/* ═══════════════════════════════════════════════════════════════════
   Code Tutorium — Shared Tools Stylesheet
   Unified Theme & Layout for all Code Tutorium Tools
   ═══════════════════════════════════════════════════════════════════ */

@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:ital,wght@0,400;0,500;0,600;0,700;1,400&family=Inter:wght@300;400;500;600;700&display=swap');

/* ── 1. Design Tokens ────────────────────────────────────────────── */
:root {
  --bg: #0c0e14;
  --bg-gradient: radial-gradient(ellipse 900px 500px at 15% -8%, rgba(47, 111, 237, 0.14), transparent 65%), #0c0e14;
  --surface: #141722;
  --surface-2: #1b2030;
  --surface-3: #22293d;
  
  --border: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.16);
  --border-active: rgba(47, 111, 237, 0.6);

  --accent: #2f6fed;
  --accent-hover: #4582f7;
  --accent-dim: rgba(47, 111, 237, 0.14);
  --accent-glow: rgba(47, 111, 237, 0.25);

  --text: #e8eaf0;
  --text-muted: #8b92a5;
  --text-faint: #555c70;

  --success: #22c55e;
  --success-dim: rgba(34, 197, 94, 0.12);
  --warning: #f59e0b;
  --warning-dim: rgba(245, 158, 11, 0.12);
  --danger: #ef4444;
  --danger-dim: rgba(239, 68, 68, 0.12);

  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-xl: 22px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', Consolas, Monaco, monospace;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 50px rgba(0, 0, 0, 0.55);
}

/* ── 2. Reset & Document Setup ───────────────────────────────────── */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg-gradient);
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

::selection {
  background: var(--accent);
  color: #fff;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color 0.18s ease;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  color: inherit;
}

/* ── 3. Code Tutorium Global Navigation ──────────────────────────── */
nav.top, .ct-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem 2.5rem;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(12, 14, 20, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text);
}

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

.logo .cursor {
  display: inline-block;
  width: 0.55em;
  height: 1.05em;
  background: var(--accent);
  animation: ct-blink 1.1s steps(1) infinite;
  border-radius: 1px;
}

@keyframes ct-blink {
  50% { opacity: 0; }
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.nav-cta {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  padding: 0.5rem 0.95rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  border: 1px solid transparent;
  transition: all 0.18s ease;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.nav-cta:hover {
  color: var(--text);
  background: var(--surface-2);
  border-color: var(--border);
}

.nav-cta.active {
  color: var(--accent);
  background: var(--accent-dim);
  border-color: rgba(47, 111, 237, 0.3);
}

.nav-cta-btn {
  background: var(--accent);
  color: #fff !important;
  font-weight: 500;
}

.nav-cta-btn:hover {
  background: var(--accent-hover);
  box-shadow: 0 4px 16px var(--accent-glow);
}

/* ── 4. Main Tool Page Layout ────────────────────────────────────── */
.tool-page-wrap, main.wrap, main.tool-main-content {
  flex: 1;
  width: 100%;
  max-width: 980px;
  margin: 0 auto;
  padding: 3.5rem 1.5rem 5.5rem;
}

.tool-hero, .hero-section {
  text-align: center;
  margin-bottom: 2.5rem;
}

.tool-eyebrow, .eyebrow {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.8rem;
  background: var(--accent-dim);
  border: 1px solid rgba(47, 111, 237, 0.25);
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
}

.tool-hero h1, h1.tool-title {
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 0.75rem;
  color: var(--text);
}

.tool-hero p.lead, .tool-hero p.sub, p.tool-desc {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 620px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ── 5. Tool Panels & Cards ──────────────────────────────────────── */
.tool-panel, .tool-card, .panel, .container-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  margin-bottom: 2rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.tool-panel:hover {
  border-color: var(--border-hover);
}

.panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.panel-title {
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

/* ── 6. Tabs Component ───────────────────────────────────────────── */
.ct-tabs, .tabs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 0.6rem;
  margin-bottom: 1.8rem;
}

.ct-tab-btn, .tab-btn {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text-muted);
  padding: 0.85rem 1rem;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.88rem;
  font-weight: 600;
  font-family: var(--font-mono);
  transition: all 0.18s ease;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  text-align: center;
}

.ct-tab-btn:hover, .tab-btn:hover {
  border-color: var(--border-hover);
  color: var(--text);
  background: var(--surface-2);
}

.ct-tab-btn.active, .tab-btn.active {
  background: var(--accent-dim);
  border-color: var(--accent);
  color: #fff;
  box-shadow: 0 0 16px var(--accent-glow);
}

/* Sub-tabs */
.subtabs {
  display: flex;
  gap: 0.5rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1.6rem;
  overflow-x: auto;
  scrollbar-width: none;
}
.subtabs::-webkit-scrollbar { display: none; }

.subtab-btn {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-muted);
  padding: 0.6rem 0.9rem;
  border-bottom: 2px solid transparent;
  transition: all 0.15s ease;
  cursor: pointer;
  white-space: nowrap;
}

