/* ============================================================
   AutoDouyinSpark - Project Website
   Design: Cyberpunk UI / Developer Tool Palette / Inter System
   ============================================================ */

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: #0F172A;
  color: #F8FAFC;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

/* === CSS VARIABLES === */
:root {
  --bg: #0F172A;
  --bg-header: #0B1121;
  --bg-card: #1B2336;
  --bg-card-glass: rgba(27, 35, 54, 0.85);
  --bg-elevated: rgba(17, 24, 39, 0.9);
  --accent: #22C55E;
  --accent-dim: rgba(34, 197, 94, 0.15);
  --accent-soft: rgba(34, 197, 94, 0.08);
  --foreground: #F8FAFC;
  --muted: #94A3B8;
  --muted-light: #64748B;
  --border: #475569;
  --border-subtle: rgba(71, 85, 105, 0.5);
  --hero-gradient-start: #0F172A;
  --hero-gradient-end: #1E2F4A;
  --section-mb: 0;
  --max-width: 1200px;
}

/* === SECTION SHARED === */
.section-wrapper {
  position: relative;
  z-index: 1;
  will-change: transform;
}

.section-wrapper::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
}

/* Section stacking: each layer overlaps slightly with scale/translate */
.section-wrapper:nth-child(2) { z-index: 2; }  /* features */
.section-wrapper:nth-child(3) { z-index: 3; }  /* how-it-works */
.section-wrapper:nth-child(4) { z-index: 4; }  /* tech-stack */
.section-wrapper:nth-child(5) { z-index: 5; }  /* download */
.section-wrapper:nth-child(6) { z-index: 6; }  /* footer */

/* Depth gradient overlays between sections */
.features-wrap::before,
.how-wrap::before,
.tech-wrap::before,
.download-wrap::before {
  content: '';
  position: absolute;
  left: 0;
  right: 0;
  height: 160px;
  bottom: -80px;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(
    to bottom,
    rgba(15, 23, 42, 0) 0%,
    rgba(15, 23, 42, 0.6) 100%
  );
}

.section-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 100px 24px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  position: relative;
  z-index: 1;
}

.section-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 2px;
  text-transform: uppercase;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--foreground);
  text-align: center;
}

.section-subtitle {
  font-size: 16px;
  color: var(--muted);
  text-align: center;
  max-width: 600px;
  line-height: 1.6;
}

/* ============================================================
   HEADER
   ============================================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-header);
  border-bottom: 1px solid rgba(71, 85, 105, 0.3);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-container {
  max-width: 1440px;
  margin: 0 auto;
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 40px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-img {
  width: 42px;
  height: 42px;
  object-fit: contain;
  flex-shrink: 0;
  image-rendering: auto;
}

.logo-text {
  font-size: 22px;
  font-weight: 700;
  color: var(--foreground);
  line-height: 1;
}

.version-badge {
  font-size: 12px;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 2px 6px;
  border-radius: 4px;
  line-height: 1.4;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--muted);
  transition: color 0.2s;
  cursor: pointer;
}

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

.header-right {
  display: flex;
  align-items: center;
  gap: 16px;
}

.github-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: rgba(17, 24, 39, 0.8);
  font-size: 14px;
  font-weight: 500;
  color: var(--foreground);
  transition: border-color 0.2s, background 0.2s;
  cursor: pointer;
}

.github-link:hover {
  border-color: var(--accent);
  background: rgba(34, 197, 94, 0.1);
}

.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--muted);
  border-radius: 2px;
  transition: transform 0.3s, opacity 0.3s;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  padding-top: 72px;
  min-height: 100vh;
  background: linear-gradient(180deg, #0F172A 0%, #1E2F4A 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at 50% 30%, rgba(34, 197, 94, 0.03) 0%, transparent 60%);
  pointer-events: none;
}

.hero-content {
  max-width: 900px;
  padding: 80px 24px 60px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-dim);
  padding: 6px 16px;
  border-radius: 20px;
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.hero-headline {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0;
  line-height: 1.2;
}

.hero-headline-white {
  font-size: 56px;
  font-weight: 700;
  color: var(--foreground);
}

.hero-headline-accent {
  font-size: 56px;
  font-weight: 700;
  color: var(--accent);
  text-shadow:
    0 0 80px rgba(34, 197, 94, 0.10),
    0 0 40px rgba(34, 197, 94, 0.25),
    0 0 20px rgba(34, 197, 94, 0.50),
    0 0 10px rgba(34, 197, 94, 0.80);
}

.hero-subheadline {
  font-size: 18px;
  color: var(--muted);
  max-width: 640px;
  line-height: 1.6;
}

