:root {
  --bg: #fafafa;
  --surface: #ffffff;
  --surface-alt: #fafafa;
  --border: #dbdbdb;
  --text: #262626;
  --text-muted: #8e8e8e;
  --primary: #0095f6;
  --primary-hover: #1877f2;
  --danger: #ed4956;
  --divider: #c7c7c7;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
  --radius: 8px;
  --max-width: 380px;
  --font: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
  --bg: #000000;
  --surface: #000000;
  --surface-alt: #121212;
  --border: #262626;
  --text: #f5f5f5;
  --text-muted: #a8a8a8;
  --primary: #0095f6;
  --primary-hover: #1ea1ff;
  --danger: #ff5a6e;
  --divider: #262626;
  --shadow: none;
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font);
  display: flex;
  flex-direction: column;
  line-height: 1.4;
  transition: background-color 0.25s ease, color 0.25s ease;
}

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

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

button {
  font-family: inherit;
  cursor: pointer;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

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

/* Top bar */
.topbar {
  width: 100%;
  padding: 0.75rem 1rem;
}

.topbar__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: flex-end;
  align-items: center;
}

/* Footer */
.footer {
  width: 100%;
  padding: 1.25rem 1rem 2rem;
}

.footer__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

.lang select {
  background: transparent;
  color: var(--text-muted);
  border: none;
  padding: 0.25rem 0.5rem;
  font-size: 0.75rem;
  cursor: pointer;
}

.footer__copy {
  margin: 0;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.theme-toggle {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 2.4rem;
  height: 2.4rem;
  display: grid;
  place-items: center;
  font-size: 1.1rem;
  transition: background-color 0.2s ease;
}

.theme-toggle__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  line-height: 1;
}

.theme-toggle:hover {
  background: var(--surface-alt);
}

/* Layout */
.instagram-wrapper {
  flex: 1;
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem clamp(1rem, 4vw, 1.5rem) 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.instagram-continue {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.625rem;
}

.group {
  width: 100%;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2.5rem 2.5rem 1.25rem;
  box-shadow: var(--shadow);
}

/* Login card */
.login-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.instagram-logo {
  height: 3.2rem;
  margin-bottom: 1.25rem;
}

[data-theme="dark"] .instagram-logo {
  filter: brightness(0) invert(1);
}

.field {
  position: relative;
  width: 100%;
  margin-top: 0.35rem;
}

.field__box {
  position: relative;
  width: 100%;
}

.field__input {
  width: 100%;
  padding: 1.4rem 0.6rem 0.45rem;
  font-size: 0.85rem;
  color: var(--text);
  background: var(--surface-alt);
  border: 1px solid var(--border);
  border-radius: 6px;
  transition: border-color 0.2s ease;
}

.field__input:focus {
  outline: none;
  border-color: var(--text-muted);
}

.field__label {
  position: absolute;
  left: 0.6rem;
  top: 50%;
  transform: translateY(-50%);
  transform-origin: left center;
  font-size: 0.85rem;
  color: var(--text-muted);
  pointer-events: none;
  transition: transform 0.15s ease, top 0.15s ease, font-size 0.15s ease,
    color 0.15s ease;
}

.field__input:focus + .field__label,
.field__input:not(:placeholder-shown) + .field__label {
  top: 0.35rem;
  transform: translateY(0);
  font-size: 0.65rem;
}

.field__toggle {
  position: absolute;
  right: 0.5rem;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  color: var(--text);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem;
}

.field__error {
  min-height: 1rem;
  margin: 0.25rem 0 0;
  font-size: 0.72rem;
  color: var(--danger);
}

.field--invalid .field__input {
  border-color: var(--danger);
}

.login-button {
  width: 100%;
  margin-top: 0.5rem;
  padding: 0.55rem;
  border: none;
  border-radius: 8px;
  background-color: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.9rem;
  transition: background-color 0.2s ease, opacity 0.2s ease;
}

.login-button:hover {
  background-color: var(--primary-hover);
}

.login-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.divider {
  display: flex;
  align-items: center;
  width: 100%;
  gap: 1rem;
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 600;
}

.divider::before,
.divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--divider);
}

.forgot-link {
  color: var(--text-muted);
  font-size: 0.78rem;
}

.link-blue {
  color: var(--primary);
  font-weight: 600;
}

.signup-card {
  text-align: center;
  font-size: 0.85rem;
}

.signup-card__text {
  margin: 0;
}

/* Get the app */
.get-the-app {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
  padding: 0.5rem 0;
}

