/* Bondhu AI — Material 3 Expressive Design */
@import url('https://fonts.googleapis.com/css2?family=Google+Sans:wght@400;500;700&family=Google+Sans+Display:wght@700&display=swap');

/* ── M3 Color Tokens ── */
:root {
  --md-primary: #0061A4;
  --md-on-primary: #FFFFFF;
  --md-primary-container: #D1E4FF;
  --md-on-primary-container: #001D36;

  --md-secondary: #535F70;
  --md-on-secondary: #FFFFFF;
  --md-secondary-container: #D7E3F8;
  --md-on-secondary-container: #101C2B;

  --md-tertiary: #6B5778;
  --md-tertiary-container: #F2DAFF;
  --md-on-tertiary-container: #251431;

  --md-error: #BA1A1A;
  --md-error-container: #FFDAD6;

  --md-surface: #F8F9FF;
  --md-on-surface: #191C20;
  --md-on-surface-variant: #43474E;
  --md-surface-container-lowest: #FFFFFF;
  --md-surface-container-low: #F2F3FA;
  --md-surface-container: #ECEDF4;
  --md-surface-container-high: #E6E8EE;
  --md-surface-container-highest: #E1E2E9;
  --md-outline: #73777F;
  --md-outline-variant: #C3C7CF;

  --md-shape-xs: 4px;
  --md-shape-sm: 8px;
  --md-shape-md: 12px;
  --md-shape-lg: 16px;
  --md-shape-xl: 28px;
  --md-shape-full: 9999px;

  --md-elev1: 0 1px 2px rgba(0,0,0,.06), 0 1px 3px 1px rgba(0,0,0,.04);
  --md-elev2: 0 1px 2px rgba(0,0,0,.06), 0 2px 6px 2px rgba(0,0,0,.06);
  --md-elev3: 0 4px 8px 3px rgba(0,0,0,.07), 0 1px 3px rgba(0,0,0,.06);

  --font: 'Google Sans', 'Segoe UI', 'Hind Siliguri', system-ui, sans-serif;
}

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: var(--font);
  background: var(--md-surface);
  color: var(--md-on-surface);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ══ AUTH ══ */
.auth-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(145deg, #001D36 0%, #0061A4 50%, #6B5778 100%);
  padding: 1.5rem;
}

.auth-card {
  background: var(--md-surface-container-lowest);
  border-radius: var(--md-shape-xl);
  padding: 2.5rem 2rem;
  width: 100%;
  max-width: 400px;
  box-shadow: var(--md-elev3);
  animation: slideUp .4s cubic-bezier(.34,1.56,.64,1);
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(32px) scale(.97); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.auth-logo { text-align: center; margin-bottom: 2rem; }

.auth-logo h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--md-primary);
  letter-spacing: -1px;
  line-height: 1;
}

.auth-logo p {
  font-size: .875rem;
  color: var(--md-on-surface-variant);
  margin-top: .375rem;
  font-weight: 500;
}

.form-group { margin-bottom: 1rem; }

.form-group label {
  display: block;
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .5px;
  color: var(--md-primary);
  margin-bottom: .375rem;
  text-transform: uppercase;
}

.form-group input {
  width: 100%;
  padding: .875rem 1rem;
  background: var(--md-surface-container);
  border: 2px solid var(--md-outline-variant);
  border-radius: var(--md-shape-md);
  font-size: 1rem;
  font-family: var(--font);
  color: var(--md-on-surface);
  transition: all .2s;
  outline: none;
}

.form-group input:focus {
  border-color: var(--md-primary);
  background: var(--md-surface-container-lowest);
  box-shadow: 0 0 0 3px rgba(0,97,164,.12);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .875rem 1.5rem;
  border: none;
  border-radius: var(--md-shape-full);
  font-family: var(--font);
  font-size: .9375rem;
  font-weight: 600;
  letter-spacing: .1px;
  cursor: pointer;
  transition: all .25s cubic-bezier(.34,1.56,.64,1);
  text-decoration: none;
  position: relative;
  overflow: hidden;
  white-space: nowrap;
}

