/* ============================================
   小黑安装器 官网 — 日落质感版
   风格: 温暖暗色 · 层次光影 · 精致动效
   ============================================ */

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

:root {
  --bg:         #080808;
  --bg-card:    #0f0f0f;
  --bg-section: #0a0a0a;
  --text:       #ffffff;
  --text-dim:   rgba(255,255,255,0.55);
  --text-sub:   rgba(255,255,255,0.3);
  --gold:       #e8a317;
  --gold-light: #f5c542;
  --gold-glow:  rgba(232,163,23,0.12);
  --sunset:     #c45d3a;
  --sunset-dim: rgba(196,93,58,0.08);
  --border:     rgba(255,255,255,0.05);
  --radius:     14px;
  --radius-sm:  8px;
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { text-decoration: none; color: inherit; }

/* ======== NAVIGATION ======== */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(8,8,8,0.75);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: background 0.4s;
}

.nav-inner {
  max-width: 1200px; margin: 0 auto; padding: 0 30px;
  height: 68px; display: flex; align-items: center; justify-content: space-between;
}

.nav-logo {
  font-size: 1rem; font-weight: 800; letter-spacing: 2px;
  background: linear-gradient(135deg, var(--gold), var(--gold-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links { display: flex; gap: 36px; align-items: center; }

.nav-links a {
  font-size: 0.85rem; font-weight: 500;
  color: var(--text-dim); transition: color 0.25s;
  position: relative;
}
.nav-links a:not(.nav-btn)::after {
  content: ''; position: absolute; left: 0; bottom: -4px;
  width: 0; height: 1.5px;
  background: linear-gradient(90deg, var(--gold), var(--sunset));
  transition: width 0.3s; border-radius: 2px;
}
.nav-links a:not(.nav-btn):hover { color: var(--text); }
.nav-links a:not(.nav-btn):hover::after { width: 100%; }

.nav-btn {
  padding: 9px 26px;
  background: linear-gradient(135deg, var(--gold), var(--gold-light));
  color: #0a0a0a !important;
  font-weight: 700; font-size: 0.82rem;
  border-radius: var(--radius-sm);
  transition: transform 0.2s, box-shadow 0.2s;
}
/* Hamburger toggle */
  display: none;
  background: none; border: none; cursor: pointer;
  padding: 8px; z-index: 101;
  flex-shrink: 0;
}

/* ======== HERO ======== */
.hero-title { text-align: center; }
.hero {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  text-align: center; padding: 130px 24px 80px;
  position: relative; overflow: hidden;
}

.hero-bg-image {
  position: absolute; inset: -15px;
  background-image: url('images/gta5_sunset.png');
  background-size: cover;
  background-position: center;
  filter: blur(1px);
  z-index: 0;
  transform: scale(1.03);
}

.hero-overlay {
  position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background: linear-gradient(
    0deg, #080808 0%,
    rgba(8,8,8,0.75) 20%,
    rgba(8,8,8,0.35) 45%,
    rgba(8,8,8,0.1) 70%
  );
}

.hero-inner { position: relative; z-index: 2; max-width: 780px; }

.hero-kicker {
  display: inline-block;
  font-size: 0.78rem; font-weight: 600; letter-spacing: 4px; text-transform: uppercase;
  color: var(--gold); margin-bottom: 28px;
  padding: 7px 20px;
  border: 1px solid rgba(232,163,23,0.2);
  border-radius: 20px;
  background: rgba(232,163,23,0.05);
  backdrop-filter: blur(8px);
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 5rem); font-weight: 900;
  line-height: 1.08; letter-spacing: -1.5px;
  margin-bottom: 28px;
  background: linear-gradient(135deg, #fff 30%, var(--gold) 70%, var(--gold-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.08rem; color: var(--text-dim); line-height: 1.9;
  margin-bottom: 44px; max-width: 540px; margin-left: auto; margin-right: auto;
}

.hero-btns { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.hero-scroll {
  position: absolute; bottom: 34px; left: 50%; transform: translateX(-50%);
  z-index: 2;
  width: 24px; height: 40px;
  border: 2px solid rgba(255,255,255,0.15);
  border-radius: 12px;
  display: flex; align-items: flex-start; justify-content: center;
  padding-top: 8px;
}
.hero-scroll::after {
  content: '';
  width: 2px; height: 8px;
  background: var(--gold);
  border-radius: 2px;
  animation: scrollDot 2s infinite;
}
@keyframes scrollDot {
  0% { opacity: 1; transform: translateY(0); }
  100% { opacity: 0; transform: translateY(12px); }
}

