06) 20%,
    rgba(255, 255, 255, 0.06) 80%,
    transparent 100%
  );
  z-index: 2;
  pointer-events: none;
}

/* --- LEFT PANEL --- */
#left-panel {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--left-width);
  height: 100vh;
  z-index: 5;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: hidden;
  pointer-events: none;
}

#sections-container {
  position: relative;
  width: 100%;
  height: 100%;
}

.panel-fade {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 6rem;
  background: linear-gradient(to top, #000 0%, transparent 100%);
  z-index: 2;
  pointer-events: none;
}

/* --- SCROLL SECTIONS --- */
.scroll-section {
  position: absolute;
  top: 50%;
  left: 0;
  right: 0;
  transform: translateY(-50%);
  padding: 1.5rem 3vw 1.5rem 3vw;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.1s ease;
}

.scroll-section.section-stats {
  z-index: 3;
}

.section-inner {
  max-width: 100%;
}

.section-label {
  display: block;
  font-family: var(--font-en);
  font-size: 0.7rem;
  font-weight: 400;
  letter-spacing: 0.2em;
  margin-bottom: 1.2rem;
  text-transform: uppercase;
}

.section-label.silver {
  color: var(--text-muted);
}

.section-heading {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 2.8vw, 3rem);
  font-weight: 700;
  line-height: 1.15;
  color: var(--text-primary);
  margin-bottom: 1rem;
  letter-spacing: 0.02em;
}

.accent-gold {
  color: var(--accent-gold);
}

.section-formula {
  font-family: var(--font-en);
  font-size: clamp(0.85rem, 1.1vw, 1.1rem);
  font-weight: 300;
  color: var(--accent-gold);
  letter-spacing: 0.02em;
  margin-bottom: 1rem;
  padding: 0.6rem 1rem;
  background: var(--accent-gold-dim);
  border-radius: 4px;
  display: inline-block;
}

.section-body {
  font-size: clamp(0.9rem, 1.1vw, 1.1rem);
  font-weight: 400;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 0.8rem;
  letter-spacing: 0.02em;
}

.section-note {
  font-size: clamp(0.75rem, 0.9vw, 0.9rem);
  font-weight: 300;
  color: var(--text-muted);
  line-height: 1.8;
  letter-spacing: 0.02em;
}

/* --- Perf Tags --- */
.perf-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 1rem;
}

.perf-tag {
  font-family: var(--font-en);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--accent-blue);
  padding: 0.35rem 0.9rem;
  border: 1px solid rgba(74, 124, 247, 0.25);
  border-radius: 100px;
  letter-spacing: 0.02em;
}

/* --- STATS --- */
.section-stats .section-inner {
  text-align: left;
}

.stats-grid {
  display: flex;
  flex-direction: column;
  gap: 1.2rem;
  margin-top: 0.5rem;
}

.stat-item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.3rem;
}

.stat-number {
  font-family: var(--font-en);
  font-size: clamp(2.2rem, 3.5vw, 3.8rem);
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1;
  letter-spacing: -0.02em;
}

.stat-suffix {
  font-family: var(--font-en);
  font-size: clamp(0.9rem, 1.2vw, 1.3rem);
  font-weight: 300;
  color: var(--accent-gold);
  margin-left: 0.2rem;
}

.stat-label {
  width: 100%;
  font-size: clamp(0.65rem, 0.8vw, 0.8rem);
  font-weight: 300;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-top: 0.1rem;
}

/* --- DARK OVERLAY --- */
#dark-overlay {
  position: fixed;
  inset: 0;
  z-index: 3;
  background: #000;
  opacity: 0;
  pointer-events: none;
}

/* --- MARQUEE --- */
.marquee-wrap {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  z-index: 20;
  overflow: hidden;
  pointer-events: none;
  padding-bottom: 0.5rem;
  opacity: 0;
}

.marquee-track {
  display: flex;
  white-space: nowrap;
}

.marquee-text {
  font-family: var(--font-en);
  font-size: clamp(6vw, 8vw, 10vw);
  font-weight: 200;
  color: rgba(255, 255, 255, 0.04);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  line-height: 1;
  padding-right: 2rem;
}