.btn-primary {
  background: var(--md-primary);
  color: var(--md-on-primary);
  width: 100%;
  box-shadow: var(--md-elev1);
}

.btn-primary:hover { box-shadow: var(--md-elev2); transform: translateY(-2px); }
.btn-primary:active { transform: translateY(0); box-shadow: none; }

.btn-secondary {
  background: var(--md-secondary-container);
  color: var(--md-on-secondary-container);
  font-size: .875rem;
  padding: .625rem 1.25rem;
}

.btn-secondary:hover { filter: brightness(.95); }

.alert {
  padding: .875rem 1rem;
  border-radius: var(--md-shape-md);
  margin-bottom: 1rem;
  font-size: .875rem;
  font-weight: 500;
}

.alert-error { background: var(--md-error-container); color: var(--md-error); }
.alert-success { background: #D6F4E0; color: #0E4D26; }

/* ══ APP LAYOUT ══ */
.app-layout {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* ── Navigation Rail ── */
.sidebar {
  width: 88px;
  background: var(--md-surface-container-low);
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: .75rem 0;
  border-right: 1px solid var(--md-outline-variant);
  transition: width .3s cubic-bezier(.34,1.56,.64,1);
  flex-shrink: 0;
  overflow: hidden;
}

.sidebar:hover { width: 240px; }

.sidebar-header {
  padding: .75rem;
  width: 100%;
  display: flex;
  align-items: center;
  gap: .875rem;
  margin-bottom: .5rem;
}

.sidebar-logo {
  width: 44px;
  height: 44px;
  background: var(--md-primary-container);
  border-radius: var(--md-shape-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.sidebar-header-text {
  opacity: 0;
  transition: opacity .15s;
  white-space: nowrap;
  overflow: hidden;
}

.sidebar:hover .sidebar-header-text { opacity: 1; }

.sidebar-header-text h2 {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--md-primary);
}

.sidebar-header-text p {
  font-size: .7rem;
  color: var(--md-on-surface-variant);
}

.sidebar-nav {
  flex: 1;
  width: 100%;
  padding: .5rem 0;
  overflow-y: auto;
  overflow-x: hidden;
}

.nav-section-label {
  font-size: .625rem;
  font-weight: 700;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--md-on-surface-variant);
  padding: .75rem .875rem .25rem;
  opacity: 0;
  transition: opacity .15s;
  white-space: nowrap;
}

.sidebar:hover .nav-section-label { opacity: 1; }

.nav-item {
  display: flex;
  align-items: center;
  gap: 0;
  padding: .375rem .5rem;
  border-radius: var(--md-shape-full);
  cursor: pointer;
  border: none;
  background: none;
  width: calc(100% - 1rem);
  margin: .125rem .5rem;
  color: var(--md-on-surface-variant);
  font-family: var(--font);
  font-size: .875rem;
  font-weight: 500;
  transition: all .2s;
  white-space: nowrap;
  text-align: left;
}

.nav-icon {
  width: 56px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--md-shape-full);
  font-size: 1.1rem;
  flex-shrink: 0;
  transition: all .2s cubic-bezier(.34,1.56,.64,1);
}

.nav-item span.nav-label {
  opacity: 0;
  transition: opacity .15s;
  overflow: hidden;
}

.sidebar:hover .nav-item span.nav-label { opacity: 1; }

.nav-item:hover .nav-icon { background: var(--md-surface-container-highest); }
.nav-item:hover { color: var(--md-on-surface); }

.nav-item.active { color: var(--md-on-secondary-container); }
.nav-item.active .nav-icon { background: var(--md-secondary-container); }

.sidebar-user {
  width: 100%;
  padding: .75rem .5rem;
  display: flex;
  align-items: center;
  gap: .875rem;
  border-top: 1px solid var(--md-outline-variant);
  overflow: hidden;
}