.hero-ctas {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  justify-content: center;
  padding: 8px 0;
}

/* === BUTTONS === */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  border-radius: 8px;
  font-size: 17px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent);
  color: #0F172A;
}

.btn-primary:hover {
  background: #16a34a;
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(34, 197, 94, 0.3);
}

.btn-secondary {
  background: rgba(17, 24, 39, 0.8);
  color: var(--foreground);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  border-color: var(--accent);
  background: rgba(34, 197, 94, 0.1);
}

.btn-lg {
  padding: 14px 32px;
}

.btn-ghost {
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 500;
}

.btn-ghost:hover {
  color: var(--foreground);
  border-color: var(--muted);
}

/* === APP PREVIEW MOCKUP === */
.app-preview {
  width: 800px;
  max-width: 100%;
  margin-top: 16px;
  border-radius: 8px;
  border: 1px solid rgba(34, 197, 94, 0.2);
  overflow: hidden;
  box-shadow:
    0 0 60px rgba(34, 197, 94, 0.06),
    0 8px 32px rgba(34, 197, 94, 0.12);
  background: linear-gradient(180deg, #1B2336 0%, #1E2F4A 100%);
}

.mockup-frame {
  display: flex;
  height: 400px;
  background: #0F172A;
  border-radius: 4px;
  border: 1px solid rgba(51, 65, 85, 0.5);
  overflow: hidden;
}

.mockup-sidebar {
  width: 180px;
  background: #162140;
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  flex-shrink: 0;
}

.mockup-sidebar-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.mockup-sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.mockup-nav-item {
  font-size: 13px;
  padding: 6px 8px;
  border-radius: 4px;
  color: var(--muted-light);
  text-decoration: none;
  display: block;
  transition: all 0.2s;
}

.mockup-nav-item.active {
  color: var(--foreground);
  background: rgba(34, 197, 94, 0.1);
}

.mockup-main {
  flex: 1;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  background: #0F172A;
}

.mockup-status-bar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 0 12px;
  height: 40px;
  background: #1B2336;
  border-radius: 4px;
  font-size: 13px;
  color: var(--muted);
}

.mockup-status-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  background: var(--accent);
  border-radius: 50%;
  flex-shrink: 0;
}

.mockup-chart-area {
  flex: 1;
  background: linear-gradient(180deg, rgba(34, 197, 94, 0.05) 0%, transparent 100%);
  border-radius: 4px;
  position: relative;
  display: flex;
  align-items: flex-end;
  padding: 16px;
}

.mockup-chart-line {
  width: 100%;
  height: 60px;
  background: repeating-linear-gradient(
    90deg,
    transparent 0px,
    transparent 80px,
    rgba(34, 197, 94, 0.15) 80px,
    rgba(34, 197, 94, 0.15) 100px,
    transparent 100px,
    transparent 110px
  );
  clip-path: polygon(
    0% 100%, 5% 80%, 10% 85%, 15% 60%, 20% 70%,
    25% 40%, 30% 55%, 35% 30%, 40% 45%, 45% 20%,
    50% 35%, 55% 15%, 60% 25%, 65% 10%, 70% 20%,
    75% 8%, 80% 15%, 85% 5%, 90% 12%, 95% 3%, 100% 8%,
    100% 100%, 0% 100%
  );
  background-color: rgba(34, 197, 94, 0.08);
}

/* ============================================================
   FEATURES
   ============================================================ */
.features {
  background: var(--bg);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  width: 100%;
  margin-top: 16px;
}

.feature-card {
  background: var(--bg-card-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(34, 197, 94, 0.15);
  border-radius: 12px;
  padding: 28px 24px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: all 0.3s;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

.feature-card:hover {
  transform: translateY(-4px);
  border-color: rgba(34, 197, 94, 0.3);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.35), 0 0 20px rgba(34, 197, 94, 0.05);
}

.feature-icon {
  font-size: 32px;
  line-height: 1;
  color: var(--accent);
}

.feature-card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--foreground);
}

.feature-card-desc {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

/* ============================================================
   HOW IT WORKS
   ============================================================ */
.how-it-works {
  background: var(--bg);
}

.steps-grid {
  display: flex;
  align-items: center;
  gap: 24px;
  width: 100%;
  margin-top: 16px;
}

.step-card {
  flex: 1;
  background: var(--bg-card-glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(34, 197, 94, 0.1);
  border-radius: 12px;
  padding: 32px 28px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.step-number {
  font-size: 48px;
  font-weight: 700;
  color: rgba(34, 197, 94, 0.13);
  line-height: 1;
}

