:root {
  --bg: #0f0f0f;
  --bg-card: #1a1a1a;
  --bg-input: #252525;
  --border: #2d2d2d;
  --text: #e8e8e8;
  --text-muted: #888;
  --accent: #f59e0b;
  --accent-hover: #fbbf24;
  --success: #22c55e;
  --error: #ef4444;
  --radius: 12px;
  --font: 'Outfit', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header */
.header {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--border);
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

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

.tagline {
  margin-top: 0.25rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* Nav */
.tool-nav {
  display: flex;
  gap: 0.5rem;
  margin: 1.5rem 0;
  flex-wrap: wrap;
}

.nav-btn {
  padding: 0.6rem 1rem;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.2s, border-color 0.2s, color 0.2s;
}

.nav-btn:hover {
  background: var(--bg-input);
  border-color: var(--accent);
  color: var(--accent);
}

.nav-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--bg);
}

/* Sections */
.tool-section {
  display: none;
  animation: fadeIn 0.25s ease;
}

.tool-section.active {
  display: block;
}

.section-note {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
  padding: 0.75rem 1rem;
  background: var(--bg-input);
  border-radius: var(--radius);
  border-left: 3px solid var(--accent);
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* Tool grid */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  cursor: pointer;
  transition: transform 0.15s, border-color 0.2s, box-shadow 0.2s;
}

.tool-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(245, 158, 11, 0.12);
}

.tool-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
  line-height: 1;
}

.tool-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.tool-card p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Modal */
.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s, visibility 0.2s;
}

.modal[aria-hidden="false"] {
  opacity: 1;
  visibility: visible;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
}

.modal-content {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  max-width: 520px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  padding: 1.5rem;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4);
}

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 36px;
  height: 36px;
  border: none;
  background: var(--bg-input);
  color: var(--text);
  font-size: 1.5rem;
  line-height: 1;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s;
}

.modal-close:hover {
  background: var(--error);
}

/* Tool panel common */
.tool-panel h2 {
  font-size: 1.25rem;
  margin-bottom: 1rem;
  padding-right: 2.5rem;
}

.tool-panel .form-group {
  margin-bottom: 1rem;
}

.tool-panel label {
  display: block;
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 0.4rem;
  color: var(--text-muted);
}

.tool-panel input[type="file"] {
  width: 100%;
  padding: 0.75rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: var(--font);
  font-size: 0.9rem;
}

.tool-panel input[type="text"],
.tool-panel textarea {
  width: 100%;
  padding: 0.75rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 0.9rem;
  resize: vertical;
}

.tool-panel textarea {
  min-height: 120px;
}

.tool-panel .btn {
  display: inline-block;
  padding: 0.7rem 1.25rem;
  background: var(--accent);
  color: var(--bg);
  border: none;
  border-radius: 8px;
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

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

.tool-panel .btn:active {
  transform: scale(0.98);
}

.tool-panel .btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.tool-panel .msg {
  margin-top: 0.75rem;
  font-size: 0.9rem;
  padding: 0.5rem;
  border-radius: 8px;
}

.tool-panel .msg.success {
  background: rgba(34, 197, 94, 0.15);
  color: var(--success);
}

.tool-panel .msg.error {
  background: rgba(239, 68, 68, 0.15);
  color: var(--error);
}

.tool-panel .preview-area {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--bg-input);
  border-radius: 8px;
  max-height: 200px;
  overflow: auto;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

/* Footer */
.footer {
  margin-top: 3rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* File drop zone */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}

.drop-zone:hover,
.drop-zone.dragover {
  border-color: var(--accent);
  background: rgba(245, 158, 11, 0.05);
}

.drop-zone input {
  display: none;
}

/* QR preview */
.qr-preview {
  margin-top: 1rem;
  text-align: center;
}

.qr-preview canvas,
.qr-preview img {
  max-width: 200px;
  border-radius: 8px;
  background: #fff;
  padding: 8px;
}

/* Color picker preview */
.color-preview-box {
  width: 100%;
  height: 80px;
  border-radius: 8px;
  margin-top: 0.5rem;
  border: 1px solid var(--border);
}

.tool-preview-video img {
  max-width: 100%;
  border-radius: var(--radius);
}

/* Mobile: দুইটা বক্স পাশাপাশি */
@media (max-width: 768px) {
  .tool-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.6rem;
  }
  .tool-card {
    padding: 0.75rem;
  }
  .tool-icon {
    font-size: 1.5rem;
    margin-bottom: 0.4rem;
  }
  .tool-card h3 {
    font-size: 0.9rem;
    margin-bottom: 0.2rem;
  }
  .tool-card p {
    font-size: 0.75rem;
  }
  .container {
    padding: 0 0.75rem;
  }
  .header {
    padding: 1rem 0;
  }
  .logo {
    font-size: 1.25rem;
  }
  .tagline {
    font-size: 0.8rem;
  }
  .tool-nav {
    margin: 1rem 0;
    gap: 0.4rem;
  }
  .nav-btn {
    padding: 0.5rem 0.7rem;
    font-size: 0.8rem;
  }
  .section-note {
    font-size: 0.8rem;
    padding: 0.5rem 0.75rem;
  }
  .modal-content {
    margin: 0.5rem;
    padding: 1rem;
    max-height: 85vh;
  }
}

@media (max-width: 400px) {
  .tool-grid {
    gap: 0.5rem;
  }
  .tool-card h3 {
    font-size: 0.85rem;
  }
  .tool-card p {
    font-size: 0.7rem;
  }
}