/* ========================================================================
   UNIT / TIMESTAMP / COUNTDOWN TOOLS — DESIGN SYSTEM
   Target: RO / DACH / EN | Psychological: Trust + Clarity + Precision
   ======================================================================== */

/* 1. VARIABLES & THEME =================================================== */
:root {
  /* Colors — flat only, no gradients */
  --bg-page: #F8FAFC;
  --bg-card: #FFFFFF;
  --bg-surface: #F1F5F9;
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  --accent: #2563EB;
  --accent-hover: #1D4ED8;
  --warm: #D97706;
  --success: #10B981;
  --error: #EF4444;
  --info: #3B82F6;
  --border: #E2E8F0;
  --shadow-sm: 0 1px 3px rgba(15,23,42,0.08);
  --shadow-md: 0 4px 12px rgba(15,23,42,0.12);
  --focus-ring: 0 0 0 3px rgba(37,99,235,0.25);

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;

  /* Layout */
  --radius: 12px;
  --radius-sm: 8px;
  --radius-xs: 4px;
  --max-width: 1200px;
  --header-height: 64px;

  /* Typography */
  --font-sans: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "JetBrains Mono", "Fira Code", "Cascadia Code", "Consolas", monospace;
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.8125rem, 0.75rem + 0.3vw, 0.9375rem);
  --text-base: clamp(0.875rem, 0.8rem + 0.3vw, 1rem);
  --text-lg: clamp(1rem, 0.9rem + 0.4vw, 1.125rem);
  --text-xl: clamp(1.25rem, 1rem + 1vw, 1.5rem);
  --text-2xl: clamp(1.5rem, 1.2rem + 1.2vw, 1.875rem);
  --text-3xl: clamp(1.875rem, 1.5rem + 1.5vw, 2.25rem);

  /* Motion */
  --ease: 0.18s cubic-bezier(0.4, 0, 0.2, 1);
  --ease-slow: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-page: #0B1120;
    --bg-card: #111827;
    --bg-surface: #1E293B;
    --text-primary: #F1F5F9;
    --text-secondary: #CBD5E1;
    --text-muted: #64748B;
    --border: #334155;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  }
}

html.theme-dark {
  --bg-page: #0B1120;
  --bg-card: #111827;
  --bg-surface: #1E293B;
  --text-primary: #F1F5F9;
  --text-secondary: #CBD5E1;
  --text-muted: #64748B;
  --border: #334155;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
}

/* 2. BASE & RESET ======================================================== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1;
}
body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
img, svg { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
button { cursor: pointer; font: inherit; }
ul, ol { list-style: none; }

/* 3. LAYOUT & CONTAINERS ================================================ */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding-inline: var(--space-lg);
}
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-height);
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.logo {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-primary);
  font-size: var(--text-lg);
  line-height: 1.2;
  transition: opacity var(--ease);
}
.logo:hover { opacity: 0.9; }
.logo-img {
  width: 32px;
  height: 32px;
  flex-shrink: 0;
  display: block;
  border-radius: var(--radius-sm);
}
.logo strong {
  font-weight: 700;
  letter-spacing: -0.02em;
}
main { flex: 1; padding-block: var(--space-2xl); }

/* 4. TYPOGRAPHY & UTILITY =============================================== */
h1, h2, h3, h4 {
  text-wrap: balance;
  line-height: 1.2;
  font-weight: 600;
}
h1 { font-size: var(--text-3xl); margin-bottom: var(--space-md); }
h2 { font-size: var(--text-2xl); margin-bottom: var(--space-lg); }
h3 { font-size: var(--text-xl); }
.text-center { text-align: center; }
.text-muted  { color: var(--text-muted); }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-xs { gap: var(--space-xs); }
.gap-sm { gap: var(--space-sm); }
.gap-md { gap: var(--space-md); }
.gap-lg { gap: var(--space-lg); }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}

/* 5. COMPONENTS ========================================================= */

/* Language Switcher — Pill Design */
.lang-switch {
  display: inline-flex;
  background: var(--bg-surface);
  padding: 4px;
  border-radius: 999px;
  gap: 4px;
  align-items: center;
  width: auto;
}
.lang-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 999px;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  transition: all 0.2s ease;
  white-space: nowrap;
  cursor: pointer;
}
.lang-btn:hover { color: var(--text-primary); }
.lang-btn.active,
.lang-btn[aria-current="true"] {
  background: var(--bg-card);
  color: var(--accent);
  font-weight: 600;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
}

