/* ============================================
   MD3 Input Area & Components
   ============================================ */
.message-input { width: 100%; display: flex; align-items: flex-end; }
.input-wrapper { display: flex; align-items: flex-end; gap: 8px; width: 100%; }

/* ---- MD3 Outlined Text Field ---- */
.input-field-container {
  flex: 1;
  display: flex;
  align-items: flex-end;
  background: var(--md-sys-color-surface);
  border: 1px solid var(--md-sys-color-outline-variant);
  border-radius: var(--md-outlined-text-field-container-shape);
  position: relative;
  min-height: var(--input-min-height);
  transition: border var(--md-sys-duration-medium1) var(--md-sys-motion-easing-standard);
}

.input-field-container:focus-within {
  border: 2px solid var(--md-sys-color-primary);
}

.input-field-container textarea {
  flex: 1;
  border: none;
  padding: 10px 40px 10px 14px;
  font-size: var(--md-sys-typescale-body-large-size);
  line-height: var(--md-sys-typescale-body-large-line);
  letter-spacing: var(--md-sys-typescale-body-large-tracking);
  resize: none;
  min-height: 20px;
  max-height: 100px;
  background: transparent;
  font-family: var(--font-family);
  outline: none;
  -webkit-user-select: text;
  user-select: text;
  color: var(--md-sys-color-on-surface);
}

.input-field-container textarea::placeholder {
  color: var(--md-outlined-text-field-input-text-placeholder-color);
}

/* ---- File Button ---- */
.file-button {
  color: var(--md-sys-color-on-surface-variant);
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  border-radius: var(--md-sys-shape-corner-full);
  transition: background var(--md-sys-duration-short3) ease;
}
.file-button:hover { background: var(--md-sys-color-surface-variant); }
.file-button:active { background: var(--md-sys-color-outline-variant); }

/* ---- Send Button (MD3 FAB mini) ---- */
.send-button {
  background: var(--md-sys-color-primary);
  color: var(--md-sys-color-on-primary);
  border-radius: var(--md-filled-button-container-shape);
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  position: absolute;
  right: 4px;
  bottom: 5px;
  transform: scale(0);
  opacity: 0;
  transition: transform var(--md-sys-duration-medium2) var(--md-sys-motion-easing-emphasized-decelerate),
              opacity var(--md-sys-duration-medium1) var(--md-sys-motion-easing-standard);
  will-change: transform, opacity;
}
.send-button.show { transform: scale(1); opacity: 1; }
.send-button:active:not(:disabled) {
  transform: scale(0.85);
  transition-duration: var(--md-sys-duration-short2);
}
.send-button:disabled {
  background: var(--md-sys-color-outline-variant);
  cursor: not-allowed;
}

/* ---- Function Button ---- */
.function-button {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--md-sys-color-on-surface-variant);
  flex-shrink: 0;
  position: absolute;
  right: 4px;
  bottom: 5px;
  transition: transform var(--md-sys-duration-medium2) var(--md-sys-motion-easing-emphasized-decelerate),
              opacity var(--md-sys-duration-medium1) var(--md-sys-motion-easing-standard);
}
.function-button.show { transform: scale(1); opacity: 1; }
.function-button:not(.show) { transform: scale(0); opacity: 0; pointer-events: none; }
.function-button:active { color: var(--md-sys-color-primary); }

/* ---- Send Icon ---- */
.send-icon { width: 16px; height: 16px; }
.send-button.loading .send-icon { animation: spin 1s linear infinite; }

/* ---- AI Mode Indicator (MD3 Chip) ---- */
.ai-mode-indicator {
  position: absolute;
  top: -12px;
  right: 12px;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: white;
  padding: 2px 10px;
  border-radius: var(--md-sys-shape-corner-full);
  font-size: var(--md-sys-typescale-label-small-size);
  letter-spacing: var(--md-sys-typescale-label-small-tracking);
  animation: slideDown var(--md-sys-duration-medium2) var(--md-sys-motion-easing-emphasized-decelerate);
  box-shadow: var(--md-sys-elevation-level1);
}

/* ---- MD3 Drag & Drop Overlay ---- */
.drag-overlay {
  position: fixed;
  inset: 0;
  z-index: var(--z-overlay);
  background: color-mix(in srgb, var(--md-sys-color-primary-container) 60%, transparent);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--md-sys-duration-medium2) var(--md-sys-motion-easing-standard);
  display: flex;
  align-items: center;
  justify-content: center;
}
.drag-overlay.active { opacity: 1; pointer-events: auto; }

.drag-content {
  text-align: center;
  color: var(--md-sys-color-primary);
  transform: scale(0.92);
  transition: transform var(--md-sys-duration-medium2) var(--md-sys-motion-easing-emphasized-decelerate);
}
.drag-overlay.active .drag-content { transform: scale(1); }
.drag-content .drag-icon { font-size: 56px; margin-bottom: 12px; }
.drag-content .drag-text {
  font-size: var(--md-sys-typescale-title-medium-size);
  font-weight: var(--md-sys-typescale-title-medium-weight);
}
.drag-content .drag-hint {
  font-size: var(--md-sys-typescale-body-small-size);
  color: var(--md-sys-color-on-surface-variant);
  margin-top: 4px;
}

/* ---- MD3 Upload Status ---- */
.upload-status {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--md-sys-color-surface-container-low);
  border-radius: var(--md-sys-shape-corner-small);
  margin-bottom: 8px;
  font-size: var(--md-sys-typescale-body-small-size);
  color: var(--md-sys-color-on-surface-variant);
}
.upload-spinner { font-size: 18px; animation: spin 1s linear infinite; }
.upload-progress { flex: 1; height: var(--md-linear-progress-track-height); background: var(--md-sys-color-surface-variant); border-radius: var(--md-sys-shape-corner-full); overflow: hidden; }
.progress-bar {
  height: 100%;
  background: var(--md-linear-progress-active-indicator-color);
  width: 0%;
  border-radius: var(--md-sys-shape-corner-full);
  transition: width var(--md-sys-duration-medium2) var(--md-sys-motion-easing-standard);
}

/* ---- Keyboard Open ---- */
body.keyboard-open .input-container { position: sticky; bottom: 0; }
body.keyboard-open .message-list { padding-bottom: 8px; }