/*
Theme Name: ClearSkill
Theme URI: https://example.com/clearskill
Author: ClearSkill
Author URI: https://example.com
Description: Multilingual (English / Deutsch / 简体中文) marketing theme for the ClearSkill. Contains a self-contained language engine — no plugins required. Placeholder SVGs in assets/images should be replaced with final artwork.
Version: 1.3.0
Requires at least: 6.0
Tested up to: 6.8
Requires PHP: 7.4
License: GNU General Public License v2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
Text Domain: ai-act-ready
Tags: one-column, custom-logo, custom-menu, featured-images, threaded-comments, translation-ready
*/

/* ---------- Design tokens ---------- */
:root {
  --color-navy: #0A1F44;
  --color-navy-deep: #071631;
  --color-primary: #1D4ED8;
  --color-primary-dark: #1638A8;
  --color-accent: #06B6D4;
  --color-accent-light: #0EA5E9;
  --color-gold: #F59E0B;
  --color-bg: #FFFFFF;
  --color-bg-muted: #F4F7FB;
  --color-bg-dark: #0E2448;
  --color-text: #1E293B;
  --color-text-muted: #5B6B84;
  --color-text-invert: #FFFFFF;
  --color-border: #E2E8F0;
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow-sm: 0 2px 8px rgba(10, 31, 68, 0.06);
  --shadow: 0 10px 30px rgba(10, 31, 68, 0.08);
  --shadow-lg: 0 24px 60px rgba(10, 31, 68, 0.14);
  --font-sans: 'Segoe UI', system-ui, -apple-system, 'Helvetica Neue', Arial, sans-serif;
  --container: 1180px;
  --header-h: 76px;
}

/* ---------- Reset & base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.65;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--color-primary); text-decoration: none; transition: color .18s ease; }
a:hover, a:focus { color: var(--color-primary-dark); }
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 .6em;
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-navy);
  letter-spacing: -0.01em;
}
p { margin: 0 0 1.1em; }
ul, ol { margin: 0 0 1.2em; padding-left: 1.4em; }
li { margin-bottom: .35em; }

/* ---------- Layout ---------- */
.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }
.section { padding: 84px 0; }
.section--muted { background: var(--color-bg-muted); }
.section--dark { background: var(--color-bg-dark); }
.section--dark h1, .section--dark h2, .section--dark h3, .section--dark p { color: var(--color-text-invert); }
.section--accent { background: linear-gradient(135deg, var(--color-navy) 0%, var(--color-primary) 100%); }
.section--accent h2, .section--accent p { color: var(--color-text-invert); }
.section-label {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 14px;
}
.section-title { font-size: clamp(28px, 4vw, 40px); margin-bottom: 18px; }
.section-text { font-size: 18px; color: var(--color-text-muted); max-width: 780px; }
.section--dark .section-text, .section--accent .section-text { color: rgba(255,255,255,.8); }

/* ---------- Grid ---------- */
.grid { display: grid; gap: 28px; }
.grid--2 { grid-template-columns: repeat(2, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 15px;
  line-height: 1.2;
  text-align: center;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all .2s ease;
}
.btn--primary { background: var(--color-primary); color: #fff; }
.btn--primary:hover, .btn--primary:focus { background: var(--color-primary-dark); color: #fff; }
.btn--ghost { background: transparent; border-color: rgba(255,255,255,.65); color: #fff; }
.btn--ghost:hover, .btn--ghost:focus { background: rgba(255,255,255,.14); border-color: #fff; color: #fff; }
.btn--outline { background: transparent; border-color: var(--color-primary); color: var(--color-primary); }
.btn--outline:hover, .btn--outline:focus { background: var(--color-primary); color: #fff; }
.btn--accent { background: var(--color-accent); color: var(--color-navy); }
.btn--accent:hover, .btn--accent:focus { background: #0ba5c4; color: var(--color-navy); }
.btn--sm { padding: 9px 18px; font-size: 13.5px; }
.btn--lg { padding: 16px 34px; font-size: 16px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow 0.2s ease;
}
.site-header.is-scrolled { box-shadow: var(--shadow-sm); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 20px; min-height: var(--header-h); }
.site-branding__link { display: flex; align-items: center; gap: 12px; }
.site-logo { height: 44px; width: auto; }
.site-name { display: block; font-size: 18px; font-weight: 700; color: var(--color-navy); line-height: 1.2; }
.site-tagline { display: block; font-size: 12.5px; color: var(--color-text-muted); max-width: 320px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.main-nav { display: flex; align-items: center; gap: 18px; }
.menu { display: flex; align-items: center; gap: 4px; list-style: none; margin: 0; padding: 0; }
.menu li { margin: 0; }
.menu a {
  display: inline-block;
  padding: 10px 13px;
  font-size: 14.5px;
  font-weight: 600;
  color: var(--color-text);
  border-radius: 8px;
}
.menu a:hover, .menu a:focus { color: var(--color-primary); background: rgba(29, 78, 216, 0.06); }
.menu .cta-item { margin-left: 8px; }

