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

:root {
  --black: #111;
  --dark: #222;
  --gray: #666;
  --light-gray: #e8e8e8;
  --bg: #fafafa;
  --white: #fff;
  --accent: #ff6b00;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-xs: 6px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--black);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.center { text-align: center; }

/* ===== Typography ===== */
.section-label {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--gray);
  margin-bottom: 12px;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 16px;
}

.section-text {
  font-size: 1.05rem;
  color: var(--gray);
  line-height: 1.7;
  max-width: 560px;
}

.center .section-text {
  margin: 0 auto;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.95rem;
  border: 2px solid var(--black);
  border-radius: 100px;
  padding: 12px 28px;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--black);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--dark);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--black);
}

.btn-outline:hover {
  background: var(--black);
  color: var(--white);
}

.btn-sm { padding: 8px 20px; font-size: 0.85rem; }
.btn-lg { padding: 16px 40px; font-size: 1.05rem; }

.btn-disabled {
  opacity: 0.5;
  cursor: default;
  pointer-events: none;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(250, 250, 250, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.06);
  transition: var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  font-size: 1.4rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.nav {
  display: flex;
  gap: 32px;
}

.nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray);
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--black);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

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

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--black);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
  padding: 140px 0 80px;
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-label {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--gray);
  margin-bottom: 16px;
}

.hero-title {
  font-size: clamp(2rem, 4.5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 20px;
}

.hero-text {
  font-size: 1.05rem;
  color: var(--gray);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 500px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

/* ===== Sections ===== */
.section {
  padding: 100px 0;
}

/* Problem/Solution Split */
.split-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
}

.section-problem {
  background: var(--white);
}

/* ===== Features ===== */
.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  margin-bottom: 100px;
}

.feature-block:last-child {
  margin-bottom: 0;
}

.feature-block-reverse {
  direction: rtl;
}

.feature-block-reverse > * {
  direction: ltr;
}

.placeholder-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.06);
  border: 1px solid var(--light-gray);
}

/* ===== How It Works ===== */
.steps {
  margin-top: 60px;
  display: flex;
  flex-direction: column;
  gap: 60px;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 32px;
  align-items: center;
}

.step-number {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--black);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  font-weight: 700;
  flex-shrink: 0;
}

.step-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.step-content p {
  color: var(--gray);
  font-size: 0.95rem;
  line-height: 1.6;
}

.section-how {
  background: var(--white);
}

/* ===== Phone Mockup ===== */
.placeholder-phone {
  display: flex;
  justify-content: center;
}

.phone-frame {
  width: 280px;
  background: var(--black);
  border-radius: 36px;
  padding: 12px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.15);
}

.phone-notch {
  width: 120px;
  height: 28px;
  background: var(--black);
  border-radius: 0 0 16px 16px;
  margin: 0 auto 12px;
}

.phone-screen {
  background: var(--bg);
  border-radius: 24px;
  padding: 20px 16px;
  min-height: 400px;
}

.phone-header {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 20px;
  text-align: center;
}

/* ===== ShutterFinder Phone UI ===== */
.phone-app-ui {
  text-align: center;
  padding: 12px 0;
}

.sf-frequency {
  margin-bottom: 4px;
}

.sf-hz {
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent);
  line-height: 1;
}

.sf-unit {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--accent);
  margin-left: 4px;
}

.sf-label {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--gray);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 24px;
}

.sf-result {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 20px;
}

.sf-shutter, .sf-angle {
  background: var(--white);
  border-radius: var(--radius-sm);
  padding: 16px 8px;
}

.sf-value {
  font-size: 1.5rem;
  font-weight: 800;
  display: block;
  line-height: 1.2;
}

.sf-caption {
  font-size: 0.65rem;
  color: var(--gray);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-top: 4px;
  display: block;
}

.sf-source {
  font-size: 0.8rem;
  font-weight: 600;
  background: var(--white);
  display: inline-block;
  padding: 6px 16px;
  border-radius: 100px;
  margin-bottom: 8px;
}

.sf-framerate {
  font-size: 0.75rem;
  color: var(--gray);
}

/* ===== ShutterFinder Feature Visuals ===== */

/* FFT Spectrum */
.sf-fft-visual {
  display: flex;
  align-items: flex-end;
  gap: 6px;
  height: 200px;
  padding: 16px 0;
}

.fft-bar {
  flex: 1;
  background: var(--light-gray);
  border-radius: 4px 4px 0 0;
  transition: height 0.6s ease;
  min-height: 4px;
}

.fft-bar.accent {
  background: var(--accent);
}

.fft-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.7rem;
  color: var(--gray);
  margin-top: 8px;
}

.fft-peak {
  color: var(--accent);
  font-weight: 700;
}

/* Framerates Table */
.sf-framerates-visual {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.fr-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  padding: 14px 16px;
  font-size: 0.85rem;
  border-bottom: 1px solid var(--light-gray);
  transition: var(--transition);
}

