/* ==========================================================================
   CtoFTemp Theme — Main Stylesheet
   Design: Clean & Minimal with Blue/Teal palette + Dark Mode
   Font: DM Sans (body) + Outfit (headings)
   ========================================================================== */

/* ---------- CSS Custom Properties ---------- */
:root {
  /* Light theme (default) */
  --color-bg: #f8fafb;
  --color-bg-alt: #ffffff;
  --color-bg-elevated: #ffffff;
  --color-surface: #eef3f6;
  --color-surface-hover: #e2eaef;
  --color-border: #d4dfe6;
  --color-border-subtle: #e8eff3;
  --color-text: #1a2b3c;
  --color-text-secondary: #4a6274;
  --color-text-muted: #7a95a8;
  --color-primary: #0891b2;
  --color-primary-hover: #0e7490;
  --color-primary-light: #e0f7fa;
  --color-primary-subtle: #f0fbfd;
  --color-accent: #f59e0b;
  --color-accent-light: #fef3c7;
  --color-danger: #ef4444;
  --color-success: #10b981;
  --color-converter-bg: #ffffff;
  --color-converter-input-bg: #f0f7fa;
  --color-converter-border: #c8dce6;
  --color-converter-result-bg: linear-gradient(135deg, #0891b2 0%, #06b6d4 100%);
  --color-faq-bg: #ffffff;
  --color-faq-border: #e2eaef;
  --color-footer-bg: #0f2232;
  --color-footer-text: #94b0c4;
  --color-code-bg: #eef3f6;
  --shadow-sm: 0 1px 2px rgba(15, 34, 50, 0.04);
  --shadow-md: 0 4px 12px rgba(15, 34, 50, 0.06);
  --shadow-lg: 0 8px 30px rgba(15, 34, 50, 0.08);
  --shadow-xl: 0 16px 48px rgba(15, 34, 50, 0.10);
  --shadow-converter: 0 8px 40px rgba(8, 145, 178, 0.10);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --font-body: 'DM Sans', system-ui, -apple-system, sans-serif;
  --font-heading: 'Outfit', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --max-width: 720px;
  --max-width-wide: 1080px;
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme="dark"] {
  --color-bg: #0c1820;
  --color-bg-alt: #111f2a;
  --color-bg-elevated: #162635;
  --color-surface: #1a2e3d;
  --color-surface-hover: #213a4d;
  --color-border: #2a4458;
  --color-border-subtle: #1e3345;
  --color-text: #e4eff5;
  --color-text-secondary: #94b4c8;
  --color-text-muted: #607d90;
  --color-primary: #22d3ee;
  --color-primary-hover: #06b6d4;
  --color-primary-light: #0c2a35;
  --color-primary-subtle: #0a1f28;
  --color-accent: #fbbf24;
  --color-accent-light: #2a2008;
  --color-converter-bg: #162635;
  --color-converter-input-bg: #1a2e3d;
  --color-converter-border: #2a4458;
  --color-converter-result-bg: linear-gradient(135deg, #0e7490 0%, #0891b2 100%);
  --color-faq-bg: #162635;
  --color-faq-border: #2a4458;
  --color-footer-bg: #060e14;
  --color-footer-text: #607d90;
  --color-code-bg: #1a2e3d;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.35);
  --shadow-converter: 0 8px 40px rgba(0, 0, 0, 0.3);
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition-base), color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover {
  color: var(--color-primary-hover);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 600;
  line-height: 1.25;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2rem, 4vw, 2.75rem); font-weight: 700; }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: clamp(1.2rem, 2.5vw, 1.5rem); }
h4 { font-size: 1.125rem; }

p {
  margin-bottom: 1.25em;
  color: var(--color-text-secondary);
}

p:last-child {
  margin-bottom: 0;
}

strong, b {
  font-weight: 600;
  color: var(--color-text);
}

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-code-bg);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

/* ---------- Layout Containers ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
}

.container--wide {
  max-width: var(--max-width-wide);
}

/* ---------- Skip Link (a11y) ---------- */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 10000;
  padding: 0.75rem 1.25rem;
  background: var(--color-primary);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 500;
}
.skip-link:focus {
  top: 1rem;
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--color-bg-alt);
  border-bottom: 1px solid var(--color-border-subtle);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-text);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.site-logo__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--color-converter-result-bg);
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  flex-shrink: 0;
}