.user-avatar {
  width: 44px;
  height: 44px;
  background: var(--md-tertiary-container);
  color: var(--md-on-tertiary-container);
  border-radius: var(--md-shape-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: .9rem;
  flex-shrink: 0;
}

.user-name {
  font-size: .8rem;
  font-weight: 600;
  flex: 1;
  opacity: 0;
  transition: opacity .15s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar:hover .user-name { opacity: 1; }

.btn-logout {
  background: none;
  border: none;
  color: var(--md-on-surface-variant);
  cursor: pointer;
  width: 36px;
  height: 36px;
  border-radius: var(--md-shape-full);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 1rem;
  transition: all .2s;
  opacity: 0;
}

.sidebar:hover .btn-logout { opacity: 1; }
.btn-logout:hover { background: var(--md-error-container); color: var(--md-error); }

/* ── Main ── */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--md-surface);
}

.content-header {
  padding: 1rem 1.5rem;
  background: var(--md-surface);
  border-bottom: 1px solid var(--md-outline-variant);
  display: flex;
  align-items: center;
  gap: .875rem;
  min-height: 64px;
}

.content-header h2 {
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -.25px;
}

.mode-badge {
  padding: .3rem .875rem;
  border-radius: var(--md-shape-full);
  font-size: .75rem;
  font-weight: 600;
  background: var(--md-secondary-container);
  color: var(--md-on-secondary-container);
}

/* ── Chat ── */
.chat-container {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: .75rem;
  scroll-behavior: smooth;
}

.message {
  display: flex;
  gap: .75rem;
  max-width: 78%;
  animation: msgPop .35s cubic-bezier(.34,1.56,.64,1);
}

@keyframes msgPop {
  from { opacity: 0; transform: scale(.92) translateY(12px); }
  to   { opacity: 1; transform: scale(1) translateY(0); }
}

.message.user { align-self: flex-end; flex-direction: row-reverse; }
.message.assistant { align-self: flex-start; }

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: var(--md-shape-full);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  flex-shrink: 0;
  margin-top: 2px;
}

.message.user .message-avatar { background: var(--md-primary-container); }
.message.assistant .message-avatar { background: var(--md-tertiary-container); }

.message-bubble {
  padding: .875rem 1.125rem;
  line-height: 1.65;
  font-size: .9375rem;
}

.message.user .message-bubble {
  background: var(--md-primary);
  color: var(--md-on-primary);
  border-radius: var(--md-shape-xl) var(--md-shape-xl) var(--md-shape-sm) var(--md-shape-xl);
  box-shadow: var(--md-elev1);
}

.message.assistant .message-bubble {
  background: var(--md-surface-container-low);
  color: var(--md-on-surface);
  border-radius: var(--md-shape-xl) var(--md-shape-xl) var(--md-shape-xl) var(--md-shape-sm);
  border: 1px solid var(--md-outline-variant);
}

.message.assistant .message-bubble pre {
  background: var(--md-on-surface);
  color: #E1E4ED;
  padding: 1rem;
  border-radius: var(--md-shape-lg);
  overflow-x: auto;
  margin: .75rem 0;
  font-size: .8125rem;
  line-height: 1.6;
}

.message.assistant .message-bubble code {
  background: var(--md-surface-container-high);
  color: var(--md-tertiary);
  padding: .15em .45em;
  border-radius: var(--md-shape-sm);
  font-size: .875em;
}

.message.assistant .message-bubble strong { color: var(--md-primary); }

/* Typing */
.typing-indicator {
  display: flex;
  gap: 5px;
  align-items: center;
  padding: .875rem 1.125rem;
}

.typing-dot {
  width: 8px; height: 8px;
  background: var(--md-outline);
  border-radius: var(--md-shape-full);
  animation: typingBounce 1.4s ease-in-out infinite;
}

.typing-dot:nth-child(2) { animation-delay: .16s; }
.typing-dot:nth-child(3) { animation-delay: .32s; }

@keyframes typingBounce {
  0%, 60%, 100% { transform: translateY(0); opacity: .5; }
  30% { transform: translateY(-8px); opacity: 1; }
}