.get-app {
  margin: 0;
  font-size: 0.85rem;
  color: var(--text);
}

.download {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.app-download {
  height: 2.6rem;
  width: clamp(7rem, 40vw, 8.5rem);
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  border-radius: 4px;
}

.app-download--apple {
  background-image: url("./img/apple-button.png");
}

.app-download--google {
  background-image: url("./img/googleplay-button.png");
}

.form-status {
  min-height: 1rem;
  margin: 0.25rem 0 0;
  font-size: 0.78rem;
  text-align: center;
}

.form-status--success {
  color: var(--primary);
}

.form-status--error {
  color: var(--danger);
}

/* Responsive */
@media (max-width: 450px) {
  body {
    background-color: var(--surface);
  }

  .topbar {
    padding: 0.5rem 1rem;
  }

  .instagram-wrapper {
    padding: 0.5rem 1rem 1.5rem;
  }

  .group {
    border: none;
    box-shadow: none;
    background: transparent;
    padding: 1.5rem 0.75rem 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}

/* ===== App shell ===== */
#app {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.view {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}

.view[hidden] {
  display: none;
}

[data-view-heading]:focus {
  outline: none;
}

.instagram-continue {
  max-width: var(--max-width);
  margin: 0 auto;
}

.demo-hint {
  margin: 0.25rem 0 0;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

/* ===== Signup ===== */
.signup-form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.instagram-logo--small {
  height: 2.6rem;
  margin-bottom: 0.25rem;
}

.signup-intro {
  margin: 0 0 0.75rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-muted);
  text-align: center;
}

.strength {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  width: 100%;
  padding: 0 0.1rem;
}

.strength__track {
  flex: 1;
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.strength__bar {
  height: 100%;
  width: 0;
  border-radius: 2px;
  transition: width 0.25s ease, background-color 0.25s ease;
}

.strength__bar--weak {
  background: var(--danger);
}

.strength__bar--medium {
  background: #f5a623;
}

.strength__bar--strong {
  background: #2ecc71;
}

.strength__label {
  font-size: 0.7rem;
  color: var(--text-muted);
  min-width: 2.75rem;
  text-align: right;
}

.caps-hint {
  display: none;
  margin: 0;
  font-size: 0.72rem;
  color: var(--text-muted);
}

.caps-hint--visible {
  display: block;
}

/* ===== Loading spinner ===== */
.login-button {
  position: relative;
}

.login-button.is-loading {
  color: transparent;
}

.login-button.is-loading::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 1.1rem;
  height: 1.1rem;
  margin: -0.55rem 0 0 -0.55rem;
  border: 2px solid rgba(255, 255, 255, 0.4);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ===== Feed ===== */
.feed {
  width: 100%;
  max-width: 470px;
  margin: 0 auto;
  padding: 1rem;
}

.feed-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.5rem 0.25rem 0.75rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.75rem;
}

.feed-header__brand {
  display: flex;
  align-items: center;
}

.feed-logo {
  height: 2.1rem;
}

[data-theme="dark"] .feed-logo {
  filter: brightness(0) invert(1);
}

.feed-header__right {
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.avatar {
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: linear-gradient(45deg, #f09433, #e6683c, #dc2743, #cc2366, #bc1888);
  color: #fff;
  font-weight: 700;
}

.avatar--header {
  width: 2rem;
  height: 2rem;
  font-size: 0.9rem;
}

.avatar--post {
  width: 2rem;
  height: 2rem;
  font-size: 0.85rem;
}

.avatar--story {
  width: 3rem;
  height: 3rem;
  font-size: 1.2rem;
  border: 2px solid var(--surface);
}

.logout-button {
  background: none;
  border: none;
  color: var(--text);
  width: 2.2rem;
  height: 2.2rem;
  display: grid;
  place-items: center;
  border-radius: var(--radius);
  transition: background-color 0.2s ease;
}

.logout-button:hover {
  background: var(--surface-alt);
}

.logout-button svg {
  width: 1.35rem;
  height: 1.35rem;
}

.stories {
  display: flex;
  gap: 1rem;
  overflow-x: auto;
  padding: 0.5rem 0.25rem 0.9rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 1rem;
  scrollbar-width: none;
}