/* ======== BUTTONS ======== */
.btn-yellow {
  display: inline-block; padding: 16px 44px;
  background: linear-gradient(135deg, var(--gold), var(--gold-light));
  color: #0a0a0a; border-radius: var(--radius-sm);
  font-size: 1rem; font-weight: 700; letter-spacing: 0.3px;
  transition: transform 0.25s, box-shadow 0.25s;
  box-shadow: 0 4px 24px rgba(232,163,23,0.2);
}
.btn-yellow:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 32px rgba(232,163,23,0.35);
}
.btn-yellow--lg { padding: 18px 52px; font-size: 1.08rem; }

.btn-outline {
  display: inline-block; padding: 16px 44px;
  border: 2px solid rgba(255,255,255,0.15); color: var(--text);
  border-radius: var(--radius-sm);
  font-size: 1rem; font-weight: 600; letter-spacing: 0.3px;
  transition: border-color 0.25s, background 0.25s, transform 0.25s;
}
.btn-outline:hover {
  border-color: var(--gold);
  background: rgba(232,163,23,0.06);
  transform: translateY(-2px);
}

/* ======== SECTION COMMON ======== */
.section,
.features,
.screenshots,
.cta {
  padding: 100px 28px;
  position: relative;
}

/* Section gradient divider */
.section::before,
.features::before,
.screenshots::before,
.cta::before {
  content: '';
  position: absolute; top: 0; left: 50%;
  transform: translateX(-50%);
  width: 120px; height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  opacity: 0.4;
}

/* Section warm glow */
.section::after,
.features::after,
.screenshots::after {
  content: '';
  position: absolute; top: 0; left: 50%;
  transform: translateX(-50%);
  width: 500px; height: 200px;
  background: radial-gradient(ellipse, rgba(232,163,23,0.03) 0%, transparent 70%);
  pointer-events: none;
}

/* Section title area wrapper */
.sec-header {
  text-align: center;
  margin-bottom: 60px;
  position: relative;
  z-index: 1;
}

.sec-title {
  font-size: clamp(1.8rem, 3.2vw, 2.4rem);
  font-weight: 800; letter-spacing: -0.5px;
  margin-bottom: 14px;
}

.sec-sub {
  font-size: 0.95rem; color: var(--text-dim);
  max-width: 480px; margin: 0 auto;
  line-height: 1.8;
}

/* ======== FEATURES ======== */
.features {
  border-top: none;
  background: linear-gradient(180deg, var(--bg) 0%, #0c0a08 50%, var(--bg) 100%);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  max-width: 1080px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.feat-card {
  background: linear-gradient(160deg, #12100e 0%, #0f0f0f 100%);
  padding: 48px 32px 44px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  transition: transform 0.35s, box-shadow 0.35s, border-color 0.35s;
  position: relative; overflow: hidden;
}

/* Big background number */
.feat-card::before {
  content: attr(data-number);
  position: absolute;
  font-size: 7rem;
  font-weight: 900;
  color: rgba(232,163,23,0.03);
  line-height: 1;
  top: -12px; right: 10px;
  pointer-events: none;
  transition: color 0.4s, transform 0.4s;
}

/* Corner gradient accent */
.feat-card::after {
  content: '';
  position: absolute; top: 0; left: 0;
  width: 100%; height: 100%;
  background: linear-gradient(135deg, rgba(232,163,23,0.03) 0%, transparent 50%);
  pointer-events: none;
  opacity: 0; transition: opacity 0.4s;
}

.feat-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 48px rgba(0,0,0,0.35);
  border-color: rgba(232,163,23,0.15);
}
.feat-card:hover::before {
  color: rgba(232,163,23,0.08);
  transform: scale(1.05);
}
.feat-card:hover::after { opacity: 1; }

/* Number badge */
.feat-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 48px; height: 48px;
  font-size: 0.9rem; font-weight: 800;
  color: var(--gold);
  background: rgba(232,163,23,0.06);
  border-radius: 14px; margin-bottom: 22px;
  position: relative; z-index: 1;
  transition: background 0.3s, transform 0.3s;
}
.feat-card:hover .feat-num {
  background: rgba(232,163,23,0.12);
  transform: scale(1.06);
}

.feat-card h3 {
  font-size: 1.15rem; font-weight: 700;
  margin-bottom: 12px; letter-spacing: 0.3px;
  position: relative; z-index: 1;
}

