/* ==========================================================
   ListenEachOther — Material Design 3 (tự viết, không CDN)
   ========================================================== */

:root {
  /* Bảng màu (tông xanh lá dịu + tím nhạt, gợi sự lắng nghe) */
  --md-primary: #3d6a57;
  --md-on-primary: #ffffff;
  --md-primary-container: #c5ecd9;
  --md-on-primary-container: #0a2e20;

  --md-secondary: #4c6358;
  --md-on-secondary: #ffffff;
  --md-secondary-container: #cfe9db;
  --md-on-secondary-container: #0a2016;

  --md-tertiary: #3e6376;
  --md-tertiary-container: #c3e8ff;

  --md-error: #ba1a1a;
  --md-on-error: #ffffff;
  --md-error-container: #ffdad6;

  --md-background: #f6fbf7;
  --md-on-background: #171d1a;
  --md-surface: #f6fbf7;
  --md-surface-variant: #dce5df;
  --md-on-surface: #171d1a;
  --md-on-surface-variant: #404943;
  --md-surface-container-low: #f0f5f1;
  --md-surface-container: #eaefeb;
  --md-surface-container-high: #e4e9e5;
  --md-outline: #707973;
  --md-outline-variant: #c0c9c2;

  /* Elevation */
  --md-elev-1: 0 1px 2px rgba(0,0,0,.3), 0 1px 3px 1px rgba(0,0,0,.15);
  --md-elev-2: 0 1px 2px rgba(0,0,0,.3), 0 2px 6px 2px rgba(0,0,0,.15);
  --md-elev-3: 0 1px 3px rgba(0,0,0,.3), 0 4px 8px 3px rgba(0,0,0,.15);

  /* Hình dạng */
  --md-radius-xs: 4px;
  --md-radius-s: 8px;
  --md-radius-m: 12px;
  --md-radius-l: 16px;
  --md-radius-xl: 28px;
  --md-radius-full: 999px;

  /* Typography */
  --md-font: 'Roboto', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --md-font-mono: ui-monospace, 'SFMono-Regular', Menlo, monospace;

  /* Khoảng cách */
  --md-space-1: 4px;
  --md-space-2: 8px;
  --md-space-3: 12px;
  --md-space-4: 16px;
  --md-space-5: 24px;
  --md-space-6: 32px;

  --md-motion: cubic-bezier(.2, 0, 0, 1);
}

@media (prefers-color-scheme: dark) {
  :root {
    --md-primary: #a8d1bd;
    --md-on-primary: #113828;
    --md-primary-container: #2a4f3d;
    --md-on-primary-container: #c5ecd9;
    --md-secondary: #b4ccbe;
    --md-on-secondary: #203529;
    --md-secondary-container: #364b3f;
    --md-on-secondary-container: #cfe9db;
    --md-error: #ffb4ab;
    --md-error-container: #93000a;
    --md-background: #0f1512;
    --md-on-background: #dfe4e0;
    --md-surface: #0f1512;
    --md-surface-variant: #404943;
    --md-on-surface: #dfe4e0;
    --md-on-surface-variant: #c0c9c2;
    --md-surface-container-low: #171d1a;
    --md-surface-container: #1b211e;
    --md-surface-container-high: #262b28;
    --md-outline: #8a938d;
    --md-outline-variant: #404943;
  }
}

/* ---------- Nền & reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--md-font);
  font-size: 16px;
  line-height: 1.5;
  color: var(--md-on-background);
  background: var(--md-background);
  -webkit-font-smoothing: antialiased;
}
a { color: var(--md-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }
h1, h2, h3, h4 { margin: 0; font-weight: 500; line-height: 1.25; }
h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
p { margin: 0 0 var(--md-space-3); }
.muted { color: var(--md-on-surface-variant); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* ---------- Top App Bar ---------- */
.md-top-app-bar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: var(--md-space-3);
  height: 64px;
  padding: 0 var(--md-space-4);
  background: var(--md-surface-container);
  color: var(--md-on-surface);
  box-shadow: var(--md-elev-1);
}
.md-top-app-bar__title { font-size: 1.25rem; font-weight: 500; flex: 1; }
.md-top-app-bar__brand { display: flex; align-items: center; gap: var(--md-space-2); color: var(--md-on-surface); }
.md-top-app-bar__brand:hover { text-decoration: none; }
.md-logo {
  width: 36px; height: 36px; border-radius: 10px;
  background: linear-gradient(135deg, var(--md-primary), var(--md-tertiary));
  display: grid; place-items: center; color: var(--md-on-primary); font-weight: 700;
}