.lang-switcher { display: flex; align-items: center; list-style: none; margin: 0; padding: 0; border: 1px solid var(--color-border); border-radius: 999px; overflow: hidden; }
.lang-switcher li { margin: 0; }
.lang-switcher a { display: block; padding: 7px 12px; font-size: 13px; font-weight: 700; color: var(--color-text-muted); }
.lang-switcher li.current a { background: var(--color-navy); color: #fff; }
.lang-switcher a:hover, .lang-switcher a:focus { background: var(--color-bg-muted); color: var(--color-primary); }

.nav-toggle { display: none; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav-toggle .bar { display: block; width: 24px; height: 2px; background: var(--color-navy); margin: 5px 0; border-radius: 2px; }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  background: linear-gradient(135deg, var(--color-navy-deep) 0%, var(--color-navy) 55%, var(--color-primary) 100%);
  color: #fff;
  overflow: hidden;
  padding: 96px 0 88px;
}
.hero::after {
  content: '';
  position: absolute;
  right: -120px;
  bottom: -120px;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(6, 182, 212, 0.28) 0%, transparent 70%);
}
.hero-inner { display: grid; grid-template-columns: 1.4fr 1fr; gap: 40px; align-items: center; position: relative; z-index: 1; }
.hero-badge {
  display: inline-block;
  padding: 7px 16px;
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 999px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: #cfe3ff;
  margin-bottom: 22px;
}
.hero-title { font-size: clamp(34px, 5vw, 56px); color: #fff; margin-bottom: 20px; letter-spacing: -0.02em; }
.hero-subtitle { font-size: 19px; color: rgba(255, 255, 255, 0.85); max-width: 620px; margin-bottom: 32px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 22px; }
.hero-note { font-size: 14.5px; color: rgba(255, 255, 255, 0.65); }
.hero-media { position: relative; z-index: 1; }

/* ---------- Hero slider ---------- */
.hero-slider {
  position: relative;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.04);
}
.hero-slider__track { position: relative; aspect-ratio: 16 / 9; }
.hero-slider__slide {
  position: absolute;
  inset: 0;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.6s ease, visibility 0.6s ease;
}
.hero-slider__slide.is-active { opacity: 1; visibility: visible; }
.hero-slider__slide img { width: 100%; height: 100%; object-fit: cover; }
.hero-slider__arrow {
  position: absolute;
  top: 50%;
  z-index: 3;
  width: 40px;
  height: 40px;
  transform: translateY(-50%);
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(255, 255, 255, 0.45);
  border-radius: 50%;
  background: rgba(7, 22, 49, 0.45);
  color: #fff;
  font-size: 26px;
  line-height: 1;
  cursor: pointer;
  transition: background 0.2s ease;
}
.hero-slider__arrow:hover, .hero-slider__arrow:focus { background: var(--color-navy); }
.hero-slider__arrow--prev { left: 14px; }
.hero-slider__arrow--next { right: 14px; }
.hero-slider__dots {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 18px;
  z-index: 3;
  display: flex;
  justify-content: center;
  gap: 8px;
}
.hero-slider__dot {
  width: 10px;
  height: 10px;
  padding: 0;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.55);
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease;
}
.hero-slider__dot:hover { background: rgba(255, 255, 255, 0.85); }
.hero-slider__dot.is-active { background: #fff; transform: scale(1.25); }

