/* ==========================================================================
   Sheffield Arrhythmia Centre — shared stylesheet
   Design concept: "Rhythm line" — a calm clinical navy/teal system built
   around a heartbeat-trace motif used sparingly as a structural device.
   ========================================================================== */

:root {
  /* Colour */
  --ink: #10233b;
  --ink-soft: #3b5170;
  --ink-faint: #6b7d95;
  --bg: #f4f6f9;
  --surface: #ffffff;
  --line: #dde3ea;
  --line-strong: #c3ccd8;
  --rhythm: #0d7a6c;
  --rhythm-dark: #095e53;
  --rhythm-tint: #e4f2ef;
  --pulse: #b6503f;
  --pulse-tint: #f8e9e6;
  --focus: #1f6fb2;

  /* Type */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo,
    "Courier New", monospace;

  /* Rhythm */
  --radius: 8px;
  --radius-sm: 4px;
  --gutter: clamp(1.25rem, 3vw, 2.5rem);
  --maxw: 1180px;
}

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

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

a {
  color: var(--rhythm-dark);
}

a:not([class]) {
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

h1, h2, h3, h4 {
  line-height: 1.2;
  color: var(--ink);
  font-weight: 700;
  letter-spacing: -0.01em;
}

h1 { font-size: clamp(2rem, 3.4vw, 2.9rem); }
h2 { font-size: clamp(1.5rem, 2.4vw, 2rem); }
h3 { font-size: 1.2rem; }

p { margin: 0 0 1em; }

.container {
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* Focus states — always visible */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: auto;
  background: var(--ink);
  color: #fff;
  padding: 0.75em 1.25em;
  z-index: 1000;
  border-radius: 0 0 var(--radius-sm) 0;
}

.skip-link:focus {
  left: 0;
  top: 0;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--rhythm-dark);
  font-weight: 600;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(244, 246, 249, 0.94);
  backdrop-filter: saturate(180%) blur(6px);
  border-bottom: 1px solid var(--line);
}

.header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 0.85rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--ink);
}

.brand-mark {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  object-fit: contain;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--ink);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--rhythm-dark);
}

.nav-toggle {
  display: none;
  background: transparent;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.6rem;
  cursor: pointer;
}

.nav-toggle-bar {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--ink);
  margin: 4px 0;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.main-nav ul {
  list-style: none;
  display: flex;
  gap: 1.75rem;
  margin: 0;
  padding: 0;
}

.main-nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  padding: 0.4rem 0.1rem;
  border-bottom: 2px solid transparent;
}

.main-nav a:hover,
.main-nav a[aria-current="page"] {
  color: var(--rhythm-dark);
  border-bottom-color: var(--rhythm);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 1.1rem;
}

.header-phone {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--ink-soft);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
  white-space: nowrap;
}

.header-phone:hover {
  color: var(--rhythm-dark);
}

.header-phone-icon {
  width: 15px;
  height: 15px;
  flex-shrink: 0;
}

.header-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

@media (max-width: 860px) {
  .nav-toggle {
    display: inline-block;
  }

  .main-nav {
    position: absolute;
    inset: 100% 0 auto 0;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 12px 24px -18px rgba(16, 35, 59, 0.35);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.25s ease;
  }

  .main-nav.is-open {
    max-height: 480px;
  }

  .main-nav ul {
    flex-direction: column;
    gap: 0;
    padding: 0.5rem var(--gutter) 1rem;
  }

  .main-nav a {
    display: block;
    padding: 0.75rem 0.2rem;
    border-bottom: 1px solid var(--line);
  }

  .header-phone {
    font-size: 0.85rem;
  }

  .header-cta {
    display: none;
  }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 0.95rem;
  padding: 0.72em 1.4em;
  border-radius: 999px;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease, color 0.15s ease,
    border-color 0.15s ease;
}

.btn-primary {
  background: var(--rhythm);
  color: #fff;
}

.btn-primary:hover {
  background: var(--rhythm-dark);
}

.btn-outline {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--ink);
}

.btn-outline:hover {
  border-color: var(--rhythm);
  color: var(--rhythm-dark);
}

.btn-sm {
  padding: 0.5em 1.1em;
  font-size: 0.85rem;
}

/* ---------- Hero ---------- */
.hero {
  padding-block: clamp(2.5rem, 6vw, 5rem);
}

.hero-single {
  max-width: 640px;
  margin-inline: auto;
  text-align: center;
}

.hero h1 {
  margin-top: 0.5rem;
}

.hero-lede {
  font-size: 1.1rem;
  color: var(--ink-soft);
  max-width: 52ch;
  margin-inline: auto;
}

.hero-actions {
  display: flex;
  gap: 0.9rem;
  flex-wrap: wrap;
  margin-top: 1.5rem;
}

.hero-single .hero-actions {
  justify-content: center;
}

/* ---------- Section divider (rhythm trace) ---------- */
.divider {
  width: 100%;
  height: 28px;
  display: block;
  margin-block: 0.5rem;
}