/* ---------- Navigation Drawer / Bottom nav ---------- */
.md-nav {
  display: flex; gap: var(--md-space-1);
  padding: var(--md-space-2);
  background: var(--md-surface-container-low);
  border-bottom: 1px solid var(--md-outline-variant);
  overflow-x: auto;
}
.md-nav a {
  display: inline-flex; align-items: center; gap: var(--md-space-2);
  padding: 8px 16px; border-radius: var(--md-radius-full);
  color: var(--md-on-surface-variant); white-space: nowrap;
  transition: background .2s var(--md-motion);
}
.md-nav a:hover { background: var(--md-surface-variant); text-decoration: none; }
.md-nav a[aria-current="page"] { background: var(--md-secondary-container); color: var(--md-on-secondary-container); font-weight: 500; }

/* ---------- Layout ---------- */
.md-container { max-width: 1040px; margin: 0 auto; padding: var(--md-space-5) var(--md-space-4); }
.md-grid { display: grid; gap: var(--md-space-4); }
.md-grid--2 { grid-template-columns: 1fr; }
.md-grid--sidebar { grid-template-columns: 1fr; }
@media (min-width: 840px) {
  .md-grid--2 { grid-template-columns: 1fr 1fr; }
  .md-grid--sidebar { grid-template-columns: 2fr 1fr; }
}
.md-stack { display: flex; flex-direction: column; gap: var(--md-space-4); }
.md-row { display: flex; align-items: center; gap: var(--md-space-3); flex-wrap: wrap; }
.md-spacer { flex: 1; }

/* ---------- Links & Interactions ---------- */
a {
  color: var(--md-primary);
  text-decoration: none;
  transition: color .2s var(--md-motion), transform .2s var(--md-motion);
  position: relative;
}
a:hover {
  text-decoration: none;
  color: var(--md-primary);
  filter: brightness(1.15);
}
.author-link {
  font-weight: 500;
  color: var(--md-on-surface);
  transition: color .2s ease, transform .2s ease;
  display: inline-flex;
  align-items: center;
  gap: 2px;
}
.author-link:hover {
  color: var(--md-primary);
  transform: translateY(-1px);
}

/* ---------- Huy hiệu Tick vàng (Gold Verified Badge) ---------- */
.leo-gold-tick {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  margin-left: 4px;
  vertical-align: -2px;
  cursor: pointer;
  flex-shrink: 0;
}
.leo-gold-tick__svg {
  width: 18px;
  height: 18px;
  display: block;
  filter: drop-shadow(0 1px 3px rgba(245, 158, 11, 0.45));
  transition: transform .25s cubic-bezier(.34, 1.56, .64, 1), filter .25s ease;
}
.leo-gold-tick:hover .leo-gold-tick__svg {
  transform: scale(1.22) rotate(6deg);
  filter: drop-shadow(0 0 7px rgba(245, 158, 11, 0.85));
}
.md-top-app-bar__user-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 14px 4px 6px;
  border-radius: var(--md-radius-full);
  background: var(--md-surface-container);
  color: var(--md-on-surface);
  text-decoration: none;
  transition: all .24s var(--md-motion);
}
.md-top-app-bar__user-chip:hover {
  background: var(--md-surface-container-high);
  transform: translateY(-2px);
  box-shadow: var(--md-elev-1);
}
.md-top-app-bar__name {
  font-size: .875rem;
  font-weight: 500;
  display: flex;
  align-items: center;
}

/* ---------- Card ---------- */
.md-card {
  background: var(--md-surface-container-low);
  color: var(--md-on-surface);
  border-radius: var(--md-radius-m);
  padding: var(--md-space-4);
  box-shadow: var(--md-elev-1);
  transition: transform .24s var(--md-motion), box-shadow .24s var(--md-motion);
  animation: leoCardFadeIn .32s cubic-bezier(.2, 0, 0, 1) both;
}
@keyframes leoCardFadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.md-card--outlined { box-shadow: none; border: 1px solid var(--md-outline-variant); background: var(--md-surface); }
.md-card__header { display: flex; align-items: center; gap: var(--md-space-3); margin-bottom: var(--md-space-3); }
.md-card__title { font-size: 1.1rem; font-weight: 500; }
.md-card__subtitle { font-size: .875rem; color: var(--md-on-surface-variant); }
.md-card__body { margin-bottom: var(--md-space-3); white-space: pre-wrap; word-wrap: break-word; }
.md-card__actions { display: flex; gap: var(--md-space-2); align-items: center; }

/* ---------- Avatar ---------- */
.md-avatar {
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--md-primary-container); color: var(--md-on-primary-container);
  display: grid; place-items: center; font-weight: 500; flex-shrink: 0; overflow: hidden;
  transition: transform .2s ease;
}
.md-avatar:hover { transform: scale(1.05); }
.md-avatar img { width: 100%; height: 100%; object-fit: cover; display: block; }
.md-avatar--lg { width: 72px; height: 72px; font-size: 1.5rem; }
.md-avatar--sm { width: 32px; height: 32px; font-size: .875rem; }

