/*
  MyHeating Designer — mhd.petkov-tech.de
  Warm heat + cool water accents on a technical slate canvas
*/

:root {
  --hero-bg: #0b1120;
  --hero-bg-soft: #151d33;
  --hero-text: #f8fafc;
  --hero-text-soft: #94a3b8;

  --bg: #ffffff;
  --bg-alt: #f4f6fb;
  --bg-warm: #fff7ed;

  --text: #0f172a;
  --text-soft: #475569;

  --heat: #ea580c;
  --heat-hover: #c2410c;
  --heat-light: #ffedd5;
  --water: #2563eb;
  --water-light: #dbeafe;
  --pipe-supply: #dc2626;
  --pipe-return: #2563eb;

  --accent: #ea580c;
  --accent-hover: #c2410c;
  --accent-light: #ffedd5;

  --border: #e2e8f0;
  --radius: 14px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(15, 23, 42, 0.06);
  --shadow-hover: 0 24px 48px rgba(15, 23, 42, 0.12);
  --max-width: 1140px;
  --font-heading: "Sora", system-ui, sans-serif;
  --font-body: "Inter", system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
}

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

html {
  scroll-behavior: smooth;
}

section[id] {
  scroll-margin-top: 5.5rem;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}

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

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

a:hover,
a:focus-visible {
  text-decoration: underline;
}

a:focus-visible {
  outline: 2px solid var(--water);
  outline-offset: 2px;
}

.container {
  width: min(100% - 2rem, var(--max-width));
  margin-inline: auto;
}

.narrow {
  max-width: 760px;
}

.section {
  padding: 5rem 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-warm {
  background: var(--bg-warm);
}

/* ----- Header ----- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(11, 17, 32, 0.9);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(248, 250, 252, 0.06);
}

.header-inner {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 1rem;
  padding: 0.9rem 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--hero-text);
}

.logo:hover,
.logo:focus {
  text-decoration: none;
  color: var(--hero-text);
}

.logo-mark {
  width: 2rem;
  height: 2rem;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--pipe-supply) 0%, var(--pipe-return) 100%);
  display: grid;
  place-items: center;
  font-size: 0.7rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: -0.04em;
}

.site-nav ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 1.1rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav a {
  color: var(--hero-text-soft);
  font-weight: 600;
  font-size: 0.92rem;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--hero-text);
  text-decoration: none;
}

.lang a {
  font-weight: 700;
  color: var(--hero-text);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 0.35rem 0.7rem;
  border-radius: 8px;
}

.lang a:hover,
.lang a:focus-visible {
  background: rgba(255, 255, 255, 0.14);
  text-decoration: none;
}

/* ----- Hero ----- */
.hero {
  position: relative;
  background: var(--hero-bg);
  color: var(--hero-text);
  padding: 5rem 0 4rem;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(148, 163, 184, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.07) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 0%, black, transparent);
  pointer-events: none;
}

.hero-grid {
  position: relative;
  display: grid;
  gap: 2.5rem;
  align-items: center;
}

.hero-copy .eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0 0 1rem;
  padding: 0.35rem 0.85rem;
  border-radius: 999px;
  background: rgba(234, 88, 12, 0.15);
  border: 1px solid rgba(234, 88, 12, 0.35);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #fdba74;
}

.hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.12;
  margin: 0 0 1.1rem;
  color: var(--hero-text);
}

.hero .lead {
  font-size: 1.12rem;
  color: var(--hero-text-soft);
  max-width: 34rem;
  margin: 0 0 1.75rem;
  line-height: 1.75;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  align-items: center;
  margin-bottom: 1.25rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.4rem;
  border-radius: 999px;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.95rem;
  border: 2px solid transparent;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.15s ease;
  cursor: pointer;
  text-decoration: none;
}

.button-primary {
  background: var(--heat);
  color: #fff;
  border-color: var(--heat);
}

