/* ===========================
   SmartCut - Apple-Style Light Theme
   =========================== */

/* --- Custom Properties --- */
:root {
  --bg: #ffffff;
  --bg-secondary: #f5f5f7;
  --bg-card: #ffffff;
  --bg-card-hover: #fafafa;
  --text: #1d1d1f;
  --text-secondary: #424245;
  --text-muted: #86868b;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --gradient: linear-gradient(135deg, #0071e3, #00c7ff);
  --border: rgba(0, 0, 0, 0.08);
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --radius: 16px;
  --radius-sm: 12px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --nav-height: 52px;
  --container: 1080px;
  --container-wide: 1200px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 20px);
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

ul { list-style: none; }

img, video {
  max-width: 100%;
  display: block;
}

/* --- Container --- */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

.container-wide {
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Section Titles --- */
.section-title {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 600;
  text-align: center;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1.25rem;
  font-weight: 400;
  margin-bottom: 64px;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font);
  font-weight: 400;
  border: none;
  border-radius: 980px;
  cursor: pointer;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  padding: 12px 28px;
  font-size: 1rem;
}

.btn-primary:hover {
  background: var(--accent-hover);
}

.btn-secondary {
  background: transparent;
  color: var(--accent);
  padding: 12px 28px;
  font-size: 1rem;
}

.btn-secondary:hover {
  text-decoration: underline;
}

.btn-lg {
  padding: 16px 32px;
  font-size: 1.1rem;
}

.btn-xl {
  padding: 18px 40px;
  font-size: 1.2rem;
}

.btn-nav {
  background: var(--accent);
  color: #fff;
  padding: 8px 18px;
  font-size: 0.85rem;
}

.btn-nav:hover {
  background: var(--accent-hover);
}

/* ==========================
   NAVIGATION
   ========================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--text);
}

.logo-icon {
  color: var(--accent);
}

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

.nav-links a {
  font-size: 0.85rem;
  color: var(--text-secondary);
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--text);
}

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

.nav-toggle span {
  width: 18px;
  height: 1.5px;
  background: var(--text);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ==========================
   HERO
   ========================== */
.hero {
  padding: calc(var(--nav-height) + 80px) 0 100px;
  text-align: center;
}

.hero-content {
  max-width: 720px;
  margin: 0 auto;
}

.hero-title {
  font-size: clamp(2.5rem, 7vw, 4.5rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 20px;
  color: var(--text);
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 36px;
  font-weight: 400;
}

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

/* Hero Visual */
.hero-visual {
  margin-top: 64px;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-screenshot {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.screenshot-header {
  display: flex;
  gap: 8px;
  padding: 14px 18px;
  background: #e8e8ed;
}

.dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}

.dot:nth-child(1) { background: #ff5f57; }
.dot:nth-child(2) { background: #ffbd2e; }
.dot:nth-child(3) { background: #28ca41; }

.screenshot-body {
  display: flex;
  min-height: 320px;
}

.screenshot-sidebar {
  width: 35%;
  padding: 20px;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: #fff;
}

.sb-line {
  height: 10px;
  border-radius: 5px;
  background: #e5e5ea;
  width: 90%;
}

.sb-line.active {
  background: #d1e6ff;
  width: 85%;
}

.sb-line.highlight {
  background: var(--accent);
  width: 75%;
  opacity: 0.8;
}

.screenshot-main {
  flex: 1;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  background: #fafafa;
}

.sm-player {
  flex: 1;
  background: #e5e5ea;
  border-radius: var(--radius-sm);
  min-height: 200px;
}

.sm-timeline {
  display: flex;
  gap: 4px;
  height: 28px;
}

.tl-bar {
  flex: 1;
  background: var(--accent);
  border-radius: 4px;
  opacity: 0.6;
}

.tl-bar.cut {
  background: #ff9500;
  flex: 0.6;
  opacity: 0.8;
}

/* ==========================
   FEATURES (with Video)
   ========================== */
.features {
  padding: 100px 0;
}

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

.feature-section:nth-child(even) {
  background: var(--bg-secondary);
}

.feature-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

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

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

.feature-content {
  max-width: 480px;
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 16px;
}

