/* ============================================================
   艾宾浩斯背单词 — 官网设计系统
   Design System v2.0 · Dark Premium Theme
   ============================================================ */

/* ── 设计令牌 ─────────────────────────────────────────────── */
:root {
  /* 颜色 */
  --clr-bg:          #09090f;
  --clr-bg-2:        #0f0f1a;
  --clr-bg-3:        #14142a;
  --clr-surface:     rgba(255,255,255,0.04);
  --clr-surface-2:   rgba(255,255,255,0.07);
  --clr-border:      rgba(255,255,255,0.08);
  --clr-border-2:    rgba(255,255,255,0.14);

  --clr-primary:     #6366f1;
  --clr-primary-2:   #818cf8;
  --clr-accent:      #a78bfa;
  --clr-accent-2:    #c4b5fd;
  --clr-green:       #34d399;
  --clr-pink:        #f472b6;

  --clr-text:        #f1f5f9;
  --clr-text-2:      #94a3b8;
  --clr-text-3:      #64748b;

  /* 渐变 */
  --grad-primary:    linear-gradient(135deg, #6366f1 0%, #a78bfa 100%);
  --grad-glow:       linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --grad-section:    linear-gradient(180deg, #09090f 0%, #0f0f1a 100%);
  --grad-dark:       linear-gradient(135deg, #0f0f1a 0%, #14142a 100%);
  --grad-card:       linear-gradient(145deg, rgba(99,102,241,0.12) 0%, rgba(167,139,250,0.06) 100%);

  /* 阴影 */
  --shadow-sm:       0 1px 3px rgba(0,0,0,0.4);
  --shadow-md:       0 8px 24px rgba(0,0,0,0.5);
  --shadow-lg:       0 24px 48px rgba(0,0,0,0.6);
  --shadow-glow:     0 0 40px rgba(99,102,241,0.25);
  --shadow-glow-lg:  0 0 80px rgba(99,102,241,0.2);

  /* 圆角 */
  --radius-sm:   8px;
  --radius-md:   16px;
  --radius-lg:   24px;
  --radius-xl:   32px;
  --radius-full: 9999px;

  /* 过渡 */
  --trans-fast:   all 0.15s ease;
  --trans-base:   all 0.25s cubic-bezier(0.4,0,0.2,1);
  --trans-slow:   all 0.4s cubic-bezier(0.4,0,0.2,1);

  /* 排版 */
  --font-body: 'Inter', 'Noto Sans SC', -apple-system, sans-serif;
  --font-display: 'Inter', 'Noto Sans SC', sans-serif;

  /* 间距 */
  --space-section: 120px;
  --space-section-sm: 80px;
}

/* ── 重置 ─────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  background: var(--clr-bg);
  color: var(--clr-text);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
ul { list-style: none; }

/* ── 工具类 ──────────────────────────────────────────────── */
.text-accent  { background: var(--grad-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.text-accent-light { background: linear-gradient(135deg, #c4b5fd, #f0abfc); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

/* ── NAVBAR ─────────────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0;
  transition: var(--trans-base);
}
.navbar.scrolled {
  background: rgba(9,9,15,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--clr-border);
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 18px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 600;
  color: var(--clr-text);
}
.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  filter: drop-shadow(0 0 8px rgba(99,102,241,0.5));
}
.logo-text em {
  font-style: normal;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-link {
  padding: 8px 16px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 500;
  color: var(--clr-text-2);
  transition: var(--trans-base);
}
.nav-link:hover { color: var(--clr-text); background: var(--clr-surface); }
.nav-link-cta {
  background: var(--grad-primary);
  color: white !important;
  font-weight: 600;
  box-shadow: var(--shadow-glow);
}
.nav-link-cta:hover { opacity: 0.9; transform: translateY(-1px); }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  border-radius: var(--radius-sm);
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--clr-text);
  border-radius: 2px;
  transition: var(--trans-base);
}

/* ── HERO ────────────────────────────────────────────────── */
.hero {
  min-height: 100vh;
  position: relative;
  display: flex;
  align-items: center;
  padding: 120px 24px 80px;
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.hero-bg-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.35;
}
.hero-bg-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    135deg,
    rgba(9,9,15,0.85) 0%,
    rgba(15,15,26,0.7) 50%,
    rgba(9,9,15,0.9) 100%
  );
}
.hero-particles {
  position: absolute;
  inset: 0;
  overflow: hidden;
}
.particle {
  position: absolute;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(99,102,241,0.8), transparent);
  animation: float linear infinite;
  pointer-events: none;
}
@keyframes float {
  0%   { transform: translateY(100vh) translateX(0) scale(0); opacity: 0; }
  10%  { opacity: 1; }
  90%  { opacity: 0.6; }
  100% { transform: translateY(-100px) translateX(var(--drift)) scale(1); opacity: 0; }
}

