:root {
  color-scheme: light;
  --ink: #10141f;
  --ink-soft: #364050;
  --paper: #f7f8fb;
  --white: #ffffff;
  --card-bg: var(--white);
  --line: #dce2ea;
  --cyan: #00b9d8;
  --cyan-deep: #0085a5;
  --red: #ff4a55;
  --red-deep: #c82634;
  --yellow: #ffd23f;
  --green: #36c275;
  --dark: #111622;
  --dark-2: #1a2130;
  --shadow: 0 22px 60px rgba(16, 20, 31, 0.18);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  letter-spacing: 0;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
}

.inner {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  min-height: 72px;
  padding: 14px max(20px, calc((100% - 1120px) / 2));
  background: rgba(247, 248, 251, 0.9);
  border-bottom: 1px solid rgba(16, 20, 31, 0.08);
  backdrop-filter: blur(16px);
}

.site-header.is-scrolled {
  box-shadow: 0 12px 28px rgba(16, 20, 31, 0.08);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  font-weight: 850;
  font-size: 1rem;
}

.brand-logo {
  width: 76px;
  height: 44px;
  object-fit: contain;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}



.site-nav a {
  border-radius: 30px;
  padding: 10px 18px;
  color: var(--ink-soft);
  font-weight: 720;
  font-size: 0.95rem;
}

.site-nav a:hover,
.site-nav a:focus-visible {
  color: var(--ink);
  background: rgba(0, 185, 216, 0.1);
  outline: none;
}

.site-nav .nav-action {
  color: var(--white);
  background: var(--ink);
}

.site-nav .nav-action:hover,
.site-nav .nav-action:focus-visible {
  color: var(--white);
  background: var(--red-deep);
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--card-bg);
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 5px auto;
  background: var(--ink);
}

.hero {
  position: relative;
  display: grid;
  align-items: center;
  min-height: 78svh;
  overflow: hidden;
  padding: 112px 0 60px;
  color: var(--white);
  isolation: isolate;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -2;
  background:
    linear-gradient(90deg, rgba(11, 15, 24, 0.94) 0%, rgba(11, 15, 24, 0.76) 42%, rgba(11, 15, 24, 0.18) 74%),
    linear-gradient(180deg, rgba(16, 20, 31, 0.08), rgba(16, 20, 31, 0.28)),
    url("assets/console-hero-app.png") center right / cover no-repeat;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 9px;
  background: linear-gradient(90deg, var(--red) 0 33.33%, var(--yellow) 33.33% 66.66%, var(--cyan) 66.66% 100%);
}

.hero-content {
  width: min(680px, calc(100% - 32px));
  margin: 0 auto;
  transform: translateX(max(-220px, calc((1120px - 100vw) / 2)));
}

.kicker {
  margin: 0 0 14px;
  color: var(--cyan);
  font-size: 0.82rem;
  font-weight: 850;
  text-transform: uppercase;
}

.hero h1,
.section-heading h2,
.preview-copy h2,
.tinfoil-heading h2,
.cta-inner h2 {
  margin: 0;
  letter-spacing: 0;
  line-height: 1.03;
  text-wrap: balance;
}

.hero h1 {
  max-width: 720px;
  font-size: 4.6rem;
}

.hero-copy {
  max-width: 610px;
  margin: 22px 0 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: 1.16rem;
  line-height: 1.72;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  border: 0;
  border-radius: 8px;
  padding: 0 18px;
  cursor: pointer;
  font-weight: 850;
}

.button-primary {
  color: var(--white);
  background: var(--red);
  box-shadow: 0 12px 28px rgba(255, 74, 85, 0.28);
}

.button-primary:hover,
.button-primary:focus-visible {
  background: var(--red-deep);
  outline: none;
}

.button-ghost {
  color: var(--white);
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.24);
}

.button-ghost:hover,
.button-ghost:focus-visible {
  background: rgba(255, 255, 255, 0.2);
  outline: none;
}

.button-icon {
  display: inline-grid;
  width: 22px;
  height: 22px;
  place-items: center;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.18);
  line-height: 1;
}

.signal-strip {
  background: var(--card-bg);
  border-bottom: 1px solid var(--line);
}

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

.signal-grid div {
  min-height: 118px;
  padding: 26px 28px;
  border-right: 1px solid var(--line);
}

.signal-grid div:first-child {
  border-left: 1px solid var(--line);
}

.signal-grid strong,
.signal-grid span {
  display: block;
}

.signal-grid strong {
  font-size: 1.55rem;
  line-height: 1;
}

.signal-grid span {
  margin-top: 9px;
  color: var(--ink-soft);
  line-height: 1.55;
}