.button-primary:hover {
  background: var(--heat-hover);
  border-color: var(--heat-hover);
  text-decoration: none;
  color: #fff;
}

.button-secondary {
  background: transparent;
  color: var(--hero-text);
  border-color: rgba(255, 255, 255, 0.35);
}

.button-secondary:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.55);
  color: var(--hero-text);
  text-decoration: none;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--hero-text-soft);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.pill-dot {
  width: 0.45rem;
  height: 0.45rem;
  border-radius: 50%;
  background: #22c55e;
}

.hero-shot {
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.12);
  box-shadow: 0 32px 64px rgba(0, 0, 0, 0.45);
}

.hero-shot img {
  width: 100%;
}

/* App Store placeholder */
.store-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.55rem 1rem 0.55rem 0.65rem;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px dashed rgba(255, 255, 255, 0.25);
  color: var(--hero-text-soft);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: default;
  text-decoration: none;
}

.store-badge svg {
  flex-shrink: 0;
}

.store-badge.is-live {
  border-style: solid;
  border-color: rgba(255, 255, 255, 0.2);
  background: #000;
  color: #fff;
  cursor: pointer;
}

.store-badge.is-live:hover {
  text-decoration: none;
  opacity: 0.92;
}

/* ----- Section headings ----- */
.section-heading {
  margin-bottom: 2.5rem;
}

.section-heading.center {
  text-align: center;
}

.section-heading .eyebrow {
  margin: 0 0 0.5rem;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--heat);
}

.section-heading h2 {
  font-family: var(--font-heading);
  font-size: clamp(1.55rem, 3.5vw, 2.35rem);
  font-weight: 700;
  line-height: 1.2;
  margin: 0;
}

.section-heading p.sub {
  margin: 0.85rem auto 0;
  max-width: 40rem;
  color: var(--text-soft);
  font-size: 1.05rem;
}

/* ----- Disclaimer callout ----- */
.disclaimer-box {
  border-radius: var(--radius-lg);
  border: 1px solid #fcd34d;
  background: linear-gradient(180deg, #fffbeb 0%, #fff7ed 100%);
  padding: 1.5rem 1.75rem;
  box-shadow: var(--shadow);
}

.disclaimer-box h3 {
  margin: 0 0 0.65rem;
  font-family: var(--font-heading);
  font-size: 1.05rem;
  color: #92400e;
}

.disclaimer-box p {
  margin: 0;
  color: #78350f;
  font-size: 0.98rem;
  line-height: 1.7;
}

/* ----- Cards ----- */
.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}

.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-hover);
  border-color: #fdba74;
}

.card-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 10px;
  display: grid;
  place-items: center;
  font-size: 1.2rem;
  margin-bottom: 1rem;
  background: var(--accent-light);
}

.card h3 {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  margin: 0 0 0.5rem;
}

.card p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.96rem;
}

/* ----- Steps ----- */
.steps {
  display: grid;
  gap: 1rem;
  counter-reset: step;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.25rem;
  align-items: start;
  padding: 1.35rem 1.5rem;
  border-radius: var(--radius-lg);
  background: var(--bg);
  border: 1px solid var(--border);
}

.step-num {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.95rem;
  color: #fff;
  background: linear-gradient(135deg, var(--pipe-supply), var(--pipe-return));
}

.step h3 {
  margin: 0 0 0.35rem;
  font-size: 1.05rem;
}

.step p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.95rem;
}

/* ----- Deliverables ----- */
.deliverables {
  display: grid;
  gap: 0.75rem;
}

.deliverable {
  display: flex;
  gap: 0.85rem;
  align-items: flex-start;
  padding: 1rem 1.15rem;
  border-radius: var(--radius);
  background: var(--bg);
  border: 1px solid var(--border);
}

.deliverable-check {
  flex-shrink: 0;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  background: var(--water-light);
  color: var(--water);
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 0.8rem;
}