.hero-container {
  position: relative;
  z-index: 2;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(99,102,241,0.12);
  border: 1px solid rgba(99,102,241,0.3);
  font-size: 13px;
  font-weight: 500;
  color: var(--clr-primary-2);
  width: fit-content;
  margin-bottom: 24px;
  animation: fadeSlideUp 0.6s ease both;
}
.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--clr-green);
  box-shadow: 0 0 8px var(--clr-green);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%       { opacity: 0.4; }
}
.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  animation: fadeSlideUp 0.6s 0.1s ease both;
}
.hero-title-accent {
  display: block;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-desc {
  font-size: 17px;
  line-height: 1.7;
  color: var(--clr-text-2);
  margin-bottom: 36px;
  animation: fadeSlideUp 0.6s 0.2s ease both;
}
.hero-stats {
  display: flex;
  align-items: center;
  gap: 24px;
  margin-bottom: 40px;
  animation: fadeSlideUp 0.6s 0.3s ease both;
}
.stat-item { display: flex; flex-direction: column; gap: 2px; }
.stat-num {
  font-size: 28px;
  font-weight: 800;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
}
.stat-label { font-size: 12px; color: var(--clr-text-3); line-height: 1.4; }
.stat-divider {
  width: 1px;
  height: 40px;
  background: var(--clr-border-2);
}
.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  animation: fadeSlideUp 0.6s 0.4s ease both;
}
.btn-primary-hero {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  background: var(--grad-primary);
  color: white;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-glow);
  transition: var(--trans-base);
}
.btn-primary-hero:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 60px rgba(99,102,241,0.4);
}
.btn-ghost-hero {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 24px;
  color: var(--clr-text-2);
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1px solid var(--clr-border-2);
  background: var(--clr-surface);
  transition: var(--trans-base);
}
.btn-ghost-hero:hover { color: var(--clr-text); border-color: var(--clr-primary); }

.hero-visual {
  position: relative;
  z-index: 2;
  display: flex;
  justify-content: center;
  align-items: center;
}
.hero-phone-wrap {
  position: relative;
  width: 100%;
  max-width: 420px;
  animation: fadeSlideUp 0.8s 0.2s ease both;
}
.hero-brain-img {
  width: 100%;
  filter: drop-shadow(0 0 60px rgba(99,102,241,0.4));
  animation: breathe 4s ease-in-out infinite;
}
@keyframes breathe {
  0%, 100% { transform: scale(1) translateY(0); filter: drop-shadow(0 0 60px rgba(99,102,241,0.4)); }
  50%       { transform: scale(1.03) translateY(-8px); filter: drop-shadow(0 0 80px rgba(167,139,250,0.5)); }
}
.hero-float-card {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: rgba(15,15,26,0.9);
  border: 1px solid var(--clr-border-2);
  border-radius: var(--radius-md);
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow-md);
  animation: floatCard 3s ease-in-out infinite;
}
.card-1 { top: 15%; right: -20px; animation-delay: 0s; }
.card-2 { bottom: 20%; left: -20px; animation-delay: 1.5s; }
@keyframes floatCard {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-8px); }
}
.float-icon { font-size: 24px; }
.float-title { font-size: 13px; font-weight: 600; margin-bottom: 1px; }
.float-sub { font-size: 11px; color: var(--clr-primary-2); }

.hero-scroll-hint {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--clr-text-3);
  font-size: 12px;
}
.scroll-arrow {
  width: 20px;
  height: 32px;
  border: 2px solid var(--clr-border-2);
  border-radius: 12px;
  position: relative;
}
.scroll-arrow::after {
  content: '';
  position: absolute;
  top: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 4px;
  height: 8px;
  background: var(--clr-primary-2);
  border-radius: 2px;
  animation: scrollDot 1.5s ease infinite;
}
@keyframes scrollDot {
  0%, 100% { opacity: 1; top: 4px; }
  50%       { opacity: 0.3; top: 14px; }
}

