/* ═══════════════════════════════════════════════════════════
   DARTNEST STUDIO — Portfolio stylesheet
═══════════════════════════════════════════════════════════ */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --billig: #1976D2;
  --billig-dark: #0D47A1;
  --qr: #7C3AED;
  --qr-dark: #5B21B6;
  --accent: #F9A825;

  --text: #1a1a1a;
  --text-muted: #5a6473;
  --text-light: #8a93a4;

  --bg: #ffffff;
  --bg-alt: #F5F7FA;
  --bg-dark: #0F1621;
  --bg-dark-2: #131C2B;

  --border: #E4E7EC;
  --border-light: #F0F2F5;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);

  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 24px;

  --container: 1200px;
  --header-height: 72px;

  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ── HEADER ── */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-height);
  background: rgba(15, 22, 33, 0.7);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  z-index: 1000;
  transition: background 0.2s ease, box-shadow 0.2s ease;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.header-scrolled {
  background: rgba(15, 22, 33, 0.95);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.2);
}

.header-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.01em;
}

.logo-icon {
  width: 26px;
  height: 26px;
  stroke-width: 2.2;
  color: var(--accent);
}

.logo-text { color: #fff; }

.nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
}

.nav a {
  padding: 8px 14px;
  font-size: 14px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.7);
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background 0.15s ease;
}

.nav a:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
}

.header-actions { display: flex; align-items: center; gap: 12px; }

.lang-select {
  padding: 7px 10px;
  font-size: 13px;
  font-weight: 500;
  font-family: inherit;
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.lang-select:hover, .lang-select:focus {
  outline: none;
  border-color: var(--accent);
}

.lang-select option {
  color: var(--text);
  background: #fff;
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
}

.menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  margin: 0 auto;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.menu-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.menu-toggle.open span:nth-child(2) { opacity: 0; }
.menu-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── HERO ── */
.hero {
  position: relative;
  padding: calc(var(--header-height) + 100px) 0 140px;
  overflow: hidden;
  background: var(--bg-dark);
  color: #fff;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.55;
}

.blob-1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, var(--billig) 0%, transparent 70%);
  top: -200px; right: -100px;
}

.blob-2 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, var(--qr) 0%, transparent 70%);
  bottom: -150px; left: -100px;
  opacity: 0.45;
}

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 80%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 780px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-block;
  padding: 8px 16px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: rgba(255, 255, 255, 0.9);
  font-size: 13px;
  font-weight: 600;
  border-radius: 999px;
  margin-bottom: 24px;
  backdrop-filter: blur(8px);
}

.hero-title {
  font-size: clamp(40px, 7vw, 72px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
  background: linear-gradient(135deg, #fff 0%, #A5B4FC 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-tagline {
  font-size: clamp(20px, 2.5vw, 26px);
  font-weight: 600;
  color: rgba(255, 255, 255, 0.9);
  letter-spacing: -0.01em;
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 17px;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.65);
  max-width: 620px;
  margin: 0 auto 36px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
  cursor: pointer;
  white-space: nowrap;
}

.btn:hover { transform: translateY(-2px); }

.btn-primary {
  background: linear-gradient(135deg, var(--billig) 0%, var(--qr) 100%);
  color: #fff;
  box-shadow: 0 8px 24px rgba(124, 58, 237, 0.35);
}

.btn-primary:hover {
  box-shadow: 0 14px 32px rgba(124, 58, 237, 0.45);
}

.btn-ghost {
  background: transparent;
  color: #fff;
  border: 1.5px solid rgba(255, 255, 255, 0.25);
}

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

/* ── SECTION HEADER ── */
.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 60px;
}

.section-header h2 {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 14px;
  color: var(--text);
}

.section-header p {
  font-size: 17px;
  color: var(--text-muted);
}

/* ── PROJECTS ── */
.projects {
  padding: 120px 0;
  background: var(--bg);
  position: relative;
}

.projects::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 28px;
  max-width: 920px;
  margin: 0 auto;
}

.project-card {
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
  position: relative;
}

.project-card:hover {
  transform: translateY(-6px);
  border-color: transparent;
}

.project-card.project-billig:hover {
  box-shadow: 0 24px 48px rgba(25, 118, 210, 0.2);
}

.project-card.project-qr:hover {
  box-shadow: 0 24px 48px rgba(124, 58, 237, 0.2);
}

.project-visual {
  padding: 48px 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.project-billig .project-visual {
  background: linear-gradient(135deg, var(--billig) 0%, var(--billig-dark) 100%);
}

.project-qr .project-visual {
  background: linear-gradient(135deg, var(--qr) 0%, var(--qr-dark) 100%);
}