.step-icon {
  font-size: 40px;
  line-height: 1;
  color: var(--accent);
}

.step-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--foreground);
}

.step-desc {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
}

.step-arrow {
  font-size: 28px;
  color: var(--accent);
  flex-shrink: 0;
}

/* ============================================================
   TECH STACK
   ============================================================ */
.tech-stack {
  background: var(--bg);
}

.tech-grid {
  display: flex;
  gap: 20px;
  width: 100%;
  margin-top: 16px;
  justify-content: center;
}

.tech-card {
  width: 180px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  text-align: center;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  transition: all 0.3s;
}

.tech-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
}

.tech-icon {
  font-size: 36px;
  line-height: 1;
  color: var(--foreground);
}

.tech-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--foreground);
}

.tech-sub {
  font-size: 12px;
  color: var(--muted-light);
}

/* ============================================================
   DOWNLOAD
   ============================================================ */
.download {
  background: linear-gradient(180deg, #0B1121 0%, #1B2336 100%);
}

.download-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 900px;
  background: #1B2336;
  border: 1px solid rgba(34, 197, 94, 0.12);
  border-radius: 12px;
  padding: 40px 48px;
  margin-top: 16px;
  box-shadow:
    0 0 48px rgba(34, 197, 94, 0.08),
    0 8px 24px rgba(34, 197, 94, 0.15);
}

.download-left {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.download-icon {
  font-size: 48px;
  line-height: 1;
  color: var(--accent);
}

.download-icon-img .dl-icon {
  width: 64px;
  height: 64px;
  object-fit: contain;
}

.download-title {
  font-size: 22px;
  font-weight: 600;
  color: var(--foreground);
}

.download-version {
  font-size: 14px;
  font-weight: 500;
  color: var(--accent);
}

.download-desc {
  font-size: 14px;
  color: var(--muted);
  max-width: 400px;
  line-height: 1.6;
}

.download-right {
  display: flex;
  flex-direction: column;
  gap: 12px;
  align-items: center;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--bg-header);
  padding: 60px 24px 24px;
}

.footer-content {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 40px;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-width: 320px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 20px;
  font-weight: 700;
  color: var(--foreground);
}

.footer-logo-img {
  width: 32px;
  height: 32px;
  object-fit: contain;
  flex-shrink: 0;
}

.footer-tagline {
  font-size: 14px;
  color: var(--muted-light);
  line-height: 1.5;
}

.footer-github {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--muted);
  transition: color 0.2s;
}

.footer-github:hover {
  color: var(--foreground);
}

.footer-links {
  display: flex;
  gap: 60px;
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-col-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 4px;
}

.footer-link {
  font-size: 14px;
  color: var(--muted);
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--foreground);
}

.footer-divider {
  max-width: var(--max-width);
  margin: 40px auto 24px;
  height: 1px;
  background: var(--border);
  opacity: 0.3;
}

.footer-bottom {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  gap: 24px;
  align-items: center;
  font-size: 13px;
  color: var(--border);
}

.footer-bottom a {
  color: var(--border);
  transition: color 0.2s;
}

.footer-bottom a:hover {
  color: var(--muted);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
/* Tablet: 768-1024px */
@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps-grid {
    flex-direction: column;
  }

  .step-arrow {
    transform: rotate(90deg);
  }

  .tech-grid {
    flex-wrap: wrap;
  }

  .download-card {
    flex-direction: column;
    gap: 24px;
    text-align: center;
  }

  .download-left {
    align-items: center;
  }
}

/* Mobile: <768px */
@media (max-width: 767px) {
  .header-container {
    padding: 0 16px;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-header);
    flex-direction: column;
    padding: 16px;
    gap: 16px;
    border-bottom: 1px solid rgba(71, 85, 105, 0.3);
  }

  .nav-links.open {
    display: flex;
  }

  .header-right {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero-headline-white,
  .hero-headline-accent {
    font-size: 36px;
  }

  .hero-subheadline {
    font-size: 16px;
  }

  .app-preview {
    width: 100%;
  }

  .mockup-frame {
    height: 280px;
  }

  .mockup-sidebar {
    width: 120px;
    padding: 12px 8px;
  }

  .mockup-sidebar-title {
    font-size: 12px;
  }

  .mockup-nav-item {
    font-size: 11px;
    padding: 4px 6px;
  }

  .section-title {
    font-size: 28px;
  }

  .features-grid {
    grid-template-columns: 1fr;
  }

  .download-card {
    padding: 24px 20px;
  }

  .footer-content {
    flex-direction: column;
    gap: 32px;
  }

  .footer-links {
    gap: 32px;
    flex-wrap: wrap;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    align-items: flex-start;
  }