/* ── Input Area ── */
.chat-input-area {
  padding: 1rem 1.5rem;
  background: var(--md-surface);
  border-top: 1px solid var(--md-outline-variant);
  display: flex;
  gap: .75rem;
  align-items: flex-end;
}

.chat-input-wrapper {
  flex: 1;
  display: flex;
  align-items: flex-end;
  background: var(--md-surface-container-highest);
  border-radius: var(--md-shape-xl);
  border: 2px solid transparent;
  transition: all .2s;
  padding: .5rem .75rem;
}

.chat-input-wrapper:focus-within {
  background: var(--md-surface-container-lowest);
  border-color: var(--md-primary);
  box-shadow: 0 0 0 3px rgba(0,97,164,.1);
}

.chat-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  font-family: var(--font);
  font-size: .9375rem;
  color: var(--md-on-surface);
  resize: none;
  min-height: 28px;
  max-height: 120px;
  padding: .25rem .25rem;
  line-height: 1.5;
}

.chat-input::placeholder { color: var(--md-on-surface-variant); }

.btn-send {
  width: 52px;
  height: 52px;
  background: var(--md-primary);
  color: var(--md-on-primary);
  border: none;
  border-radius: var(--md-shape-lg);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  box-shadow: var(--md-elev2);
  transition: all .25s cubic-bezier(.34,1.56,.64,1);
  flex-shrink: 0;
}

.btn-send:hover {
  background: var(--md-on-surface);
  box-shadow: var(--md-elev3);
  transform: scale(1.08);
}

.btn-send:active { transform: scale(.95); }

.btn-send:disabled {
  background: var(--md-surface-container-high);
  color: var(--md-outline);
  box-shadow: none;
  cursor: not-allowed;
  transform: none;
}

/* ══ PROGRESS ══ */
.progress-container { flex: 1; overflow-y: auto; padding: 1.5rem; }

.progress-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.25rem;
}

.progress-card {
  background: var(--md-surface-container-low);
  border-radius: var(--md-shape-xl);
  padding: 1.5rem;
  border: 1px solid var(--md-outline-variant);
  transition: box-shadow .2s, transform .2s;
}

.progress-card:hover { box-shadow: var(--md-elev2); transform: translateY(-2px); }

.progress-card h4 {
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .5px;
  color: var(--md-on-surface-variant);
  margin-bottom: .5rem;
}

.track-name {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--md-on-surface);
  margin-bottom: 1rem;
}

.progress-item {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .625rem 0;
  border-bottom: 1px solid var(--md-outline-variant);
  font-size: .875rem;
}

.progress-item:last-child { border-bottom: none; }

.status-badge {
  padding: .2rem .625rem;
  border-radius: var(--md-shape-full);
  font-size: .6875rem;
  font-weight: 600;
  white-space: nowrap;
}

.status-completed { background: #D6F4E0; color: #0E4D26; }
.status-in_progress { background: var(--md-primary-container); color: var(--md-on-primary-container); }
.status-started { background: var(--md-surface-container-high); color: var(--md-on-surface-variant); }

.score-bar {
  width: 56px;
  height: 6px;
  background: var(--md-outline-variant);
  border-radius: var(--md-shape-full);
  overflow: hidden;
}

.score-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--md-primary), var(--md-tertiary));
  border-radius: var(--md-shape-full);
  transition: width .6s cubic-bezier(.34,1.56,.64,1);
}

.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--md-on-surface-variant);
  grid-column: 1/-1;
}

.empty-state .icon { font-size: 3.5rem; margin-bottom: 1rem; opacity: .7; }
.empty-state p { font-size: 1rem; line-height: 1.6; }

.hidden { display: none !important; }

/* Scrollbar */
* { scrollbar-width: thin; scrollbar-color: var(--md-outline-variant) transparent; }

@media (max-width: 600px) {
  .sidebar { width: 72px; }
  .sidebar:hover { width: 72px; }
  .message { max-width: 92%; }
}