/* ------------------------------------------------------------
   NexA AI ? Design System v3
   Dark-first, glassmorphism, immersive, mobile-native
------------------------------------------------------------ */

/* -- TOKENS ----------------------------------------------- */
:root {
  --primary:        #625BEE;
  --primary-strong: #4F46E5;
  --accent:         #6B6EF3;
  --accent2:        #8E8BFF;
  --bg:             #000000;
  --bg2:            #0A0A0C;
  --bg3:            #121216;
  --surface:        #0A0A0C;
  --surface2:       #121216;
  --border:         #1C1C20;
  --border2:        #2A2A30;
  --text:           #FFFFFF;
  --text2:          #E2E8F0;
  --text3:          #A0AEC0;
  --sans:           'Outfit', system-ui, sans-serif;
  --sans-bn:        'Hind Siliguri', 'Noto Sans Bengali', 'Nirmala UI', 'Shonar Bangla', 'Kalpurush', 'Vrinda', system-ui, sans-serif;
  --mono:           'JetBrains Mono', 'Fira Code', monospace;
  --radius:         18px;
  --radius-sm:      10px;
  --shadow:         0 8px 32px rgba(0,0,0,0.85);
  --shadow-sm:      0 4px 16px rgba(0,0,0,0.6);
  --glow-primary:   0 0 40px rgba(98,91,238,0.25);
  --glow-blue:      0 0 40px rgba(107,110,243,0.2);
  --header-h:       60px;
  --island-h:       auto;
  --transition:     0.25s cubic-bezier(0.16,1,0.3,1);
}

[data-theme="dark"] {
  --bg:             #000000;
  --bg2:            #0A0A0C;
  --bg3:            #121216;
  --surface:        #0A0A0C;
  --surface2:       #121216;
  --border:         #1C1C20;
  --border2:        #2A2A30;
  --text:           #FFFFFF;
  --text2:          #E2E8F0;
  --text3:          #A0AEC0;
}

[data-theme="light"] {
  --bg:         #F7F8FC;
  --bg2:        #F1F2F9;
  --bg3:        #EBEDFB;
  --surface:    rgba(244,248,255,0.88);
  --surface2:   rgba(234,243,255,0.9);
  --border:     rgba(0,0,0,0.07);
  --border2:    rgba(0,0,0,0.12);
  --text:       #1B2430;
  --text2:      #9099A8;
  --text3:      #B2B8C3;
  --shadow:     0 8px 32px rgba(0,0,0,0.12);
}

/* -- RESET ------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html {
  height: 100%;
  /* Use dvh (dynamic viewport height) ? fixes iOS Safari address-bar collapse */
  height: 100dvh;
  overflow: hidden;
  overscroll-behavior: none;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%; /* Prevent font size inflation on orientation change */
}
body {
  font-family: var(--sans);
  background: var(--bg);
  color: var(--text);
  height: 100%;
  height: 100dvh;
  overflow: hidden;
  overscroll-behavior: none; /* Prevent iOS rubber-band / Android pull-to-refresh */
  -webkit-font-smoothing: antialiased;
  /* Prevent callout menu on long press */
  -webkit-touch-callout: none;
}

/* -- UTILITIES -------------------------------------------- */
.hidden { display: none !important; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0,0,0,0);
  clip-path: inset(50%);
  border: 0;
  white-space: nowrap;
}

/* -- SPLASH SCREEN ---------------------------------------- */
.splash {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0;
  transition: opacity 0.34s cubic-bezier(0.16, 1, 0.3, 1), visibility 0s linear 0.34s;
}
.splash.fade-out { opacity: 0; visibility: hidden; pointer-events: none; }
.splash-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.45;
  animation: floatOrb 18s ease-in-out infinite;
  pointer-events: none;
}
.splash-orb-1 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(98,91,238,0.5) 0%, transparent 70%);
  top: -100px; right: -80px;
  animation-duration: 20s;
}
.splash-orb-2 {
  width: 350px; height: 350px;
  background: radial-gradient(circle, rgba(107,110,243,0.4) 0%, transparent 70%);
  bottom: -80px; left: -60px;
  animation-duration: 25s;
  animation-delay: -5s;
}
@keyframes floatOrb {
  0%,100% { transform: translate(0,0) scale(1); }
  33%      { transform: translate(-30px,40px) scale(1.08); }
  66%      { transform: translate(40px,-20px) scale(0.95); }
}
.splash-logo {
  position: relative;
  width: 88px; height: 88px;
  border-radius: 50%;
  background: white;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 0 0 8px rgba(98,91,238,0.12), 0 0 60px rgba(98,91,238,0.35);
  margin-bottom: 20px;
  animation: splashLogoIn 0.44s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.splash-logo img { width: 72px; height: 72px; object-fit: contain; padding: 10px; }
.splash-glow {
  position: absolute;
  inset: -12px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(98,91,238,0.18), transparent 70%);
  animation: pulseGlow 2s ease-in-out infinite;
}

@keyframes pulseGlow {
  0%,100% { opacity: 0.6; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.1); }
}
.splash-brand {
  font-size: 32px; font-weight: 800; color: white; letter-spacing: -1px;
  line-height: 1; height: 32px;
  animation: splashContentIn 0.32s 0.06s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.splash-brand span { color: var(--primary); }
.splash-sub {
  font-size: 13px; color: var(--text2); margin-top: 6px; margin-bottom: 32px;
  letter-spacing: 0.5px;
  line-height: 1; height: 13px;
  animation: splashContentIn 0.3s 0.1s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.splash-dots {
  display: flex; gap: 7px;
  animation: splashContentIn 0.26s 0.14s cubic-bezier(0.16, 1, 0.3, 1) both;
}
.splash-dots .dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--text3);
  animation: dotBounce 1.4s ease-in-out infinite;
}
.splash-dots .dot:nth-child(2) { animation-delay: 0.2s; }
.splash-dots .dot:nth-child(3) { animation-delay: 0.4s; }
@keyframes dotBounce {
  0%,80%,100% { transform: scale(0.8) translateZ(0); background: var(--text3); }
  40% { transform: scale(1.2) translateZ(0); background: var(--primary); }
}
@keyframes splashLogoIn {
  from { opacity: 0; transform: translateY(8px) scale(0.92) rotate(-4deg); }
  to { opacity: 1; transform: translateY(0) scale(1) rotate(0); }
}
@keyframes splashContentIn {
  from { opacity: 0; transform: translateY(7px); }
  to { opacity: 1; transform: translateY(0); }
}

/* -- TOAST ------------------------------------------------ */
#toast {
  position: fixed;
  top: 20px; left: 50%;
  transform: translateX(-50%) translateY(-80px);
  background: var(--primary); color: white;
  padding: 12px 22px; border-radius: 14px;
  font-size: 14px; font-weight: 600;
  box-shadow: var(--shadow);
  z-index: 9998;
  opacity: 0;
  pointer-events: none;
  transition: all 0.35s cubic-bezier(0.16,1,0.3,1);
  white-space: nowrap; max-width: 90vw;
  text-align: center;
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }
#toast.success { background: #10b981; }
#toast.info    { background: var(--accent); }
#toast.warning { background: #f59e0b; }