.divider path {
  stroke: var(--line-strong);
  stroke-width: 2;
  fill: none;
}

/* ---------- Sections ---------- */
.section {
  padding-block: clamp(2.5rem, 5vw, 4rem);
}

.section-head {
  max-width: 62ch;
  margin-bottom: 2rem;
}

.section-alt {
  background: var(--surface);
  border-block: 1px solid var(--line);
}

/* ---------- Cards ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.25rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 4px solid var(--rhythm);
  border-radius: var(--radius-sm) var(--radius) var(--radius) var(--radius-sm);
  padding: 1.5rem;
}

.card h3 {
  margin-top: 0;
}

.card-link {
  display: inline-block;
  margin-top: 0.75rem;
  font-weight: 700;
  font-size: 0.9rem;
  text-decoration: none;
}

.card-link::after {
  content: " \2192";
}

/* ---------- Stats ---------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.25rem;
}

.stat {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem 1.4rem 1.2rem;
}

.stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 700;
  color: var(--pulse);
  display: block;
}

.stat-label {
  color: var(--ink-soft);
  font-size: 0.92rem;
}

/* ---------- Doctor summary (home) ---------- */
.people-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.person-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.person-photo {
  aspect-ratio: 4 / 3;
  background: var(--rhythm-tint);
  border-bottom: 1px solid var(--line);
}

.person-body {
  padding: 1.4rem;
}

.person-role {
  color: var(--rhythm-dark);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.6rem;
}

/* ---------- Full bio (about page) ---------- */
.bio {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: clamp(1.5rem, 3vw, 2.5rem);
  margin-bottom: 2.5rem;
}

.bio-head {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
  align-items: center;
}

@media (max-width: 620px) {
  .bio-head {
    grid-template-columns: 1fr;
  }
  .bio-head .person-photo {
    max-width: 200px;
  }
}

.bio-head .person-photo {
  border-radius: var(--radius);
  border: 1px solid var(--line);
}

.bio h4 {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--rhythm-dark);
  border-top: 1px solid var(--line);
  padding-top: 1.25rem;
  margin-top: 1.75rem;
}

.bio dl {
  display: grid;
  grid-template-columns: minmax(120px, 200px) 1fr;
  gap: 0.5rem 1rem;
  margin: 0;
}

.bio dt {
  font-weight: 700;
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.bio dd {
  margin: 0;
  font-size: 0.95rem;
}

.pub-list {
  padding-left: 1.2rem;
}

.pub-list li {
  margin-bottom: 0.6rem;
  font-size: 0.93rem;
  color: var(--ink-soft);
}

.placeholder-box {
  background: var(--pulse-tint);
  border: 1px dashed var(--pulse);
  border-radius: var(--radius-sm);
  padding: 1rem 1.2rem;
  font-size: 0.9rem;
  color: var(--ink);
}

.placeholder-box strong {
  color: var(--pulse);
}

details.pub-details {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.2rem 1rem;
  margin-top: 0.5rem;
}

details.pub-details summary {
  cursor: pointer;
  font-weight: 700;
  padding: 0.8rem 0;
  color: var(--ink);
}

/* ---------- Subnav (arrhythmias page) ---------- */
.subnav {
  position: sticky;
  top: 66px;
  z-index: 50;
  background: var(--rhythm-tint);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
}

.subnav ul {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0.75rem var(--gutter);
  max-width: var(--maxw);
  margin-inline: auto;
  white-space: nowrap;
}

.subnav a {
  color: var(--rhythm-dark);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
}

.subnav a:hover {
  text-decoration: underline;
}

.condition-block {
  padding-block: 2.5rem;
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 130px;
}

.condition-block:last-child {
  border-bottom: none;
}

.condition-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #fff;
  background: var(--ink-soft);
  padding: 0.25em 0.7em;
  border-radius: 999px;
  margin-bottom: 0.75rem;
}

.condition-links {
  margin-top: 1.25rem;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.external-link {
  font-size: 0.9rem;
  font-weight: 600;
}

/* ---------- ECG rhythm strips (arrhythmias.html) ---------- */
.ecg-strip {
  margin: 0 0 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.ecg-track {
  display: block;
  width: 100%;
  height: 72px;
}

.ecg-baseline {
  fill: none;
  stroke: var(--rhythm);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.ecg-beat {
  fill: none;
  stroke: var(--pulse);
  stroke-width: 2.4;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.ecg-scroll {
  animation-name: ecg-scroll;
  animation-timing-function: linear;
  animation-iteration-count: infinite;
}

@keyframes ecg-scroll {
  to {
    transform: translateX(-300px);
  }
}

.ecg-strip--svt .ecg-scroll {
  animation-duration: 2.2s;
}

.ecg-strip--flutter .ecg-scroll {
  animation-duration: 4.2s;
}

.ecg-strip--af .ecg-scroll {
  animation-duration: 4.6s;
}

.ecg-strip--pacemaker .ecg-scroll {
  animation-duration: 5s;
}

@media (prefers-reduced-motion: reduce) {
  .ecg-scroll {
    animation: none;
    transform: translateX(0);
  }
}