/* ---------- Buttons with Rich Motion ---------- */
.md-btn {
  display: inline-flex; align-items: center; justify-content: center; gap: var(--md-space-2);
  height: 40px; padding: 0 var(--md-space-4);
  border: none; border-radius: var(--md-radius-full);
  font: inherit; font-size: .875rem; font-weight: 500; letter-spacing: .1px;
  cursor: pointer; text-decoration: none;
  transition: all .24s cubic-bezier(.34, 1.56, .64, 1);
  position: relative; overflow: hidden;
}
.md-btn:hover {
  text-decoration: none;
  box-shadow: 0 4px 14px rgba(0,0,0,.15);
  transform: translateY(-2px);
}
.md-btn:active {
  transform: translateY(1px) scale(0.97);
  box-shadow: 0 1px 3px rgba(0,0,0,.12);
}
.md-btn:focus-visible { outline: 2px solid var(--md-primary); outline-offset: 2px; }
.md-btn:disabled { opacity: .38; cursor: not-allowed; box-shadow: none; transform: none; }
.md-btn--filled {
  background: linear-gradient(135deg, var(--md-primary) 0%, #2f5645 100%);
  color: var(--md-on-primary);
}
.md-btn--filled:hover {
  filter: brightness(1.08);
  box-shadow: 0 6px 18px rgba(61, 106, 87, 0.35);
}
.md-btn--tonal {
  background: var(--md-secondary-container);
  color: var(--md-on-secondary-container);
}
.md-btn--tonal:hover {
  filter: brightness(1.04);
}
.md-btn--outlined {
  background: transparent;
  color: var(--md-primary);
  border: 1px solid var(--md-outline);
}
.md-btn--outlined:hover {
  background: rgba(61, 106, 87, 0.08);
  border-color: var(--md-primary);
}
.md-btn--text {
  background: transparent;
  color: var(--md-primary);
  padding: 0 var(--md-space-3);
}
.md-btn--text:hover {
  background: rgba(61, 106, 87, 0.08);
}
.md-btn--danger { background: var(--md-error); color: var(--md-on-error); }
.md-btn--icon { width: 40px; padding: 0; }
.md-btn--block { width: 100%; }
.md-btn--sm { height: 32px; padding: 0 12px; font-size: .8125rem; }

/* ---------- Text field (filled) ---------- */
.md-field { position: relative; display: flex; flex-direction: column; gap: 4px; width: 100%; }
.md-field__label { font-size: .75rem; color: var(--md-on-surface-variant); padding-left: 16px; }
.md-field__input,
.md-field__textarea,
.md-field__select {
  font: inherit; font-size: 1rem; color: var(--md-on-surface);
  background: var(--md-surface-container-high);
  border: none; border-bottom: 1px solid var(--md-outline);
  border-radius: var(--md-radius-xs) var(--md-radius-xs) 0 0;
  padding: 16px; width: 100%;
  transition: border-color .2s, background .2s;
}
.md-field__textarea { min-height: 96px; resize: vertical; }
.md-field__input:hover, .md-field__textarea:hover, .md-field__select:hover { background: var(--md-surface-variant); }
.md-field__input:focus, .md-field__textarea:focus, .md-field__select:focus {
  outline: none; border-bottom: 2px solid var(--md-primary);
}
.md-field--error .md-field__input { border-bottom-color: var(--md-error); }
.md-field__helper { font-size: .75rem; color: var(--md-on-surface-variant); padding-left: 16px; }
.md-field__helper--error { color: var(--md-error); }

/* ---------- Chip ---------- */
.md-chip {
  display: inline-flex; align-items: center; gap: 6px;
  height: 32px; padding: 0 12px; border-radius: var(--md-radius-s);
  border: 1px solid var(--md-outline); background: transparent;
  color: var(--md-on-surface); font: inherit; font-size: .875rem; cursor: pointer;
}
.md-chip[aria-pressed="true"], .md-chip--selected {
  background: var(--md-secondary-container); color: var(--md-on-secondary-container); border-color: transparent;
}
.md-chip:hover { background: var(--md-surface-variant); }

/* ---------- Segmented (chọn vai trò) ---------- */
.md-segmented { display: inline-flex; border: 1px solid var(--md-outline); border-radius: var(--md-radius-full); overflow: hidden; }
.md-segmented button {
  font: inherit; font-size: .875rem; padding: 8px 16px; border: none; background: transparent;
  color: var(--md-on-surface); cursor: pointer;
}
.md-segmented button[aria-pressed="true"] { background: var(--md-secondary-container); color: var(--md-on-secondary-container); }