/* -- APP SHELL -------------------------------------------- */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;    /* legacy fallback */
  height: 100svh;   /* stable viewport while browser chrome is visible */
  height: 100dvh;   /* follow dynamic mobile viewport changes when supported */
  position: relative;
  overflow: hidden;
  padding-top:    env(safe-area-inset-top);
  padding-bottom: env(safe-area-inset-bottom);
  padding-left:   env(safe-area-inset-left);
  padding-right:  env(safe-area-inset-right);
}

/* Background orbs */
.bg-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(100px);
  pointer-events: none;
  opacity: 0.4;
  animation: floatOrb 22s ease-in-out infinite;
}
[data-theme="dark"] .bg-orb {
  display: none !important;
}
.bg-orb-1 {
  width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(98,91,238,0.35) 0%, transparent 70%);
  top: -200px; right: -150px;
}
.bg-orb-2 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(107,110,243,0.3) 0%, transparent 70%);
  bottom: -150px; left: -100px;
  animation-duration: 28s; animation-delay: -8s;
}
.bg-orb-3 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(124,146,255,0.2) 0%, transparent 70%);
  top: 40%; left: 35%;
  animation-duration: 18s; animation-delay: -3s;
}

/* -- HEADER ----------------------------------------------- */
.app-header {
  height: var(--header-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 20px;
  background: rgba(8,9,15,0.75);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  position: relative;
  z-index: 100;
}
.header-left { display: flex; align-items: center; gap: 10px; }
.header-logo {
  width: 34px; height: 34px; border-radius: 50%;
  background: white; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 0 20px rgba(98,91,238,0.3);
  overflow: hidden; flex-shrink: 0;
}
.header-logo img { width: 100%; height: 100%; object-fit: contain; padding: 5px; }
.header-titles {}
.header-brand { font-size: 18px; font-weight: 800; color: white; letter-spacing: -0.3px; line-height: 1; }
.header-brand span { color: var(--primary); }
.header-sub { font-size: 10px; color: var(--text2); letter-spacing: 0.3px; }

.header-center { flex: 1; display: flex; justify-content: center; min-width: 0; }

/* Announcement banner bar below header */
#headerAnnouncement:empty { display: none; }
.announcement-banner {
  font-size: 13px; color: var(--primary-strong);
  background: linear-gradient(90deg, rgba(98,91,238,0.1), rgba(107,110,243,0.08));
  border-bottom: 1px solid rgba(98,91,238,0.15);
  padding: 8px 20px;
  text-align: center;
  font-weight: 600;
  animation: bannerPulse 3s ease-in-out infinite;
  flex-shrink: 0;
}
@keyframes bannerPulse { 0%,100%{opacity:1} 50%{opacity:0.75} }

.header-right { display: flex; align-items: center; gap: 6px; flex-shrink: 0; }
.stat-pill {
  display: flex; align-items: center; gap: 5px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border2);
  border-radius: 20px; padding: 5px 11px;
  font-size: 12px; color: var(--text2);
  font-family: var(--mono);
  transition: all 0.2s;
}
.stat-pill.warning { color: #f59e0b; border-color: rgba(245,158,11,0.3); }
.stat-pill.danger  { color: var(--primary-strong); border-color: rgba(98,91,238,0.3); }
.stat-icon { font-size: 11px; }

/* -- ICON BUTTONS ----------------------------------------- */
.icon-btn {
  width: 36px; height: 36px; border-radius: 10px;
  background: rgba(255,255,255,0.05);
  border: 1px solid var(--border);
  color: var(--text2);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer;
  touch-action: manipulation; /* Remove 300ms tap delay on mobile */
  transition: all var(--transition);
  flex-shrink: 0;
}
.icon-btn:hover { background: rgba(255,255,255,0.1); color: var(--text); border-color: var(--border2); }
.icon-btn:active { transform: scale(0.95); }
.icon-btn.active { color: var(--primary); border-color: rgba(98,91,238,0.3); background: rgba(98,91,238,0.08); }

/* Profile button */
.profile-btn {
  width: 36px; height: 36px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  border: none; cursor: pointer;
  touch-action: manipulation;
  display: flex; align-items: center; justify-content: center;
  transition: all var(--transition);
  box-shadow: 0 0 16px rgba(98,91,238,0.35);
}
.profile-btn:hover { transform: scale(1.08); box-shadow: 0 0 24px rgba(98,91,238,0.5); }
.avatar { font-size: 14px; font-weight: 700; color: white; user-select: none; }

/* -- MAIN CONTENT ----------------------------------------- */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-height: 0;
  position: relative;
}

/* -- CHAT AREA -------------------------------------------- */
.chat-area {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 24px 20px 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  scroll-behavior: smooth;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: contain;
}
.chat-area::-webkit-scrollbar { width: 4px; }
.chat-area::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 4px; }
.chat-area::-webkit-scrollbar-track { background: transparent; }
/* -- WELCOME STATE ---------------------------------------- */
.welcome-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  flex: 1;
  text-align: center;
  padding: 40px 20px;
  gap: 24px;
  animation: fadeUp 0.6s cubic-bezier(0.16,1,0.3,1) both;
}
@keyframes fadeUp { from{opacity:0;transform:translateY(20px)} to{opacity:1;transform:translateY(0)} }
.welcome-logo {
  width: 72px; height: 72px; border-radius: 50%;
  background: white;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--glow-primary);
}
.welcome-logo img { width: 100%; height: 100%; object-fit: contain; padding: 10px; }
.welcome-title { font-size: clamp(22px,5vw,32px); font-weight: 800; color: var(--text, #0F172A); letter-spacing: -0.5px; }
[data-theme="dark"] .welcome-title { color: #FFFFFF !important; }
.welcome-title em {
  font-style: normal;
  background: linear-gradient(120deg, var(--primary) 0%, var(--primary-strong) 100%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}
.welcome-sub { font-size: 15px; color: var(--text2); line-height: 1.65; max-width: 400px; }
.welcome-chips { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; max-width: 480px; }
.welcome-chip {
  touch-action: manipulation; /* Remove tap delay on chips */
  padding: 8px 16px; border-radius: 20px;
  background: var(--surface2); border: 1px solid var(--border2);
  font-size: 13px; color: var(--text, #0F172A);
  cursor: pointer; transition: all 0.2s;
}
[data-theme="dark"] .welcome-chip {
  background: #141724 !important;
  border-color: #282F48 !important;
  color: #F8FAFC !important;
}
[data-theme="light"] .welcome-chip {
  background: #F8FAFC !important;
  border-color: #E2E8F0 !important;
  color: #0F172A !important;
}
.welcome-chip:hover { background: rgba(98,91,238,0.1); border-color: rgba(98,91,238,0.3); color: var(--primary-strong); }

