/* Station 3 — platform styles. */
.platform-screen {
  padding-block: var(--s-7) var(--s-9);
}
.platform-screen > section,
.platform-screen > .platform-anatomy {
  margin-block-start: var(--s-9);
}
.platform-header {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(18rem, 0.85fr);
  gap: var(--s-7);
  align-items: center;
}
.platform-stamp {
  margin-block-start: var(--s-5);
  max-inline-size: var(--reading-max);
}
.platform-browser {
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--surface);
  box-shadow: var(--shadow-2);
}
.platform-dots {
  display: flex;
  gap: var(--s-2);
  padding: var(--s-3);
  border-block-end: 1px solid var(--border);
  background: var(--surface-tint);
}
.platform-dots i {
  inline-size: 0.6rem;
  block-size: 0.6rem;
  border-radius: 50%;
  background: var(--border-strong);
}
.platform-url {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  margin: var(--s-4);
  padding: var(--s-2) var(--s-3);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  direction: ltr;
}
.platform-url svg {
  inline-size: 1rem;
  color: var(--teal-700);
}
.platform-address {
  min-inline-size: 14ch;
  font-family: ui-monospace, monospace;
}
.platform-browser > p {
  margin: var(--s-6);
  font-size: var(--fs-h3);
  font-weight: var(--fw-bold);
}
.platform-heading {
  display: flex;
  justify-content: space-between;
  align-items: end;
  gap: var(--s-5);
  margin-block-end: var(--s-5);
  border-block-end: 1px solid var(--border);
}
.platform-heading h2,
.platform-heading p {
  margin-block-end: var(--s-3);
}
.platform-heading p {
  max-inline-size: var(--reading-max);
  color: var(--ink-2);
}
.platform-quotes {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(14rem, 0.6fr);
  gap: var(--s-4);
}
.platform-quotes blockquote {
  margin: 0;
  padding: var(--s-6);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface);
  box-shadow: var(--shadow-1);
}
.quote-badge {
  display: grid;
  place-items: center;
  inline-size: 3rem;
  block-size: 3rem;
  color: var(--gold-400);
  background: var(--surface-gold);
  border-radius: var(--r-pill);
  margin-block-end: var(--s-3);
}
.quote-badge svg {
  inline-size: 28px;
  block-size: 28px;
}
.platform-quotes p {
  margin: 0 0 var(--s-4);
  font-size: var(--fs-h3);
}
.platform-quotes footer,
.platform-source,
.platform-note {
  color: var(--ink-3);
  font-size: var(--fs-small);
}
.platform-quote-main {
  background: var(--surface-tint) !important;
}
.platform-areas {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--s-3);
}
.platform-tile {
  min-block-size: 12rem;
  padding: 0;
  border: 0;
  border-radius: var(--r-md);
  background: transparent;
  color: var(--ink);
  text-align: inherit;
  perspective: 800px;
}
.platform-tile-inner {
  position: relative;
  display: block;
  min-block-size: 12rem;
  transition: transform var(--dur-slow) var(--ease-in-out);
  transform-style: preserve-3d;
}
.platform-tile.is-flipped .platform-tile-inner {
  transform: rotateY(180deg);
}
.platform-tile-face {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  gap: var(--s-3);
  padding: var(--s-4);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface);
  box-shadow: var(--shadow-1);
  backface-visibility: hidden;
}
.platform-tile-front {
  justify-items: center;
  font-weight: var(--fw-bold);
}
.platform-tile-back {
  display: grid;
  justify-items: center;
  gap: var(--s-2);
  transform: rotateY(180deg);
  color: var(--ink-2);
  font-size: var(--fs-small);
  text-align: center;
}
.platform-tile-back-title {
  color: var(--ink);
  font-size: var(--fs-small);
  font-weight: var(--fw-bold);
}
.platform-tile-back-detail {
  color: var(--ink-2);
}
.platform-tile-icon {
  display: grid;
  place-items: center;
  inline-size: 3.4rem;
  block-size: 3.4rem;
  color: var(--teal-700);
