/* Melodia's landing page. Colors, radii, spacing and motion come from docs/design.md. The
   backdrop is the backdrop of the app (backdrop.rs). main.js turns its hue with the scroll. */

:root {
  color-scheme: dark;

  /* theme.rs */
  --bg: rgb(11 11 14);
  --surface: rgb(23 23 29);
  --surface-hover: rgb(32 32 40);
  --border: rgb(42 42 52);
  --text: rgb(242 242 247);
  --text-dim: rgb(166 166 180);
  --text-faint: rgb(128 128 142);
  --focus-ring: rgb(206 206 210 / 0.85);
  --dark-ink: rgb(8 8 10);

  --radius-small: 4px;
  --radius-medium: 6px;
  --radius-large: 8px;

  /* The tint, as "r g b": the accent and the light at the center of each glow. main.js changes
     them. These start values (Spotify green) stay without scripts or with reduced motion. */
  --accent: 30 215 96;
  --light-accent: 3.8 40.8 16.4;
  --light-complement: 28.56 2.66 26.04;
  /* The two other stops of the title gradient: a quarter turn and half a turn from the accent. */
  --quarter: 30 135 215;
  --complement: 215 30 200;

  /* anim.rs: ease-out cubic */
  --ease-out: cubic-bezier(0.33, 1, 0.68, 1);

  --font: Inter, "Segoe UI", system-ui, -apple-system, "Helvetica Neue", Roboto, Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Mono", Consolas, "DejaVu Sans Mono", monospace;
}

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

html {
  scroll-behavior: smooth;
  /* Tinted with the accent, as the scroll bars of the app. */
  scrollbar-color: rgb(var(--accent) / 0.45) var(--bg);
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 16px/1.6 var(--font);
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
}

/* --- Backdrop ------------------------------------------------------------ */

.backdrop {
  position: fixed;
  inset: 0;
  z-index: -1;
  background: var(--bg);
  isolation: isolate;
  /* The larger side of the window, as `glows` in backdrop.rs. */
  --size: max(100vw, 100vh);
}

/* Each glow adds light to the base, as in the app. The stops sample `falloff` of backdrop.rs
   from the center to its reach (1.1 radii). */
.glow {
  position: absolute;
  inset: 0;
  mix-blend-mode: plus-lighter;
  --falloff:
    rgb(var(--light) / 0.9570) 0%,
    rgb(var(--light) / 0.9302) 4.55%,
    rgb(var(--light) / 0.8711) 9.09%,
    rgb(var(--light) / 0.8067) 13.64%,
    rgb(var(--light) / 0.7422) 18.18%,
    rgb(var(--light) / 0.6778) 22.73%,
    rgb(var(--light) / 0.6133) 27.27%,
    rgb(var(--light) / 0.5489) 31.82%,
    rgb(var(--light) / 0.4855) 36.36%,
    rgb(var(--light) / 0.4288) 40.91%,
    rgb(var(--light) / 0.3829) 45.45%,
    rgb(var(--light) / 0.3436) 50%,
    rgb(var(--light) / 0.3055) 54.55%,
    rgb(var(--light) / 0.2673) 59.09%,
    rgb(var(--light) / 0.2291) 63.64%,
    rgb(var(--light) / 0.1909) 68.18%,
    rgb(var(--light) / 0.1527) 72.73%,
    rgb(var(--light) / 0.1145) 77.27%,
    rgb(var(--light) / 0.0764) 81.82%,
    rgb(var(--light) / 0.0398) 86.36%,
    rgb(var(--light) / 0.0127) 90.91%,
    rgb(var(--light) / 0.0016) 95.45%,
    rgb(var(--light) / 0) 100%;
}

.glow-accent {
  --light: var(--light-accent);
  background: radial-gradient(circle calc(var(--size) * 0.75 * 1.1) at 22% 42%, var(--falloff));
}

.glow-complement {
  --light: var(--light-complement);
  background: radial-gradient(circle calc(var(--size) * 0.6 * 1.1) at 100% 100%, var(--falloff));
}

/* --- Shared pieces ------------------------------------------------------- */

a {
  color: var(--text-dim);
  text-decoration: underline;
  text-decoration-color: transparent;
  text-underline-offset: 3px;
  transition: color 0.16s var(--ease-out), text-decoration-color 0.16s var(--ease-out);
}

a:hover {
  color: var(--text);
  text-decoration-color: var(--text-dim);
}

:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 1px;
}

strong {
  font-weight: 600;
}

code {
  font-family: var(--mono);
  font-size: 0.9em;
  padding: 1px 6px;
  border-radius: var(--radius-small);
  background: rgb(255 255 255 / 0.055);
}

/* widgets::pill_button: on hover and press, only the fill changes. The text does not move. */
.pill {
  position: relative;
  isolation: isolate;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 44px;
  padding: 0 24px;
  border-radius: 999px;
  color: var(--dark-ink);
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  white-space: nowrap;
}

.pill::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  border-radius: inherit;
  background: var(--text);
  box-shadow: 0 8px 24px rgb(0 0 0 / 0.35);
  transition: transform 0.16s var(--ease-out), background-color 0.16s var(--ease-out);
}