/* ── SECTION COMMONS ──────────────────────────────────────── */
.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 64px;
}
.section-tag {
  display: inline-block;
  padding: 5px 14px;
  border-radius: var(--radius-full);
  background: rgba(99,102,241,0.12);
  border: 1px solid rgba(99,102,241,0.25);
  font-size: 12px;
  font-weight: 600;
  color: var(--clr-primary-2);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 16px;
}
.section-tag.light { background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.2); color: rgba(255,255,255,0.7); }
.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.8rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 16px;
  color: var(--clr-text);
}
.section-title.light { color: white; }
.section-desc { font-size: 17px; color: var(--clr-text-2); line-height: 1.7; }
.section-desc.light { color: rgba(255,255,255,0.65); }

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ── ABOUT ───────────────────────────────────────────────── */
.about {
  padding: var(--space-section) 24px;
  background: var(--clr-bg);
}
.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.about-card {
  padding: 32px;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  transition: var(--trans-slow);
}
.about-card:hover {
  background: var(--clr-surface-2);
  border-color: var(--clr-border-2);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}
.about-card-featured {
  background: var(--grad-card);
  border-color: rgba(99,102,241,0.2);
}
.about-card-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  background: rgba(var(--icon-color), 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--icon-color);
  background: color-mix(in srgb, var(--icon-color) 12%, transparent);
}
.about-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--clr-text);
}
.about-card p { font-size: 15px; color: var(--clr-text-2); line-height: 1.7; }
.about-card-highlight {
  margin-top: 20px;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--clr-border);
}
.about-card-highlight img { width: 100%; height: 140px; object-fit: cover; }

/* ── FEATURES ────────────────────────────────────────────── */
.features {
  padding: var(--space-section) 24px;
  background: linear-gradient(180deg, var(--clr-bg-2) 0%, var(--clr-bg-3) 100%);
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--clr-border);
  border: 1px solid var(--clr-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.feature-item {
  padding: 36px 32px;
  background: var(--clr-bg-2);
  transition: var(--trans-base);
  position: relative;
}
.feature-item:hover { background: var(--clr-bg-3); }
.feature-num {
  font-size: 13px;
  font-weight: 700;
  color: var(--clr-primary);
  letter-spacing: 0.05em;
  margin-bottom: 20px;
  opacity: 0.7;
}
.feature-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(99,102,241,0.1);
  border-radius: var(--radius-md);
  color: var(--clr-primary-2);
  margin-bottom: 20px;
}
.feature-item h4 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--clr-text);
}
.feature-item p { font-size: 14px; color: var(--clr-text-2); line-height: 1.7; }
.feature-item-highlight {
  background: linear-gradient(135deg, rgba(99,102,241,0.1), rgba(167,139,250,0.07));
}
.feature-item-highlight .feature-icon {
  background: rgba(99,102,241,0.2);
  color: var(--clr-accent-2);
}

/* ── HOW TO ───────────────────────────────────────────────── */
.howto {
  padding: var(--space-section) 24px;
  background: var(--clr-bg);
}
.howto-steps {
  display: flex;
  justify-content: center;
  gap: 0;
  margin-bottom: 80px;
  flex-wrap: wrap;
}
.howto-step {
  flex: 1;
  min-width: 200px;
  max-width: 300px;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 0 24px;
  position: relative;
}
.step-circle {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--grad-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 800;
  color: white;
  margin-bottom: 20px;
  position: relative;
  z-index: 1;
  box-shadow: var(--shadow-glow);
}
.step-connector {
  position: absolute;
  top: 32px;
  left: calc(50% + 32px);
  right: calc(-50% + 32px);
  height: 2px;
  background: linear-gradient(90deg, var(--clr-primary), transparent);
  display: none;
}
.howto-step:not(:last-child) .step-connector { display: block; }
.howto-step h4 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--clr-text);
}
.howto-step p { font-size: 14px; color: var(--clr-text-2); line-height: 1.7; }

.howto-feature-banner {
  border-radius: var(--radius-xl);
  background: var(--grad-dark);
  border: 1px solid var(--clr-border-2);
  overflow: hidden;
}
.banner-content {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  align-items: center;
}
.banner-content > img {
  width: 100%;
  height: 100%;
  max-height: 420px;
  object-fit: cover;
  opacity: 0.85;
}
.banner-text {
  padding: 48px 48px 48px 40px;
}
.banner-text h3 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: -0.03em;
}
.banner-text h3 span {
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.banner-text > p {
  font-size: 15px;
  color: var(--clr-text-2);
  line-height: 1.8;
  margin-bottom: 28px;
}
.banner-list { display: flex; flex-direction: column; gap: 12px; }
.banner-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  color: var(--clr-text-2);
}
.banner-list li svg { color: var(--clr-green); flex-shrink: 0; }