/* -- MESSAGES --------------------------------------------- */
@keyframes msgGpuEntrance {
  0% {
    opacity: 0;
    transform: translate3d(0, 18px, 0) scale(0.96);
  }
  65% {
    opacity: 0.95;
    transform: translate3d(0, -2px, 0) scale(1.005);
  }
  100% {
    opacity: 1;
    transform: translate3d(0, 0, 0) scale(1);
  }
}

.msg {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
  align-items: flex-start;
  width: 100%;
}

.msg.ai {
  justify-content: flex-start;
}

.msg.user {
  display: flex !important;
  flex-direction: row-reverse !important;
  justify-content: flex-start !important;
  align-items: flex-start !important;
  margin-left: auto !important;
  margin-right: 0 !important;
  align-self: flex-end !important;
  width: auto !important;
  max-width: 85% !important;
}

.msg-avatar {
  width: 36px; height: 36px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 13px; font-weight: 700; flex-shrink: 0;
  margin-top: 2px;
}
.msg.user .msg-avatar {
  order: 1 !important;
  margin-left: 12px !important;
  margin-right: 0 !important;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: white;
  box-shadow: 0 4px 14px rgba(98, 91, 238, 0.3);
}

.msg.user .bubble {
  order: 2 !important;
  margin-left: auto !important;
  margin-right: 0 !important;
  border-bottom-right-radius: 4px;
}
.msg.ai .msg-avatar {
  background: #141724;
  border: 1px solid #282F48;
  overflow: hidden;
  box-shadow: 0 4px 14px rgba(0,0,0,0.6);
}
.msg.ai .msg-avatar img {
  width: 100%; height: 100%; object-fit: contain; padding: 6px;
}

[data-theme="light"] .msg.ai .msg-avatar {
  background: #FFFFFF;
  border: 1px solid #E2E8F0;
  box-shadow: 0 4px 12px rgba(38,43,93,0.1);
}

/* Bubble */
.bubble {
  max-width: min(80%, 640px);
  border-radius: var(--radius);
  padding: 14px 18px;
  position: relative;
  word-break: break-word;
  line-height: 1.7;
}
.msg.user .bubble {
  background: linear-gradient(135deg, var(--primary), #4F46E5);
  color: white;
  border-bottom-right-radius: 6px;
  box-shadow: 0 4px 20px rgba(98,91,238,0.3);
}
.msg.ai .bubble {
  background: var(--surface);
  border: 1px solid var(--border2);
  color: var(--text);
  border-bottom-left-radius: 6px;
  backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
}

/* Finished responses must never inherit the temporary typing layout. */
.msg:not(.typing-indicator) .bubble { display: block; }

/* AI text markdown rendering */
.ai-text { font-size: 15px; }
/* Bengali text gets Hind Siliguri for proper rendering */
.ai-text, .ai-text p, .ai-text li, .ai-text td { font-family: var(--sans); }
.lang-bn .ai-text, .ai-text:lang(bn) { font-family: var(--sans-bn); line-height: 1.85; }
.ai-text p { margin-bottom: 10px; }
.ai-text p:last-child { margin-bottom: 0; }
.ai-text h1,.ai-text h2,.ai-text h3 { font-weight: 700; margin: 14px 0 8px; color: var(--text, #0F172A); }
.ai-text h1 { font-size: 20px; } .ai-text h2 { font-size: 18px; } .ai-text h3 { font-size: 16px; }
.ai-text ul, .ai-text ol { padding-left: 22px; margin-bottom: 10px; }
.ai-text li { margin-bottom: 4px; }
.ai-text strong { font-weight: 700; color: var(--text, #0F172A); }
.ai-text em { color: var(--accent2); font-style: italic; }

[data-theme="dark"] .ai-text h1,
[data-theme="dark"] .ai-text h2,
[data-theme="dark"] .ai-text h3,
[data-theme="dark"] .ai-text strong {
  color: #F8FAFC !important;
}
.ai-text hr { border: none; border-top: 1px solid var(--border2); margin: 14px 0; }
.ai-text a { color: var(--accent2); text-decoration: none; }
.ai-text a:hover { text-decoration: underline; }
.ai-text table { border-collapse: collapse; width: 100%; margin: 12px 0; font-size: 13px; }
.ai-text th, .ai-text td { border: 1px solid var(--border2); padding: 8px 12px; text-align: left; }
.ai-text th { background: rgba(255,255,255,0.06); font-weight: 600; }
.ai-text code:not(pre code) {
  background: rgba(255,255,255,0.08); border-radius: 6px;
  padding: 1px 6px; font-family: var(--mono); font-size: 13px; color: var(--accent2);
}
.ai-text pre {
  background: #0d0e1a;
  border: 1px solid var(--border2);
  border-radius: var(--radius-sm);
  overflow-x: auto; margin: 12px 0;
  position: relative;
}
.ai-text pre code { font-family: var(--mono); font-size: 13px; padding: 14px; display: block; color: #e8eaf0; }
.code-header {
  display: flex; justify-content: space-between; align-items: center;
  padding: 8px 14px; border-bottom: 1px solid var(--border);
  font-size: 11px; color: var(--text2); font-family: var(--mono);
}
.copy-code-btn {
  background: none; border: none; color: var(--text2); cursor: pointer;
  font-size: 11px; padding: 2px 6px; border-radius: 6px; transition: all 0.2s;
}
.copy-code-btn:hover { color: white; background: rgba(255,255,255,0.1); }

/* Reaction bar */
.reaction-bar {
  display: flex; align-items: center; gap: 6px;
  margin-top: 8px; padding-top: 8px;
  border-top: 1px solid var(--border);
  width: 100%;
  flex: 0 0 100%;
  flex-wrap: wrap;
}
.reaction-bar button {
  background: none; border: 1px solid transparent; color: var(--text2);
  cursor: pointer; padding: 8px 12px; border-radius: 10px;
  font-size: 13px; transition: all 0.2s;
  display: flex; align-items: center; gap: 5px;
  min-height: 36px; /* accessibility */
  min-width: 72px;
  flex: 0 0 auto;
  justify-content: center;
  white-space: nowrap;
}
.reaction-bar button:hover { background: rgba(255,255,255,0.08); color: var(--text); border-color: var(--border2); }
.reaction-bar button.active { color: var(--primary); }
.chat-timestamp {
  font-size: 10px; color: var(--text3);
  font-family: var(--mono);
  margin-top: 6px; display: block;
  padding-left: 2px;
}