/* ---------- Trust bar ---------- */
.trust-bar { background: #fff; border-bottom: 1px solid var(--color-border); padding: 26px 0; }
.trust-title { text-align: center; font-size: 13px; font-weight: 700; letter-spacing: 0.1em; text-transform: uppercase; color: var(--color-text-muted); margin-bottom: 18px; }
.trust-logos { display: flex; flex-wrap: wrap; justify-content: center; gap: 28px; list-style: none; margin: 0; padding: 0; }
.trust-logos li { font-size: 17px; font-weight: 700; color: #94a3b8; }

/* ---------- Cards ---------- */
.card {
  background: #fff;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 30px 28px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card h3 { font-size: 19px; margin-bottom: 10px; }
.card p { font-size: 15.5px; color: var(--color-text-muted); margin: 0; }
.service-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  margin-bottom: 18px;
}
.card--dev { border-top: 4px solid var(--color-primary); }
.card--dep { border-top: 4px solid var(--color-accent); }
.card--dev h2, .card--dep h2 { font-size: 24px; }
.check-list { list-style: none; padding: 0; }
.check-list li { position: relative; padding-left: 30px; margin-bottom: 10px; }
.check-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  top: 2px;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: rgba(6, 182, 212, 0.15);
  color: var(--color-accent);
  font-weight: 800;
  font-size: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---------- Steps ---------- */
.how-steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 26px; margin-top: 44px; }
.how-step-num { font-size: 40px; font-weight: 800; color: var(--color-accent); line-height: 1; margin-bottom: 16px; }
.how-step-title { font-size: 18px; color: #fff; margin-bottom: 8px; }
.how-step-text { font-size: 15px; color: rgba(255, 255, 255, 0.75); margin: 0; }

/* ---------- Split ---------- */
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 56px; align-items: center; }
.split-media img { border-radius: var(--radius-lg); box-shadow: var(--shadow); }
.split-content .section-title { margin-top: 8px; }

/* ---------- Stats ---------- */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 32px; }
.stat { text-align: center; }
.stat-number { font-size: clamp(32px, 4vw, 48px); font-weight: 800; color: #fff; margin-bottom: 6px; }
.stat-label { font-size: 15px; color: rgba(255, 255, 255, 0.8); margin: 0; }

/* ---------- CTA ---------- */
.cta-section { background: linear-gradient(135deg, var(--color-navy-deep), var(--color-primary)); color: #fff; padding: 88px 0; text-align: center; }
.cta-section h2 { color: #fff; font-size: clamp(28px, 4vw, 40px); margin-bottom: 16px; }
.cta-section p { color: rgba(255, 255, 255, 0.85); max-width: 620px; margin: 0 auto 30px; font-size: 18px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--color-navy-deep); color: rgba(255, 255, 255, 0.75); padding: 72px 0 32px; font-size: 15px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 48px; }
.site-footer h3 { color: #fff; font-size: 14px; letter-spacing: 0.06em; text-transform: uppercase; margin-bottom: 16px; }
.site-footer ul { list-style: none; margin: 0; padding: 0; }
.site-footer ul li { margin-bottom: 9px; }
.site-footer a { color: rgba(255, 255, 255, 0.75); }
.site-footer a:hover, .site-footer a:focus { color: #fff; }
.footer-about .site-logo { margin-bottom: 16px; }
.footer-lang-title { font-weight: 600; color: #fff; margin: 18px 0 8px; }
.lang-switcher--footer { justify-content: flex-start; }
.lang-switcher--footer a { color: #fff; }
.footer-bottom { border-top: 1px solid rgba(255, 255, 255, 0.14); padding-top: 24px; display: flex; flex-direction: column; gap: 6px; font-size: 13.5px; color: rgba(255, 255, 255, 0.55); }

/* ---------- Page hero ---------- */
.page-hero { background: linear-gradient(135deg, var(--color-navy-deep), var(--color-primary)); color: #fff; padding: 76px 0 64px; }
.page-hero .page-title { color: #fff; font-size: clamp(30px, 4.4vw, 46px); margin-bottom: 14px; }
.page-hero .page-intro { font-size: 18px; color: rgba(255, 255, 255, 0.85); max-width: 760px; margin: 0; }
.page-content { max-width: 860px; }
.page-content h2 { margin-top: 2.2em; }

