/* Duo — Styles */

/* ── Theme: Dark (default) ── */
:root {
  --bg-primary: #0f0f0f;
  --bg-secondary: #1a1a2e;
  --bg-chat: #0f0f0f;
  --bubble-own: #4f46e5;
  --bubble-own-text: #ffffff;
  --bubble-partner: #1e1e3a;
  --bubble-partner-text: #e2e8f0;
  --accent: #818cf8;
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --online-green: #22c55e;
  --input-bg: #1e1e2e;
  --input-border: #2e2e4a;
  --danger: #ef4444;
  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --radius-bubble: 18px;
  --radius-card: 12px;
  --transition-fast: 150ms ease;
  --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  --login-bg: #0f0f0f;
  --card-bg: #1a1a2e;
  --input-text: #f1f5f9;
  --btn-bg: #4f46e5;
  --btn-text: #ffffff;
  --btn-hover: #6366f1;
  --topbar-bg: #1a1a2e;
  --topbar-border: #2e2e4a;
  --input-area-bg: #1a1a2e;
  --desktop-bg: #090912;
}

/* ── Theme: Light ── */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-chat: #f1f5f9;
  --bubble-own: #4f46e5;
  --bubble-own-text: #ffffff;
  --bubble-partner: #e2e8f0;
  --bubble-partner-text: #1e293b;
  --accent: #4f46e5;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --online-green: #16a34a;
  --input-bg: #ffffff;
  --input-border: #cbd5e1;
  --danger: #dc2626;
  --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
  --login-bg: #f1f5f9;
  --card-bg: #ffffff;
  --input-text: #0f172a;
  --btn-bg: #4f46e5;
  --btn-text: #ffffff;
  --btn-hover: #6366f1;
  --topbar-bg: #ffffff;
  --topbar-border: #e2e8f0;
  --input-area-bg: #ffffff;
  --desktop-bg: #e2e8f0;
}

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

html {
  height: 100%;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  background: var(--login-bg);
  color: var(--text-primary);
  height: 100dvh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, textarea {
  font-family: inherit;
  border: none;
  outline: none;
  background: none;
}

/* ── Screens ── */
.screen {
  display: none;
  height: 100dvh;
  width: 100%;
}

.screen.active {
  display: flex;
}

/* ── Login Screen ── */
#login-screen {
  align-items: center;
  justify-content: center;
  background: var(--login-bg);
  position: relative;
}

.login-card {
  background: var(--card-bg);
  border-radius: var(--radius-card);
  box-shadow: var(--card-shadow);
  padding: 2.5rem 2rem 2rem;
  width: 100%;
  max-width: 380px;
  margin: 1rem;
}

.login-logo {
  text-align: center;
  font-size: 3rem;
  margin-bottom: 0.25rem;
}

.login-title {
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.login-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  margin-bottom: 2rem;
}

/* Floating label input group */
.input-group {
  position: relative;
  margin-bottom: 1.25rem;
}

.input-group input {
  width: 100%;
  padding: 1rem 0.875rem 0.5rem;
  font-size: 1rem;
  color: var(--input-text);
  background: var(--input-bg);
  border: 1.5px solid var(--input-border);
  border-radius: 8px;
  transition: border-color var(--transition-fast);
}

.input-group input:focus {
  border-color: var(--accent);
}

.input-group label {
  position: absolute;
  left: 0.875rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1rem;
  color: var(--text-muted);
  pointer-events: none;
  transition: all var(--transition-fast);
}

.input-group input:focus + label,
.input-group input:not(:placeholder-shown) + label {
  top: 0.5rem;
  transform: none;
  font-size: 0.7rem;
  color: var(--accent);
}

.login-error {
  color: var(--danger);
  font-size: 0.8125rem;
  min-height: 1.25rem;
  margin-bottom: 0.5rem;
  text-align: center;
}

.login-btn {
  width: 100%;
  padding: 0.875rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--btn-text);
  background: var(--btn-bg);
  border-radius: 8px;
  transition: background var(--transition-fast), opacity var(--transition-fast);
}

.login-btn:hover {
  background: var(--btn-hover);
}

.login-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Shake animation */
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  10%, 30%, 50%, 70%, 90% { transform: translateX(-6px); }
  20%, 40%, 60%, 80% { transform: translateX(6px); }
}

.login-card.shake {
  animation: shake 0.5s ease;
}

/* ── Chat Screen ── */
#chat-screen {
  flex-direction: column;
  background: var(--bg-chat);
}

/* Top bar */
.topbar {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--topbar-bg);
  border-bottom: 1px solid var(--topbar-border);
  min-height: 56px;
  flex-shrink: 0;
}

