/* ============================================================
   SECURE CHAT — CNS Lab Assignment
   Dark hacker-style theme with neon green accents
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Share+Tech+Mono&family=Inter:wght@400;500;600;700&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
  --bg-dark:       #0a0e17;
  --bg-panel:      #111827;
  --bg-card:       #1a2236;
  --bg-input:      #0f1729;
  --border:        #1e2d4a;
  --neon:          #00ff88;
  --neon-dim:      #00cc6a;
  --neon-glow:     rgba(0,255,136,.15);
  --cyan:          #00e5ff;
  --purple:        #a855f7;
  --amber:         #fbbf24;
  --red:           #ef4444;
  --text:          #e2e8f0;
  --text-dim:      #94a3b8;
  --mono:          'Share Tech Mono', monospace;
  --sans:          'Inter', sans-serif;
  --radius:        10px;
  --transition:    .25s ease;
}

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

html { font-size: 15px; }

body {
  font-family: var(--sans);
  background: var(--bg-dark);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
}

/* subtle animated grid background */
body::before {
  content: '';
  position: fixed; inset: 0;
  background-image:
    linear-gradient(rgba(0,255,136,.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0,255,136,.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

/* ---------- Utility ---------- */
.hidden { display: none !important; }

/* ---------- Scanline overlay (aesthetic) ---------- */
#scanline {
  position: fixed; inset: 0;
  background: repeating-linear-gradient(
    0deg,
    transparent,
    transparent 2px,
    rgba(0,0,0,.06) 2px,
    rgba(0,0,0,.06) 4px
  );
  pointer-events: none;
  z-index: 9999;
}

/* ============================================================
   LOGIN SCREEN
   ============================================================ */
#login-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  position: relative;
  z-index: 1;
  padding: 1rem;
}

.login-container {
  width: 100%;
  max-width: 440px;
  animation: fadeSlideUp .6s ease;
}

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(30px); }
  to   { opacity: 1; transform: translateY(0); }
}

.login-header {
  text-align: center;
  margin-bottom: 2rem;
}

.login-header .lock-icon {
  font-size: 2.5rem;
  margin-bottom: .5rem;
}

.login-header h1 {
  font-family: var(--mono);
  font-size: 1.6rem;
  color: var(--neon);
  text-shadow: 0 0 20px var(--neon-glow);
  letter-spacing: 2px;
}

.login-header p {
  color: var(--text-dim);
  font-size: .85rem;
  margin-top: .4rem;
}

/* Login Card */
.login-card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: 0 0 40px rgba(0,255,136,.04);
}

.form-group {
  margin-bottom: 1.2rem;
}

.form-group label {
  display: block;
  font-size: .75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: .4rem;
  font-family: var(--mono);
}

.form-group input {
  width: 100%;
  padding: .7rem 1rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  font-family: var(--mono);
  font-size: .95rem;
  outline: none;
  transition: border var(--transition);
}

.form-group input:focus {
  border-color: var(--neon);
  box-shadow: 0 0 8px var(--neon-glow);
}

.login-btn {
  width: 100%;
  padding: .8rem;
  background: linear-gradient(135deg, var(--neon-dim), var(--neon));
  color: #000;
  font-weight: 700;
  font-family: var(--mono);
  font-size: .95rem;
  letter-spacing: 1px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
  text-transform: uppercase;
}

.login-btn:hover {
  box-shadow: 0 0 20px rgba(0,255,136,.35);
  transform: translateY(-1px);
}

.login-btn:active {
  transform: translateY(0);
}

/* Hint */
.credentials-hint {
  text-align: center;
  margin-top: 1rem;
  font-size: .75rem;
  color: var(--text-dim);
  font-family: var(--mono);
}

.credentials-hint span {
  color: var(--neon);
}

/* Auth Details Panel (visible after login attempt) */
.auth-details {
  margin-top: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.2rem;
  animation: fadeSlideUp .4s ease;
}

.auth-details h3 {
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: .8rem;
  display: flex;
  align-items: center;
  gap: .4rem;
}

.detail-row {
  display: flex;
  flex-direction: column;
  margin-bottom: .7rem;
}

.detail-row .label {
  font-size: .65rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: .2rem;
  font-family: var(--mono);
}

.detail-row .value {
  font-family: var(--mono);
  font-size: .78rem;
  color: var(--neon);
  word-break: break-all;
  background: var(--bg-input);
  padding: .4rem .6rem;
  border-radius: 4px;
  border: 1px solid var(--border);
}

.auth-result {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding: .5rem .8rem;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: .8rem;
  font-weight: 600;
  margin-top: .5rem;
}

.auth-result.success {
  background: rgba(0,255,136,.1);
  color: var(--neon);
  border: 1px solid rgba(0,255,136,.25);
}

.auth-result.failure {
  background: rgba(239,68,68,.1);
  color: var(--red);
  border: 1px solid rgba(239,68,68,.25);
}

/* Proceed Button (shown after successful auth) */
.proceed-btn {
  width: 100%;
  padding: .8rem;
  margin-top: 1rem;
  background: linear-gradient(135deg, var(--neon-dim), var(--neon));
  color: #000;
  font-weight: 700;
  font-family: var(--mono);
  font-size: .9rem;
  letter-spacing: 1px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
  text-transform: uppercase;
  animation: fadeSlideUp .4s ease;
}

.proceed-btn:hover {
  box-shadow: 0 0 20px rgba(0,255,136,.35);
  transform: translateY(-1px);
}