.pill:hover {
  color: var(--dark-ink);
}

.pill:hover::before {
  transform: scaleX(1.05);
  background: color-mix(in srgb, var(--text), white 12%);
}

.pill:active::before {
  transform: scaleX(0.96);
  transition-duration: 0.08s;
}

.pill-icon {
  flex: none;
  margin: 0 10px 0 -4px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* The version is a segment of its own, after a thin divider. */
.pill-version {
  margin-left: 14px;
  padding-left: 14px;
  border-left: 1px solid rgb(8 8 10 / 0.18);
  font-weight: 400;
  font-variant-numeric: tabular-nums;
  opacity: 0.6;
}

.pill:focus-visible {
  outline-offset: 2px;
}

/* widgets::text_button */
.text-button {
  font-size: 15px;
  text-decoration: none;
  border-radius: var(--radius-medium);
}

/* As previous / next in the app: on hover, the glyph moves 2 px in its direction. */
.text-button-down {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.text-button-down svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 0.16s var(--ease-out);
}

.text-button-down:hover svg {
  transform: translateY(2px);
}

/* --- Hero ---------------------------------------------------------------- */

main {
  max-width: 1168px;
  margin: 0 auto;
  padding: 0 24px;
}

.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-top: clamp(40px, 8vh, 80px);
  text-align: center;
}

/* The icon over the name. The halo behind the icon has the tint of the backdrop. */
.brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  color: var(--text-dim);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: 0.01em;
  text-decoration: none;
  border-radius: var(--radius-large);
}

.brand:hover {
  color: var(--text);
}

.brand-mark {
  position: relative;
  display: block;
  width: 96px;
  height: 96px;
}

.brand-mark::before {
  content: "";
  position: absolute;
  inset: -40%;
  z-index: -1;
  border-radius: 50%;
  background: radial-gradient(
    closest-side,
    rgb(var(--accent) / 0.32),
    rgb(var(--complement) / 0.12) 55%,
    transparent
  );
}

.brand-mark img {
  display: block;
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 10px 24px rgb(0 0 0 / 0.45));
}

h1 {
  margin: 32px 0 0;
  font-size: clamp(44px, 8vw, 84px);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.03em;
}

/* From the accent to the complementary color through a quarter turn, as the ring of the icon. A
   direct mix of two opposite hues goes through gray. White makes all hues light enough to read. */
.tinted {
  /* Space for the descender: background-clip cuts the text at the box of the line. */
  padding-bottom: 0.08em;
  background: linear-gradient(
    100deg,
    color-mix(in srgb, rgb(var(--accent)), white 30%),
    color-mix(in srgb, rgb(var(--quarter)), white 30%),
    color-mix(in srgb, rgb(var(--complement)), white 30%)
  );
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.subtitle {
  max-width: 34em;
  margin: 20px 0 0;
  color: var(--text-dim);
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.5;
  text-wrap: balance;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 16px 32px;
  margin-top: 36px;
}

.pill-download {
  height: 50px;
  padding: 0 26px;
}

.hint {
  margin: 18px 0 0;
  color: var(--text-faint);
  font-size: 13px;
  text-wrap: balance;
}

.hint > span {
  margin: 0 8px;
}

/* The window, with its shadow (docs/design.md «Elevation»). */
.shot {
  width: 100%;
  margin: clamp(48px, 8vh, 72px) auto 0;
  max-width: 1200px;
}

.shot img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-large);
  box-shadow: 0 12px 32px rgb(0 0 0 / 0.59);
}

/* --- Guide --------------------------------------------------------------- */

.guide {
  max-width: 720px;
  margin: 128px auto 0;
  scroll-margin-top: 32px;
}

.guide > h2 {
  margin: 0;
  font-size: clamp(26px, 3.4vw, 34px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

/* As the notices of the app (toasts.rs): a card with a dot in the accent. */
.notice {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-top: 24px;
  padding: 14px 26px 14px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius-large);
  background: var(--surface-hover);
  box-shadow: 0 8px 24px rgb(0 0 0 / 0.55);
}

.notice .dot {
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: rgb(var(--accent));
  transform: translateY(-1px);
}

.notice p {
  margin: 0;
  color: var(--text-dim);
  font-size: 15px;
}

.notice strong {
  color: var(--text);
}

/* Not a step: a card without a number. The prerequisites come before the list, and the check of
   the download comes after it. */
.requirements,
.check {
  margin-top: 40px;
  padding: 22px 24px 24px;
  border: 1px solid var(--border);
  border-radius: var(--radius-large);
  background:
    linear-gradient(135deg, rgb(var(--accent) / 0.08), transparent 60%),
    rgb(23 23 29 / 0.6);
}

/* The last step already has space below it. */
.check {
  margin-top: 4px;
}

.requirements h3,
.check h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
}

.requirements p,
.check p {
  margin: 6px 0 0;
  color: var(--text-dim);
}

.needs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.need {
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 64px;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-medium);
  background: var(--surface);
}