/* Theme Toggle */
.theme-toggle {
  width: 36px; height: 36px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-surface);
  display: grid; place-items: center;
  font-size: 1.1rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  font-weight: 500;
  border: 1px solid transparent;
  background: var(--accent);
  color: #fff;
  transition: var(--ease);
}
.btn:hover { background: var(--accent-hover); }
.btn--outline {
  background: transparent;
  border-color: var(--border);
  color: var(--text-primary);
}
.btn--outline:hover { background: var(--bg-surface); }
.btn--sm {
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--text-xs);
}
.btn--success { background: var(--success); }
.btn--success:hover { background: #059669; }
.btn--danger { background: var(--error); }
.btn--danger:hover { background: #DC2626; }

/* Forms */
.form-group { margin-bottom: var(--space-md); }
.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  margin-bottom: var(--space-xs);
}
.form-input, .form-textarea, .form-select {
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: var(--text-base);
  transition: var(--ease);
}
.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23475569' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}
.form-input:focus, .form-textarea:focus, .form-select:focus {
  outline: none;
  box-shadow: var(--focus-ring);
  border-color: var(--accent);
}
.form-input.is-error, .form-textarea.is-error {
  border-color: var(--error);
  box-shadow: 0 0 0 3px rgba(239,68,68,0.2);
}
.form-input[readonly] {
  background: var(--bg-surface);
  color: var(--text-secondary);
  cursor: default;
}
.form-help { font-size: var(--text-xs); color: var(--text-muted); margin-top: var(--space-xs); }

/* Tool Card */
.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-lg);
  box-shadow: var(--shadow-sm);
  transition: var(--ease-slow);
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  position: relative;
  contain: layout style;
}

/* 6. TOOL-SPECIFIC ====================================================== */

/* Tab Navigation */
.tool-tabs {
  display: flex;
  gap: var(--space-xs);
  border-bottom: 2px solid var(--border);
  padding-bottom: 0;
  margin-bottom: var(--space-lg);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
.tool-tab {
  padding: var(--space-sm) var(--space-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--text-secondary);
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
  transition: color var(--ease), border-color var(--ease);
  white-space: nowrap;
  cursor: pointer;
}
.tool-tab:hover {
  color: var(--text-primary);
}
.tool-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

/* Tab Panels */
.tool-panel {
  display: none;
}
.tool-panel.active {
  display: block;
}

/* Unit Converter — Category Selector */
.unit-category-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
}
.unit-cat-btn {
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: var(--ease);
}
.unit-cat-btn:hover {
  color: var(--text-primary);
  border-color: var(--accent);
}
.unit-cat-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* Unit Converter — Conversion Row */
.unit-convert-row {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: var(--space-md);
  align-items: end;
}
.unit-field-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}
.unit-swap-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 1px solid var(--border);
  display: grid;
  place-items: center;
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: var(--ease);
  align-self: end;
  margin-bottom: 2px;
  cursor: pointer;
}
.unit-swap-btn:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.unit-result-box {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-md);
  margin-top: var(--space-md);
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  text-align: center;
  color: var(--text-primary);
  min-height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  word-break: break-all;
}
.unit-result-box .result-value {
  font-weight: 600;
  color: var(--accent);
}

/* Timestamp Tool */
.ts-live-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-sm) var(--space-md);
  margin-bottom: var(--space-lg);
  flex-wrap: wrap;
}
.ts-live-value {
  font-family: var(--font-mono);
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--accent);
}
.ts-live-label {
  font-size: var(--text-sm);
  color: var(--text-secondary);
}
.ts-convert-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  margin-bottom: var(--space-md);
}
.ts-field-pair {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}
.ts-result-box {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-md);
  font-family: var(--font-mono);
  font-size: var(--text-base);
  color: var(--text-primary);
  min-height: 48px;
  display: flex;
  align-items: center;
  word-break: break-all;
}
.ts-arrow-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--accent);
  color: #fff;
  border: none;
  display: grid;
  place-items: center;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--ease);
  align-self: center;
}
.ts-arrow-btn:hover {
  background: var(--accent-hover);
}
.ts-relative-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  background: var(--bg-surface);
  border-radius: 999px;
  font-size: var(--text-xs);
  color: var(--text-secondary);
  margin-top: var(--space-sm);
}

/* Countdown Timer */
.cd-target-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-md);
  align-items: end;
  margin-bottom: var(--space-lg);
}
.cd-presets-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
}
.cd-preset-btn {
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
  transition: var(--ease);
}
.cd-preset-btn:hover {
  color: var(--text-primary);
  border-color: var(--accent);
}
.cd-preset-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}
.cd-display {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}
.cd-digit-box {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-md) var(--space-sm);
  text-align: center;
}
.cd-digit-value {
  font-family: var(--font-mono);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}
.cd-digit-label {
  font-size: var(--text-xs);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: var(--space-xs);
}
.cd-expired {
  text-align: center;
  padding: var(--space-xl);
  color: var(--error);
  font-weight: 600;
  font-size: var(--text-lg);
}
.cd-elapsed-info {
  text-align: center;
  color: var(--text-muted);
  font-size: var(--text-sm);
  margin-top: var(--space-sm);
}