.topbar-avatar {
  font-size: 1.75rem;
  line-height: 1;
}

.topbar-info {
  flex: 1;
  min-width: 0;
}

.topbar-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-muted);
  flex-shrink: 0;
}

.status-dot.online {
  background: var(--online-green);
  animation: pulse-online 2s ease-in-out infinite;
}

.topbar-status {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.topbar-actions {
  display: flex;
  gap: 0.5rem;
}

.topbar-btn {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--text-secondary);
  font-size: 1.125rem;
  transition: background var(--transition-fast);
}

.topbar-btn:hover {
  background: var(--input-bg);
}

/* Message area */
.messages {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  overscroll-behavior-y: contain;
}

.messages::-webkit-scrollbar {
  width: 4px;
}

.messages::-webkit-scrollbar-thumb {
  background: var(--input-border);
  border-radius: 2px;
}

/* Message bubbles */
.message {
  max-width: 80%;
  padding: 0.625rem 0.875rem;
  border-radius: var(--radius-bubble);
  font-size: 0.9375rem;
  line-height: 1.45;
  animation: slide-up 150ms ease-out;
  word-wrap: break-word;
}

.message.own {
  align-self: flex-end;
  background: var(--bubble-own);
  color: var(--bubble-own-text);
  border-bottom-right-radius: 4px;
}

.message.partner {
  align-self: flex-start;
  background: var(--bubble-partner);
  color: var(--bubble-partner-text);
  border-bottom-left-radius: 4px;
}

.message.sending {
  opacity: 0.7;
  transition: opacity var(--transition-fast);
}

.message-text {
  white-space: pre-wrap;
}

.message-meta {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.25rem;
  margin-top: 0.125rem;
}

.message-time {
  font-size: 0.6875rem;
  opacity: 0.7;
}

.message-read {
  font-size: 0.75rem;
  opacity: 0.7;
}

.message-read.delivered {
  opacity: 0.85;
}

.message-read.read {
  opacity: 1;
  color: var(--accent);
}

/* Date separator */
.date-separator {
  text-align: center;
  padding: 0.75rem 0;
}

.date-separator span {
  font-size: 0.75rem;
  color: var(--text-muted);
  background: var(--bg-secondary);
  padding: 0.25rem 0.75rem;
  border-radius: 999px;
}

/* Typing indicator */
.typing-indicator {
  display: none;
  align-items: center;
  gap: 0.375rem;
  padding: 0.5rem 0.875rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.typing-indicator.visible {
  display: flex;
}

.typing-dots {
  display: flex;
  gap: 3px;
}

.typing-dots span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--text-muted);
  animation: typing-dot 1.4s ease-in-out infinite;
}

.typing-dots span:nth-child(2) { animation-delay: 0.2s; }
.typing-dots span:nth-child(3) { animation-delay: 0.4s; }

/* Empty state */
.messages-empty {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  text-align: center;
  padding: 2rem;
}

/* Input area */
.input-area {
  display: flex;
  align-items: flex-end;
  gap: 0.5rem;
  padding: 0.625rem 0.75rem;
  background: var(--input-area-bg);
  border-top: 1px solid var(--topbar-border);
  flex-shrink: 0;
}

.input-area textarea {
  flex: 1;
  resize: none;
  padding: 0.625rem 0.875rem;
  font-size: 1rem;
  line-height: 1.4;
  color: var(--input-text);
  background: var(--input-bg);
  border: 1.5px solid var(--input-border);
  border-radius: 20px;
  max-height: calc(1.4em * 4 + 1.25rem + 3px);
  overflow-y: auto;
  transition: border-color var(--transition-fast);
}

.input-area textarea:focus {
  border-color: var(--accent);
}

.input-area textarea::placeholder {
  color: var(--text-muted);
}

.attach-btn,
.send-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  flex-shrink: 0;
  font-size: 1.25rem;
  transition: background var(--transition-fast), opacity var(--transition-fast);
}

.attach-btn {
  color: var(--text-secondary);
}

.attach-btn:hover {
  background: var(--input-bg);
}

.send-btn {
  background: var(--btn-bg);
  color: var(--btn-text);
}

.send-btn:hover {
  background: var(--btn-hover);
}

.send-btn:disabled {
  opacity: 0.4;
  cursor: default;
}

/* ── Theme Toggle ── */
.theme-toggle {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--text-secondary);
  font-size: 1.25rem;
  transition: background var(--transition-fast);
  z-index: 10;
}

.theme-toggle:hover {
  background: var(--input-bg);
}

/* ── Animations ── */
@keyframes slide-up {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes typing-dot {
  0%, 60%, 100% { opacity: 0.3; transform: translateY(0); }
  30% { opacity: 1; transform: translateY(-3px); }
}