/* --- CTA --- */
.cta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.2rem;
  margin-top: 0.5rem;
}

.cta-button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-en);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--bg-primary);
  background: var(--accent-gold);
  padding: 0.7rem 1.8rem;
  border-radius: 100px;
  text-decoration: none;
  letter-spacing: 0.05em;
  transition: all 0.3s ease;
  pointer-events: auto;
  border: none;
  cursor: pointer;
}

.cta-button:hover {
  background: #dab974;
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(200, 166, 94, 0.3);
}

.cta-arrow {
  transition: transform 0.3s ease;
}

.cta-button:hover .cta-arrow {
  transform: translateX(4px);
}

.cta-note {
  font-size: 0.75rem;
  font-weight: 300;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* --- SCROLL CONTAINER --- */
#scroll-container {
  position: relative;
  z-index: 1;
  pointer-events: none;
}

/* --- SELECTION --- */
::selection {
  background: var(--accent-gold);
  color: #000;
}

/* --- SCROLLBAR --- */
::-webkit-scrollbar {
  width: 0;
  background: transparent;
}

/* ============================================
   RESPONSIVE: MOBILE (< 768px)
   ============================================ */
@media (max-width: 768px) {
  :root {
    --left-width: 100%;
    --right-width: 100%;
  }

  .site-header {
    padding: 1.2rem 1.5rem;
  }

  .header-nav {
    gap: 1.2rem;
  }

  .hero-content {
    padding-left: 1.5rem;
    max-width: 85%;
  }

  .hero-title {
    font-size: clamp(2.5rem, 12vw, 3.5rem);
  }

  .hero-sub {
    font-size: 0.85rem;
    flex-wrap: wrap;
  }

  .scroll-indicator {
    left: 1.5rem;
    bottom: 2rem;
  }

  /* Stack layout: text sections scroll, canvas below */
  #left-panel {
    position: relative;
    width: 100%;
    height: auto;
    pointer-events: auto;
    z-index: 10;
    background: #000;
  }

  #sections-container {
    height: auto;
    position: relative;
  }

  .scroll-section {
    position: relative;
    top: auto;
    left: auto;
    transform: none;
    padding: 2rem 1.5rem;
    opacity: 1 !important;
    min-height: auto;
  }

  .scroll-section::after {
    content: '';
    display: block;
    width: 100%;
    height: 1px;
    background: var(--border-subtle);
    margin-top: 2rem;
  }

  .section-heading {
    font-size: 1.8rem;
  }

  .section-formula {
    font-size: 0.85rem;
  }

  #right-panel {
    position: relative;
    left: 0;
    width: 100%;
    height: 60vh;
    clip-path: none !important;
    z-index: 1;
    order: -1;
  }

  #right-panel::before {
    display: none;
  }

  .marquee-wrap {
    position: relative;
    margin-top: -1px;
    opacity: 1 !important;
    padding: 0.5rem 0;
    background: var(--bg-secondary);
  }

  .marquee-text {
    font-size: 3rem;
  }

  #scroll-container {
    display: none;
  }

  #dark-overlay {
    display: none;
  }

  .stats-grid {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 1.5rem;
  }

  .stat-item {
    flex: 1;
    min-width: 40%;
  }

  .stat-number {
    font-size: 2rem;
  }

  .perf-tags {
    gap: 0.4rem;
  }

  .perf-tag {
    font-size: 0.7rem;
    padding: 0.25rem 0.7rem;
  }

  .cta-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.8rem;
  }

  .panel-fade {
    display: none;
  }

  body {
    display: flex;
    flex-direction: column;
  }
}

/* ============================================
   TABLET (768px - 1024px)
   ============================================ */
@media (min-width: 769px) and (max-width: 1024px) {
  :root {
    --left-width: 40vw;
    --right-width: 60vw;
  }

  .section-heading {
    font-size: clamp(1.5rem, 2.5vw, 2.2rem);
  }

  .stat-number {
    font-size: clamp(1.8rem, 3vw, 2.8rem);
  }
}