.project-visual::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(255, 255, 255, 0.2) 0%, transparent 60%);
  pointer-events: none;
}

.project-icon-wrap {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 96px;
  height: 96px;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.25);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
  transition: transform 0.25s ease;
}

.project-card:hover .project-icon-wrap {
  transform: scale(1.08) rotate(-3deg);
}

.project-icon {
  width: 48px;
  height: 48px;
  color: #fff;
  stroke-width: 1.8;
}

.project-body {
  padding: 32px 28px 28px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.project-name {
  font-size: 24px;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 6px;
  color: var(--text);
}

.project-tagline {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.project-billig .project-tagline { color: var(--billig); }
.project-qr .project-tagline { color: var(--qr); }

.project-desc {
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--text-muted);
  margin-bottom: 24px;
  flex: 1;
}

.project-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 700;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  align-self: flex-start;
  transition: gap 0.15s ease;
}

.project-billig .project-cta {
  color: var(--billig);
  background: rgba(25, 118, 210, 0.08);
}

.project-qr .project-cta {
  color: var(--qr);
  background: rgba(124, 58, 237, 0.08);
}

.project-card:hover .project-cta { gap: 10px; }

.project-cta svg {
  width: 14px;
  height: 14px;
}

/* ── ABOUT ── */
.about {
  padding: 120px 0;
  background: var(--bg-alt);
}

.about-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 60px;
}

.about-header h2 {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
  color: var(--text);
}

.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: start;
  max-width: 1000px;
  margin: 0 auto;
}

.about-text p {
  font-size: 16px;
  line-height: 1.75;
  color: var(--text-muted);
  margin-bottom: 18px;
}

.about-text p:last-child { margin-bottom: 0; }

.about-values {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.value-card {
  padding: 20px 22px;
  background: #fff;
  border-radius: var(--radius);
  border: 1px solid var(--border-light);
  display: flex;
  gap: 16px;
  align-items: flex-start;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.value-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.value-icon {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--icon-color) 12%, transparent);
  color: var(--icon-color);
}

.value-icon svg {
  width: 22px;
  height: 22px;
}

.value-card h4 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
  letter-spacing: -0.01em;
  color: var(--text);
}

.value-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ── CONTACT ── */
.contact {
  padding: 100px 0;
  background: var(--bg);
}

.contact-card {
  position: relative;
  padding: 64px 40px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--bg-dark) 0%, var(--bg-dark-2) 100%);
  text-align: center;
  overflow: hidden;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.15);
}

.contact-card::before,
.contact-card::after {
  content: '';
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.4;
}

.contact-card::before {
  width: 300px; height: 300px;
  background: var(--billig);
  top: -150px; left: -80px;
}

.contact-card::after {
  width: 250px; height: 250px;
  background: var(--qr);
  bottom: -100px; right: -60px;
}

.contact-card h2,
.contact-card p,
.contact-card .contact-actions {
  position: relative;
  z-index: 1;
}

.contact-card h2 {
  font-size: clamp(26px, 4vw, 38px);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: #fff;
  margin-bottom: 12px;
}

.contact-card p {
  font-size: 17px;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 32px;
  max-width: 540px;
  margin-left: auto;
  margin-right: auto;
}

.contact-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}

/* ── FOOTER ── */
.footer {
  background: var(--bg-dark);
  color: #cbd3dd;
  padding: 60px 0 0;
}

.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
}

.footer .logo { color: #fff; margin-bottom: 12px; }
.footer .logo-text { color: #fff; }

.footer-brand p {
  font-size: 14px;
  color: #8a93a4;
  line-height: 1.6;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: 16px;
}

.footer-col a {
  display: block;
  font-size: 14px;
  color: #8a93a4;
  margin-bottom: 10px;
  transition: color 0.15s ease;
}

.footer-col a:hover { color: #fff; }

.footer-bottom {
  padding: 24px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 13px;
  color: #8a93a4;
  text-align: center;
}

/* ── RESPONSIVE ── */
@media (max-width: 960px) {
  .hero {
    padding: calc(var(--header-height) + 70px) 0 100px;
  }
  .projects, .about, .contact {
    padding: 80px 0;
  }
  .projects-grid {
    grid-template-columns: 1fr;
    max-width: 520px;
  }
  .about-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .footer-inner {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 720px) {
  :root { --header-height: 64px; }

  .nav {
    position: fixed;
    top: var(--header-height);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    background: var(--bg-dark);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
    transform: translateY(-120%);
    opacity: 0;
    pointer-events: none;
    transition: transform 0.2s ease, opacity 0.2s ease;
    gap: 0;
    z-index: 999;
  }