/* ── SCREENSHOTS ─────────────────────────────────────────── */
.screenshots-section {
  padding: var(--space-section) 24px;
  background: var(--clr-bg-2);
}
.screenshots-track-wrap {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
}
.screenshots-track {
  display: flex;
  gap: 16px;
  transition: transform 0.4s cubic-bezier(0.4,0,0.2,1);
  will-change: transform;
}
.screenshot-slide {
  flex-shrink: 0;
  width: calc(25% - 12px);
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--clr-border);
  transition: var(--trans-base);
  cursor: pointer;
}
.screenshot-slide:hover {
  border-color: var(--clr-primary);
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(99,102,241,0.2);
}
.screenshot-slide img {
  width: 100%;
  aspect-ratio: 9/16;
  object-fit: cover;
  display: block;
}
.screenshots-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(9,9,15,0.8);
  border: 1px solid var(--clr-border-2);
  color: var(--clr-text);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 10;
  transition: var(--trans-base);
  backdrop-filter: blur(8px);
}
.screenshots-btn:hover { background: var(--clr-primary); border-color: var(--clr-primary); }
.screenshots-btn.prev { left: 12px; }
.screenshots-btn.next { right: 12px; }
.screenshots-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 24px;
}
.dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--clr-border-2);
  cursor: pointer;
  transition: var(--trans-base);
}
.dot.active {
  background: var(--clr-primary);
  width: 20px;
  border-radius: 3px;
  box-shadow: 0 0 8px var(--clr-primary);
}

/* ── DOWNLOAD ─────────────────────────────────────────────── */
.download {
  padding: var(--space-section) 24px;
  background: linear-gradient(180deg, var(--clr-bg) 0%, var(--clr-bg-2) 100%);
  position: relative;
  text-align: center;
  overflow: hidden;
}
.download-glow {
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(99,102,241,0.15) 0%, transparent 70%);
  pointer-events: none;
}
.download-content { position: relative; z-index: 1; max-width: 640px; margin: 0 auto; }
.download-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 14px;
  border-radius: var(--radius-full);
  background: rgba(52,211,153,0.1);
  border: 1px solid rgba(52,211,153,0.3);
  font-size: 12px;
  font-weight: 600;
  color: var(--clr-green);
  margin-bottom: 24px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.download-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}
.download-title span {
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.download-desc {
  font-size: 17px;
  color: var(--clr-text-2);
  line-height: 1.7;
  margin-bottom: 48px;
}
.download-platforms { display: flex; justify-content: center; gap: 16px; margin-bottom: 48px; flex-wrap: wrap; }
.platform-card {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px 28px;
  border-radius: var(--radius-lg);
  background: var(--clr-surface);
  border: 1px solid var(--clr-border-2);
  min-width: 220px;
  transition: var(--trans-base);
  position: relative;
}
.platform-card:hover { transform: translateY(-2px); border-color: var(--clr-primary); }
.platform-android { color: #34d399; }
.coming-soon { opacity: 0.7; }
.platform-icon { font-size: 36px; line-height: 1; }
.platform-label { display: block; font-size: 11px; color: var(--clr-text-3); margin-bottom: 3px; }
.platform-name { font-size: 16px; font-weight: 700; }
.coming-soon-badge {
  position: absolute;
  top: -8px;
  right: 16px;
  padding: 3px 10px;
  background: var(--grad-primary);
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 700;
  color: white;
}
.notify-form p { font-size: 15px; color: var(--clr-text-2); margin-bottom: 16px; }
.notify-input-wrap {
  display: flex;
  gap: 8px;
  max-width: 420px;
  margin: 0 auto 12px;
}
.notify-input {
  flex: 1;
  padding: 12px 18px;
  background: var(--clr-surface);
  border: 1px solid var(--clr-border-2);
  border-radius: var(--radius-full);
  color: var(--clr-text);
  font-size: 14px;
  font-family: var(--font-body);
  outline: none;
  transition: var(--trans-base);
}
.notify-input:focus { border-color: var(--clr-primary); box-shadow: 0 0 0 3px rgba(99,102,241,0.15); }
.notify-input::placeholder { color: var(--clr-text-3); }
.notify-btn {
  padding: 12px 24px;
  background: var(--grad-primary);
  color: white;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: var(--trans-base);
  white-space: nowrap;
  font-family: var(--font-body);
}
.notify-btn:hover { opacity: 0.9; transform: translateY(-1px); }
.notify-note { font-size: 13px; color: var(--clr-green); min-height: 20px; }