/* ── CHATGPT / GEMINI GLOWING STREAMING CURSOR ── */
.nexa-cursor {
  display: inline-block;
  width: 7px;
  height: 1.15em;
  margin-left: 4px;
  vertical-align: -2px;
  background: linear-gradient(180deg, #818CF8, #625BEE);
  border-radius: 2px;
  box-shadow: 0 0 10px rgba(99, 102, 241, 0.8), 0 0 4px #FFFFFF;
  animation: nexaCursorPulse 0.75s ease-in-out infinite alternate;
  will-change: transform, opacity;
}

[data-theme="light"] .nexa-cursor {
  background: linear-gradient(180deg, #625BEE, #4F46E5);
  box-shadow: 0 0 8px rgba(98, 91, 238, 0.6);
}

@keyframes nexaCursorPulse {
  0% {
    opacity: 0.25;
    transform: scaleY(0.85);
  }
  100% {
    opacity: 1;
    transform: scaleY(1.1);
    box-shadow: 0 0 14px rgba(129, 124, 255, 1);
  }
}

/* Typing indicator */
.typing-indicator .bubble {
  padding: 12px 18px !important;
  min-height: 40px !important;
  display: inline-flex !important;
  align-items: center !important;
}

/* ── HIGH VISIBILITY WAVE TYPING ANIMATION ── */
.typing-dots {
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  gap: 7px !important;
  min-height: 24px !important;
  min-width: 48px !important;
  padding: 4px 6px !important;
  visibility: visible !important;
  opacity: 1 !important;
}

.typing-dots span {
  width: 9px !important;
  height: 9px !important;
  border-radius: 50% !important;
  background: #818CF8 !important;
  box-shadow: 0 0 10px rgba(129, 124, 255, 0.9) !important;
  display: inline-block !important;
  visibility: visible !important;
  opacity: 1 !important;
  animation: wavePulse 1.1s cubic-bezier(0.45, 0.05, 0.55, 0.95) infinite !important;
  will-change: transform, opacity, background-color !important;
}

[data-theme="light"] .typing-dots span {
  background: #625BEE !important;
  box-shadow: 0 0 8px rgba(98, 91, 238, 0.6) !important;
}

.typing-dots span:nth-child(1) { animation-delay: 0s !important; }
.typing-dots span:nth-child(2) { animation-delay: 0.18s !important; }
.typing-dots span:nth-child(3) { animation-delay: 0.36s !important; }

@keyframes wavePulse {
  0%, 100% {
    transform: translate3d(0, 0, 0) scale(0.7);
    opacity: 0.35;
    background: #625BEE !important;
  }
  50% {
    transform: translate3d(0, -8px, 0) scale(1.35);
    opacity: 1;
    background: #A5B4FC !important;
    box-shadow: 0 0 14px #A5B4FC !important;
  }
}

/* Image in user message */
.msg-image {
  max-width: 100%; max-height: 250px;
  border-radius: 12px; object-fit: cover;
  margin-bottom: 8px; display: block;
}

/* -- INPUT FOOTER WRAP (in document flow) ---------------- */
.input-footer-wrap {
  position: relative;
  inset: auto;
  width: min(100%, 960px);
  flex: 0 0 auto;
  margin: 0 auto;
  padding: 0 16px max(24px, env(safe-area-inset-bottom));
  background: transparent;
  pointer-events: auto;
  z-index: 20;
}
.input-footer-wrap > * { pointer-events: auto; }
/* -- INPUT ISLAND ------------------------------------------- */
.input-island {
  margin: 0 16px 0;
  background: var(--surface);
  border: 1px solid var(--border2);
  border-radius: 22px;
  padding: 10px 14px 8px;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 -4px 32px rgba(0,0,0,0.3), var(--shadow);
  transition: border-color 0.2s, box-shadow 0.2s;
  flex-shrink: 0;
}
.input-island:focus-within {
  border-color: rgba(98,91,238,0.4);
  box-shadow: 0 -4px 32px rgba(0,0,0,0.3), 0 0 0 3px rgba(98,91,238,0.08);
}

/* Image preview strip */
.image-preview-strip {
  display: flex; gap: 8px; flex-wrap: wrap;
  padding-bottom: 10px; margin-bottom: 4px;
  border-bottom: 1px solid var(--border);
}
.img-thumb {
  position: relative; width: 60px; height: 60px;
}
.img-thumb img {
  width: 60px; height: 60px; border-radius: 10px; object-fit: cover;
}
.img-thumb-remove {
  position: absolute; top: -4px; right: -4px;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--primary); color: white; border: none;
  font-size: 11px; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  line-height: 1;
}

/* Input row */
.input-row {
  display: flex; align-items: flex-end; gap: 8px;
}
.input-wrap { flex: 1; position: relative; }
.question-input {
  width: 100%;
  background: none;
  border: none; outline: none;
  color: var(--text);
  font-family: var(--sans); font-size: 15px; line-height: 1.5;
  resize: none;
  max-height: 140px; min-height: 36px;
  overflow-y: auto;
  padding: 6px 0;
  display: block;
}
.question-input::placeholder { color: var(--text3); }
.question-input::-webkit-scrollbar { width: 3px; }
.question-input::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 3px; }

.char-count {
  font-size: 10px; color: var(--text3); position: absolute; right: 0; bottom: -16px;
  font-family: var(--mono);
  opacity: 0; transition: opacity 0.2s;
}
.char-count.visible { opacity: 1; }
.char-count.warn { color: #f59e0b; }

.input-actions { display: flex; align-items: center; gap: 5px; flex-shrink: 0; padding-bottom: 2px; }

/* Attach button */
.attach-btn {
  cursor: pointer;
}
/* Voice button */
.voice-btn.recording {
  color: var(--primary); border-color: rgba(98,91,238,0.4);
  background: rgba(98,91,238,0.08);
  animation: recPulse 1s ease-in-out infinite;
}
@keyframes recPulse {
  0%,100% { box-shadow: 0 0 0 0 rgba(98,91,238,0.4); }
  50% { box-shadow: 0 0 0 6px rgba(98,91,238,0); }
}

/* Send button */
.send-btn {
  width: 40px; height: 40px; border-radius: 14px;
  background: linear-gradient(135deg, var(--primary), #4F46E5);
  border: none; color: white; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 4px 16px rgba(98,91,238,0.4);
  transition: all var(--transition);
  flex-shrink: 0;
}
.send-btn:hover:not(:disabled) { transform: translateY(-2px); box-shadow: 0 6px 24px rgba(98,91,238,0.55); }
.send-btn:active:not(:disabled) { transform: scale(0.95); }
.send-btn:disabled { opacity: 0.4; cursor: not-allowed; transform: none; }
.send-btn.streaming {
  background: linear-gradient(135deg, #707A95, #252943);
  box-shadow: none;
}