/* ---------- Dialog / Snackbar ---------- */
.md-snackbar {
  position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%);
  background: #2b312e; color: #eef2ef; padding: 14px 20px; border-radius: var(--md-radius-s);
  box-shadow: var(--md-elev-3); z-index: 100; font-size: .875rem; max-width: calc(100% - 32px);
  opacity: 0; pointer-events: none; transition: opacity .25s var(--md-motion);
}
.md-snackbar--show { opacity: 1; }
.md-snackbar--error { background: var(--md-error); color: var(--md-on-error); }

.md-dialog-scrim {
  position: fixed; inset: 0; background: rgba(0,0,0,.4);
  display: none; align-items: center; justify-content: center; z-index: 50; padding: 16px;
}
.md-dialog-scrim--open { display: flex; }
.md-dialog {
  background: var(--md-surface-container-high); color: var(--md-on-surface);
  border-radius: var(--md-radius-xl); padding: 24px; width: 100%; max-width: 420px;
  box-shadow: var(--md-elev-3);
}
.md-dialog__title { font-size: 1.25rem; margin-bottom: var(--md-space-3); }
.md-dialog__actions { display: flex; justify-content: flex-end; gap: var(--md-space-2); margin-top: var(--md-space-5); }

/* ---------- Tabs ---------- */
.md-tabs { display: flex; border-bottom: 1px solid var(--md-outline-variant); overflow-x: auto; }
.md-tab {
  flex: 1; min-width: max-content; padding: 14px 16px; border: none; background: transparent;
  font: inherit; font-size: .875rem; font-weight: 500; color: var(--md-on-surface-variant); cursor: pointer;
  border-bottom: 3px solid transparent;
}
.md-tab[aria-selected="true"] { color: var(--md-primary); border-bottom-color: var(--md-primary); }

/* ---------- List (forum) ---------- */
.md-list { list-style: none; margin: 0; padding: 0; background: var(--md-surface-container-low); border-radius: var(--md-radius-m); overflow: hidden; box-shadow: var(--md-elev-1); }
.md-list-item {
  display: flex; align-items: center; gap: var(--md-space-3);
  padding: 14px 16px; border-bottom: 1px solid var(--md-outline-variant);
  transition: background .15s;
}
.md-list-item:last-child { border-bottom: none; }
.md-list-item:hover { background: var(--md-surface-variant); }
.md-list-item__main { flex: 1; min-width: 0; }
.md-list-item__title { font-weight: 500; color: var(--md-on-surface); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.md-list-item__meta { font-size: .8125rem; color: var(--md-on-surface-variant); }

/* ---------- Badge ---------- */
.md-badge {
  display: inline-block; min-width: 20px; height: 20px; line-height: 20px; padding: 0 6px;
  border-radius: var(--md-radius-full); font-size: .75rem; text-align: center;
  background: var(--md-error); color: var(--md-on-error);
}
.md-tag {
  display: inline-block; padding: 2px 8px; border-radius: var(--md-radius-xs);
  font-size: .75rem; background: var(--md-tertiary-container); color: var(--md-tertiary);
}

/* ---------- Banner (an toàn) ---------- */
.md-banner {
  display: flex; gap: var(--md-space-3); align-items: flex-start;
  padding: var(--md-space-4); border-radius: var(--md-radius-m);
  background: var(--md-tertiary-container); color: var(--md-on-surface);
}
.md-banner--warn { background: var(--md-error-container); }

/* ---------- Progress ---------- */
.md-spinner {
  width: 24px; height: 24px; border: 3px solid var(--md-primary-container);
  border-top-color: var(--md-primary); border-radius: 50%;
  animation: md-spin 1s linear infinite; margin: 24px auto;
}
@keyframes md-spin { to { transform: rotate(360deg); } }

.md-empty { text-align: center; padding: var(--md-space-6) var(--md-space-4); color: var(--md-on-surface-variant); }
.md-fab {
  position: fixed; right: 20px; bottom: 20px; height: 56px; padding: 0 20px;
  border-radius: var(--md-radius-l); background: var(--md-primary-container);
  color: var(--md-on-primary-container); border: none; box-shadow: var(--md-elev-3);
  font: inherit; font-weight: 500; cursor: pointer; display: inline-flex; align-items: center; gap: 8px; z-index: 5;
}
.md-fab:hover { box-shadow: 0 6px 12px rgba(0,0,0,.25); }

/* ---------- Responsive nhỏ ---------- */
@media (max-width: 599px) {
  h1 { font-size: 1.6rem; }
  .md-container { padding: var(--md-space-4) 12px; }
}