.ecg-caption {
  margin: 0;
  padding: 0.6rem 1rem 0.75rem;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.02em;
  color: var(--ink-soft);
}

/* ---------- Visit page ---------- */
.steps {
  counter-reset: step;
  display: grid;
  gap: 1.25rem;
}

.step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 1.1rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.4rem;
}

.step-num {
  counter-increment: step;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--rhythm);
  font-size: 1.3rem;
  width: 2.2rem;
  height: 2.2rem;
  border: 1.5px solid var(--rhythm);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.step-num::before {
  content: counter(step);
}

.tests-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
}

.test-pill {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 0.9rem 1.1rem;
  font-weight: 600;
  font-size: 0.93rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.test-pill .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--rhythm);
  flex-shrink: 0;
}

/* ---------- Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

@media (max-width: 860px) {
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

.location-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
}

.location-card h3 {
  margin-top: 0;
}

.location-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--rhythm-dark);
}

.contact-details {
  list-style: none;
  padding: 0;
  margin: 1rem 0 0;
}

.contact-details li {
  margin-bottom: 0.5rem;
}

.form-field {
  margin-bottom: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-field label {
  font-weight: 700;
  font-size: 0.9rem;
}

.form-field input,
.form-field textarea,
.form-field select {
  font: inherit;
  padding: 0.7em 0.85em;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--ink);
}

.form-field input:focus,
.form-field textarea:focus,
.form-field select:focus {
  border-color: var(--rhythm);
}

.form-field--checkbox {
  flex-direction: row;
  align-items: flex-start;
  gap: 0.65rem;
}

.form-field--checkbox input[type="checkbox"] {
  width: 1.1rem;
  height: 1.1rem;
  margin-top: 0.15rem;
  flex-shrink: 0;
  accent-color: var(--rhythm);
}

.form-field--checkbox label {
  font-weight: 400;
  font-size: 0.92rem;
}

.form-status {
  margin-top: 1rem;
  font-weight: 600;
}

.required {
  color: var(--pulse);
}

/* ---------- Partners ---------- */
.partner-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
}

.partner-card {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 3px solid var(--line-strong);
  border-radius: var(--radius-sm) var(--radius-sm) var(--radius) var(--radius);
  padding: 1.25rem 1.4rem;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.15s ease, transform 0.15s ease;
}

a.partner-card:hover,
a.partner-card:focus-visible {
  transform: translateY(-2px);
}

.partner-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.partner-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--line-strong);
  flex-shrink: 0;
}

.partner-name {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--ink);
}

.partner-detail {
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.partner-card--hospital { border-top-color: var(--rhythm); }
.partner-card--hospital .partner-dot { background: var(--rhythm); }

.partner-card--nhs { border-top-color: var(--ink-soft); }
.partner-card--nhs .partner-dot { background: var(--ink-soft); }

.partner-card--charity { border-top-color: var(--pulse); }
.partner-card--charity .partner-dot { background: var(--pulse); }

a.partner-card.partner-card--hospital:hover,
a.partner-card.partner-card--hospital:focus-visible { border-top-color: var(--rhythm-dark); }

a.partner-card.partner-card--nhs:hover,
a.partner-card.partner-card--nhs:focus-visible { border-top-color: var(--ink); }

a.partner-card.partner-card--charity:hover,
a.partner-card.partner-card--charity:focus-visible { border-top-color: var(--pulse); }

/* ---------- Footer ---------- */
.site-footer {
  background: var(--ink);
  color: #cdd6e3;
  margin-top: 3rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr 1fr 1fr;
  gap: 2rem;
  padding-block: 3rem 2rem;
}

@media (max-width: 760px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.site-footer h4 {
  color: #fff;
  font-size: 0.85rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-family: var(--font-mono);
  margin-bottom: 1rem;
}

.site-footer ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.site-footer li {
  margin-bottom: 0.55rem;
}

.site-footer a {
  color: #cdd6e3;
  text-decoration: none;
  font-size: 0.92rem;
}

.site-footer a:hover {
  color: #fff;
  text-decoration: underline;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  margin-bottom: 1rem;
}

.footer-logo {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  object-fit: contain;
}

.footer-brand-name {
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
  line-height: 1.2;
}

.footer-bottom {
  border-top: 1px solid #26374e;
  padding-block: 1.25rem;
  font-size: 0.82rem;
  color: #93a3ba;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.footer-bottom a {
  color: #93a3ba;
}

/* ---------- Page intro banner (non-home pages) ---------- */
.page-banner {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding-block: clamp(2rem, 4vw, 3rem);
}

.page-banner .eyebrow {
  display: block;
  margin-bottom: 0.5rem;
}

.page-banner p {
  max-width: 60ch;
  color: var(--ink-soft);
  font-size: 1.05rem;
}

/* ---------- Utility ---------- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.mt-0 { margin-top: 0; }
.text-soft { color: var(--ink-soft); }