.section {
  scroll-margin-top: 88px;
  padding: 88px 0;
}

.section-light {
  background:
    linear-gradient(180deg, var(--card-bg) 0%, var(--paper) 100%);
}

.section-dark {
  color: var(--white);
  background:
    linear-gradient(135deg, #10141f 0%, #202836 58%, #111622 100%);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-heading h2,
.preview-copy h2,
.tinfoil-heading h2,
.cta-inner h2 {
  font-size: 3rem;
}

.section-heading > p:last-child,
.preview-copy > p,
.tinfoil-heading > p:not(.kicker),
.cta-inner > p {
  margin: 18px 0 0;
  color: var(--ink-soft);
  font-size: 1.06rem;
  line-height: 1.75;
}

.section-dark .preview-copy > p {
  color: rgba(255, 255, 255, 0.72);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.feature-card {
  display: grid;
  grid-template-rows: auto 1fr;
  overflow: hidden;
  min-height: 430px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--card-bg);
  box-shadow: 0 12px 30px rgba(16, 20, 31, 0.07);
}

.feature-visual {
  position: relative;
  display: grid;
  min-height: 210px;
  margin: 0;
  place-items: center;
  overflow: hidden;
  background: var(--dark);
  isolation: isolate;
}

.feature-visual::before {
  content: "";
  position: absolute;
  inset: 20px;
  border: 10px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.16) 0 12%, transparent 12% 18%, rgba(255, 255, 255, 0.16) 18% 38%, transparent 38% 44%, rgba(255, 255, 255, 0.16) 44% 68%, transparent 68%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.1) 0 22%, transparent 22% 100%);
}

.feature-visual::after {
  content: "";
  position: absolute;
  inset: auto 34px 32px;
  height: 10px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.22);
}

.feature-visual span {
  position: relative;
  z-index: 1;
  padding: 8px 12px;
  border: 1px solid rgba(255, 255, 255, 0.26);
  border-radius: 8px;
  color: var(--white);
  background: rgba(16, 20, 31, 0.62);
  font-weight: 800;
}

.feature-visual.has-image {
  aspect-ratio: 16 / 9;
  min-height: 0;
  background: var(--dark);
}

.feature-visual.has-image::before,
.feature-visual.has-image::after {
  display: none;
}

.feature-visual.has-image img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
  transform: none;
}

.feature-visual.has-image span {
  align-self: end;
  justify-self: start;
  margin: 0 0 14px 14px;
  color: var(--white);
  background: rgba(16, 20, 31, 0.78);
  backdrop-filter: blur(10px);
}

.feature-body {
  padding: 24px;
}

.feature-label {
  margin: 0 0 9px;
  color: var(--red-deep);
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
}

.feature-body h3 {
  margin: 0;
  font-size: 1.35rem;
  line-height: 1.24;
}

.feature-body p:last-child {
  margin: 12px 0 0;
  color: var(--ink-soft);
  line-height: 1.68;
}

.preview-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.86fr) minmax(520px, 1.14fr);
  gap: 46px;
  align-items: center;
}

.preview-copy .kicker,
.section-dark .kicker {
  color: var(--yellow);
}

.tab-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.tab-button {
  min-height: 42px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 8px;
  padding: 0 14px;
  color: rgba(255, 255, 255, 0.76);
  background: rgba(255, 255, 255, 0.08);
  cursor: pointer;
  font-weight: 800;
}

.tab-button:hover,
.tab-button:focus-visible,
.tab-button.active {
  color: var(--ink);
  background: var(--yellow);
  outline: none;
}

.preview-console {
  margin: 0;
}

.preview-console img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 8px;
  filter: drop-shadow(0 30px 46px rgba(0, 0, 0, 0.38));
}

.preview-console-caption {
  width: min(640px, calc(100% - 48px));
  margin: -10px auto 0;
  padding: 14px 16px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: 8px;
  color: var(--white);
  background: rgba(16, 20, 31, 0.84);
  box-shadow: 0 18px 36px rgba(0, 0, 0, 0.22);
}

.preview-console-caption strong,
.preview-console-caption p {
  display: block;
}

.preview-console-caption p {
  margin: 5px 0 0;
  color: rgba(255, 255, 255, 0.74);
  font-size: 0.94rem;
  line-height: 1.45;
}

