/* ===== DESIGN SYSTEM: Cyan Logic ===== */
:root {
  --surface: #101415;
  --surface-dim: #101415;
  --surface-container-lowest: #0b0f10;
  --surface-container-low: #191c1e;
  --surface-container: #1d2022;
  --surface-container-high: #272a2c;
  --surface-container-highest: #323537;
  --on-surface: #e0e3e5;
  --on-surface-variant: #bfc7d5;
  --outline: #89919e;
  --outline-variant: #3f4753;
  --primary: #9fcaff;
  --primary-container: #0099ff;
  --secondary: #a2e7ff;
  --secondary-container: #00d2fd;
  --on-primary: #003259;
  --error: #ffb4ab;

  --font: 'Hanken Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --rounded-sm: 0.25rem;
  --rounded: 0.5rem;
  --rounded-md: 0.75rem;
  --rounded-lg: 1rem;
  --rounded-xl: 1.5rem;
  --rounded-full: 9999px;
  --max-w: 1200px;
  --gutter: 24px;
  --section-gap: 80px;
}

/* ===== RESET ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: var(--font);
  background: var(--surface);
  color: var(--on-surface);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  padding-bottom: 72px;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button, input, textarea { font-family: inherit; border: none; outline: none; background: none; }
button { cursor: pointer; }

.container { max-width: var(--max-w); margin: 0 auto; padding: 0 var(--gutter); }

/* ===== HEADER ===== */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(16, 20, 21, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--outline-variant);
}
.header__inner {
  max-width: var(--max-w); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px var(--gutter);
}
.header__logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 18px; color: var(--on-surface);
}
.header__logo-icon { color: var(--primary-container); }
.header__nav { display: flex; gap: 32px; }
.header__nav a {
  font-size: 14px; font-weight: 500; color: var(--outline);
  transition: color 0.2s;
}
.header__nav a:hover { color: var(--on-surface); }
.header__menu-btn {
  display: none; flex-direction: column; gap: 5px; padding: 4px;
}
.header__menu-btn span {
  display: block; width: 22px; height: 2px;
  background: var(--on-surface); border-radius: 2px;
  transition: 0.3s;
}

/* ===== HERO ===== */
.hero {
  padding-top: 120px;
  padding-bottom: var(--section-gap);
  text-align: center;
}
.hero__container { max-width: 680px; margin: 0 auto; padding: 0 var(--gutter); }
.hero__title {
  font-size: 48px; font-weight: 800; line-height: 1.08;
  letter-spacing: -0.03em; margin-bottom: 20px;
}
.gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary-container) 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero__subtitle {
  font-size: 16px; color: var(--outline); line-height: 1.7;
  margin-bottom: 40px;
}

/* ===== GENERATOR ===== */
.generator {
  background: var(--surface-container-low);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-lg);
  padding: 20px;
  display: flex; flex-direction: column; gap: 12px;
}
.generator__input-group {
  display: flex; align-items: center; gap: 12px;
  background: var(--surface-container-lowest);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded);
  padding: 14px 16px;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.generator__input-group:focus-within {
  border-color: var(--secondary-container);
  box-shadow: 0 0 0 3px rgba(0, 210, 253, 0.12);
}
.generator__input-icon { color: var(--outline); flex-shrink: 0; }
.generator__input {
  flex: 1; font-size: 15px; color: var(--on-surface);
  background: transparent; min-width: 0;
}
.generator__input::placeholder { color: var(--outline); }

.generator__logo-upload {
  display: flex; align-items: center; gap: 8px;
}
.generator__logo-label {
  display: flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--outline);
  cursor: pointer; padding: 8px 12px;
  border: 1px dashed var(--outline-variant);
  border-radius: var(--rounded);
  transition: border-color 0.2s, color 0.2s;
  flex: 1;
}
.generator__logo-label:hover {
  border-color: var(--secondary-container);
  color: var(--secondary);
}
.generator__logo-label.has-file {
  border-color: var(--primary-container);
  color: var(--primary);
  border-style: solid;
}
.generator__logo-remove {
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; color: var(--outline);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded);
  transition: 0.2s;
}
.generator__logo-remove:hover { color: var(--error); border-color: var(--error); }

