:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-muted: #f1f5f9;
  --border: #e2e8f0;
  --border-strong: #cbd5e1;
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --accent: #e11d48;
  --accent-hover: #be123c;
  --accent-soft: #fff1f2;
  --primary: #0f172a;
  --primary-hover: #1e293b;
  --success: #047857;
  --success-bg: #ecfdf5;
  --success-border: #a7f3d0;
  --error: #b91c1c;
  --error-bg: #fef2f2;
  --error-border: #fecaca;
  --warn: #92400e;
  --warn-bg: #fffbeb;
  --warn-border: #fde68a;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.06), 0 8px 24px rgba(15, 23, 42, 0.04);
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --max-w: 920px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.65;
  overflow-x: hidden;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  width: 100%;
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 60px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: -0.01em;
}

.brand:hover {
  text-decoration: none;
}

.brand svg {
  flex-shrink: 0;
}

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

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--text);
  text-decoration: none;
}

/* Hero & Tool Card */
.hero {
  padding: 36px 0 28px;
  text-align: center;
}

.hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1.18;
  letter-spacing: -0.025em;
  color: var(--text);
}

.hero-lead {
  margin: 0 auto 24px;
  max-width: 650px;
  color: var(--text-secondary);
  font-size: 1.0625rem;
}

.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
  text-align: left;
}

.input-form {
  display: flex;
  gap: 10px;
  align-items: stretch;
}

.input-wrap {
  position: relative;
  flex: 1;
  min-width: 0;
}

.url-input {
  width: 100%;
  height: 48px;
  padding: 0 38px 0 14px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.96875rem;
  color: var(--text);
  background: var(--surface);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.url-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(15, 23, 42, 0.1);
}

.clear-btn {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: var(--text-muted);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 1.125rem;
  line-height: 1;
}

.clear-btn:hover {
  background: var(--surface-muted);
  color: var(--text);
}

.clear-btn[hidden] {
  display: none;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 48px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: background-color 0.15s ease, border-color 0.15s ease, opacity 0.15s ease;
}

.btn:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
}

.btn-primary:hover:not(:disabled) {
  background: var(--primary-hover);
}

.btn-sm {
  height: 36px;
  padding: 0 12px;
  font-size: 0.85rem;
}

.btn-secondary {
  background: var(--surface);
  border-color: var(--border-strong);
  color: var(--text);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--surface-muted);
}

.tool-meta-bar {
  margin-top: 12px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.sample-btn {
  background: none;
  border: none;
  padding: 0;
  color: var(--accent);
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.sample-btn:hover {
  color: var(--accent-hover);
}

.turnstile-slot {
  margin-top: 12px;
}

.turnstile-slot[hidden] {
  display: none;
}

/* Status Banner */
.status-box {
  margin-top: 16px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  font-size: 0.9375rem;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

.status-box[hidden] {
  display: none;
}

.status-loading {
  background: var(--surface-muted);
  border-color: var(--border-strong);
  color: var(--text);
}

.status-error {
  background: var(--error-bg);
  border-color: var(--error-border);
  color: var(--error);
}

.status-warn {
  background: var(--warn-bg);
  border-color: var(--warn-border);
  color: var(--warn);
}

.spinner {
  width: 18px;
  height: 18px;
  margin-top: 3px;
  border: 2.5px solid var(--border-strong);
  border-top-color: var(--primary);
  border-radius: 50%;
  flex-shrink: 0;
  animation: spin 0.75s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* Result Panel */
.result-panel {
  margin-top: 20px;
  border-top: 1px solid var(--border);
  padding-top: 18px;
}

.result-panel[hidden] {
  display: none;
}

.result-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.tabs {
  display: inline-flex;
  background: var(--surface-muted);
  padding: 3px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.tab-btn {
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 6px 12px;
  border-radius: 6px;
  cursor: pointer;
}

.tab-btn[aria-selected="true"] {
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.08);
}

.result-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.result-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--surface-muted);
  color: var(--text-secondary);
  font-size: 0.8125rem;
  font-weight: 500;
}

.badge-cached {
  background: var(--success-bg);
  color: var(--success);
  border: 1px solid var(--success-border);
}

.transcript-output {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
  max-height: 360px;
  overflow-y: auto;
  font-size: 0.96875rem;
  line-height: 1.7;
  color: var(--text);
}

.segment-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.segment-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 12px;
  align-items: baseline;
}

.segment-time {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  font-weight: 600;
}

.plain-output {
  margin: 0;
  white-space: pre-wrap;
}

.srt-output {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}

/* Content Sections */
.content-section {
  padding: 34px 0;
  border-top: 1px solid var(--border);
}

.content-section h2 {
  margin: 0 0 16px;
  font-size: 1.5rem;
  line-height: 1.28;
  letter-spacing: -0.015em;
}

.content-section p {
  margin: 0 0 14px;
  color: var(--text-secondary);
}

.steps-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
}

.step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 700;
  font-size: 0.875rem;
  margin-bottom: 10px;
}

.card h3 {
  margin: 0 0 8px;
  font-size: 1.0625rem;
  line-height: 1.35;
}

.card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.bullet-list {
  margin: 0;
  padding-left: 20px;
  color: var(--text-secondary);
}

.bullet-list li + li {
  margin-top: 8px;
}

/* FAQ */
.faq-list {
  display: grid;
  gap: 12px;
}

.faq-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 18px;
}

.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--text);
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: "+";
  font-size: 1.2rem;
  color: var(--text-muted);
  flex-shrink: 0;
}

.faq-item[open] summary::after {
  content: "−";
}

.faq-item p {
  margin: 10px 0 0;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

/* Subpages (About / Contact / Privacy / Terms) */
.prose-page {
  padding: 40px 0 56px;
}

.prose-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.prose-card h1 {
  margin: 0 0 12px;
  font-size: clamp(1.625rem, 3.5vw, 2.125rem);
  line-height: 1.2;
}

.prose-card h2 {
  margin: 26px 0 10px;
  font-size: 1.25rem;
}

.prose-card p,
.prose-card li {
  color: var(--text-secondary);
}

.prose-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

/* Footer */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 28px 0;
  margin-top: 16px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.footer-links a {
  color: var(--text-secondary);
}

.footer-note {
  margin: 14px 0 0;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* Responsive (including 390px mobile) */
@media (max-width: 720px) {
  .hero {
    padding: 24px 0 20px;
    text-align: left;
  }

  .hero-lead {
    margin-left: 0;
  }

  .tool-card {
    padding: 16px;
  }

  .input-form {
    flex-direction: column;
  }

  .btn-primary {
    width: 100%;
  }

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

  .prose-card {
    padding: 20px;
  }

  .segment-item {
    grid-template-columns: 48px 1fr;
    gap: 8px;
  }
}