/* ---------- Forms ---------- */
.contact-form { background: #fff; border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 36px; box-shadow: var(--shadow); }
.contact-form .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.form-field { margin-bottom: 20px; }
.form-field label { display: block; font-weight: 600; font-size: 14.5px; margin-bottom: 7px; color: var(--color-navy); }
.form-field input[type="text"], .form-field input[type="email"], .form-field input[type="tel"], .form-field select, .form-field textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 15.5px;
  color: var(--color-text);
  background: var(--color-bg-muted);
}
.form-field input:focus, .form-field textarea:focus, .form-field select:focus {
  outline: none;
  border-color: var(--color-primary);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(29, 78, 216, 0.15);
}
.form-field textarea { min-height: 160px; resize: vertical; }
.form-note { font-size: 13.5px; color: var(--color-text-muted); margin-top: 14px; }
.notice { border-radius: var(--radius-sm); padding: 14px 18px; margin-bottom: 24px; font-weight: 600; }
.notice--success { background: #ecfdf5; color: #065f46; border: 1px solid #a7f3d0; }
.notice--info { background: #eff6ff; color: #1e40af; border: 1px solid #bfdbfe; }

/* ---------- Blog ---------- */
.blog-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 28px; margin: 48px 0; }
.entry-title { font-size: 20px; }
.entry-meta { font-size: 13.5px; color: var(--color-text-muted); margin-bottom: 12px; }
.entry-summary { font-size: 15px; color: var(--color-text-muted); }
.pagination { display: flex; gap: 8px; margin: 40px 0; }
.pagination .page-numbers { padding: 8px 14px; border: 1px solid var(--color-border); border-radius: 8px; }
.pagination .current { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* ---------- Single post ---------- */
.single .page-content .entry-meta { margin-bottom: 20px; }
.single .page-content img { border-radius: var(--radius); margin: 24px 0; }

/* ---------- 404 ---------- */
.error-404 { text-align: center; padding: 110px 0; }
.error-404 .error-code { font-size: 120px; font-weight: 800; color: var(--color-navy); line-height: 1; margin-bottom: 12px; }
.error-404 .section-title { margin-bottom: 26px; }

/* ---------- Legal ---------- */
.legal-section { margin-bottom: 44px; }
.legal-section h2 { font-size: 26px; }

/* ---------- Utility ---------- */
.screen-reader-text { border: 0; clip: rect(1px, 1px, 1px, 1px); clip-path: inset(50%); height: 1px; width: 1px; margin: -1px; overflow: hidden; padding: 0; position: absolute !important; word-wrap: normal !important; }
.skip-link { position: absolute; left: -9999px; top: 0; z-index: 999; background: var(--color-navy); color: #fff; padding: 12px 18px; border-radius: 0 0 8px 0; }
.skip-link:focus { left: 0; }
:focus-visible { outline: 3px solid var(--color-accent); outline-offset: 2px; }
.img-round { border-radius: var(--radius-lg); }
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .grid--4, .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .how-steps { grid-template-columns: repeat(2, 1fr); }
  .split { grid-template-columns: 1fr; gap: 36px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 24px; }
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-media { margin-top: 0; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
}

@media (max-width: 768px) {
  body { font-size: 16px; }
  .section { padding: 60px 0; }
  .site-tagline { display: none; }
  .nav-toggle { display: block; }
  .main-nav { position: relative; }
  .menu {
    position: absolute;
    top: 100%;
    right: 0;
    left: 0;
    flex-direction: column;
    align-items: stretch;
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: 0 0 12px 12px;
    box-shadow: var(--shadow);
    padding: 12px;
    display: none;
    gap: 2px;
  }
  .menu.is-open { display: flex; }
  .menu a { padding: 12px 14px; }
  .menu .cta-item { margin-left: 0; margin-top: 8px; text-align: center; }
  .lang-switcher { margin-left: auto; }
  .grid--2 { grid-template-columns: 1fr; }
  .how-steps { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .blog-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; gap: 28px; }
  .contact-form .form-row { grid-template-columns: 1fr; }
  .hero { padding: 64px 0 56px; }
  .page-hero { padding: 56px 0 48px; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .hero-cta .btn { width: 100%; }
}