/* Input footer */
.input-footer {
  display: flex; justify-content: center; align-items: center;
  margin-top: 8px;
  font-size: 10px; color: var(--text3);
}
.model-badge {
  background: rgba(98,91,238,0.1);
  border: 1px solid rgba(98,91,238,0.2);
  border-radius: 10px; padding: 2px 9px;
  font-size: 10px; color: var(--primary-strong);
  font-family: var(--sans); font-weight: 600; letter-spacing: 0.3px;
}

/* -- PROMINENT QUIZ BANNER --------------------------------- */
.prominent-quiz-banner {
  padding: 4px 16px 4px;
  display: flex; justify-content: center;
  flex-shrink: 0; /* CRITICAL: never let this shrink */
}
.prominent-quiz-btn {
  background: linear-gradient(135deg, rgba(98,91,238,0.15), rgba(107,110,243,0.12));
  border: 1.5px solid rgba(98,91,238,0.3);
  color: var(--text); font-family: var(--sans); font-size: 13px; font-weight: 700;
  padding: 10px 20px; border-radius: 20px; cursor: pointer;
  display: flex; align-items: center; justify-content: center; gap: 8px;
  transition: all 0.25s cubic-bezier(0.16,1,0.3,1); width: 100%; max-width: 340px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.2);
}
.prominent-quiz-btn:hover { background: rgba(98,91,238,0.2); border-color: rgba(98,91,238,0.5); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(98,91,238,0.15); }
.pq-icon { font-size: 16px; }
.pq-text { flex: 1; text-align: left; margin-left: 4px; color: var(--text); }
.pq-arrow { color: var(--primary-strong); font-weight: 800; }
.stop-inline-btn {
  width: 36px; height: 36px; border-radius: 10px;
  background: rgba(98,91,238,0.15); border: 1px solid rgba(98,91,238,0.4);
  color: var(--primary); display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: all 0.2s; flex-shrink: 0;
}
.stop-inline-btn:hover { background: rgba(98,91,238,0.25); }

/* -- SCROLL FAB ------------------------------------------- */
.scroll-fab {
  position: absolute;
  bottom: 110px; right: 20px;
  width: 40px; height: 40px; border-radius: 50%;
  background: var(--surface2);
  border: 1px solid var(--border2);
  color: var(--text2); cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition);
  z-index: 50;
}
.scroll-fab:hover { background: rgba(255,255,255,0.1); color: var(--text); transform: translateY(-2px); }

/* -- PROFILE DRAWER --------------------------------------- */
.profile-drawer-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 200;
  backdrop-filter: blur(4px);
  animation: fadeIn 0.2s ease both;
}
@keyframes fadeIn { from{opacity:0} to{opacity:1} }

.profile-drawer {
  position: fixed;
  top: 0; right: 0; bottom: 0;
  width: min(340px, 92vw);
  background: var(--bg2);
  border-left: 1px solid var(--border2);
  z-index: 201;
  display: flex; flex-direction: column;
  animation: slideInRight 0.3s cubic-bezier(0.16,1,0.3,1) both;
  overflow: hidden;
}
@keyframes slideInRight { from{transform:translateX(100%)} to{transform:translateX(0)} }
.profile-drawer.closing { animation: slideOutRight 0.25s ease forwards; }
@keyframes slideOutRight { to{transform:translateX(100%)} }

.drawer-header {
  display: flex; align-items: center; gap: 12px;
  padding: 20px 18px 16px;
  border-bottom: 1px solid var(--border);
}
.drawer-avatar {
  width: 52px; height: 52px; border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; font-weight: 700; color: white; flex-shrink: 0;
}
.drawer-info { flex: 1; min-width: 0; }
.drawer-name { font-size: 15px; font-weight: 700; color: var(--text); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.drawer-email { font-size: 12px; color: var(--text2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; margin-top: 2px; }
.drawer-type-badge {
  display: inline-block; margin-top: 5px;
  font-size: 10px; font-weight: 700; padding: 2px 8px; border-radius: 8px;
  background: rgba(98,91,238,0.15); color: var(--primary-strong); border: 1px solid rgba(98,91,238,0.25);
  text-transform: uppercase; letter-spacing: 0.5px;
}
.drawer-close-btn { margin-left: auto; flex-shrink: 0; }

.drawer-body { flex: 1; overflow-y: auto; padding: 4px 0; }
.drawer-section { padding: 16px 18px 12px; border-bottom: 1px solid var(--border); }
.drawer-section:last-child { border-bottom: none; }
.drawer-section-title { font-size: 11px; font-weight: 700; color: var(--text3); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 12px; }

/* Usage */
.usage-bar-wrap { display: flex; flex-direction: column; gap: 7px; }
.usage-bar {
  height: 6px; border-radius: 6px; background: var(--border2); overflow: hidden;
}
.usage-bar-fill {
  height: 100%; border-radius: 6px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width 0.6s cubic-bezier(0.16,1,0.3,1);
}
.usage-bar-fill.warn { background: linear-gradient(90deg, #f59e0b, #fcd34d); }
.usage-bar-fill.danger { background: linear-gradient(90deg, var(--primary), var(--primary-strong)); }
.usage-label { font-size: 12px; color: var(--text2); font-family: var(--mono); }

/* Referral */
.ref-row { display: flex; align-items: center; gap: 10px; margin-bottom: 6px; }
.ref-code {
  flex: 1; background: rgba(255,255,255,0.05);
  border: 1px solid var(--border2); border-radius: 10px;
  padding: 8px 14px; font-family: var(--mono);
  font-size: 16px; font-weight: 700; color: var(--accent2);
  letter-spacing: 2px; text-align: center;
}
.ref-copy-btn {
  padding: 8px 14px; border-radius: 10px;
  background: rgba(107,110,243,0.15); border: 1px solid rgba(107,110,243,0.3);
  color: var(--accent2); font-size: 13px; font-weight: 600;
  cursor: pointer; transition: all 0.2s; white-space: nowrap;
}
.ref-copy-btn:hover { background: rgba(107,110,243,0.25); }
.ref-hint { font-size: 11px; color: var(--text3); }

/* Settings */
.settings-list { display: flex; flex-direction: column; gap: 2px; }
.setting-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 11px 14px; border-radius: 12px;
  font-size: 14px; color: var(--text2);
  cursor: pointer; transition: all 0.2s;
  background: none; border: none; width: 100%; text-align: left;
}
.setting-row:hover { background: rgba(255,255,255,0.05); color: var(--text); }
.setting-icon { font-size: 15px; }
.setting-btn { }

/* Toggle switch */
.toggle-switch { position: relative; width: 40px; height: 22px; }
.toggle-switch input { opacity: 0; width: 0; height: 0; }
.toggle-slider {
  position: absolute; inset: 0; border-radius: 22px;
  background: var(--border2); cursor: pointer; transition: 0.3s;
}
.toggle-slider::before {
  content: ''; position: absolute;
  height: 16px; width: 16px; border-radius: 50%;
  left: 3px; bottom: 3px;
  background: white; transition: 0.3s;
}
.toggle-switch input:checked + .toggle-slider { background: var(--primary); }
.toggle-switch input:checked + .toggle-slider::before { transform: translateX(18px); }