.deliverable strong {
  display: block;
  margin-bottom: 0.15rem;
}

.deliverable span {
  color: var(--text-soft);
  font-size: 0.92rem;
}

/* ----- Screenshots ----- */
.gallery {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

.shot-card {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.shot-thumb {
  position: relative;
  display: block;
  cursor: zoom-in;
  border: none;
  padding: 0;
  width: 100%;
  background: #0b1120;
  text-align: left;
}

.shot-thumb img {
  width: 100%;
  opacity: 0.96;
  transition: opacity 0.2s ease, transform 0.25s ease;
}

.shot-thumb:hover img,
.shot-thumb:focus-visible img {
  opacity: 1;
  transform: scale(1.01);
}

.shot-zoom-hint {
  position: absolute;
  right: 0.75rem;
  bottom: 0.75rem;
  padding: 0.3rem 0.65rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.75);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  pointer-events: none;
}

.shot-caption {
  padding: 1rem 1.15rem 1.15rem;
}

.shot-caption h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
}

.shot-caption p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.9rem;
}

/* Lightbox */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 2000;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  background: rgba(11, 17, 32, 0.92);
  backdrop-filter: blur(8px);
}

.lightbox.is-open {
  display: flex;
}

.lightbox-dialog {
  position: relative;
  max-width: min(96vw, 1280px);
  max-height: 92vh;
  width: 100%;
}

.lightbox img {
  width: 100%;
  max-height: 82vh;
  object-fit: contain;
  border-radius: var(--radius);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
}

.lightbox-caption {
  margin-top: 0.85rem;
  text-align: center;
  color: #e2e8f0;
  font-size: 0.95rem;
}

.lightbox-close {
  position: absolute;
  top: -2.75rem;
  right: 0;
  width: 2.5rem;
  height: 2.5rem;
  border: none;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  font-size: 1.4rem;
  cursor: pointer;
  line-height: 1;
}

.lightbox-close:hover {
  background: rgba(255, 255, 255, 0.2);
}

/* ----- Audience ----- */
.audience-grid {
  display: grid;
  gap: 1.25rem;
}

.audience-card {
  padding: 1.75rem;
  border-radius: var(--radius-lg);
  background: var(--bg);
  border: 1px solid var(--border);
}

.audience-card h3 {
  margin: 0 0 0.5rem;
}

.audience-card p {
  margin: 0;
  color: var(--text-soft);
}

/* ----- Contact ----- */
.contact-box {
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.contact-email {
  font-size: 1.2rem;
  font-weight: 700;
  margin: 0.5rem 0 1rem;
}

.contact-email a {
  color: var(--heat);
}

/* ----- Legal pages ----- */
.legal h2 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  margin: 2rem 0 0.75rem;
}

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

.legal p,
.legal li {
  color: var(--text-soft);
}

.legal ul {
  padding-left: 1.25rem;
}

/* ----- Footer ----- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  background: var(--bg-alt);
}

.footer-grid {
  display: grid;
  gap: 1.5rem;
}

.footer-brand {
  font-family: var(--font-heading);
  font-weight: 700;
  margin: 0 0 0.35rem;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-links a {
  font-weight: 600;
  font-size: 0.92rem;
}

.footer-meta {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.9rem;
}

/* ----- SEO prose & FAQ ----- */
.seo-prose p {
  margin: 0 0 1rem;
  color: var(--text-soft);
  font-size: 1.05rem;
  line-height: 1.75;
}

.seo-keywords {
  margin: 1.25rem 0 0;
  padding-left: 1.25rem;
  color: var(--text-soft);
  line-height: 1.8;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--bg);
  padding: 0 1.25rem;
  box-shadow: var(--shadow);
}

.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  font-family: var(--font-heading);
  padding: 1rem 0;
  list-style: none;
}

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

.faq-item summary::after {
  content: "+";
  float: right;
  font-weight: 400;
  color: var(--text-soft);
}