.tinfoil-section {
  background:
    linear-gradient(180deg, var(--paper) 0%, var(--card-bg) 100%);
}

.tinfoil-shell {
  display: grid;
  gap: 22px;
}

.tinfoil-heading {
  max-width: 760px;
}

.tinfoil-steps code,
.issue-list code,
.signal-grid code {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 3px 8px;
  color: var(--ink);
  background: var(--card-bg);
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", monospace;
  font-size: 0.94em;
}

.tinfoil-accordion-list {
  display: grid;
  gap: 12px;
}

.tinfoil-accordion {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--card-bg);
  box-shadow: 0 14px 34px rgba(16, 20, 31, 0.08);
}

.tinfoil-accordion summary {
  display: grid;
  grid-template-columns: 46px 1fr auto;
  gap: 16px;
  align-items: center;
  min-height: 76px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

.tinfoil-accordion summary::-webkit-details-marker {
  display: none;
}

.tinfoil-accordion summary::after {
  content: "+";
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border-radius: 50%;
  color: var(--white);
  background: var(--ink);
  font-weight: 900;
}

.tinfoil-accordion[open] summary::after {
  content: "-";
  background: var(--red);
}

.accordion-number {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 8px;
  color: var(--white);
  background: linear-gradient(135deg, var(--cyan), var(--red));
  font-weight: 900;
}

.tinfoil-accordion summary span:nth-child(2) {
  display: grid;
  gap: 4px;
}

.tinfoil-accordion summary strong,
.tinfoil-accordion summary small {
  display: block;
}

.tinfoil-accordion summary strong {
  font-size: 1.08rem;
}

.tinfoil-accordion summary small {
  color: var(--ink-soft);
  font-weight: 700;
}

.tinfoil-steps,
.issue-list {
  margin: 0;
  padding: 0 22px 22px 80px;
}

.tinfoil-steps {
  display: grid;
  gap: 12px;
  list-style: none;
}

.tinfoil-steps li {
  display: grid;
  grid-template-columns: 34px 1fr;
  gap: 12px;
  align-items: start;
}

.tinfoil-steps li > span {
  display: grid;
  width: 30px;
  height: 30px;
  place-items: center;
  border-radius: 8px;
  color: var(--white);
  background: linear-gradient(135deg, var(--cyan), var(--red));
  box-shadow: 0 10px 20px rgba(255, 74, 85, 0.2);
  font-weight: 900;
}

.tinfoil-steps p {
  margin: 0;
  color: var(--ink-soft);
  line-height: 1.55;
}

.issue-list {
  display: grid;
  gap: 10px;
  padding-left: 102px;
  color: var(--ink-soft);
  line-height: 1.6;
}

.issue-list strong {
  color: var(--ink);
}

.issue-list code {
  display: inline-block;
  margin-top: 6px;
  line-height: 1.45;
}

.video-panel {
  padding: 0 22px 22px 80px;
}

.video-panel iframe {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  border: 0;
  border-radius: 8px;
  background: var(--dark);
}

.cta-section {
  padding: 86px 0;
  color: var(--white);
  background:
    linear-gradient(90deg, rgba(255, 74, 85, 0.95), rgba(0, 185, 216, 0.95)),
    var(--dark);
}

.cta-inner {
  display: grid;
  grid-template-columns: minmax(0, 0.75fr) minmax(480px, 0.85fr);
  gap: 34px;
  align-items: center;
}

.cta-copy .kicker,
.cta-copy > p {
  color: rgba(255, 255, 255, 0.86);
}

.cta-copy p:last-child {
  margin: 16px 0 0;
  max-width: 620px;
  color: rgba(255, 255, 255, 0.82);
  font-size: 1.04rem;
  line-height: 1.68;
}

.download-panel {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  padding: 22px;
  border: 1px solid rgba(255, 255, 255, 0.25);
  border-radius: 8px;
  background: rgba(16, 20, 31, 0.2);
}

.download-button {
  display: flex;
  min-height: 76px;
  align-items: center;
  justify-content: flex-start;
  gap: 14px;
  overflow: hidden;
  position: relative;
  padding: 16px 18px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
  color: var(--white);
  box-shadow: 0 14px 28px rgba(16, 20, 31, 0.2);
  font-weight: 800;
  text-align: left;
  line-height: 1.35;
  isolation: isolate;
}

.download-button::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: 0.92;
  transition: transform 180ms ease, opacity 180ms ease;
}