.fr-row:last-child {
  border-bottom: none;
}

.fr-row.active {
  background: var(--accent);
  color: var(--white);
  border-radius: var(--radius-xs);
  font-weight: 600;
}

.fr-fps { font-weight: 500; }
.fr-shutter { text-align: center; }
.fr-angle { text-align: right; }

/* Source Detection */
.sf-source-visual {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.src-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  transition: var(--transition);
}

.src-item.detected {
  border-color: var(--accent);
  background: rgba(255, 107, 0, 0.04);
}

.src-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  flex-shrink: 0;
}

.src-info {
  flex: 1;
  text-align: left;
}

.src-info strong {
  font-size: 0.9rem;
  display: block;
  margin-bottom: 2px;
}

.src-info p {
  font-size: 0.75rem;
  color: var(--gray);
}

.src-freq {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  white-space: nowrap;
}

/* ===== Specs Section ===== */
.section-specs {
  background: var(--bg);
}

.specs-block {
  max-width: 720px;
}

.specs-list {
  list-style: none;
  margin-top: 24px;
}

.specs-list li {
  position: relative;
  padding: 14px 0 14px 28px;
  border-bottom: 1px solid var(--light-gray);
  font-size: 0.95rem;
  color: var(--gray);
  line-height: 1.6;
}

.specs-list li:last-child {
  border-bottom: none;
}

.specs-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 20px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

/* ===== CTA Section ===== */
.section-cta {
  background: var(--white);
  padding: 120px 0;
}

.requires-text {
  margin-top: 16px;
  font-size: 0.8rem;
  color: var(--gray);
}

/* ===== Apps Grid (Landing Page) ===== */
.apps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.app-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 40px 32px;
  border: 1px solid var(--light-gray);
  transition: var(--transition);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.app-card:hover {
  box-shadow: 0 8px 32px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}

.app-card-icon {
  width: 80px;
  height: 80px;
  border-radius: 18px;
}

.app-card-icon-placeholder {
  width: 80px;
  height: 80px;
  border-radius: 18px;
  background: var(--black);
  color: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 800;
}

.app-card-name {
  font-size: 1.25rem;
  font-weight: 700;
}

.app-card-tagline {
  font-size: 0.9rem;
  color: var(--gray);
  line-height: 1.6;
}

/* ===== Footer ===== */
.footer {
  padding: 40px 0;
  border-top: 1px solid var(--light-gray);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer-nav {
  display: flex;
  gap: 24px;
}

.footer-nav a {
  font-size: 0.85rem;
  color: var(--gray);
  transition: var(--transition);
}

.footer-nav a:hover {
  color: var(--black);
}

.footer-copy {
  font-size: 0.8rem;
  color: var(--gray);
}

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--bg);
    flex-direction: column;
    padding: 24px;
    gap: 16px;
    border-bottom: 1px solid var(--light-gray);
    z-index: 999;
  }

  .nav.open {
    display: flex;
  }

  .menu-toggle {
    display: flex;
  }

  .menu-toggle.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  .menu-toggle.open span:nth-child(2) {
    opacity: 0;
  }

  .menu-toggle.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .hero .container {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .hero-text {
    margin: 0 auto 32px;
  }

  .hero-actions {
    justify-content: center;
  }

  .split-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .feature-block,
  .feature-block-reverse {
    grid-template-columns: 1fr;
    gap: 32px;
    direction: ltr;
    margin-bottom: 60px;
  }

  .step {
    grid-template-columns: auto 1fr;
    gap: 20px;
  }

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

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }

  .footer-nav {
    flex-wrap: wrap;
    justify-content: center;
  }

  .phone-frame {
    width: 240px;
  }

  .phone-screen {
    min-height: 340px;
    padding: 16px 12px;
  }

  .sf-hz {
    font-size: 2.5rem;
  }

  .sf-value {
    font-size: 1.2rem;
  }

  .header-actions .btn {
    display: none;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 120px 0 60px;
  }

  .section {
    padding: 60px 0;
  }

  .section-cta {
    padding: 80px 0;
  }

  .hero-title {
    font-size: 1.75rem;
  }

  .fr-row {
    font-size: 0.75rem;
    padding: 10px 12px;
  }

  .screenshots-carousel {
    gap: 12px;
  }

  .screenshot-item img {
    max-height: 400px;
  }
}

/* Screenshot Carousel */
.screenshots-carousel {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  padding: 24px 0;
  scrollbar-width: thin;
}

.screenshot-item {
  flex: 0 0 auto;
  scroll-snap-align: center;
}

.screenshot-item img {
  max-height: 500px;
  width: auto;
  border-radius: var(--radius);
  box-shadow: 0 8px 32px rgba(0,0,0,0.12);
}

/* Privacy Policy */
.privacy-text {
  font-size: 1rem;
  line-height: 1.8;
  color: var(--dark);
}