  .hero-ctas {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-ctas .btn {
    justify-content: center;
  }
}

/* Very small screens */
@media (max-width: 480px) {
  .hero-headline-white,
  .hero-headline-accent {
    font-size: 28px;
  }

  .mockup-frame {
    height: 220px;
  }

  .mockup-sidebar {
    display: none;
  }

  .section-container {
    padding: 60px 16px;
  }
}

/* ============================================================
   SECTION LAYERING — STACKED DEPTH
   ============================================================ */
.section-wrapper {
  position: relative;
  z-index: 1;
  will-change: transform;
}

/* Each section has its own depth layer */
.section-wrapper.features-wrap { z-index: 2; }
.section-wrapper.how-wrap { z-index: 3; }
.section-wrapper.tech-wrap { z-index: 4; }
.section-wrapper.download-wrap { z-index: 5; }
.section-wrapper.footer-wrap { z-index: 6; }

/* === ENTRANCE REVEAL ANIMATIONS === */

/* Base: all reveal elements start invisible & shifted */
.section-reveal,
.feature-card,
.step-card,
.tech-card {
  opacity: 0;
  transition: all 0.8s cubic-bezier(0.22, 1, 0.36, 1);
}

/* Features slide-up from below */
.features .section-reveal,
.feature-card {
  transform: translateY(48px);
}

/* How It Works slides from left */
.how-it-works .section-reveal {
  transform: translateX(-40px);
}
.step-card:nth-child(1) { transform: translateX(-60px); }
.step-card:nth-child(3) { transform: translateY(40px); }
.step-card:nth-child(5) { transform: translateX(60px); }

/* Tech Stack scales in */
.tech-stack .section-reveal {
  transform: scale(0.85);
}
.tech-card {
  transform: scale(0.8) translateY(30px);
}

/* Download zooms from bottom */
.download .section-reveal {
  transform: translateY(60px);
}

/* === VISIBLE STATE === */
.section-reveal.visible,
.feature-card.visible,
.step-card.visible,
.tech-card.visible {
  opacity: 1;
  transform: translateX(0) translateY(0) scale(1);
}

/* Stagger delays for grid children */
.features-grid .feature-card:nth-child(1) { transition-delay: 0.05s; }
.features-grid .feature-card:nth-child(2) { transition-delay: 0.10s; }
.features-grid .feature-card:nth-child(3) { transition-delay: 0.15s; }
.features-grid .feature-card:nth-child(4) { transition-delay: 0.20s; }
.features-grid .feature-card:nth-child(5) { transition-delay: 0.25s; }
.features-grid .feature-card:nth-child(6) { transition-delay: 0.30s; }

.steps-grid .step-card:nth-child(1) { transition-delay: 0.05s; }
.steps-grid .step-card:nth-child(3) { transition-delay: 0.15s; }
.steps-grid .step-card:nth-child(5) { transition-delay: 0.25s; }

.tech-grid .tech-card:nth-child(1) { transition-delay: 0.05s; }
.tech-grid .tech-card:nth-child(2) { transition-delay: 0.10s; }
.tech-grid .tech-card:nth-child(3) { transition-delay: 0.15s; }
.tech-grid .tech-card:nth-child(4) { transition-delay: 0.20s; }
.tech-grid .tech-card:nth-child(5) { transition-delay: 0.25s; }

/* Hero entrance is immediate */
.hero-content {
  animation: heroFadeIn 1s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

@keyframes heroFadeIn {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   BACK TO TOP — 重置所有动画
   ============================================================ */
.back-to-top {
  position: fixed;
  bottom: 40px;
  right: 40px;
  z-index: 999;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 10px 18px;
  border-radius: 24px;
  border: 1px solid rgba(34, 197, 94, 0.3);
  background: rgba(11, 17, 33, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  color: var(--accent);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  font-family: 'Inter', sans-serif;
  opacity: 0;
  transform: translateY(16px);
  pointer-events: none;
  transition: opacity 0.4s ease, transform 0.4s ease, border-color 0.2s, background 0.2s;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  border-color: var(--accent);
  background: rgba(34, 197, 94, 0.15);
  box-shadow: 0 0 20px rgba(34, 197, 94, 0.15);
}

.back-to-top svg {
  transition: transform 0.3s ease;
}

.back-to-top:hover svg {
  transform: translateY(-2px);
}

.back-to-top-text {
  font-size: 13px;
}

@media (max-width: 767px) {
  .back-to-top {
    bottom: 24px;
    right: 24px;
    padding: 8px 14px;
  }
  .back-to-top-text {
    display: none;
  }
}