.download-nro::before {
  background:
    radial-gradient(circle at 18% 18%, rgba(255, 210, 63, 0.58), transparent 34%),
    linear-gradient(135deg, var(--red) 0%, #9d255d 52%, var(--dark-2) 100%);
}

.download-nsp::before {
  background:
    radial-gradient(circle at 18% 18%, rgba(255, 255, 255, 0.42), transparent 34%),
    linear-gradient(135deg, var(--cyan) 0%, #196f82 48%, var(--dark-2) 100%);
}

.download-icon {
  display: grid;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 50%;
  color: var(--ink);
  background: var(--white);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.22);
  font-size: 1.45rem;
  line-height: 1;
}

.download-button span:last-child {
  display: grid;
  gap: 3px;
  min-width: 0;
}

.download-button strong,
.download-button small {
  display: block;
}

.download-button strong {
  font-size: 1rem;
}

.download-button small {
  color: rgba(255, 255, 255, 0.76);
  font-size: 0.82rem;
  font-weight: 750;
}

.download-button:hover,
.download-button:focus-visible {
  outline: none;
  transform: translateY(-1px);
}

.download-button:hover::before,
.download-button:focus-visible::before {
  opacity: 1;
  transform: scale(1.04);
}

.site-footer {
  border-top: 1px solid var(--line);
  background: var(--card-bg);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 78px;
  color: var(--ink-soft);
}

.footer-inner a {
  font-weight: 850;
}

@media (max-width: 1080px) {
  .hero-content {
    margin-left: 32px;
    transform: none;
  }

  .hero h1 {
    font-size: 3.6rem;
  }

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

  .preview-layout,
  .cta-inner {
    grid-template-columns: 1fr;
  }

  .preview-console {
    max-width: 820px;
    margin: 0 auto;
  }
}

@media (max-width: 820px) {
  .site-header {
    min-height: 66px;
    padding: 12px 16px;
  }

  .nav-toggle {
    display: inline-block;
  }

  .site-nav {
    position: absolute;
    top: calc(100% + 8px);
    left: 16px;
    right: 16px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--card-bg);
    box-shadow: var(--shadow);
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a {
    padding: 13px 12px;
  }

  .hero {
    min-height: 74svh;
    padding: 94px 0 42px;
  }

  .hero-bg {
    background:
      linear-gradient(180deg, rgba(11, 15, 24, 0.94) 0%, rgba(11, 15, 24, 0.78) 52%, rgba(11, 15, 24, 0.48) 100%),
      url("assets/console-hero-app.png") center right / cover no-repeat;
  }

  .hero-content {
    width: min(640px, calc(100% - 32px));
    margin: 0 auto;
  }

  .hero h1 {
    font-size: 2.72rem;
    line-height: 1.07;
  }

  .hero-copy {
    font-size: 1rem;
    line-height: 1.64;
  }

  .signal-grid {
    grid-template-columns: 1fr;
  }

  .signal-grid div,
  .signal-grid div:first-child {
    border-right: 1px solid var(--line);
    border-left: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
  }

  .section {
    padding: 66px 0;
  }

  .section-heading h2,
  .preview-copy h2,
  .tinfoil-heading h2,
  .cta-inner h2 {
    font-size: 2.18rem;
    line-height: 1.1;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature-card {
    min-height: auto;
  }

  .preview-console-caption {
    width: min(620px, calc(100% - 28px));
    margin-top: -6px;
    padding: 12px;
  }

  .download-panel {
    grid-template-columns: 1fr;
  }

  .tinfoil-steps,
  .issue-list,
  .video-panel {
    padding-right: 18px;
    padding-left: 76px;
  }
}

@media (max-width: 520px) {
  .inner {
    width: min(1120px, calc(100% - 24px));
  }

  .hero-actions {
    display: grid;
  }

  .button {
    width: 100%;
  }

  .preview-console-caption p {
    display: none;
  }

  .tinfoil-accordion summary {
    align-items: start;
  }

  .tinfoil-accordion summary {
    grid-template-columns: 42px 1fr 32px;
    gap: 10px;
  }

  .tinfoil-steps,
  .issue-list,
  .video-panel {
    padding: 0 16px 18px;
  }
}

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

/* Floating Contact Buttons */
.floating-contact {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.contact-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 54px;
  height: 54px;
  border-radius: 50%;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15), 0 2px 4px rgba(0, 0, 0, 0.1);
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.contact-btn svg {
  width: 26px;
  height: 26px;
  transition: transform 0.3s ease;
}