.site-logo__text span {
  color: var(--color-primary);
}

/* Navigation */
.site-nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-nav__link {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 0.875rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: color var(--transition-fast), background var(--transition-fast);
}
.site-nav__link:hover,
.site-nav__link--active {
  color: var(--color-text);
  background: var(--color-surface);
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-left: 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: 1.1rem;
  line-height: 1;
}
.theme-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-subtle);
}
.theme-toggle svg {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-base);
}
.theme-toggle:hover svg {
  transform: rotate(15deg);
}

/* Mobile menu toggle */
.mobile-menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  background: none;
  color: var(--color-text);
  cursor: pointer;
  font-size: 1.25rem;
}

@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }
  .site-nav {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-bg-alt);
    border-bottom: 1px solid var(--color-border);
    padding: 0.75rem 1.25rem;
    gap: 0.25rem;
  }
  .site-nav.is-open {
    display: flex;
  }
  .site-nav__link {
    width: 100%;
    padding: 0.75rem;
  }
}

/* ==========================================================================
   Hero / Page Header
   ========================================================================== */
.page-hero {
  text-align: center;
  padding: 3.5rem 1.25rem 2rem;
}

.page-hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  margin-bottom: 1.25rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-radius: var(--radius-full);
  border: 1px solid transparent;
}

[data-theme="dark"] .page-hero__badge {
  border-color: var(--color-border);
}

.page-hero__title {
  margin-bottom: 0.75rem;
}

.page-hero__subtitle {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 540px;
  margin: 0 auto;
  line-height: 1.6;
}

/* ==========================================================================
   Converter Widget
   ========================================================================== */
.converter {
  max-width: 520px;
  margin: 0 auto 3rem;
  background: var(--color-converter-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-converter);
  overflow: hidden;
  transition: background var(--transition-base), border-color var(--transition-base), box-shadow var(--transition-base);
}

.converter__header {
  display: flex;
  border-bottom: 1px solid var(--color-border-subtle);
}

.converter__tab {
  flex: 1;
  padding: 0.875rem;
  border: none;
  background: none;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}
.converter__tab::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 1rem;
  right: 1rem;
  height: 2px;
  border-radius: 2px;
  background: transparent;
  transition: background var(--transition-fast);
}
.converter__tab--active {
  color: var(--color-primary);
  background: var(--color-primary-subtle);
}
.converter__tab--active::after {
  background: var(--color-primary);
}
.converter__tab:hover:not(.converter__tab--active) {
  color: var(--color-text-secondary);
  background: var(--color-surface);
}

.converter__body {
  padding: 1.75rem;
}

.converter__input-group {
  margin-bottom: 1.25rem;
}

.converter__label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}

.converter__input-wrap {
  position: relative;
  display: flex;
  align-items: center;
}

.converter__input {
  width: 100%;
  padding: 0.875rem 1rem;
  padding-right: 3rem;
  font-family: var(--font-heading);
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--color-text);
  background: var(--color-converter-input-bg);
  border: 2px solid var(--color-converter-border);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  -moz-appearance: textfield;
}
.converter__input::-webkit-outer-spin-button,
.converter__input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
.converter__input:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(8, 145, 178, 0.12);
}

.converter__unit {
  position: absolute;
  right: 1rem;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-text-muted);
  pointer-events: none;
}

/* Arrow / equals divider */
.converter__divider {
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0.75rem 0;
  color: var(--color-text-muted);
}
.converter__divider svg {
  width: 24px;
  height: 24px;
}

/* Result display */
.converter__result {
  background: var(--color-converter-result-bg);
  border-radius: var(--radius-md);
  padding: 1.25rem 1rem;
  text-align: center;
}

.converter__result-value {
  font-family: var(--font-heading);
  font-size: 2.25rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.2;
}

.converter__result-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.75);
  margin-top: 0.25rem;
}

/* Formula display */
.converter__formula {
  margin-top: 1.25rem;
  padding: 0.875rem 1rem;
  background: var(--color-surface);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  text-align: center;
  line-height: 1.6;
}
.converter__formula strong {
  color: var(--color-primary);
  font-weight: 600;
}

/* Quick-convert chips */
.converter__quick {
  margin-top: 1.25rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.converter__chip {
  display: inline-flex;
  align-items: center;
  padding: 0.375rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--color-surface);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: var(--font-body);
}
.converter__chip:hover {
  color: var(--color-primary);
  background: var(--color-primary-light);
  border-color: var(--color-primary);
}

/* ==========================================================================
   Content Sections
   ========================================================================== */
.content-section {
  padding: 2.5rem 0;
}

.content-section__heading {
  margin-bottom: 1rem;
}

.content-section p {
  font-size: 1.025rem;
  line-height: 1.8;
}

/* Conversion Table */
.conversion-table-wrap {
  margin: 2rem 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.conversion-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.925rem;
}