/* ── FOOTER ──────────────────────────────────────────────── */
.footer {
  background: var(--clr-bg);
  border-top: 1px solid var(--clr-border);
  padding: 60px 24px 0;
}
.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 64px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--clr-border);
}
.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 16px;
}
.footer-brand p { font-size: 14px; color: var(--clr-text-3); line-height: 1.7; max-width: 280px; }
.footer-links { display: grid; grid-template-columns: repeat(2, 1fr); gap: 32px; }
.footer-link-group h5 {
  font-size: 13px;
  font-weight: 700;
  color: var(--clr-text);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.footer-link-group a {
  display: block;
  font-size: 14px;
  color: var(--clr-text-3);
  padding: 4px 0;
  transition: var(--trans-fast);
}
.footer-link-group a:hover { color: var(--clr-primary-2); }
.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 0;
  font-size: 13px;
  color: var(--clr-text-3);
}

/* ── BACK TO TOP ──────────────────────────────────────────── */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--grad-primary);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(12px);
  transition: var(--trans-base);
  z-index: 500;
}
.back-to-top.visible { opacity: 1; pointer-events: auto; transform: translateY(0); }
.back-to-top:hover { transform: translateY(-2px); }

/* ── RESPONSIVE ──────────────────────────────────────────── */
@media (max-width: 1024px) {
  :root { --space-section: 80px; }
  .hero-container { grid-template-columns: 1fr; gap: 48px; text-align: center; }
  .hero-badge, .hero-stats, .hero-actions { justify-content: center; }
  .hero-visual { max-width: 400px; margin: 0 auto; }
  .card-1 { right: 0; }
  .card-2 { left: 0; }
  .about-grid { grid-template-columns: 1fr 1fr; }
  .about-card:nth-child(2) { grid-column: span 2; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .banner-content { grid-template-columns: 1fr; }
  .banner-content > img { max-height: 240px; }
  .footer-container { grid-template-columns: 1fr; gap: 40px; }
}

@media (max-width: 768px) {
  :root { --space-section: 64px; }
  body { font-size: 15px; }

  /* Nav */
  .nav-toggle { display: flex; }
  .nav-menu {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    left: 12px;
    right: 12px;
    flex-direction: column;
    gap: 4px;
    background: rgba(9,9,15,0.96);
    border: 1px solid var(--clr-border-2);
    border-radius: var(--radius-lg);
    padding: 16px;
    backdrop-filter: blur(20px);
  }
  .nav-menu.open { display: flex; }
  .nav-link { width: 100%; text-align: center; border-radius: var(--radius-md); }

  .hero { padding: 100px 20px 60px; }
  .hero-title { font-size: 2.4rem; }
  .hero-desc br { display: none; }
  .hero-stats { gap: 16px; }
  .stat-num { font-size: 22px; }

  .about-grid { grid-template-columns: 1fr; }
  .about-card:nth-child(2) { grid-column: span 1; }
  .features-grid { grid-template-columns: 1fr; }

  .howto-steps { flex-direction: column; align-items: center; gap: 40px; }
  .step-connector { display: none !important; }
  .banner-text { padding: 32px 24px; }
  .banner-text h3 { font-size: 1.6rem; }

  .screenshot-slide { width: calc(50% - 8px); }

  .download-title { font-size: 2rem; }
  .notify-input-wrap { flex-direction: column; }
  .notify-input, .notify-btn { width: 100%; border-radius: var(--radius-md); }

  .footer-links { grid-template-columns: repeat(2, 1fr); }
  .hero-scroll-hint { display: none; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 2rem; }
  .hero-actions { flex-direction: column; align-items: center; }
  .btn-primary-hero, .btn-ghost-hero { width: 100%; justify-content: center; }
  .screenshot-slide { width: calc(80% - 8px); }
  .hero-float-card { display: none; }
  .section-header { margin-bottom: 40px; }
}