/* Facebook Button specific styles */
.contact-btn.contact-facebook {
  background-color: #1877F2;
  color: #ffffff;
}

.contact-btn.contact-facebook svg {
  fill: currentColor;
  width: 22px;
  height: 22px;
}

/* Zalo Button specific styles */
.contact-btn.contact-zalo {
  background-color: #ffffff;
  border: 1px solid rgba(0, 0, 0, 0.05);
}

.contact-btn.contact-zalo svg {
  width: 54px; /* fills the button since it has a built-in white background circle */
  height: 54px;
}

/* Hover & Active states */
.contact-btn:hover {
  transform: translateY(-5px) scale(1.08);
  box-shadow: 0 8px 24px rgba(24, 119, 242, 0.25), 0 4px 8px rgba(0, 0, 0, 0.12);
}

.contact-btn.contact-zalo:hover {
  box-shadow: 0 8px 24px rgba(0, 104, 255, 0.2), 0 4px 8px rgba(0, 0, 0, 0.12);
}

.contact-btn:hover svg {
  transform: scale(1.08);
}

.contact-btn:active {
  transform: translateY(-2px) scale(0.96);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* Soft floating animation */
@keyframes floatBubble {
  0% { transform: translateY(0px); }
  50% { transform: translateY(-5px); }
  100% { transform: translateY(0px); }
}

.contact-btn.contact-zalo {
  animation: floatBubble 4s ease-in-out infinite;
}

.contact-btn.contact-facebook {
  animation: floatBubble 4s ease-in-out infinite 2s; /* offset phase */
}

/* Pause animation on hover */
.contact-btn:hover {
  animation-play-state: paused;
}

/* Responsive adjustments */
@media (max-width: 820px) {
  .floating-contact {
    bottom: 20px;
    right: 20px;
    gap: 10px;
  }
  .contact-btn {
    width: 48px;
    height: 48px;
  }
  .contact-btn.contact-zalo svg {
    width: 48px;
    height: 48px;
  }
  .contact-btn.contact-facebook svg {
    width: 18px;
    height: 18px;
  }
}

/* Header Right Layout */
.header-right {
  display: flex;
  align-items: center;
  gap: 16px;
}/* Theme Toggle Button Redesign */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: rgba(16, 20, 31, 0.05);
  color: var(--ink);
  cursor: pointer;
  padding: 0;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.theme-toggle:hover {
  background: rgba(0, 185, 216, 0.1);
  border-color: var(--cyan);
  color: var(--cyan);
  transform: scale(1.05);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  stroke: currentColor;
  transition: transform 0.5s ease;
}

/* Toggle icon display based on active theme */
.sun-icon {
  display: none;
}

.moon-icon {
  display: block;
}

html[data-theme="dark"] .sun-icon {
  display: block;
}

html[data-theme="dark"] .moon-icon {
  display: none;
}

html[data-theme="dark"] .theme-toggle svg {
  transform: rotate(360deg);
}

/* Dark Mode Theme Variables & Overrides */
html[data-theme="dark"] {
  color-scheme: dark;
  --ink: #f8fafc;
  --ink-soft: #94a3b8;
  --paper: #090d16;
  --card-bg: #111726;
  --line: #1e293b;
  --shadow: 0 22px 60px rgba(0, 0, 0, 0.45);
}

html[data-theme="dark"] .site-header {
  background: rgba(9, 13, 22, 0.85);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

/* Custom button styles in Dark Mode for high contrast readability */
html[data-theme="dark"] .site-nav .nav-action {
  color: #090d16 !important;
  background: #ffffff !important;
}

html[data-theme="dark"] .site-nav .nav-action:hover,
html[data-theme="dark"] .site-nav .nav-action:focus-visible {
  color: #ffffff !important;
  background: var(--cyan) !important;
}

html[data-theme="dark"] .theme-toggle {
  border-color: rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.08);
  color: #f8fafc;
}

html[data-theme="dark"] .theme-toggle:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: rgba(255, 255, 255, 0.25);
  color: #ffffff;
}

/* Smooth color transitions for dark/light switch */
body,
.site-header,
.signal-strip,
.feature-card,
.tinfoil-accordion,
.site-footer,
.brand,
.site-nav a,
.tinfoil-steps li > span,
.accordion-number,
.theme-toggle,
.floating-contact a {
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease;
}

/* Adjustments for images/branding in dark mode */
html[data-theme="dark"] .brand-logo {
  filter: drop-shadow(0 0 8px rgba(0, 185, 216, 0.2));
}