/* ==========================================================================
   向日葵背单词 (Sunflower Memorize Words) - Official Product Web Site Styles
   ========================================================================== */

:root {
  /* Brand Color Palette */
  --color-bg-main: #0B0E14;
  --color-bg-surface: #121824;
  --color-bg-card: rgba(22, 30, 46, 0.75);
  --color-bg-glass: rgba(255, 255, 255, 0.04);
  
  --color-gold-primary: #F5B027;
  --color-gold-glow: #FFC857;
  --color-gold-dark: #C6800C;
  --color-amber-gradient: linear-gradient(135deg, #FFE17D 0%, #F5B027 50%, #E68A00 100%);
  --color-gold-subtle: rgba(245, 176, 39, 0.12);
  --color-gold-border: rgba(245, 176, 39, 0.3);

  --color-text-main: #F1F5F9;
  --color-text-sub: #94A3B8;
  --color-text-muted: #64748B;
  
  --color-border-subtle: rgba(255, 255, 255, 0.08);
  --color-border-card: rgba(245, 176, 39, 0.15);

  --font-family-base: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --shadow-glow: 0 0 35px rgba(245, 176, 39, 0.25);
  --shadow-card: 0 12px 32px rgba(0, 0, 0, 0.4);
  --shadow-drop: 0 20px 50px rgba(0, 0, 0, 0.6);

  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Reset & Basic Base */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-family-base);
  background-color: var(--color-bg-main);
  color: var(--color-text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
}

/* Background Glowing Accents */
.bg-glow-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
}

.orb-1 {
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(245, 176, 39, 0.18) 0%, rgba(0, 0, 0, 0) 70%);
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
}

.orb-2 {
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(230, 138, 0, 0.12) 0%, rgba(0, 0, 0, 0) 70%);
  top: 40%;
  right: -100px;
}

.orb-3 {
  width: 450px;
  height: 450px;
  background: radial-gradient(circle, rgba(245, 176, 39, 0.1) 0%, rgba(0, 0, 0, 0) 70%);
  bottom: 10%;
  left: -100px;
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

/* Header & Navbar */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(11, 14, 20, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: var(--transition-fast);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--color-text-main);
}

.brand-logo {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 12px rgba(245, 176, 39, 0.3);
}

.brand-name {
  font-size: 1.25rem;
  font-weight: 700;
  background: var(--color-amber-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -0.5px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  color: var(--color-text-sub);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  transition: var(--transition-fast);
}

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

.btn-nav-download {
  background: var(--color-amber-gradient);
  color: #0B0E14;
  font-weight: 700;
  padding: 0.6rem 1.4rem;
  border-radius: var(--radius-full);
  text-decoration: none;
  box-shadow: 0 4px 15px rgba(245, 176, 39, 0.3);
  transition: var(--transition-fast);
}

.btn-nav-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(245, 176, 39, 0.5);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero-section {
  padding-top: 160px;
  padding-bottom: 90px;
  text-align: center;
  position: relative;
}

.badge-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--color-gold-subtle);
  border: 1px solid var(--color-gold-border);
  color: var(--color-gold-primary);
  padding: 6px 16px;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.badge-pulse {
  width: 8px;
  height: 8px;
  background-color: var(--color-gold-primary);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--color-gold-primary);
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(245, 176, 39, 0.7); }
  70% { transform: scale(1.1); box-shadow: 0 0 0 10px rgba(245, 176, 39, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(245, 176, 39, 0); }
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1px;
  margin-bottom: 1.25rem;
}

.hero-title-highlight {
  background: var(--color-amber-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--color-text-sub);
  max-width: 720px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  flex-wrap: wrap;
  margin-bottom: 3.5rem;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--color-amber-gradient);
  color: #0B0E14;
  font-size: 1.05rem;
  font-weight: 700;
  padding: 0.9rem 2.2rem;
  border-radius: var(--radius-full);
  text-decoration: none;
  box-shadow: var(--shadow-glow);
  transition: var(--transition-fast);
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 0 45px rgba(245, 176, 39, 0.45);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--color-bg-glass);
  color: var(--color-text-main);
  border: 1px solid var(--color-border-subtle);
  font-size: 1.05rem;
  font-weight: 600;
  padding: 0.9rem 2.2rem;
  border-radius: var(--radius-full);
  text-decoration: none;
  transition: var(--transition-fast);
  cursor: pointer;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-gold-border);
  color: var(--color-gold-primary);
  transform: translateY(-3px);
}