/* Copy feedback */
.copy-feedback {
  position: relative;
}
.copy-feedback::after {
  content: attr(data-feedback);
  position: absolute;
  top: -8px;
  right: -8px;
  background: var(--success);
  color: #fff;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}
.copy-feedback.show::after {
  opacity: 1;
}

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-sm);
  border-radius: 999px;
  font-size: var(--text-xs);
  font-weight: 500;
  line-height: 1;
}
.badge--live {
  background: var(--success);
  color: #fff;
  animation: pulse 2s infinite;
}
.badge--info {
  background: #DBEAFE;
  color: #1E40AF;
}
html.theme-dark .badge--info {
  background: #1E3A5F;
  color: #93C5FD;
}

/* Result copy row */
.result-copy-row {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-top: var(--space-sm);
}
.result-copy-row .form-input {
  flex: 1;
  font-family: var(--font-mono);
}

/* 7. STICKY DONATE ====================================================== */
.sticky-donate-wrapper {
  position: fixed;
  bottom: 44px;
  right: 24px;
  z-index: 90;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--ease), transform var(--ease);
  pointer-events: none;
}
.sticky-donate-wrapper.is-visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.sticky-donate-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  background: #FFDD00;
  color: #111;
  font-weight: 600;
  font-size: var(--text-sm);
  border-radius: 999px;
  box-shadow: var(--shadow-md);
  border: none;
  text-decoration: none;
  transition: transform var(--ease), box-shadow var(--ease);
}
.sticky-donate-btn:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 6px 16px rgba(255,221,0,0.35);
}
.sticky-donate-btn:focus-visible {
  outline: none;
  box-shadow: var(--focus-ring);
}
.donate-icon { font-size: 1.2em; }

/* Sub-site banner */
.subsite-banner {
  background: var(--accent);
  color: #fff;
  text-align: center;
  padding: 10px 16px;
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.3px;
  position: sticky;
  top: var(--header-height);
  z-index: 49;
}
.subsite-banner a {
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 700;
}

/* Sub-site legal footer */
.subsite-legal-footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 8px 16px;
  z-index: 9998;
  text-align: center;
  font-size: var(--text-sm);
}
.subsite-legal-footer a {
  color: var(--accent);
  text-decoration: none;
  font-weight: 600;
}
.subsite-legal-footer a span {
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* 8. MODAL ============================================================= */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}
.modal-overlay.is-active {
  opacity: 1;
  visibility: visible;
}
.modal-container {
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
  max-width: 90vw;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  position: relative;
}
.modal-close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-muted);
  z-index: 1;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: background 0.2s ease;
}
.modal-close:hover {
  background: var(--bg-surface);
  color: var(--text-primary);
}
.modal-content {
  padding: var(--space-2xl);
  overflow-y: auto;
  max-height: 80vh;
}
.modal-loading {
  text-align: center;
  padding: var(--space-2xl);
  color: var(--text-muted);
}

/* 9. ANIMATIONS ========================================================= */
@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.15); }
}
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.tool-panel.active {
  animation: fadeIn 0.25s ease-out;
}

/* 10. RESPONSIVE ======================================================== */
@media (max-width: 640px) {
  :root {
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
  }
  .tool-card { padding: var(--space-md); }
  .unit-convert-row {
    grid-template-columns: 1fr;
  }
  .unit-swap-btn {
    transform: rotate(90deg);
    justify-self: center;
  }
  .ts-convert-grid {
    grid-template-columns: 1fr;
  }
  .cd-target-row {
    grid-template-columns: 1fr;
  }
  .cd-display {
    grid-template-columns: repeat(2, 1fr);
  }
  .lang-btn span { display: none; }
  .lang-btn { padding: 6px 8px; font-size: 1.2rem; }
  .sticky-donate-wrapper { bottom: 40px; right: 16px; }
  .sticky-donate-btn { padding: 8px 14px; font-size: var(--text-xs); }
  .tool-tabs { gap: 0; }
  .tool-tab { padding: var(--space-xs) var(--space-sm); font-size: var(--text-xs); }
}

/* 11. REDUCED MOTION ==================================================== */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  .tool-panel.active {
    animation: none;
  }
}

/* 12. PRINT ============================================================= */
@media print {
  .site-header,
  .subsite-banner,
  .sticky-donate-wrapper,
  .subsite-legal-footer,
  .theme-toggle,
  .lang-switch,
  .btn,
  .tool-tabs { display: none; }
  body { background: #fff; color: #000; padding-bottom: 0; }
  .tool-card { break-inside: avoid; box-shadow: none; border: 1px solid #000; }
  .tool-panel { display: block !important; }
}