:root {
  --bg-color: #0f172a;
  --card-bg: #1e293b;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --success: #10b981;
  --danger: #ef4444;
  --border: #334155;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-main);
  line-height: 1.6;
  scroll-behavior: smooth;
}

.wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header & Nav */
header {
  background: rgba(15, 23, 42, 0.9);
  backdrop-filter: blur(10px);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid var(--border);
}

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

.brand {
  font-size: 1.5rem;
  font-weight: 800;
  text-decoration: none;
  color: var(--text-main);
}

.brand span { color: var(--accent); }

.menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.menu a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
}

.menu a:hover { color: var(--accent); }

/* Hero & Tool Card */
.hero { padding: 80px 0; text-align: center; }
.lead { color: var(--text-muted); font-size: 1.2rem; margin: 1rem 0 2rem; }

.tool-card {
  background: var(--card-bg);
  border: 2px dashed var(--border);
  border-radius: 16px;
  padding: 40px;
  max-width: 600px;
  margin: 0 auto;
  transition: border-color 0.3s;
}

.dropzone { cursor: pointer; }
.dropzone:hover { border-color: var(--accent); }

.dz-content svg { margin-bottom: 1rem; color: var(--accent); }

.hidden { display: none !important; }

/* Preview & Buttons */
.preview-box img {
  max-width: 100%;
  max-height: 300px;
  border-radius: 8px;
  margin-bottom: 20px;
}

.actions { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

.btn {
  padding: 12px 24px;
  border-radius: 8px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, opacity 0.2s;
}

.btn:active { transform: scale(0.98); }
.primary { background: var(--accent); color: white; }
.success { background: var(--success); color: white; }
.ghost { background: transparent; border: 1px solid var(--border); color: var(--text-muted); }

/* Grid Sections */
.content-section, .features-section, .how-to-section, .faq-section {
  padding: 80px 0;
  border-top: 1px solid var(--border);
}

.grid, .feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.f-item {
  background: var(--card-bg);
  padding: 24px;
  border-radius: 12px;
}

/* Steps */
.steps-container {
  display: flex;
  gap: 20px;
  margin-top: 40px;
  flex-wrap: wrap;
}

.step {
  flex: 1;
  min-width: 250px;
  background: var(--card-bg);
  padding: 30px;
  border-radius: 12px;
  position: relative;
}

.step-num {
  position: absolute;
  top: -15px;
  left: 20px;
  background: var(--accent);
  width: 35px;
  height: 35px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
}

/* FAQ */
details {
  background: var(--card-bg);
  margin-bottom: 10px;
  border-radius: 8px;
  overflow: hidden;
}

summary {
  padding: 15px;
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}

details p { padding: 0 15px 15px; color: var(--text-muted); }

/* Footer */
footer { padding: 40px 0; text-align: center; border-top: 1px solid var(--border); color: var(--text-muted); }
.footer-nav a { color: var(--accent); text-decoration: none; margin: 0 10px; }

/* Responsive Hamburger (Simple CSS) */
#menu-toggle { display: none; }
@media (max-width: 768px) {
  .menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 70px;
    left: 0;
    width: 100%;
    background: var(--bg-color);
    padding: 20px;
    border-bottom: 1px solid var(--border);
  }
  #menu-toggle:checked ~ #nav-menu .menu { display: flex; }
  .hamburger-icon { display: block; cursor: pointer; }
  .hamburger-icon span { display: block; width: 25px; height: 3px; background: var(--text-main); margin: 5px 0; }
}