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

.faq-item p {
  margin: 0 0 1rem;
  color: var(--text-soft);
  line-height: 1.7;
  font-size: 0.98rem;
}

/* ----- Guide / article pages ----- */
.page-hero {
  background: linear-gradient(165deg, var(--hero-bg) 0%, var(--hero-bg-soft) 100%);
  color: var(--hero-text);
  padding: 4.5rem 0 3.5rem;
}

.page-hero h1 {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  line-height: 1.2;
  margin: 0.5rem 0 1rem;
  max-width: 42rem;
}

.page-hero .lead {
  margin: 0;
  max-width: 40rem;
  color: var(--hero-text-soft);
  font-size: 1.08rem;
  line-height: 1.7;
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.5rem;
  margin: 0 0 0.75rem;
  padding: 0;
  list-style: none;
  font-size: 0.88rem;
  color: var(--hero-text-soft);
}

.breadcrumb a {
  color: #cbd5e1;
}

.breadcrumb li + li::before {
  content: "›";
  margin-right: 0.5rem;
  opacity: 0.6;
}

.article-body {
  padding: 3.5rem 0 4rem;
}

.article-body .prose {
  max-width: 42rem;
}

.article-body .prose h2 {
  font-family: var(--font-heading);
  font-size: 1.45rem;
  margin: 2.25rem 0 0.75rem;
  line-height: 1.25;
}

.article-body .prose h3 {
  font-family: var(--font-heading);
  font-size: 1.12rem;
  margin: 1.75rem 0 0.5rem;
}

.article-body .prose p,
.article-body .prose li {
  color: var(--text-soft);
  line-height: 1.75;
}

.article-body .prose ul,
.article-body .prose ol {
  padding-left: 1.25rem;
  margin: 0 0 1rem;
}

.article-body .prose li {
  margin-bottom: 0.45rem;
}

.article-meta {
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.92rem;
  color: var(--text-soft);
}

.article-cta {
  margin: 2.5rem 0 0;
  padding: 1.5rem 1.75rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg-alt);
  box-shadow: var(--shadow);
}

.article-cta h2 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  margin: 0 0 0.65rem;
}

.article-cta p {
  margin: 0 0 1rem;
  color: var(--text-soft);
  font-size: 0.98rem;
}

.article-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  align-items: center;
}

.guide-grid {
  display: grid;
  gap: 1.25rem;
  margin-top: 2rem;
}

.guide-card {
  display: block;
  padding: 1.5rem 1.6rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--bg);
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  text-decoration: none;
  color: inherit;
}

.guide-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hover);
  border-color: #fdba74;
  text-decoration: none;
}

.guide-card h2 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  margin: 0 0 0.5rem;
  color: var(--text);
}

.guide-card p {
  margin: 0;
  color: var(--text-soft);
  font-size: 0.98rem;
  line-height: 1.65;
}

.guide-card .read-more {
  display: inline-block;
  margin-top: 0.85rem;
  font-weight: 600;
  color: var(--water);
  font-size: 0.92rem;
}

.nav-active {
  color: #fff !important;
  text-decoration: underline;
}

/* ----- Responsive ----- */
@media (min-width: 768px) {
  .header-inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .hero {
    padding: 6rem 0 5rem;
  }

  .hero-grid {
    grid-template-columns: 1fr 1.15fr;
    gap: 3rem;
  }

  .cards {
    grid-template-columns: repeat(2, 1fr);
  }

  .cards.cols-3 {
    grid-template-columns: repeat(3, 1fr);
  }

  .gallery {
    grid-template-columns: repeat(2, 1fr);
  }

  .audience-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer-grid {
    grid-template-columns: 1.5fr 1fr;
    align-items: start;
  }

  .section {
    padding: 6rem 0;
  }
}

@media (min-width: 1024px) {
  .cards.cols-4 {
    grid-template-columns: repeat(4, 1fr);
  }
}