.proceed-btn:active {
  transform: translateY(0);
}

/* ============================================================
   CHAT SCREEN
   ============================================================ */
#chat-screen {
  display: none;
  flex-direction: column;
  height: 100vh;
  position: relative;
  z-index: 1;
}

/* Top Bar */
.chat-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: .7rem 1.2rem;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: .6rem;
}

.topbar-left .dot {
  width: 10px; height: 10px;
  background: var(--neon);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--neon);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50%      { opacity: .4; }
}

.topbar-left h2 {
  font-family: var(--mono);
  font-size: 1rem;
  color: var(--neon);
  letter-spacing: 1px;
}

.topbar-left span {
  font-size: .7rem;
  color: var(--text-dim);
  font-family: var(--mono);
}

.logout-btn {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: .35rem .9rem;
  border-radius: 6px;
  font-family: var(--mono);
  font-size: .75rem;
  cursor: pointer;
  transition: var(--transition);
}

.logout-btn:hover {
  border-color: var(--red);
  color: var(--red);
}

/* Main layout: sidebar + chat */
.chat-main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Key Exchange Sidebar */
.key-panel {
  width: 320px;
  background: var(--bg-panel);
  border-right: 1px solid var(--border);
  padding: 1.2rem;
  overflow-y: auto;
  flex-shrink: 0;
}

.key-panel h3 {
  font-family: var(--mono);
  font-size: .8rem;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: .4rem;
}

.key-section {
  margin-bottom: 1.2rem;
}

.key-section h4 {
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--purple);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: .5rem;
}

.key-value {
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--neon);
  word-break: break-all;
  background: var(--bg-input);
  padding: .5rem .6rem;
  border-radius: 4px;
  border: 1px solid var(--border);
  line-height: 1.5;
}

.key-label {
  font-size: .6rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: .2rem;
  font-family: var(--mono);
}

.key-item {
  margin-bottom: .7rem;
}

/* Chat Area */
.chat-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 1.2rem;
}

/* Message block (user msg + crypto details) */
.message-block {
  margin-bottom: 1.8rem;
  animation: fadeSlideUp .4s ease;
}

/* Bubbles */
.bubble {
  max-width: 70%;
  padding: .7rem 1rem;
  border-radius: 12px;
  font-size: .9rem;
  line-height: 1.5;
  position: relative;
}

.bubble.sent {
  background: linear-gradient(135deg, #0e3a2a, #0d2f22);
  border: 1px solid rgba(0,255,136,.2);
  margin-left: auto;
  border-bottom-right-radius: 4px;
}

.bubble.received {
  background: var(--bg-card);
  border: 1px solid var(--border);
  margin-right: auto;
  border-bottom-left-radius: 4px;
}

.bubble .meta {
  font-size: .6rem;
  color: var(--text-dim);
  margin-top: .3rem;
  font-family: var(--mono);
}

/* Crypto Details Card */
.crypto-card {
  margin-top: .8rem;
  max-width: 85%;
  margin-left: auto;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.crypto-card-header {
  display: flex;
  align-items: center;
  gap: .4rem;
  padding: .6rem .9rem;
  background: rgba(0,229,255,.05);
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  transition: background var(--transition);
}

.crypto-card-header:hover {
  background: rgba(0,229,255,.1);
}

.crypto-card-header span {
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: .5px;
}

.crypto-card-header .toggle-icon {
  margin-left: auto;
  font-size: .7rem;
  color: var(--text-dim);
  transition: transform var(--transition);
}

.crypto-card-header.open .toggle-icon {
  transform: rotate(180deg);
}

.crypto-card-body {
  padding: .8rem .9rem;
}

.crypto-row {
  margin-bottom: .6rem;
}

.crypto-row:last-child {
  margin-bottom: 0;
}

.crypto-label {
  font-family: var(--mono);
  font-size: .6rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: .2rem;
}

.crypto-value {
  font-family: var(--mono);
  font-size: .72rem;
  word-break: break-all;
  background: var(--bg-input);
  padding: .4rem .6rem;
  border-radius: 4px;
  border: 1px solid var(--border);
  line-height: 1.5;
}

.crypto-value.original  { color: var(--text); }
.crypto-value.encrypted { color: var(--amber); }
.crypto-value.decrypted { color: var(--neon); }
.crypto-value.hash      { color: var(--purple); }
.crypto-value.hmac      { color: var(--cyan); }
.crypto-value.match     { color: var(--neon); }
.crypto-value.mismatch  { color: var(--red); }

/* Input Area */
.chat-input-area {
  display: flex;
  align-items: center;
  gap: .6rem;
  padding: .8rem 1.2rem;
  background: var(--bg-panel);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.chat-input-area input {
  flex: 1;
  padding: .7rem 1rem;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: var(--mono);
  font-size: .9rem;
  outline: none;
  transition: border var(--transition);
}

.chat-input-area input:focus {
  border-color: var(--neon);
  box-shadow: 0 0 8px var(--neon-glow);
}

.send-btn {
  padding: .7rem 1.4rem;
  background: linear-gradient(135deg, var(--neon-dim), var(--neon));
  color: #000;
  font-weight: 700;
  font-family: var(--mono);
  font-size: .85rem;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: var(--transition);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.send-btn:hover {
  box-shadow: 0 0 16px rgba(0,255,136,.35);
  transform: translateY(-1px);
}

.send-btn:active {
  transform: translateY(0);
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--neon-dim); }

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .key-panel {
    display: none;
  }

  .bubble {
    max-width: 90%;
  }

  .crypto-card {
    max-width: 95%;
  }
}