.stories::-webkit-scrollbar {
  display: none;
}

.story {
  background: none;
  border: none;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.3rem;
  min-width: 3.9rem;
  padding: 0;
  cursor: pointer;
}

.story__ring {
  display: grid;
  place-items: center;
  padding: 3px;
  border-radius: 50%;
  background: linear-gradient(45deg, #f09433, #e6683c, #dc2743, #cc2366, #bc1888);
}

.story__name {
  max-width: 3.9rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-size: 0.72rem;
  color: var(--text);
}

.post {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 1.25rem;
}

.post__header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 0.75rem;
}

.post__user {
  font-size: 0.85rem;
  font-weight: 600;
}

.post__media {
  position: relative;
  margin: 0;
  aspect-ratio: 1 / 1;
  background: var(--surface-alt);
  overflow: hidden;
}

.post__media::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    100deg,
    transparent 35%,
    rgba(255, 255, 255, 0.35) 50%,
    transparent 65%
  );
  transform: translateX(-100%);
  animation: shimmer 1.4s infinite;
}

[data-theme="dark"] .post__media::before {
  background: linear-gradient(
    100deg,
    transparent 35%,
    rgba(255, 255, 255, 0.08) 50%,
    transparent 65%
  );
}

.post__media.is-loaded::before {
  display: none;
}

.post__media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.post__media.is-loaded img {
  opacity: 1;
}

.post__media.is-fallback {
  background: linear-gradient(135deg, #8e8e8e, #262626);
}

.post[data-post="p1"] .post__media.is-fallback {
  background: linear-gradient(135deg, #f09433, #dc2743);
}

.post[data-post="p2"] .post__media.is-fallback {
  background: linear-gradient(135deg, #6a3093, #a044ff);
}

.post[data-post="p3"] .post__media.is-fallback {
  background: linear-gradient(135deg, #11998e, #38ef7d);
}

.post[data-post="p4"] .post__media.is-fallback {
  background: linear-gradient(135deg, #fc4a1a, #f7b733);
}

.post[data-post="p5"] .post__media.is-fallback {
  background: linear-gradient(135deg, #2193b0, #6dd5ed);
}

@keyframes shimmer {
  to {
    transform: translateX(100%);
  }
}

.post__body {
  padding: 0.5rem 0.75rem 0.75rem;
}

.post__actions {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.post__action {
  background: none;
  border: none;
  padding: 0.15rem;
  width: 1.75rem;
  height: 1.75rem;
  display: grid;
  place-items: center;
  color: var(--text);
  transition: opacity 0.15s ease;
}

.post__action:hover {
  opacity: 0.6;
}

.post__action svg {
  width: 1.5rem;
  height: 1.5rem;
}

.post__action--save {
  margin-left: auto;
}

.post__action--like.is-liked {
  color: #ed4956;
}

.post__action--like.is-pop svg {
  animation: pop 0.3s ease;
}

@keyframes pop {
  0% {
    transform: scale(1);
  }
  40% {
    transform: scale(1.35);
  }
  100% {
    transform: scale(1);
  }
}

.post__likes {
  margin: 0.5rem 0 0;
  font-size: 0.85rem;
  font-weight: 600;
}

.post__caption {
  margin: 0.3rem 0 0;
  font-size: 0.85rem;
}

.post__caption strong {
  font-weight: 600;
}

/* ===== Toasts ===== */
.toasts {
  position: fixed;
  left: 50%;
  bottom: 1.25rem;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  z-index: 1000;
  width: min(92vw, 26rem);
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: #262626;
  color: #fff;
  padding: 0.7rem 0.9rem;
  border-radius: 8px;
  border-left: 3px solid #0095f6;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
  font-size: 0.85rem;
  opacity: 0;
  transform: translateY(0.5rem);
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.toast--visible {
  opacity: 1;
  transform: none;
}

.toast--success {
  border-left-color: #2ecc71;
}

.toast--error {
  border-left-color: #ed4956;
}

.toast__close {
  background: none;
  border: none;
  color: #fff;
  opacity: 0.7;
  font-size: 1.15rem;
  line-height: 1;
  margin-left: auto;
  padding: 0 0.15rem;
  cursor: pointer;
}

.toast__close:hover {
  opacity: 1;
}

/* ===== Responsive: app ===== */
@media (max-width: 450px) {
  .feed {
    padding: 0.5rem 0.75rem 1rem;
  }
}