  transition: transform var(--dur-fast) var(--ease-out);
}
.platform-tile-icon svg {
  inline-size: 100%;
  block-size: 100%;
}
.platform-tile:hover .platform-tile-icon,
.platform-tile:focus-visible .platform-tile-icon {
  transform: translateY(-0.2rem) scale(1.1);
}
.platform-tile.is-flipped .platform-tile-icon {
  transform: scale(0.9) rotate(-6deg);
}
.platform-section > h3 {
  margin-block: var(--s-6) var(--s-3);
}
.platform-popular {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
}
.platform-popular span {
  padding: var(--s-1) var(--s-3);
  border: 1px solid var(--border);
  border-radius: var(--r-pill);
  color: var(--ink-2);
  font-size: var(--fs-small);
}
.platform-progress {
  display: flex;
  justify-content: flex-end;
  margin-block: 0 var(--s-3);
  color: var(--teal-700);
  font-weight: var(--fw-bold);
}
.platform-anatomy-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(16rem, 0.5fr);
  gap: var(--s-4);
  align-items: start;
}
.platform-mock {
  padding: var(--s-5);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-md);
  background: var(--surface);
  box-shadow: var(--shadow-1);
}
.platform-mock h3 {
  margin-block: var(--s-3) var(--s-5);
}
.platform-breadcrumb {
  margin: 0;
  color: var(--ink-3);
  font-size: var(--fs-small);
}
.platform-part {
  position: relative;
  display: block;
  inline-size: 100%;
  margin-block-start: var(--s-3);
  padding: var(--s-4);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  background: var(--bg);
  color: var(--ink);
  text-align: inherit;
  transition:
    transform var(--dur-fast) var(--ease-out),
    border-color var(--dur-fast) var(--ease-out);
}
.platform-part:hover,
.platform-part.is-active {
  border-color: var(--teal-700);
  transform: translateY(-0.15rem);
}
.platform-part-copy {
  display: grid;
  gap: var(--s-1);
  padding-inline-end: var(--s-6);
}
.platform-part-copy span {
  color: var(--ink-2);
  font-size: var(--fs-small);
}
.platform-badge {
  position: absolute;
  inset-inline-end: var(--s-3);
  inset-block-start: var(--s-3);
  display: grid;
  place-items: center;
  inline-size: 1.75rem;
  block-size: 1.75rem;
  border-radius: 50%;
  background: var(--teal-700);
  color: var(--ink-inverse);
  font-weight: var(--fw-bold);
  animation: platform-pulse var(--dur-slow) var(--ease-out) 1;
}
@keyframes platform-pulse {
  from {
    opacity: 0.4;
    transform: scale(0.75);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}
.platform-agree {
  display: flex;
  align-items: center;
  gap: var(--s-3);
}
.platform-check {
  display: grid;
  place-items: center;
  inline-size: 1.5rem;
  block-size: 1.5rem;
  border: 1px solid var(--border-strong);
  border-radius: var(--r-sm);
  color: var(--teal-700);
}
.platform-check svg {
  inline-size: 1rem;
}
.platform-login {
  display: inline-flex;
  padding: var(--s-2) var(--s-5);
  border-radius: var(--r-sm);
  background: var(--teal-700);
  color: var(--ink-inverse);
  font-weight: var(--fw-bold);
}
.platform-explain {
  position: sticky;
  inset-block-start: var(--s-4);
  min-block-size: 10rem;
  padding: var(--s-5);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface-gold);
  box-shadow: var(--shadow-1);
}
.platform-explain strong {
  display: block;
  margin-block-end: var(--s-3);
  color: var(--gold-700);
}
.platform-explain p,
.platform-lesson {
  margin: 0;
}
.platform-lesson {
  margin-block-start: var(--s-4);
  padding: var(--s-4);
  border-inline-start: 3px solid var(--gold-400);
  background: var(--surface-gold);
}
.platform-path {
  position: relative;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr)) auto;
  gap: var(--s-3);
  margin: 0 0 var(--s-5);
  padding: 0;
  list-style: none;
}
.platform-path:before {
  content: "";
  position: absolute;
  inset-inline-start: 10%;