.generator__btn {
  display: flex; align-items: center; justify-content: center; gap: 8px;
  padding: 16px 24px; font-size: 16px; font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--primary-container) 0%, var(--secondary-container) 100%);
  border-radius: var(--rounded);
  transition: transform 0.15s, box-shadow 0.2s;
  letter-spacing: 0.01em;
}
.generator__btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 24px rgba(0, 153, 255, 0.35);
}
.generator__btn:active { transform: translateY(0); }

/* ===== QR PREVIEW ===== */
.qr-preview {
  margin-top: 40px;
  display: flex; flex-direction: column; align-items: center; gap: 20px;
}
.qr-preview__frame {
  position: relative;
  background: var(--surface-container);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-lg);
  padding: 32px;
  min-width: 264px; min-height: 264px;
  display: flex; align-items: center; justify-content: center;
}
.qr-preview__brackets { position: absolute; inset: 12px; pointer-events: none; }
.bracket {
  position: absolute; width: 20px; height: 20px;
  border-color: var(--primary-container); border-style: solid;
}
.bracket.tl { top: 0; left: 0; border-width: 2px 0 0 2px; border-radius: 4px 0 0 0; }
.bracket.tr { top: 0; right: 0; border-width: 2px 2px 0 0; border-radius: 0 4px 0 0; }
.bracket.bl { bottom: 0; left: 0; border-width: 0 0 2px 2px; border-radius: 0 0 0 4px; }
.bracket.br { bottom: 0; right: 0; border-width: 0 2px 2px 0; border-radius: 0 0 4px 0; }

.qr-preview__output {
  display: flex; align-items: center; justify-content: center;
  min-width: 200px; min-height: 200px;
}
.qr-preview__output svg,
.qr-preview__output canvas,
.qr-preview__output img { border-radius: 4px; }
.qr-preview__placeholder {
  font-size: 14px; color: var(--outline); font-weight: 500;
}

.qr-preview__actions {
  display: flex; gap: 12px; flex-wrap: wrap; justify-content: center;
}
.btn-ghost {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 10px 18px; font-size: 13px; font-weight: 600;
  color: var(--on-surface-variant);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-full);
  transition: 0.2s;
}
.btn-ghost:hover {
  border-color: var(--secondary-container);
  color: var(--secondary);
}

/* ===== PROCESS ===== */
.process { padding: var(--section-gap) 0; }
.section-title {
  font-size: 32px; font-weight: 700; letter-spacing: -0.01em;
  text-align: center; margin-bottom: 48px;
}
.process__grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px;
}
.process__step {
  text-align: center;
  padding: 32px 24px;
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-lg);
  background: var(--surface-container-low);
  transition: border-color 0.3s, transform 0.2s;
}
.process__step:hover {
  border-color: var(--primary-container);
  transform: translateY(-4px);
}
.process__number {
  display: block; font-size: 13px; font-weight: 700;
  color: var(--primary-container); margin-bottom: 16px;
  letter-spacing: 0.05em;
}
.process__icon {
  width: 56px; height: 56px; margin: 0 auto 16px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--rounded-lg);
  background: rgba(0, 153, 255, 0.08);
  color: var(--primary-container);
}
.process__step h3 {
  font-size: 18px; font-weight: 700; margin-bottom: 10px;
}
.process__step p {
  font-size: 14px; color: var(--outline); line-height: 1.6;
}

/* ===== FEATURES ===== */
.features { padding: 0 0 var(--section-gap); }
.features__hero-card {
  display: grid; grid-template-columns: 1fr 1fr; gap: 40px;
  background: var(--surface-container-low);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-xl);
  padding: 48px; margin-bottom: 32px;
  overflow: hidden; position: relative;
}
.features__hero-text p { color: var(--outline); margin-top: 16px; font-size: 15px; }
.features__hero-visual {
  display: flex; align-items: center; justify-content: center;
  position: relative;
}
.features__glow-orb {
  width: 200px; height: 200px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(0, 210, 253, 0.25) 0%, transparent 70%);
  animation: pulse-glow 3s ease-in-out infinite;
}
@keyframes pulse-glow {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50% { transform: scale(1.15); opacity: 1; }
}