.feat-card p {
  font-size: 0.88rem; color: var(--text-dim);
  line-height: 1.75;
  position: relative; z-index: 1;
}

/* ======== SCREENSHOTS ======== */
.screenshots {
  border-top: none;
}

.shot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  max-width: 1080px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.shot-placeholder {
  aspect-ratio: 16/11;
  background: linear-gradient(160deg, #12100e 0%, #0f0f0f 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center;
  transition: border-color 0.3s, transform 0.35s, box-shadow 0.35s;
  cursor: pointer; overflow: hidden;
  position: relative;
}

.shot-placeholder::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(232,163,23,0.02) 0%, transparent 50%);
  opacity: 0; transition: opacity 0.3s;
}

.shot-placeholder:hover {
  border-color: rgba(232,163,23,0.2);
  transform: translateY(-5px);
  box-shadow: 0 16px 48px rgba(0,0,0,0.3);
}
.shot-placeholder:hover::before { opacity: 1; }

.shot-placeholder span {
  color: var(--text-sub);
  font-size: 0.85rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  position: relative; z-index: 1;
}

/* ======== CTA ======== */
.cta {
  text-align: center;
  border-top: none;
  background: linear-gradient(180deg, var(--bg) 0%, #0c0a08 50%, var(--bg) 100%);
}

.cta-title {
  font-size: clamp(1.8rem, 3.2vw, 2.4rem);
  font-weight: 800; margin-bottom: 14px;
  letter-spacing: -0.5px;
}

.cta-sub {
  color: var(--text-dim);
  font-size: 1rem;
  margin-bottom: 40px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.cta-note {
  margin-top: 22px;
  font-size: 0.8rem;
  color: var(--text-sub);
  letter-spacing: 2px;
}

/* ======== FOOTER ======== */
.footer {
  border-top: 1px solid var(--border);
  padding: 44px 28px;
  text-align: center;
}

.footer-inner { max-width: 1200px; margin: 0 auto; }
.footer-brand {
  font-size: 0.95rem; font-weight: 700;
  margin-bottom: 6px; letter-spacing: 1px;
  background: linear-gradient(135deg, var(--gold), var(--gold-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}
.footer-copy { font-size: 0.78rem; color: var(--text-sub); }

/* ======== RESPONSIVE ======== */
@media (max-width: 768px) {
  .nav-inner { padding: 0 20px; }
  .features-grid { grid-template-columns: 1fr; }
  .shot-grid { grid-template-columns: 1fr 1fr; }
  .section, .features, .screenshots, .cta { padding: 70px 20px; }
  .sec-header { margin-bottom: 44px; }
}

/* Ambient floating orbs - v17 */
.hero-ambient {
  position: absolute; inset: 0; z-index: 1; overflow: hidden;
  pointer-events: none;
}
.ambient-orb {
  position: absolute; border-radius: 50%;
  will-change: transform;
  animation: orbFloat 12s ease-in-out infinite;
}
.ambient-orb.o1 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(212,160,23,0.08) 0%, transparent 70%);
  top: -80px; left: -100px;
  animation-delay: 0s;
}
.ambient-orb.o2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(196,93,58,0.06) 0%, transparent 70%);
  bottom: -60px; right: -80px;
  animation-delay: -4s;
}
.ambient-orb.o3 {
  width: 350px; height: 350px;
  background: radial-gradient(circle, rgba(232,195,90,0.05) 0%, transparent 70%);
  top: 40%; right: 15%;
  animation-delay: -8s;
}
@keyframes orbFloat {
  0%, 100% { transform: translate(0,0) scale(1); }
  25% { transform: translate(30px,-20px) scale(1.05); }
  50% { transform: translate(-10px,30px) scale(0.95); }
  75% { transform: translate(20px,10px) scale(1.02); }
}

/* Reveal animation - v17 */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.7s cubic-bezier(0.25,0.46,0.45,0.94), transform 0.7s cubic-bezier(0.25,0.46,0.45,0.94);
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}
.features-grid .reveal:nth-child(1) { transition-delay: 0.05s; }
.features-grid .reveal:nth-child(2) { transition-delay: 0.12s; }
.features-grid .reveal:nth-child(3) { transition-delay: 0.19s; }
.features-grid .reveal:nth-child(4) { transition-delay: 0.26s; }
.features-grid .reveal:nth-child(5) { transition-delay: 0.33s; }
.features-grid .reveal:nth-child(6) { transition-delay: 0.40s; }