.subtab-btn:hover {
  color: var(--text);
}

.subtab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

/* ── 7. Form Controls & Inputs ───────────────────────────────────── */
.form-group, .field {
  margin-bottom: 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

label, .field-label {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}

input[type="text"],
input[type="number"],
input[type="email"],
input[type="password"],
input[type="url"],
select,
textarea {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  font-size: 0.92rem;
  color: var(--text);
  outline: none;
  transition: border-color 0.18s ease, box-shadow 0.18s ease;
}

input:focus, select:focus, textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-dim);
}

input::placeholder, textarea::placeholder {
  color: var(--text-faint);
}

textarea {
  min-height: 110px;
  resize: vertical;
  line-height: 1.5;
}

input[type="color"] {
  -webkit-appearance: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 48px;
  height: 40px;
  padding: 2px;
  background: var(--bg);
  cursor: pointer;
}
input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
input[type="color"]::-webkit-color-swatch { border: none; border-radius: 4px; }

/* Range sliders */
input[type="range"] {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  background: var(--surface-2);
  border-radius: 3px;
  outline: none;
  margin: 0.8rem 0;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  box-shadow: 0 0 8px var(--accent-glow);
  transition: transform 0.1s ease;
}
input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
}

/* ── 8. Buttons & Actions ────────────────────────────────────────── */
.ct-btn, .btn, button.btn-primary, button[type="submit"]:not(.subtab-btn) {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 600;
  padding: 0.8rem 1.4rem;
  border-radius: var(--radius-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  text-decoration: none;
  cursor: pointer;
  transition: all 0.18s ease;
  border: 1px solid transparent;
}

.ct-btn-primary, .btn-primary, button[type="submit"]:not(.subtab-btn) {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.ct-btn-primary:hover, .btn-primary:hover, button[type="submit"]:not(.subtab-btn):hover {
  background: var(--accent-hover);
  box-shadow: 0 6px 20px var(--accent-glow);
  transform: translateY(-1px);
}

.ct-btn-secondary, .btn-secondary, .btn-ghost {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
}

.ct-btn-secondary:hover, .btn-secondary:hover, .btn-ghost:hover {
  background: var(--surface-3);
  border-color: var(--border-hover);
}

.ct-btn-danger, .btn-danger {
  background: var(--danger-dim);
  border: 1px solid rgba(239, 68, 68, 0.3);
  color: var(--danger);
}

.ct-btn-danger:hover, .btn-danger:hover {
  background: var(--danger);
  color: #fff;
}

.ct-btn:disabled, .btn:disabled, button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
  box-shadow: none !important;
}

/* ── 9. Dropzone & File Uploads ──────────────────────────────────── */
.ct-dropzone, .dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 1.5rem;
  text-align: center;
  background: rgba(12, 14, 20, 0.4);
  cursor: pointer;
  transition: all 0.2s ease;
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
}

.ct-dropzone:hover, .dropzone:hover {
  border-color: var(--border-hover);
  background: rgba(27, 32, 48, 0.4);
}

.ct-dropzone.dragover, .dropzone.dragover {
  border-color: var(--accent);
  background: var(--accent-dim);
}

.dropzone-icon {
  font-size: 2.2rem;
  line-height: 1;
}

.dropzone-title {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}

.dropzone-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ── 10. Status Badges & Alerts ──────────────────────────────────── */
.ct-status, .status-msg, .alert {
  padding: 0.85rem 1.1rem;
  border-radius: var(--radius-sm);
  font-size: 0.88rem;
  margin: 1rem 0;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
}

.ct-status.error, .status-msg.error {
  background: var(--danger-dim);
  border-color: rgba(239, 68, 68, 0.3);
  color: #fca5a5;
}

.ct-status.success, .status-msg.success {
  background: var(--success-dim);
  border-color: rgba(34, 197, 94, 0.3);
  color: #86efac;
}

.ct-badge {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.55rem;
  border-radius: 4px;
  background: var(--surface-2);
  color: var(--text-muted);
}

/* ── 11. Code Tutorium Global Footer ─────────────────────────────── */
footer.ct-footer {
  border-top: 1px solid var(--border);
  padding: 4.5rem 2.5rem 2.5rem;
  background: rgba(10, 12, 18, 0.95);
  margin-top: auto;
  width: 100%;
}

.footer-grid {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.4fr repeat(4, 1fr);
  gap: 2.2rem;
}

.footer-col h3 {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 1.1rem;
  color: var(--text);
}

.footer-col p {
  color: var(--text-muted);
  font-size: 0.85rem;
  line-height: 1.55;
}

.footer-col ul {
  list-style: none;
}

.footer-col li {
  margin-bottom: 0.55rem;
}

.footer-col a {
  color: var(--text-muted);
  font-size: 0.85rem;
  transition: color 0.15s ease;
}

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

.copyright {
  max-width: 1180px;
  margin: 3.5rem auto 0;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.2rem;
}

.copyright p {
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.78rem;
}

.footer-social {
  display: flex;
  gap: 0.75rem;
}

.social-link {
  width: 2.2rem;
  height: 2.2rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  transition: all 0.18s ease;
}

.social-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-dim);
  transform: translateY(-2px);
}

.social-link svg {
  width: 16px;
  height: 16px;
}

/* ── 12. Responsive Breakpoints ──────────────────────────────────── */
@media (max-width: 900px) {
  nav.top, .ct-header {
    padding: 1rem 1.25rem;
  }
  .tool-page-wrap, main.wrap, main.tool-main-content {
    padding: 2.5rem 1rem 4rem;
  }
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
  }
}

@media (max-width: 600px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .copyright {
    flex-direction: column;
    text-align: center;
  }
  .ct-tabs, .tabs {
    grid-template-columns: repeat(2, 1fr);
  }
  .tool-panel, .panel {
    padding: 1.25rem;
  }
}