/* Admin link */
.admin-link-btn {
  display: flex; align-items: center; gap: 10px;
  padding: 12px 14px; border-radius: 12px;
  background: rgba(107,110,243,0.1); border: 1px solid rgba(107,110,243,0.2);
  color: var(--accent2); font-size: 14px; font-weight: 600;
  text-decoration: none; transition: all 0.2s;
}
.admin-link-btn:hover { background: rgba(107,110,243,0.2); }

.drawer-footer { padding: 16px 18px; border-top: 1px solid var(--border); }
.logout-btn {
  width: 100%; padding: 12px;
  border-radius: 14px;
  background: rgba(98,91,238,0.1); border: 1px solid rgba(98,91,238,0.2);
  color: var(--primary-strong); font-family: var(--sans);
  font-size: 14px; font-weight: 600;
  cursor: pointer; display: flex; align-items: center; justify-content: center; gap: 8px;
  transition: all 0.2s;
}
.logout-btn:hover { background: rgba(98,91,238,0.2); }

/* -- QUIZ MODE -------------------------------------------- */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.65);
  z-index: 300; backdrop-filter: blur(6px);
  animation: fadeIn 0.2s ease both;
}
.quiz-setup-card, .report-card {
  position: fixed;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: min(500px, 94vw);
  background: var(--bg2);
  border: 1px solid var(--border2);
  border-radius: 24px;
  z-index: 301;
  overflow: hidden;
  animation: cardIn 0.35s cubic-bezier(0.16,1,0.3,1) both;
}
@keyframes cardIn { from{opacity:0;transform:translate(-50%,-48%)} to{opacity:1;transform:translate(-50%,-50%)} }

.quiz-setup-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--border);
}
.quiz-setup-header h2 { font-size: 18px; font-weight: 700; color: white; }
.quiz-setup-body { padding: 20px; display: flex; flex-direction: column; gap: 18px; }
.quiz-field { display: flex; flex-direction: column; gap: 8px; }
.quiz-field label { font-size: 12px; font-weight: 600; color: var(--text2); text-transform: uppercase; letter-spacing: 0.5px; }
.quiz-field input, .quiz-field textarea {
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border2);
  border-radius: 13px; padding: 12px 16px;
  color: var(--text); font-family: var(--sans); font-size: 15px;
  outline: none; transition: 0.2s; width: 100%;
}
.quiz-field input:focus, .quiz-field textarea:focus {
  border-color: rgba(98,91,238,0.5);
  box-shadow: 0 0 0 3px rgba(98,91,238,0.08);
}
.quiz-field textarea { resize: none; }

.quiz-count-row, .quiz-diff-row { display: flex; gap: 8px; flex-wrap: wrap; }
.quiz-count-btn, .quiz-diff-btn {
  padding: 8px 18px; border-radius: 10px;
  background: rgba(255,255,255,0.04); border: 1px solid var(--border2);
  color: var(--text2); font-family: var(--sans); font-size: 14px; font-weight: 600;
  cursor: pointer; transition: all 0.2s;
}
.quiz-count-btn:hover, .quiz-diff-btn:hover { border-color: var(--border2); color: var(--text); background: rgba(255,255,255,0.08); }
.quiz-count-btn--active, .quiz-diff-btn--active {
  background: rgba(98,91,238,0.15);
  border-color: rgba(98,91,238,0.4);
  color: var(--primary-strong);
}

.start-quiz-btn, #submitReportBtn {
  width: calc(100% - 40px); margin: 0 20px 20px;
  padding: 14px;
  border: none; border-radius: 14px;
  background: linear-gradient(135deg, var(--primary), #4F46E5);
  color: white; font-family: var(--sans);
  font-size: 15px; font-weight: 700; cursor: pointer;
  box-shadow: 0 6px 24px rgba(98,91,238,0.35);
  transition: all 0.2s;
}
.start-quiz-btn:hover:not(:disabled), #submitReportBtn:hover {
  transform: translateY(-2px); box-shadow: 0 8px 32px rgba(98,91,238,0.5);
}
.start-quiz-btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

/* Quiz active in chat */
.quiz-message { display: flex; flex-direction: column; gap: 8px; }
.quiz-q-header {
  font-size: 12px;
  color: #6366F1 !important;
  font-weight: 600;
  margin-bottom: 10px;
  font-family: var(--mono);
  letter-spacing: 0.3px;
}
.quiz-question {
  font-size: 16px !important;
  font-weight: 700 !important;
  color: var(--text, #0F172A) !important;
  margin-bottom: 14px;
  line-height: 1.5;
}

[data-theme="dark"] .quiz-question {
  color: #F8FAFC !important;
}

.quiz-options-wrap { display: flex; flex-direction: column; gap: 8px; }
.quiz-option {
  padding: 12px 16px; border-radius: 12px;
  background: var(--bg2, rgba(255,255,255,0.04));
  border: 1px solid var(--border2, #E2E8F0);
  color: var(--text, #0F172A) !important;
  font-size: 14px;
  cursor: pointer; text-align: left; transition: all 0.2s;
  display: flex; align-items: flex-start; gap: 10px;
}

[data-theme="light"] .quiz-option {
  background: #F8FAFC !important;
  border-color: #E2E8F0 !important;
  color: #0F172A !important;
}

[data-theme="dark"] .quiz-option {
  background: #141724 !important;
  border-color: #282F48 !important;
  color: #F8FAFC !important;
}

.quiz-option:hover:not(.answered) {
  background: rgba(99, 102, 241, 0.1) !important;
  border-color: #6366F1 !important;
  color: var(--primary-strong, #4F46E5) !important;
}
.quiz-option.is-correct { background: rgba(16,185,129,0.15) !important; border-color: #10B981 !important; color: #10B981 !important; }
.quiz-option.is-wrong   { background: rgba(239,68,68,0.15) !important; border-color: #EF4444 !important; color: #EF4444 !important; }
.quiz-option.answered   { cursor: not-allowed; }
.quiz-option-letter { font-family: var(--mono); font-weight: 700; font-size: 13px; flex-shrink: 0; margin-top: 1px; }

.quiz-explanation-box {
  margin-top: 14px; padding: 12px 16px;
  background: rgba(99, 102, 241, 0.08); border: 1px solid rgba(99, 102, 241, 0.25);
  border-radius: 12px; font-size: 13px; color: var(--text, #0F172A) !important; line-height: 1.6;
}
[data-theme="dark"] .quiz-explanation-box {
  color: #F1F5F9 !important;
}
.expl-text { font-size: 13px; line-height: 1.65; }
.quiz-next-btn {
  margin-top: 12px; align-self: flex-end;
  padding: 9px 20px; border-radius: 10px;
  background: var(--primary); border: none;
  color: white; font-family: var(--sans);
  font-size: 13px; font-weight: 700;
  cursor: pointer; transition: all 0.2s;
}
.quiz-next-btn:hover { background: var(--primary-strong); transform: translateX(2px); }