.need span {
  display: grid;
  gap: 2px;
  line-height: 1.3;
}

.need strong {
  font-weight: 600;
}

.need small {
  color: var(--text-faint);
  font-size: 13px;
}

.need-icon {
  flex: none;
  fill: none;
  stroke: var(--text);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* In a tile, the logo is the icon. Its clear space (half the height of the Spotify icon) stays
   as the gap. */
.need .spotify-logo {
  flex: none;
  width: 80px;
  padding: 0;
  margin: 0;
}

.steps {
  list-style: none;
  counter-reset: step;
  margin: 40px 0 0;
  padding: 0;
}

.step {
  position: relative;
  counter-increment: step;
  padding: 0 0 36px 52px;
}

/* The line between the numbers. */
.step:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 15px;
  top: 38px;
  bottom: 6px;
  width: 1px;
  background: var(--border);
}

.step::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: rgb(var(--accent) / 0.16);
  box-shadow: inset 0 0 0 1px rgb(var(--accent) / 0.45);
  font-size: 14px;
  font-weight: 600;
}

.step h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 600;
  line-height: 30px;
}

.step p {
  margin: 8px 0 0;
  color: var(--text-dim);
}

.step strong,
.step em {
  color: var(--text);
}

/* Links in running text: always underlined, with the line in the accent. The accent as text can
   be too dark at some hues. */
.step p a,
.check p a,
.hint a,
.bottom a {
  color: var(--text);
  text-decoration-color: rgb(var(--accent) / 0.7);
  text-decoration-thickness: 1.5px;
}

.step p a:hover,
.check p a:hover,
.hint a:hover,
.bottom a:hover {
  text-decoration-color: var(--text);
}

/* Spotify's logo (docs/design.md «Spotify's logo»). The padding is its clear space. The
   negative margin aligns the logo itself with the text. */
.spotify-logo {
  display: block;
  width: 160px;
  height: auto;
  padding: 11px;
  margin: 2px 0 -6px -11px;
  box-sizing: content-box;
}

/* The boxed field of the forms of the app. */
.copy-field {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
  padding: 8px 8px 8px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-medium);
  background: var(--surface);
}

.copy-field code {
  min-width: 0;
  padding: 0;
  background: none;
  font-size: 14px;
  overflow-wrap: anywhere;
}

.copy {
  flex: none;
  margin-left: auto;
  height: 30px;
  padding: 0 12px;
  border: 0;
  border-radius: var(--radius-medium);
  background: rgb(255 255 255 / 0.055);
  color: var(--text-faint);
  font: 600 13px var(--font);
  cursor: pointer;
  transition: color 0.16s var(--ease-out), background-color 0.16s var(--ease-out);
}

.copy:hover {
  color: var(--text);
  background: rgb(255 255 255 / 0.1);
}

.copy.copied {
  color: rgb(var(--accent));
  background: rgb(var(--accent) / 0.14);
  animation: copy-press 0.36s var(--ease-out);
}

/* A copy: a band of light crosses the address, and a ghost of it rises out of the field. */
.copy-field code.copied {
  background: linear-gradient(90deg, transparent 33%, rgb(var(--accent) / 0.3) 50%, transparent 67%)
    no-repeat 100% 0 / 300% 100%;
  border-radius: var(--radius-small);
  animation: copy-sweep 0.7s var(--ease-out);
}

.copy-ghost {
  position: absolute;
  color: rgb(var(--accent));
  pointer-events: none;
  animation: copy-lift 0.7s var(--ease-out) forwards;
}

@keyframes copy-press {
  35% {
    transform: scale(0.92);
  }

  70% {
    transform: scale(1.06);
  }
}

@keyframes copy-sweep {
  from {
    background-position: 100% 0;
  }

  40% {
    color: rgb(var(--accent));
  }

  to {
    background-position: 0 0;
  }
}

@keyframes copy-lift {
  from {
    opacity: 0.8;
  }

  to {
    opacity: 0;
    transform: translateY(-26px) scale(0.97);
  }
}

/* --- Footer -------------------------------------------------------------- */

.bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  max-width: 1168px;
  margin: 64px auto 0;
  padding: 32px 24px 48px;
  color: var(--text-faint);
  font-size: 13px;
}

/* Spotify's brand guidelines ask for this statement. It goes on its own line below the links. */
.disclaimer {
  flex-basis: 100%;
  margin: 4px 0 0;
  text-align: center;
}

/* --- Entrance: as the empty states of the app ---------------------------- */

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
}

.hero > * {
  animation: rise 0.4s var(--ease-out) backwards;
}

.hero > :nth-child(2) { animation-delay: 0.05s; }
.hero > :nth-child(3) { animation-delay: 0.08s; }
.hero > :nth-child(4) { animation-delay: 0.11s; }
.hero > :nth-child(5) { animation-delay: 0.14s; }
.hero > :nth-child(6) { animation-delay: 0.2s; }

/* --- Narrow screens ------------------------------------------------------ */

@media (max-width: 820px) {
  .guide {
    margin-top: 88px;
  }
}

@media (max-width: 480px) {
  .step {
    padding-left: 44px;
  }

  .notice {
    padding: 14px 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation: none !important;
    transition: none !important;
  }
}