/* CTA glow - v17 */
.cta-glow {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%);
  width: 600px; height: 400px;
  background: radial-gradient(ellipse, rgba(212,160,23,0.04) 0%, transparent 60%);
  pointer-events: none;
  animation: ctaPulse 4s ease-in-out infinite;
}
@keyframes ctaPulse {
  0%, 100% { opacity: 0.6; transform: translate(-50%,-50%) scale(1); }
  50% { opacity: 1; transform: translate(-50%,-50%) scale(1.05); }
}

/* Feat-card left accent bar - v17 */
.feat-card::before {
  content: '';
  position: absolute; top: 0; left: 0;
  width: 3px; height: 100%;
  background: linear-gradient(180deg, #d4a017, #c45d3a);
  opacity: 0.4;
  transition: opacity 0.4s, width 0.4s;
}
.feat-card:hover::before {
  opacity: 1;
  width: 4px;
}
.feat-card::after {
  content: '';
  position: absolute; top: -50%; left: -50%;
  width: 200%; height: 200%;
  background: radial-gradient(ellipse at 30% 0%, rgba(212,160,23,0.03) 0%, transparent 60%);
  pointer-events: none;
  opacity: 0; transition: opacity 0.5s;
}
.feat-card:hover::after { opacity: 1; }

/* Screenshot viewer */
.shot-viewer {
  max-width: 880px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.shot-tabs {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.shot-tab {
  flex: 1;
  min-width: 110px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 18px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: linear-gradient(160deg, #12100e 0%, #0f0f0f 100%);
  color: var(--text-dim);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  letter-spacing: 0.5px;
  text-align: center;
  font-family: inherit;
  line-height: 1;
}
.shot-tab .tab-icon {
  flex-shrink: 0;
  opacity: 0.5;
  transition: opacity 0.3s;
}
.shot-tab:hover {
  border-color: rgba(232,163,23,0.25);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.25);
}
.shot-tab:hover .tab-icon {
  opacity: 0.8;
}
.shot-tab.active {
  border-color: var(--gold);
  color: var(--gold);
  background: linear-gradient(160deg, rgba(232,163,23,0.08) 0%, rgba(232,163,23,0.03) 100%);
  box-shadow: 0 4px 20px rgba(232,163,23,0.12), inset 0 1px 0 rgba(232,163,23,0.15);
}
.shot-tab.active .tab-icon {
  opacity: 1;
  stroke: var(--gold);
}
.shot-preview-area {
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border);
  background: linear-gradient(160deg, #12100e 0%, #0f0f0f 100%);
  position: relative;
}
.shot-preview-inner {
  width: 100%;
  aspect-ratio: 16/10;
  background-size: cover;
  background-position: center;
  transition: background-image 0.4s ease;
}
.shot-preview-label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 18px 24px;
  font-size: 0.9rem;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(0deg, rgba(8,8,8,0.85) 0%, transparent 100%);
  letter-spacing: 0.5px;
}
@media (max-width: 640px) {
  .shot-tab {
    min-width: auto;
    padding: 12px 14px;
    font-size: 0.8rem;
  }
  .shot-tab .tab-icon {
    display: none;
  }
}
/* ======== FAQ ======== */
.faq {
  padding: 100px 28px;
  position: relative;
  background: linear-gradient(180deg, var(--bg) 0%, #0c0a08 50%, var(--bg) 100%);
}
.faq::before {
  content: '';
  position: absolute; top: 0; left: 50%;
  transform: translateX(-50%);
  width: 120px; height: 1px;
  background: linear-gradient(90deg, transparent, var(--gold), transparent);
  opacity: 0.4;
}
.faq-list {
  max-width: 780px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}
.faq-item {
  border-bottom: 1px solid var(--border);
}
.faq-item:first-child {
  border-top: 1px solid var(--border);
}
.faq-q {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 0;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
  transition: color 0.3s;
  gap: 16px;
}
.faq-q:hover {
  color: var(--gold);
}
.faq-arrow {
  flex-shrink: 0;
  transition: transform 0.3s;
  opacity: 0.4;
}
.faq-item.open .faq-arrow {
  transform: rotate(180deg);
  opacity: 0.8;
}
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
}
.faq-item.open .faq-a {
  max-height: 200px;
  padding-bottom: 20px;
}
.faq-a p {
  font-size: 0.88rem;
  color: var(--text-dim);
  line-height: 1.8;
}
@media (max-width: 480px) {
  .shot-grid { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; align-items: center; }
}
@media (max-width: 768px) {
  .faq { padding: 70px 20px; }