.conversion-table thead {
  background: var(--color-surface);
}

.conversion-table th {
  padding: 0.875rem 1.25rem;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-muted);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
}

.conversion-table td {
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--color-border-subtle);
  color: var(--color-text-secondary);
}

.conversion-table tbody tr:last-child td {
  border-bottom: none;
}

.conversion-table tbody tr:hover {
  background: var(--color-surface);
}

.conversion-table .temp-highlight {
  font-weight: 600;
  color: var(--color-primary);
}

/* Info Cards */
.info-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.info-card {
  padding: 1.25rem;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}
.info-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.info-card__icon {
  font-size: 1.5rem;
  margin-bottom: 0.5rem;
}

.info-card__title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 0.375rem;
  color: var(--color-text);
}

.info-card__text {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: 0;
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq-section {
  padding: 3rem 0;
}

.faq-section__title {
  text-align: center;
  margin-bottom: 2rem;
}

.faq-item {
  margin-bottom: 0.5rem;
  border: 1px solid var(--color-faq-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--color-faq-bg);
  transition: box-shadow var(--transition-fast);
}
.faq-item:hover {
  box-shadow: var(--shadow-sm);
}

.faq-item__question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border: none;
  background: none;
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  cursor: pointer;
  text-align: left;
  line-height: 1.4;
  gap: 1rem;
  transition: color var(--transition-fast);
}
.faq-item__question:hover {
  color: var(--color-primary);
}

.faq-item__icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  transition: transform var(--transition-base), color var(--transition-fast);
}

.faq-item.is-open .faq-item__icon {
  transform: rotate(180deg);
  color: var(--color-primary);
}

.faq-item__answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), padding var(--transition-base);
}

.faq-item.is-open .faq-item__answer {
  max-height: 500px;
}

.faq-item__answer-inner {
  padding: 0 1.25rem 1.25rem;
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* ==========================================================================
   Breadcrumbs
   ========================================================================== */
.breadcrumbs {
  padding: 0.75rem 0;
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

.breadcrumbs a {
  color: var(--color-text-muted);
}
.breadcrumbs a:hover {
  color: var(--color-primary);
}

.breadcrumbs__sep {
  margin: 0 0.4rem;
  opacity: 0.5;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--color-footer-bg);
  color: var(--color-footer-text);
  padding: 3rem 1.25rem 1.5rem;
  margin-top: 3rem;
}

.site-footer__inner {
  max-width: var(--max-width-wide);
  margin: 0 auto;
}

.site-footer__top {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  flex-wrap: wrap;
  padding-bottom: 2rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-col__title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: rgba(255, 255, 255, 0.5);
  margin-bottom: 0.875rem;
}

.footer-col__list {
  list-style: none;
}

.footer-col__list li {
  margin-bottom: 0.5rem;
}

.footer-col__list a {
  color: var(--color-footer-text);
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}
.footer-col__list a:hover {
  color: #ffffff;
}

.footer-col__desc {
  max-width: 280px;
  font-size: 0.85rem;
  line-height: 1.6;
  margin-bottom: 0;
}

.site-footer__bottom {
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.3);
}

/* ==========================================================================
   Page Templates — About & Contact
   ========================================================================== */
.page-content {
  padding: 2rem 0 3rem;
}

.page-content h2 {
  margin-top: 2rem;
  margin-bottom: 0.75rem;
}

.page-content h2:first-child {
  margin-top: 0;
}

.contact-form {
  max-width: 480px;
  margin: 2rem 0;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.375rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  color: var(--color-text);
  background: var(--color-converter-input-bg);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(8, 145, 178, 0.1);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn--primary {
  background: var(--color-converter-result-bg);
  color: #ffffff;
}
.btn--primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

/* ==========================================================================
   WordPress Core Alignment
   ========================================================================== */
.alignleft {
  float: left;
  margin-right: 1.5rem;
  margin-bottom: 1rem;
}
.alignright {
  float: right;
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}
.aligncenter {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

/* Screen reader text */
.screen-reader-text {
  border: 0;
  clip: rect(1px, 1px, 1px, 1px);
  clip-path: inset(50%);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
  word-wrap: normal !important;
}

/* ==========================================================================
   Print Styles
   ========================================================================== */
@media print {
  .site-header,
  .site-footer,
  .theme-toggle,
  .converter__quick,
  .mobile-menu-toggle {
    display: none !important;
  }
  body {
    color: #000;
    background: #fff;
  }
}