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

:root {
  --bg: #fafaf8;
  --bg-card: #ffffff;
  --text: #111111;
  --text-muted: #666666;
  --accent: #007aff;
  --accent-hover: #0066d6;
  --border: #e8e8e4;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 4px 16px rgba(0,0,0,0.04);
}

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
}

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

/* ── Nav ── */
nav {
  position: sticky;
  top: 0;
  background: rgba(250,250,248,0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
}

.nav-logo-img {
  width: 28px;
  height: 28px;
  border-radius: 7px;
}

.hero-logo {
  width: 72px;
  height: 72px;
  border-radius: 18px;
  margin-bottom: 20px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 20px;
}

.nav-link {
  font-size: 0.875rem;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}
.nav-link:hover { color: var(--text); }

.lang-select {
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 5px 28px 5px 10px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%23666' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 8px center;
  transition: border-color 0.15s;
}
.lang-select:hover { border-color: #bbb; }
.lang-select:focus { outline: none; border-color: var(--accent); }

/* ── Buttons ── */
.btn-primary {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  padding: 13px 28px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 600;
  transition: background 0.15s, transform 0.1s;
}
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-1px); }
.btn-primary:active { transform: translateY(0); }

.btn-secondary {
  display: inline-block;
  background: var(--bg-card);
  color: var(--text);
  text-decoration: none;
  padding: 12px 26px;
  border-radius: 10px;
  font-size: 0.95rem;
  font-weight: 500;
  border: 1px solid var(--border);
  transition: border-color 0.15s, transform 0.1s, box-shadow 0.15s;
}
.btn-secondary:hover {
  border-color: #bbb;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
  transform: translateY(-1px);
}

/* ── Hero ── */
.hero {
  padding: 80px 0 64px;
}

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

.hero-text h1 {
  font-size: 2.75rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin-bottom: 20px;
}

.hero-text .lead {
  font-size: 1.1rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 32px;
}

/* ── App preview ── */
.app-mockup {
  display: flex;
  justify-content: center;
}

.app-gif {
  width: 100%;
  max-width: 660px;
  border-radius: 14px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05), 0 12px 40px rgba(0,0,0,0.12), 0 0 0 1px rgba(0,0,0,0.06);
}

/* ── Demo GIF ── */
.demo {
  padding: 64px 0;
  text-align: center;
}

.demo-gif {
  width: 100%;
  max-width: 860px;
  border-radius: 14px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05), 0 12px 40px rgba(0,0,0,0.12), 0 0 0 1px rgba(0,0,0,0.06);
}

/* ── Features ── */
.features {
  padding: 80px 0;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.features h2,
.download h2,
.support h2 {
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
}

.section-lead {
  color: var(--text-muted);
  margin-bottom: 40px;
  font-size: 1.05rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 40px;
}

.feature-card {
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg);
}

.feature-icon {
  font-size: 1.5rem;
  margin-bottom: 12px;
}

.feature-card h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature-card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.55;
}

/* ── Download ── */
.download {
  padding: 80px 0;
}

.platform-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 32px;
}

.platform-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 28px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--bg-card);
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  font-size: 0.875rem;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.1s;
  box-shadow: var(--shadow);
  text-align: center;
}

.platform-card:hover {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0,122,255,0.1), var(--shadow);
  transform: translateY(-2px);
}

.platform-card svg {
  width: 32px;
  height: 32px;
  color: var(--text-muted);
}

.platform-sub {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-weight: 400;
}

.unsigned-note {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: var(--radius);
  padding: 20px 24px;
}

.unsigned-note p:first-child {
  font-weight: 600;
  margin-bottom: 10px;
  font-size: 0.9rem;
}

.unsigned-note p {
  font-size: 0.85rem;
  color: #78350f;
  line-height: 1.6;
  margin-top: 6px;
}

.unsigned-note code {
  background: rgba(0,0,0,0.06);
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 0.82rem;
  font-family: "SF Mono", "Fira Code", monospace;
}

/* ── Support ── */
.support {
  padding: 80px 0;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  text-align: center;
}

.support p {
  color: var(--text-muted);
  margin-bottom: 28px;
  max-width: 440px;
  margin-left: auto;
  margin-right: auto;
  font-size: 1rem;
}

.support h2 { margin-bottom: 12px; }

/* ── Footer ── */
footer {
  padding: 32px 0;
}

footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
}

footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s;
}
footer a:hover { color: var(--accent); }

/* ── Modal ── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.45);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s;
}

.modal-overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}

.modal {
  background: var(--bg-card);
  border-radius: 20px;
  padding: 48px 40px 40px;
  max-width: 440px;
  width: calc(100% - 48px);
  text-align: center;
  position: relative;
  box-shadow: 0 20px 60px rgba(0,0,0,0.2);
  transform: translateY(12px);
  transition: transform 0.2s;
}

.modal-overlay.is-open .modal {
  transform: translateY(0);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  font-size: 1.4rem;
  color: var(--text-muted);
  cursor: pointer;
  line-height: 1;
  padding: 4px 8px;
  border-radius: 6px;
  transition: background 0.15s, color 0.15s;
}
.modal-close:hover { background: var(--border); color: var(--text); }

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

.modal-title {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 12px;
}

.modal-desc {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 28px;
}

.modal-actions {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.modal-support { width: 100%; text-align: center; }

.modal-skip {
  background: none;
  border: none;
  font-size: 0.875rem;
  color: var(--text-muted);
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 3px;
  font-family: inherit;
  transition: color 0.15s;
}
.modal-skip:hover { color: var(--text); }

/* ── Responsive ── */
@media (max-width: 768px) {
  .hero { padding: 48px 0 40px; }

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

  .hero-text h1 { font-size: 2rem; }

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

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

@media (max-width: 480px) {
  .hero-text h1 { font-size: 1.75rem; }
  .features-grid { grid-template-columns: 1fr; }
  .platform-grid { grid-template-columns: 1fr 1fr; }
  footer .container { flex-direction: column; gap: 8px; }
}