.hero-mockup-wrapper {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}

.hero-mockup-img {
  width: 100%;
  height: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-drop);
  border: 1px solid var(--color-border-card);
  transition: var(--transition-smooth);
}

.hero-mockup-img:hover {
  transform: scale(1.015);
  box-shadow: 0 25px 60px rgba(245, 176, 39, 0.2);
}

/* Stats Ribbon */
.stats-ribbon {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-card);
  backdrop-filter: blur(12px);
  padding: 2rem;
  border-radius: var(--radius-lg);
  margin: -40px auto 80px;
  position: relative;
  z-index: 10;
  box-shadow: var(--shadow-card);
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-size: 2.2rem;
  font-weight: 800;
  background: var(--color-amber-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 4px;
}

.stat-label {
  font-size: 0.9rem;
  color: var(--color-text-sub);
}

/* Section Header */
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 4rem;
}

.section-tag {
  color: var(--color-gold-primary);
  font-size: 0.875rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  margin-bottom: 0.75rem;
  display: block;
}

.section-title {
  font-size: 2.3rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--color-text-sub);
}

/* Features Section */
.features-section {
  padding: 80px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.feature-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: 2.2rem;
  transition: var(--transition-smooth);
  position: relative;
  overflow: hidden;
}

.feature-card:hover {
  transform: translateY(-8px);
  border-color: var(--color-gold-border);
  box-shadow: 0 15px 35px rgba(0, 0, 0, 0.5), 0 0 20px rgba(245, 176, 39, 0.12);
}

.feature-icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--color-gold-subtle);
  border: 1px solid var(--color-gold-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.6rem;
  color: var(--color-gold-primary);
  margin-bottom: 1.5rem;
}

.feature-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.feature-desc {
  color: var(--color-text-sub);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* Showcase Section */
.showcase-section {
  padding: 80px 0;
}

.showcase-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  margin-bottom: 6rem;
}

.showcase-grid.reverse {
  direction: rtl;
}

.showcase-grid.reverse > * {
  direction: ltr;
}

.showcase-content {
  max-width: 500px;
}

.showcase-pill {
  display: inline-block;
  color: var(--color-gold-primary);
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.showcase-heading {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 1.25rem;
  line-height: 1.25;
}

.showcase-text {
  color: var(--color-text-sub);
  font-size: 1rem;
  margin-bottom: 1.8rem;
  line-height: 1.7;
}

.showcase-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
}

.showcase-list-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.95rem;
  color: var(--color-text-main);
}

.showcase-list-item i {
  color: var(--color-gold-primary);
}

.showcase-card-box {
  background: linear-gradient(145deg, rgba(255, 255, 255, 0.05) 0%, rgba(245, 176, 39, 0.05) 100%);
  border: 1px solid var(--color-gold-border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-card);
}

.showcase-mini-demo {
  background: var(--color-bg-surface);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  border: 1px solid var(--color-border-subtle);
}

/* Download Section */
.download-section {
  padding: 100px 0;
  background: radial-gradient(circle at 50% 50%, rgba(245, 176, 39, 0.08) 0%, rgba(11, 14, 20, 0) 75%);
  text-align: center;
}

.download-box {
  background: var(--color-bg-card);
  border: 1px solid var(--color-gold-border);
  border-radius: var(--radius-lg);
  padding: 4rem 2rem;
  max-width: 960px;
  margin: 0 auto;
  box-shadow: var(--shadow-card);
  position: relative;
  overflow: hidden;
}

.download-title {
  font-size: 2.4rem;
  font-weight: 800;
  margin-bottom: 1rem;
}