/* Quiz End Score Card */
.quiz-score-card { text-align: center; padding: 10px 0; }
.quiz-score-stars { font-size: 28px; margin-bottom: 8px; }
.quiz-score-big { font-size: 42px; font-weight: 800; color: var(--text); line-height: 1; margin-bottom: 4px; }
.quiz-score-label { font-size: 15px; color: var(--text2); font-weight: 500; }

/* Weak Topics Section */
.weak-topics-section {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border2);
  text-align: left;
}
.wt-title { font-size: 14px; font-weight: 700; color: var(--accent); margin-bottom: 4px; }
.wt-desc { font-size: 13px; color: var(--text2); margin-bottom: 12px; }
.wt-actions { display: flex; flex-direction: column; gap: 8px; }
.weak-topic-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 16px;
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  transition: 0.2s;
  display: flex;
  align-items: center;
  gap: 8px;
}
.weak-topic-btn:hover {
  background: var(--surface3);
  border-color: var(--border2);
  transform: translateY(-1px);
}
.weak-topic-btn:active { transform: translateY(0); }

/* -- LIMIT REACHED BANNER --------------------------------- */
.limit-banner {
  margin: 8px 16px 0;
  padding: 12px 16px;
  background: rgba(98,91,238,0.08); border: 1px solid rgba(98,91,238,0.25);
  border-radius: 14px; font-size: 13px; color: var(--primary-strong);
  text-align: center; line-height: 1.5;
}

/* -- EXAM COUNTDOWN --------------------------------------- */
.exam-countdown {
  display: flex; align-items: center; gap: 6px;
  background: rgba(98,91,238,0.08);
  border: 1px solid rgba(98,91,238,0.2);
  border-radius: 20px; padding: 5px 14px;
  font-size: 12px; color: var(--primary-strong);
  font-weight: 600; cursor: default;
  animation: examPulse 3s ease-in-out infinite;
  white-space: nowrap;
}
@keyframes examPulse {
  0%,100% { border-color: rgba(98,91,238,0.2); }
  50%      { border-color: rgba(98,91,238,0.5); box-shadow: 0 0 12px rgba(98,91,238,0.15); }
}
.countdown-label { font-size: 11px; }
.countdown-sep { opacity: 0.4; }
.countdown-value { font-size: 15px; font-weight: 800; color: white; letter-spacing: -0.5px; }
.countdown-unit { font-size: 10px; color: var(--text2); }
.header-announcement-wrap { display: contents; }

/* -- STREAK BANNER ---------------------------------------- */
.streak-banner {
  display: flex; align-items: center; justify-content: center; gap: 6px;
  padding: 10px 18px;
  background: linear-gradient(135deg, rgba(245,158,11,0.1), rgba(98,91,238,0.08));
  border-bottom: 1px solid rgba(245,158,11,0.15);
  font-size: 13px; font-weight: 700; color: #fcd34d;
}
.streak-fire { font-size: 16px; }
.streak-best { font-size: 10px; color: var(--text3); font-weight: 400; margin-left: 4px; }

/* -- BOOKMARKS -------------------------------------------- */
.bookmark-empty {
  font-size: 12px; color: var(--text3); text-align: center;
  padding: 16px 0; line-height: 1.6;
}
.bookmark-item {
  padding: 10px 12px; border-radius: 12px;
  background: rgba(255,255,255,0.03); border: 1px solid var(--border);
  margin-bottom: 8px; position: relative;
  transition: background 0.2s;
}
.bookmark-item:hover { background: rgba(255,255,255,0.06); }
.bookmark-text {
  font-size: 12px; color: var(--text2); line-height: 1.55;
  max-height: 60px; overflow: hidden;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical;
}
.bookmark-time { font-size: 10px; color: var(--text3); margin-top: 5px; font-family: var(--mono); }
.bookmark-del {
  position: absolute; top: 8px; right: 8px;
  background: none; border: none; color: var(--text3);
  cursor: pointer; font-size: 14px; padding: 2px 5px;
  border-radius: 6px; transition: all 0.2s; line-height: 1;
}
.bookmark-del:hover { background: rgba(98,91,238,0.12); color: var(--primary-strong); }

/* -- LEADERBOARD MODAL ------------------------------------ */
.leaderboard-modal {
  position: fixed;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: min(420px, 94vw);
  background: var(--bg2);
  border: 1px solid var(--border2);
  border-radius: 24px; z-index: 301; overflow: hidden;
  animation: cardIn 0.35s cubic-bezier(0.16,1,0.3,1) both;
}
.leaderboard-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 20px 20px 16px;
  border-bottom: 1px solid var(--border);
  background: linear-gradient(135deg, rgba(245,158,11,0.08), transparent);
}
.leaderboard-header h2 { font-size: 18px; font-weight: 700; color: white; }
.leaderboard-list { padding: 16px; display: flex; flex-direction: column; gap: 8px; max-height: 360px; overflow-y: auto; }
.lb-row {
  display: flex; align-items: center; gap: 12px;
  padding: 10px 14px; border-radius: 12px;
  background: rgba(255,255,255,0.03); border: 1px solid var(--border);
  transition: background 0.2s;
}
.lb-row:hover { background: rgba(255,255,255,0.06); }
.lb-row.lb-top { background: rgba(245,158,11,0.08); border-color: rgba(245,158,11,0.2); }
.lb-rank { font-size: 16px; font-weight: 800; width: 28px; text-align: center; flex-shrink: 0; }
.lb-name { flex: 1; font-size: 14px; color: var(--text); font-weight: 600; }
.lb-score { font-size: 13px; font-weight: 700; color: var(--accent2); font-family: var(--mono); }
.lb-empty { text-align: center; padding: 40px; color: var(--text3); font-size: 13px; }

/* -- RESPONSIVE ------------------------------------------- */
@media (max-width: 640px) {
  .header-center { display: none; } /* Hide countdown entirely to fix mobile space constraints */
  .header-sub { display: none; }
  .stat-pill { padding: 4px 8px; font-size: 11px; }
  .input-island { margin: 0 8px 10px; border-radius: 18px; padding: 10px 12px 8px; }
  .chat-area { padding: 16px 12px 8px; gap: 14px; }
  .bubble { max-width: 92%; padding: 12px 14px; }
  .ai-text { font-size: 14px; }
  .welcome-chips { gap: 6px; }
  .welcome-chip { font-size: 12px; padding: 6px 12px; }
  .profile-drawer { width: 100%; border-left: none; border-top: 1px solid var(--border2); }
  .scroll-fab { bottom: 90px; right: 12px; width: 44px; height: 44px; }
  #toast { left: 12px; right: 12px; transform: translateY(-80px); white-space: normal; }
  #toast.show { transform: translateY(0); }
  