  inset-inline-end: 17%;
  inset-block-start: 2rem;
  block-size: 2px;
  background: var(--border-strong);
}
.platform-path-step {
  position: relative;
  display: grid;
  justify-items: center;
  gap: var(--s-2);
  text-align: center;
  opacity: 0.45;
  transition:
    opacity var(--dur-base) var(--ease-out),
    transform var(--dur-base) var(--ease-out);
}
.platform-path-step.is-active {
  opacity: 1;
  transform: translateY(-0.2rem);
}
.platform-path-step h3,
.platform-path-step p {
  margin: 0;
}
.platform-path-step p {
  color: var(--ink-2);
  font-size: var(--fs-small);
}
.platform-path-icon {
  z-index: 1;
  display: grid;
  place-items: center;
  inline-size: 4rem;
  block-size: 4rem;
  border: 2px solid var(--border-strong);
  border-radius: 50%;
  background: var(--surface);
  color: var(--teal-700);
}
.platform-path-step.is-active .platform-path-icon {
  border-color: var(--teal-700);
  color: var(--teal-800);
}
.platform-path-icon svg {
  inline-size: 1.9rem;
}
.platform-path-dot {
  position: absolute;
  z-index: 2;
  inset-block-start: 0;
  inset-inline-start: 0;
  inline-size: 0.55rem;
  block-size: 0.55rem;
  border-radius: 50%;
  background: var(--gold-400);
}
.platform-path-done {
  z-index: 1;
  display: grid;
  place-items: center;
  align-self: start;
  inline-size: 4rem;
  block-size: 4rem;
  border: 2px solid var(--ok);
  border-radius: 50%;
  color: var(--ok);
  background: var(--ok-bg);
}
.platform-path-done svg {
  inline-size: 1.8rem;
  block-size: 1.8rem;
}
.platform-three {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--s-4);
}
.platform-channel {
  padding: 0;
  overflow: hidden;
}
.platform-channel-button {
  display: flex;
  align-items: center;
  gap: var(--s-3);
  inline-size: 100%;
  padding: var(--s-5);
  border: 0;
  background: var(--surface);
  color: var(--ink);
  font-weight: var(--fw-bold);
  text-align: inherit;
}
.platform-channel-button svg {
  inline-size: 2rem;
  color: var(--teal-700);
}
.platform-channel-detail {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows var(--dur-base) var(--ease-out);
}
.platform-channel-detail > div {
  overflow: hidden;
}
.platform-channel-detail p {
  margin: 0;
  padding: 0 var(--s-5) var(--s-5);
  color: var(--ink-2);
}
.platform-channel.is-open .platform-channel-detail {
  grid-template-rows: 1fr;
}
.platform-security-card {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--s-5);
  padding: var(--s-6);
  border: 1px solid var(--border);
  border-radius: var(--r-md);
  background: var(--surface-tint);
}
.platform-security-card blockquote {
  margin: 0;
  font-size: var(--fs-h3);
}
.platform-security-icon {
  position: relative;
  display: grid;
  place-items: center;
  inline-size: 4rem;
  block-size: 4rem;
  color: var(--teal-700);
}
.platform-security-icon > svg:first-child {
  inline-size: 4rem;
}
.platform-security-icon > svg:last-child {
  position: absolute;
  inset-inline-end: -0.4rem;
  inset-block-end: -0.2rem;
  inline-size: 1.5rem;
  padding: var(--s-1);
  border-radius: 50%;
  background: var(--surface-gold);
  color: var(--gold-700);
  opacity: 0;
  transform: translateY(-0.5rem);
  transition:
    transform var(--dur-slow) var(--ease-out),
    opacity var(--dur-slow) var(--ease-out);
}
.platform-security.is-locked .platform-security-icon > svg:last-child {
  opacity: 1;
  transform: translateY(0);
}
.platform-info {
  display: flex;
  align-items: flex-start;
  gap: var(--s-3);
  margin-block: var(--s-4) 0;
  padding: var(--s-4);
  border: 1px solid var(--border);
  border-radius: var(--r-sm);
  background: var(--surface);
  color: var(--ink-2);
}
.platform-info svg {
  flex: none;
  inline-size: 1.4rem;
  color: var(--teal-700);
}
.platform-stat {
  display: grid;
  gap: var(--s-2);
  padding: var(--s-5);