.download-subtitle {
  color: var(--color-text-sub);
  max-width: 600px;
  margin: 0 auto 3rem;
  font-size: 1.05rem;
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-bottom: 2.5rem;
}

.platform-card {
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: 1.8rem 1.2rem;
  text-decoration: none;
  color: var(--color-text-main);
  transition: var(--transition-fast);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.platform-card:hover, .platform-card.active {
  border-color: var(--color-gold-primary);
  background: var(--color-gold-subtle);
  transform: translateY(-5px);
}

.platform-icon {
  font-size: 2.2rem;
  color: var(--color-gold-primary);
}

.platform-name {
  font-weight: 700;
  font-size: 1.1rem;
}

.platform-ver {
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.qr-trigger-box {
  margin-top: 1.5rem;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--color-gold-primary);
  font-weight: 600;
  cursor: pointer;
  padding: 8px 18px;
  border-radius: var(--radius-full);
  background: rgba(245, 176, 39, 0.1);
  border: 1px solid var(--color-gold-border);
  transition: var(--transition-fast);
}

.qr-trigger-box:hover {
  background: rgba(245, 176, 39, 0.2);
}

/* FAQ Accordion */
.faq-section {
  padding: 80px 0;
}

.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  margin-bottom: 1.2rem;
  overflow: hidden;
  transition: var(--transition-fast);
}

.faq-item.active {
  border-color: var(--color-gold-border);
}

.faq-header {
  padding: 1.4rem 1.8rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
  font-weight: 700;
  font-size: 1.05rem;
}

.faq-header i {
  color: var(--color-gold-primary);
  transition: transform 0.3s ease;
}

.faq-item.active .faq-header i {
  transform: rotate(180deg);
}

.faq-body {
  max-height: 0;
  overflow: hidden;
  padding: 0 1.8rem;
  color: var(--color-text-sub);
  font-size: 0.95rem;
  line-height: 1.7;
  transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-item.active .faq-body {
  max-height: 200px;
  padding: 0 1.8rem 1.4rem;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border-subtle);
  padding: 60px 0 30px;
  background: var(--color-bg-surface);
}

.footer-top {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand-desc {
  color: var(--color-text-sub);
  font-size: 0.9rem;
  margin-top: 1rem;
  line-height: 1.6;
  max-width: 340px;
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 1.2rem;
  color: var(--color-text-main);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-link {
  color: var(--color-text-sub);
  text-decoration: none;
  font-size: 0.9rem;
  transition: var(--transition-fast);
}

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

.footer-bottom {
  border-top: 1px solid var(--color-border-subtle);
  padding-top: 1.8rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  gap: 0.6rem;
}

/* QR Code Modal */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition-fast);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-gold-border);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  max-width: 380px;
  width: 90%;
  text-align: center;
  box-shadow: var(--shadow-drop);
  position: relative;
  transform: scale(0.9);
  transition: var(--transition-fast);
}

.modal-overlay.active .modal-card {
  transform: scale(1);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  color: var(--color-text-sub);
  font-size: 1.4rem;
  cursor: pointer;
  transition: var(--transition-fast);
}

.modal-close:hover {
  color: var(--color-gold-primary);
}

.modal-qr-img {
  width: 220px;
  height: 220px;
  border-radius: var(--radius-md);
  margin: 1.2rem 0;
  border: 1px solid var(--color-border-card);
}

.modal-title {
  font-size: 1.3rem;
  font-weight: 700;
}

.modal-desc {
  font-size: 0.875rem;
  color: var(--color-text-sub);
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .showcase-grid, .showcase-grid.reverse {
    grid-template-columns: 1fr;
    gap: 2.5rem;
    direction: ltr;
  }
  
  .footer-top {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    background: var(--color-bg-surface);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--color-border-subtle);
    transform: translateY(-150%);
    transition: var(--transition-fast);
  }

  .nav-links.active {
    transform: translateY(0);
  }

  .nav-toggle {
    display: block;
  }

  .hero-title {
    font-size: 2.2rem;
  }

  .footer-top {
    grid-template-columns: 1fr;
  }
}