  /* Mobile Touch Targets */
  .icon-btn, .send-btn, .stop-inline-btn { width: 36px; height: 36px; border-radius: 12px; }
  .profile-btn { width: 38px; height: 38px; }
  .input-row { gap: 6px; }
  .question-input { font-size: 15px; padding: 4px 0; min-height: 32px; }
  .icon-btn svg, .send-btn svg { width: 16px; height: 16px; }
  .quiz-option { padding: 12px 14px; font-size: 14px; touch-action: manipulation; }
  /* Prominent Quiz mobile compact */
  .prominent-quiz-banner { padding: 2px 8px 4px; }
  .prominent-quiz-btn { padding: 6px 14px; font-size: 12px; max-width: none; border-radius: 16px; }
  .pq-icon { font-size: 14px; }
  /* Input island mobile tightness ? margin set above, only override padding here */
  .input-island { padding: 8px 10px 6px; }
  /* Reaction bar touch targets */
  .reaction-bar button { min-height: 40px; min-width: 44px; }
  /* Bookmark touch targets */
  .bookmark-del { width: 32px; height: 32px; display: flex; align-items: center; justify-content: center; }
}

@media (min-width: 900px) {
  /* -- Centered column layout -- */
  .main-content {
    align-items: stretch;
  }

  .chat-area {
    padding: 40px calc((100% - 800px) / 2) 16px;
    gap: 24px;
  }

  /* Chat messages full-width within the centered column */
  .msg {
    width: 100%;
  }

  /* Wider bubbles for desktop readability */
  .bubble {
    max-width: min(72%, 680px);
    padding: 16px 22px;
    font-size: 15px;
  }

  /* Welcome screen desktop ? center it */
  .welcome-state {
    max-width: 660px;
    margin: 0 auto;
    padding: 60px 24px 40px;
  }
  .welcome-title { font-size: 38px; }
  .welcome-sub { font-size: 16px; }
  .welcome-chips { max-width: 580px; margin: 0 auto; }

  /* position:fixed footer ? use padding to simulate centering */
  .input-footer-wrap {
    padding-left: max(16px, calc((100% - 800px) / 2));
    padding-right: max(16px, calc((100% - 800px) / 2));
  }

  .prominent-quiz-banner {
    padding: 4px 0 6px;
    display: flex;
    justify-content: center;
  }
  .prominent-quiz-btn {
    max-width: 340px;
    font-size: 13px;
    padding: 8px 22px;
    border-radius: 20px;
  }

  .input-island {
    margin: 0 0 20px;
    border-radius: 20px;
    padding: 12px 16px 10px;
    box-shadow: 0 8px 40px rgba(0,0,0,0.4), 0 0 0 1px var(--border2);
  }

  /* Scroll fab relative to the centered column */
  .scroll-fab {
    right: max(16px, calc((100% - 800px) / 2 - 60px));
  }

  /* Header nicer spacing */
  .app-header {
    padding: 0 32px;
  }

  /* AI text slightly larger on desktop */
  .ai-text { font-size: 15px; line-height: 1.75; }
}

@media (min-width: 1200px) {
  /* Extra large screens get wider chat column */
  .chat-area { padding-left: calc((100% - 860px) / 2); padding-right: calc((100% - 860px) / 2); }
  .input-footer-wrap {
    padding-left: max(16px, calc((100% - 860px) / 2));
    padding-right: max(16px, calc((100% - 860px) / 2));
  }
  .bubble { max-width: min(70%, 720px); }
}

/* -- MOBILE LANDSCAPE ----------------------------------- */
@media (max-width: 900px) and (orientation: landscape) and (max-height: 500px) {
  /* Very short landscape phone ? collapse header to minimum */
  .app-header { height: 44px; padding: 0 12px; }
  .header-logo { width: 26px; height: 26px; }
  .header-brand { font-size: 14px; }
  .header-sub, .header-center { display: none; }
  .splash-logo { width: 60px; height: 60px; }
  .welcome-state { padding: 12px 16px; gap: 12px; }
}

/* -- REDUCED MOTION (Accessibility + Battery) ----------- */
@media (prefers-reduced-motion: reduce) {
  /* Kill expensive animations for users who prefer less motion */
  .bg-orb, .splash-orb { animation: none !important; }
  .exam-countdown { animation: none !important; }
  * { transition-duration: 0.01ms !important; animation-duration: 0.01ms !important; }
}

/* -- MOBILE PERFORMANCE --------------------------------- */
@media (max-width: 640px) {
  /* Disable expensive background orb animations on small screens ? saves battery */
  .bg-orb { display: none; }
  /* Kill backdrop-filter on mobile Chrome/Android ? it causes severe jank */
  .app-header {
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    background: rgba(8,9,15,0.97); /* Solid fallback */
  }
  /* Prevent text selection on UI elements */
  .header-left, .header-right, .input-island, .prominent-quiz-banner { user-select: none; }
  /* Ensure action buttons don't cramp the input width */
  .icon-btn, .send-btn, .stop-inline-btn {
    min-width: 36px; min-height: 36px;
    width: 36px; height: 36px;
    touch-action: manipulation;
  }
  /* Input island: mobile margin */
  .input-island {
    margin: 0 12px 0;
  }
}

/* -- PWA STANDALONE MODE (Added to home screen) --------- */
@media (display-mode: standalone) {
  /* Extra top padding for status bar in PWA mode */
  .app-header {
    padding-top: max(12px, env(safe-area-inset-top));
    height: calc(var(--header-h) + env(safe-area-inset-top));
  }
}

/* NexA self-contained icon system */
.nexa-icon{width:1em;height:1em;display:inline-block;flex:0 0 auto;vertical-align:-0.14em;stroke:currentColor}
.nexa-icon-slot,[data-icon]{display:inline-flex;align-items:center;justify-content:center}
.reaction-bar .nexa-icon{width:15px;height:15px}
.quiz-score-badge{display:inline-flex;align-items:center;justify-content:center;gap:8px;color:var(--primary-strong);font-size:15px;font-weight:700;margin-bottom:8px}

/* Bengali output surfaces */
.ai-text,
.ai-text p,
.ai-text li,
.ai-text td,
.msg .bubble > span,
.quiz-question,
.quiz-option,
.quiz-explanation-box,
.expl-text,
.question-input {
  font-family: var(--sans-bn);
}
.ai-text { line-height: 1.85; }
.quiz-question { line-height: 1.65; }
.quiz-option { line-height: 1.6; }
.question-input { line-height: 1.65; }

/* Bengali form surfaces */
.quiz-field input,
.quiz-field textarea {
  font-family: var(--sans-bn);
  line-height: 1.65;
}