.feature-title {
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 16px;
  color: var(--text);
}

.feature-description {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Video Container */
.feature-video {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-secondary);
  box-shadow: var(--shadow-md);
  aspect-ratio: 16 / 10;
}

.feature-video video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-placeholder {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #f5f5f7, #e8e8ed);
  color: var(--text-muted);
  font-size: 0.95rem;
}

.video-placeholder svg {
  width: 48px;
  height: 48px;
  margin-bottom: 12px;
  opacity: 0.5;
}

/* ==========================
   HOW IT WORKS
   ========================== */
.how-it-works {
  padding: 100px 0;
  background: var(--bg-secondary);
}

.steps {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 24px;
}

.step {
  text-align: center;
  flex: 0 1 200px;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.step-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 16px;
  color: var(--text-secondary);
}

.step h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.step p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.5;
}

.step-arrow {
  flex: 0 0 40px;
  padding-top: 70px;
  color: var(--text-muted);
  opacity: 0.4;
}

/* ==========================
   USE CASES
   ========================== */
.use-cases {
  padding: 100px 0;
}

.cases-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.case-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 40px 32px;
  text-align: center;
  transition: all 0.3s ease;
}

.case-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.case-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  color: var(--accent);
}

.case-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text);
}

.case-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ==========================
   SPECS
   ========================== */
.specs {
  padding: 100px 0;
  background: var(--bg-secondary);
}

.specs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.spec-item {
  text-align: center;
  padding: 36px 24px;
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.spec-value {
  font-size: 2.5rem;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.spec-label {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 12px;
  color: var(--text);
}

.spec-item p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ==========================
   DOWNLOAD CTA
   ========================== */
.download {
  padding: 120px 0;
  text-align: center;
}

.download-card {
  max-width: 680px;
  margin: 0 auto;
}

.download-card h2 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  color: var(--text);
}

.download-card > p {
  color: var(--text-muted);
  font-size: 1.2rem;
  margin-bottom: 40px;
}

.sys-req {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

.sys-req h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.sys-req ul {
  display: flex;
  justify-content: center;
  gap: 32px;
  flex-wrap: wrap;
}

.sys-req li {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ==========================
   CONTACT
   ========================== */
.contact {
  padding: 100px 0;
  background: var(--bg-secondary);
  text-align: center;
}

.contact-card {
  max-width: 320px;
  margin: 0 auto;
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-md);
}

.qr-code {
  width: 100%;
  max-width: 240px;
  margin: 0 auto 16px;
  border-radius: var(--radius-sm);
}

.contact-hint {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ==========================
   FOOTER
   ========================== */
.footer {
  padding: 24px 0;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
}

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

.footer-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-brand .logo-icon {
  color: var(--accent);
}

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

.footer-links a {
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: color 0.2s;
}

.footer-links a:hover {
  color: var(--text);
}

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

/* ==========================
   ANIMATIONS
   ========================== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ==========================
   RESPONSIVE
   ========================== */

/* Tablet */
@media (max-width: 1024px) {
  .feature-block {
    grid-template-columns: 1fr;
    gap: 40px;
  }

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

  .feature-content {
    max-width: 100%;
    text-align: center;
  }

  .feature-video {
    max-width: 600px;
    margin: 0 auto;
  }

  .specs-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Mobile */
@media (max-width: 768px) {
  :root {
    --nav-height: 48px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.96);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s ease;
  }

  .nav-links.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(4px, 4px);
  }

  .nav-toggle.active span:nth-child(2) {
    opacity: 0;
  }

  .nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(4px, -4px);
  }

  .hero {
    padding: calc(var(--nav-height) + 60px) 0 80px;
  }

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

  .specs-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .steps {
    flex-direction: column;
    align-items: center;
  }

  .step {
    width: 100%;
    max-width: 280px;
  }

  .step-arrow {
    padding-top: 0;
    transform: rotate(90deg);
  }

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

  .feature-section {
    padding: 60px 0;
  }

  .feature-title {
    font-size: 1.5rem;
  }

  .sys-req ul {
    flex-direction: column;
    gap: 8px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 20px;
  }

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

  .hero-title {
    font-size: 2rem;
  }

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