.features__grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px;
}
.features__item {
  display: flex; align-items: flex-start; gap: 16px;
  padding: 24px;
  background: var(--surface-container-low);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-lg);
  transition: border-color 0.3s;
}
.features__item:hover { border-color: var(--primary-container); }
.features__item-icon {
  width: 44px; height: 44px; flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--rounded);
  background: rgba(0, 153, 255, 0.08);
  color: var(--primary-container);
}
.features__item h4 { font-size: 16px; font-weight: 700; margin-bottom: 4px; }
.features__item p { font-size: 13px; color: var(--outline); line-height: 1.5; }

/* ===== FAQ ===== */
.faq { padding: 0 0 var(--section-gap); }
.faq__list { max-width: 720px; margin: 0 auto; display: flex; flex-direction: column; gap: 8px; }
.faq__item {
  background: var(--surface-container-low);
  border: 1px solid var(--outline-variant);
  border-radius: var(--rounded-lg);
  overflow: hidden; transition: border-color 0.3s;
}
.faq__item[open] { border-color: var(--primary-container); }
.faq__item summary {
  padding: 18px 24px; font-weight: 600; font-size: 15px;
  cursor: pointer; list-style: none;
  display: flex; align-items: center; justify-content: space-between;
}
.faq__item summary::-webkit-details-marker { display: none; }
.faq__item summary::after {
  content: '+'; font-size: 20px; color: var(--primary-container);
  font-weight: 300; transition: transform 0.2s;
}
.faq__item[open] summary::after { content: '-'; }
.faq__item p {
  padding: 0 24px 18px; font-size: 14px; color: var(--outline); line-height: 1.7;
}

/* ===== FOOTER ===== */
.footer {
  padding: 48px 0 32px;
  border-top: 1px solid var(--outline-variant);
  text-align: center;
}
.footer__brand {
  font-size: 18px; font-weight: 700; margin-bottom: 16px;
  color: var(--primary);
}
.footer__links {
  display: flex; gap: 24px; justify-content: center; margin-bottom: 24px;
}
.footer__links a { font-size: 14px; color: var(--outline); transition: color 0.2s; }
.footer__links a:hover { color: var(--on-surface); }
.footer__copy { font-size: 13px; color: var(--outline); margin-bottom: 4px; }
.footer__dev { font-size: 0.75rem; color: var(--outline); margin-top: 0.25rem; }
.footer__dev a { color: var(--primary); text-decoration: none; transition: opacity 0.2s; }
.footer__dev a:hover { opacity: 0.8; text-decoration: underline; }

/* ===== BOTTOM NAV (mobile) ===== */
.bottom-nav {
  display: none;
  position: fixed; bottom: 0; left: 0; right: 0; z-index: 100;
  background: rgba(16, 20, 21, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-top: 1px solid var(--outline-variant);
  justify-content: space-around; padding: 8px 0 env(safe-area-inset-bottom, 6px);
}
.bottom-nav__item {
  display: flex; flex-direction: column; align-items: center; gap: 3px;
  font-size: 11px; color: var(--outline); padding: 6px 12px;
  transition: color 0.2s;
}
.bottom-nav__item.active, .bottom-nav__item:hover { color: var(--primary-container); }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  body { padding-bottom: 80px; }
  .header__nav { display: none; }
  .header__menu-btn { display: flex; }
  .bottom-nav { display: flex; }

  .hero { padding-top: 100px; padding-bottom: 48px; }
  .hero__title { font-size: 32px; }
  .hero__subtitle { font-size: 14px; }

  .section-title { font-size: 28px; margin-bottom: 32px; }

  .process__grid { grid-template-columns: 1fr; gap: 16px; }

  .features__hero-card {
    grid-template-columns: 1fr; padding: 28px;
  }
  .features__hero-visual { display: none; }
  .features__hero-card .section-title { text-align: left; }
  .features__grid { grid-template-columns: 1fr; }

  .generator { padding: 16px; }
  .qr-preview__frame { padding: 24px; min-width: 220px; min-height: 220px; }
}

@media (max-width: 480px) {
  .hero__title { font-size: 28px; }
  .qr-preview__actions { gap: 8px; }
  .btn-ghost { padding: 8px 14px; font-size: 12px; }
}

/* ===== ANIMATION ===== */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.hero__title, .hero__subtitle, .generator {
  animation: fadeInUp 0.6s ease-out both;
}
.hero__subtitle { animation-delay: 0.1s; }
.generator { animation-delay: 0.2s; }