@keyframes pulse-online {
  0%, 100% { box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.4); }
  50% { box-shadow: 0 0 0 4px rgba(34, 197, 94, 0); }
}

/* ── Desktop Layout (>768px) ── */
@media (min-width: 769px) {
  body {
    background: var(--desktop-bg);
  }

  body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
      radial-gradient(circle at 20% 50%, rgba(79, 70, 229, 0.05) 0%, transparent 50%),
      radial-gradient(circle at 80% 50%, rgba(129, 140, 248, 0.05) 0%, transparent 50%);
    pointer-events: none;
    z-index: 0;
  }

  #login-screen {
    position: relative;
    z-index: 1;
  }

  #chat-screen {
    position: relative;
    z-index: 1;
    max-width: 480px;
    margin: 0 auto;
    border-left: 1px solid var(--topbar-border);
    border-right: 1px solid var(--topbar-border);
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.2);
  }
}

/* ── Mobile (<= 768px) ── */
@media (max-width: 768px) {
  .login-card {
    margin: 0.75rem;
    padding: 2rem 1.5rem 1.5rem;
  }

  .topbar {
    padding-top: max(0.75rem, env(safe-area-inset-top));
  }

  .input-area {
    padding-bottom: max(0.625rem, env(safe-area-inset-bottom));
  }
}

/* Loading spinner for pagination */
.loading-spinner {
  text-align: center;
  padding: 0.75rem;
  color: var(--text-muted);
  font-size: 0.8125rem;
}

/* ── Image Messages ── */
.message-image {
  margin: -0.25rem -0.375rem 0.25rem;
  border-radius: calc(var(--radius-bubble) - 4px);
  overflow: hidden;
  cursor: pointer;
  line-height: 0;
}

.message-image img {
  max-width: 280px;
  max-height: 320px;
  width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: calc(var(--radius-bubble) - 4px);
  display: block;
  transition: opacity var(--transition-fast);
}

.message-image img:hover {
  opacity: 0.9;
}

.message.sending .message-image img {
  opacity: 0.5;
}

/* ── Upload Progress ── */
.attach-btn {
  position: relative;
}

.attach-btn.uploading {
  pointer-events: none;
}

.attach-btn.uploading::after {
  content: '';
  position: absolute;
  inset: 2px;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: var(--accent);
  animation: spin 0.8s linear infinite;
}

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

/* ── Image Viewer ── */
.image-viewer-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(0, 0, 0, 0.95);
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-viewer-overlay.hidden {
  display: none !important;
}

.image-viewer-overlay.active {
  animation: fade-in 200ms ease;
}

.image-viewer-img {
  max-width: 95vw;
  max-height: 90vh;
  object-fit: contain;
  touch-action: none;
  user-select: none;
  -webkit-user-drag: none;
  will-change: transform;
}

.image-viewer-close {
  position: absolute;
  top: max(1rem, env(safe-area-inset-top));
  right: 1rem;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  color: #ffffff;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  z-index: 1001;
  transition: background var(--transition-fast);
}

.image-viewer-close:hover {
  background: rgba(255, 255, 255, 0.2);
}

.image-viewer-download {
  position: absolute;
  bottom: max(1.5rem, env(safe-area-inset-bottom));
  right: 1rem;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  z-index: 1001;
  transition: background var(--transition-fast);
}

.image-viewer-download:hover {
  background: rgba(255, 255, 255, 0.2);
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ── Offline Banner ── */
.offline-banner {
  position: absolute;
  top: 60px;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 0.5rem 1rem;
  background: #b45309;
  color: #ffffff;
  text-align: center;
  font-size: 0.8125rem;
  font-weight: 500;
  animation: slide-down 200ms ease;
}

@keyframes slide-down {
  from { transform: translateY(-100%); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

/* ── iOS Install Prompt ── */
.ios-prompt {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 999;
  padding: 0 1rem max(1rem, env(safe-area-inset-bottom));
  animation: slide-up-prompt 300ms ease;
}

@keyframes slide-up-prompt {
  from { transform: translateY(100%); }
  to { transform: translateY(0); }
}

.ios-prompt-content {
  position: relative;
  background: var(--bg-secondary);
  border-radius: var(--radius-card);
  padding: 1.25rem 1rem;
  text-align: center;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.3);
}

.ios-prompt-close {
  position: absolute;
  top: 0.5rem;
  right: 0.75rem;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: var(--text-muted);
  background: none;
  border: none;
  cursor: pointer;
}

.ios-prompt-title {
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.ios-prompt-text {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.ios-share-icon {
  display: inline-block;
  font-size: 1.1em;
  vertical-align: middle;
  color: var(--accent);
}

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