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

:root {
  --bg: #0b0f19;
  --surface: #131825;
  --surface2: #1a2035;
  --border: #2a3050;
  --accent: #6c5ce7;
  --accent-glow: #a29bfe;
  --green: #00cec9;
  --red: #ff6b6b;
  --text: #e2e8f0;
  --text-dim: #8892b0;
  --radius: 12px;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
}

html { font-size: 16px; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* HEADER */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  gap: 1rem;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
  color: var(--accent-glow);
}
.logo span { color: var(--text); font-weight: 400; }

nav { display: flex; gap: 0.25rem; flex-wrap: wrap; }

.nav-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-dim);
  padding: 0.5rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.2s;
}
.nav-btn:hover { color: var(--text); background: var(--surface2); }
.nav-btn.active {
  color: var(--accent-glow);
  background: rgba(108, 92, 231, 0.15);
  border-color: var(--accent);
}

/* MAIN */
main {
  flex: 1;
  max-width: 900px;
  width: 100%;
  margin: 2rem auto;
  padding: 0 1.5rem;
}

.tab-panel { display: none; animation: fadeIn 0.3s ease; }
.tab-panel.active { display: block; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

h2 { font-size: 1.75rem; margin-bottom: 0.25rem; }
.subtitle { color: var(--text-dim); margin-bottom: 1.5rem; }

/* DROP ZONE */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
  transition: all 0.2s;
  background: var(--surface);
  cursor: pointer;
}
.drop-zone:hover, .drop-zone.drag-over {
  border-color: var(--accent);
  background: rgba(108, 92, 231, 0.08);
}
.drop-icon { font-size: 2.5rem; margin-bottom: 0.5rem; }
.file-name { color: var(--green); margin-top: 0.5rem; font-weight: 600; word-break: break-all; }

/* CONVERTER GRID */
.converter-grid {
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 1.5rem;
  align-items: start;
}

.convert-options {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.convert-options label { color: var(--text-dim); font-size: 0.85rem; }

select {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 0.75rem;
  font-size: 0.95rem;
  cursor: pointer;
}
select:focus { outline: none; border-color: var(--accent); }

/* BUTTONS */
.primary-btn {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 0.7rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.primary-btn:hover { background: var(--accent-glow); }
.primary-btn:disabled { opacity: 0.4; cursor: not-allowed; }

.secondary-btn {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 1.2rem;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
}
.secondary-btn:hover { border-color: var(--accent); color: var(--accent-glow); }

.link-btn {
  background: none;
  border: none;
  color: var(--accent-glow);
  cursor: pointer;
  text-decoration: underline;
  font-size: inherit;
}

.icon-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.5rem 0.7rem;
  cursor: pointer;
  font-size: 1rem;
  transition: all 0.2s;
}
.icon-btn:hover { border-color: var(--accent); }

.download-btn {
  display: inline-block;
  text-decoration: none;
  margin-top: 0.5rem;
}

/* PROGRESS */
.progress-area { margin-top: 1.5rem; }
.progress-bar {
  height: 8px;
  background: var(--surface2);
  border-radius: 4px;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--green));
  border-radius: 4px;
  transition: width 0.3s;
}
.progress-text { color: var(--text-dim); font-size: 0.85rem; margin-top: 0.5rem; }

/* RESULT */
.result-area {
  margin-top: 1.5rem;
  padding: 1.25rem;
  background: rgba(0, 206, 201, 0.08);
  border: 1px solid var(--green);
  border-radius: var(--radius);
}
.result-area p { margin-bottom: 0.25rem; }

.hidden { display: none !important; }

/* TOGGLE ROW */
.toggle-row { display: flex; gap: 0.25rem; margin-bottom: 1.5rem; }
.toggle-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 0.5rem 1.25rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.2s;
}
.toggle-btn.active {
  background: rgba(108, 92, 231, 0.15);
  border-color: var(--accent);
  color: var(--accent-glow);
}

/* TWO COL */
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-bottom: 1rem; }

.col label { display: block; color: var(--text-dim); font-size: 0.85rem; margin-bottom: 0.4rem; }

textarea {
  width: 100%;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem;
  font-family: 'Cascadia Code', 'Fira Code', monospace;
  font-size: 0.9rem;
  resize: vertical;
}
textarea:focus { outline: none; border-color: var(--accent); }

.action-row { display: flex; gap: 0.5rem; margin-bottom: 1rem; flex-wrap: wrap; }
.options-row { display: flex; gap: 1.5rem; align-items: center; color: var(--text-dim); font-size: 0.85rem; flex-wrap: wrap; }
.options-row label { display: flex; align-items: center; gap: 0.4rem; }
.small-input {
  width: 50px;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.3rem 0.4rem;
  font-size: 0.85rem;
  text-align: center;
}

/* ENCRYPTION */
.enc-tabs { display: flex; gap: 0.25rem; margin-bottom: 1.5rem; }
.enc-tab {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 0.45rem 1.1rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.85rem;
  transition: all 0.2s;
}
.enc-tab.active { background: var(--surface2); color: var(--text); border-color: var(--accent); }

.enc-panel { display: none; }
.enc-panel.active { display: block; }

.field { margin-bottom: 1rem; }
.field label { display: block; color: var(--text-dim); font-size: 0.85rem; margin-bottom: 0.4rem; }

.password-row { display: flex; gap: 0.5rem; }
.password-row input {
  flex: 1;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 0.75rem;
  font-size: 0.95rem;
}
.password-row input:focus { outline: none; border-color: var(--accent); }

.info-box {
  margin-top: 1.5rem;
  padding: 1rem 1.25rem;
  background: rgba(108, 92, 231, 0.08);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.6;
}
.info-box strong { color: var(--text); }

/* FOOTER */
footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--text-dim);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
  margin-top: 3rem;
}

/* RESPONSIVE */
@media (max-width: 700px) {
  header { padding: 1rem; }
  .converter-grid { grid-template-columns: 1fr; }
  .two-col { grid-template-columns: 1fr; }
  main { padding: 0 1rem; }
}

/* TOAST */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-size: 0.9rem;
  opacity: 0;
  transition: all 0.3s;
  z-index: 1000;
  pointer-events: none;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
.toast.error { border-color: var(--red); color: var(--red); }