  border-block-end: 3px solid var(--teal-700);
  background: var(--surface);
  box-shadow: var(--shadow-1);
}
.platform-stat h3,
.platform-stat p {
  margin: 0;
}
.platform-years {
  display: flex;
  justify-content: space-between;
  color: var(--ink-3);
  font-size: var(--fs-small);
}
.platform-bars {
  display: flex;
  align-items: end;
  gap: var(--s-2);
  block-size: 5rem;
  padding-block-end: var(--s-2);
  border-block-end: 1px solid var(--border);
}
.platform-bar {
  display: block;
  inline-size: 45%;
  block-size: var(--size);
  border-radius: var(--r-sm) var(--r-sm) 0 0;
}
.platform-from {
  background: var(--border-strong);
}
.platform-now {
  background: var(--teal-700);
}
.platform-stat > p {
  color: var(--ink-3);
  font-size: var(--fs-small);
}
.platform-to {
  color: var(--teal-700);
  font-size: var(--fs-h3);
}
.platform-challenge {
  padding: clamp(var(--s-5), 5vw, var(--s-7));
  border: 1px solid var(--border);
  border-radius: var(--r-lg);
  background: var(--surface-tint);
}
.platform-links {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--s-3);
}
.platform-link {
  min-block-size: 4.5rem;
  padding: var(--s-3);
  border: 1px solid var(--border-strong);
  border-radius: var(--r-sm);
  background: var(--surface);
  color: var(--ink);
  font-family: ui-monospace, monospace;
  font-size: var(--fs-small);
  overflow-wrap: anywhere;
}
.platform-link:hover,
.platform-link.is-selected {
  border-color: var(--teal-700);
  background: var(--teal-100);
}
.platform-feedback {
  display: flex;
  align-items: center;
  gap: var(--s-2);
  margin: var(--s-4) 0 0;
  padding: var(--s-3);
  border-radius: var(--r-sm);
}
.platform-feedback svg {
  inline-size: 1.25rem;
}
.platform-feedback.good {
  color: var(--ok);
  background: var(--ok-bg);
}
.platform-feedback.bad {
  color: var(--warn);
  background: var(--warn-bg);
}
.platform-tip {
  margin: var(--s-3) 0 0;
  color: var(--ink-2);
}
.platform-end h2 {
  margin-block-start: var(--s-7);
}
.platform-sources {
  margin: 0;
  padding-inline-start: var(--s-5);
}
.platform-sources li {
  margin-block-end: var(--s-2);
  color: var(--ink-2);
}
@media (prefers-reduced-motion: reduce) {
  .platform-tile-inner {
    transform: none !important;
  }
  .platform-tile-back {
    opacity: 0;
    transform: none;
  }
  .platform-tile.is-flipped .platform-tile-front {
    opacity: 0;
  }
  .platform-tile.is-flipped .platform-tile-back {
    opacity: 1;
  }
}
html.motion-off .platform-tile-inner {
  transform: none !important;
}
html.motion-off .platform-tile-back {
  opacity: 0;
  transform: none;
}
html.motion-off .platform-tile.is-flipped .platform-tile-front {
  opacity: 0;
}
html.motion-off .platform-tile.is-flipped .platform-tile-back {
  opacity: 1;
}
@media (max-width: 800px) {
  .platform-header,
  .platform-quotes,
  .platform-anatomy-grid {
    grid-template-columns: 1fr;
  }
  .platform-areas {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .platform-three,
  .platform-links {
    grid-template-columns: 1fr;
  }
  .platform-heading {
    display: block;
  }
  .platform-explain {
    position: static;
  }
  .platform-path {
    grid-template-columns: 1fr;
    gap: var(--s-5);
  }
  .platform-path:before {
    inset-inline-start: 2rem;
    inset-inline-end: auto;
    inset-block: 2rem 2rem;
    inline-size: 2px;
    block-size: auto;
  }
  .platform-path-step {
    grid-template-columns: 4rem 1fr;
    justify-items: start;
    text-align: inherit;
  }
  .platform-path-step p {
    grid-column: 2;
  }
  .platform-path-dot {
    inset-inline-start: 0;
    inset-block-start: 0;
  }
  .platform-path-done {
    margin-inline-start: 0;
    justify-self: start;
  }
  .platform-security-card {
    grid-template-columns: 1fr;
  }
  .platform-security-icon {
    margin-inline: auto;
  }
}