  .nav.nav-open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav a {
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    color: rgba(255, 255, 255, 0.85);
  }

  .nav a:hover {
    background: rgba(255, 255, 255, 0.08);
  }

  .menu-toggle { display: flex; }
  .lang-select { padding: 6px 8px; font-size: 12px; max-width: 90px; }

  .hero { padding: calc(var(--header-height) + 40px) 0 70px; }
  .hero-title { font-size: 44px; }
  .hero-tagline { font-size: 19px; }
  .hero-subtitle { font-size: 15.5px; }
  .hero-actions { flex-direction: column; width: 100%; }
  .hero-actions .btn { width: 100%; }

  .projects, .about, .contact { padding: 60px 0; }
  .section-header { margin-bottom: 40px; }
  .section-header h2 { font-size: 26px; }
  .about-header { margin-bottom: 40px; }
  .about-header h2 { font-size: 26px; }

  .project-visual { padding: 36px 24px; }
  .project-icon-wrap { width: 80px; height: 80px; border-radius: 20px; }
  .project-icon { width: 40px; height: 40px; }
  .project-body { padding: 24px 22px 22px; }
  .project-name { font-size: 22px; }

  .contact-card { padding: 48px 24px; }
  .contact-card h2 { font-size: 24px; }
  .contact-card p { font-size: 15px; }
  .contact-actions { flex-direction: column; width: 100%; }
  .contact-actions .btn { width: 100%; }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 420px) {
  .hero-title { font-size: 36px; }
  .hero-badge { font-size: 12px; padding: 6px 14px; }
  .value-card { padding: 16px 18px; }
  .value-icon { width: 40px; height: 40px; }
  .value-icon svg { width: 20px; height: 20px; }
}

/* ═══════════════════════════════════════════════════════════
   INNER PAGES (privacy, imprint)
═══════════════════════════════════════════════════════════ */
:root {
  --primary: var(--billig);
  --primary-dark: var(--billig-dark);
  --primary-light: #E3F2FD;
}

.page-hero {
  padding: calc(var(--header-height) + 80px) 0 60px;
  background: var(--bg-alt);
  text-align: center;
  border-bottom: 1px solid var(--border-light);
}

.page-hero-inner {
  max-width: 720px;
  margin: 0 auto;
}

.page-hero h1 {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  color: var(--text);
}

.page-meta {
  font-size: 14px;
  color: var(--text-muted);
}

.page-content {
  padding: 60px 0 100px;
  background: var(--bg);
}

.page-content-inner {
  max-width: 780px;
  margin: 0 auto;
}

.page-notice {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 14px 18px;
  background: #FFF8E1;
  border: 1px solid #FFE082;
  border-radius: var(--radius-sm);
  color: #5D4037;
  font-size: 14px;
  line-height: 1.5;
  margin-bottom: 36px;
}

.page-notice svg {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 1px;
}

.page-content h2 {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-top: 40px;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text);
  scroll-margin-top: calc(var(--header-height) + 20px);
}

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

.page-content h3 {
  font-size: 17px;
  font-weight: 700;
  margin-top: 24px;
  margin-bottom: 8px;
  color: var(--text);
}

.page-content p {
  font-size: 15.5px;
  color: var(--text);
  line-height: 1.7;
  margin-bottom: 14px;
}

.page-content ul {
  padding-left: 22px;
  margin-bottom: 16px;
}

.page-content li {
  font-size: 15.5px;
  line-height: 1.7;
  margin-bottom: 6px;
  color: var(--text);
}

.page-content li::marker {
  color: var(--primary);
}

.page-content a {
  color: var(--primary);
  text-decoration: underline;
  text-decoration-color: var(--primary-light);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.15s ease;
}

.page-content a:hover {
  text-decoration-color: var(--primary);
}

.page-content code {
  padding: 2px 6px;
  background: var(--bg-alt);
  border-radius: 4px;
  font-size: 13px;
  font-family: ui-monospace, 'SF Mono', Menlo, Consolas, monospace;
  color: var(--primary-dark);
}

.page-content strong {
  font-weight: 700;
  color: var(--text);
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 24px;
  transition: color 0.15s ease;
}

.back-link:hover {
  color: var(--primary);
}

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

@media (max-width: 720px) {
  .page-hero {
    padding: calc(var(--header-height) + 40px) 0 32px;
  }
  .page-content {
    padding: 40px 0 60px;
  }
  .page-content h2 {
    font-size: 19px;
    margin-top: 32px;
  }
  .page-content h3 {
    font-size: 16px;
  }
  .page-content p,
  .page-content li {
    font-size: 15px;
  }
}