/* --- Base Variables & Themes --- */
:root {
  /* Default Dark Mode */
  --bg-color: #0d1117;
  --bg-gradient-1: rgba(88, 166, 255, 0.15);
  --bg-gradient-2: rgba(255, 90, 95, 0.1);
  --pane-bg: rgba(22, 27, 34, 0.7);
  --pane-border: rgba(255, 255, 255, 0.08);
  --pane-border-hover: rgba(255, 255, 255, 0.15);
  --text-main: #e6edf3;
  --text-muted: #8b949e;
  --input-bg: rgba(0, 0, 0, 0.2);
  --task-bg: rgba(255, 255, 255, 0.03);
  --task-bg-hover: rgba(255, 255, 255, 0.05);
  --task-active-bg: rgba(88, 166, 255, 0.1);
  --settings-bg: rgba(0, 0, 0, 0.2);
  --mode-btn-active: rgba(255, 255, 255, 0.1);
  
  /* Accents */
  --primary-color: #58a6ff;
  --primary-hover: #3182ce;
  --pomodoro-color: #ff5a5f;
  --pomodoro-hover: #e04a50;
  --short-break-color: #2ea043;
  --long-break-color: #8957e5;
  --danger-color: #f85149;
  --success-color: #2ea043;
  
  /* Shadows & Glass */
  --shadow-sm: 0 4px 6px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 25px rgba(0,0,0,0.5);
  --glass-blur: blur(12px);

  /* Typography */
  --font-base: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body.light-mode {
  --bg-color: #f6f8fa;
  --bg-gradient-1: rgba(88, 166, 255, 0.1);
  --bg-gradient-2: rgba(255, 90, 95, 0.08);
  --pane-bg: rgba(255, 255, 255, 0.85);
  --pane-border: rgba(27, 31, 35, 0.15);
  --pane-border-hover: rgba(27, 31, 35, 0.25);
  --text-main: #24292f;
  --text-muted: #57606a;
  --input-bg: #ffffff;
  --task-bg: #ffffff;
  --task-bg-hover: #f3f4f6;
  --task-active-bg: rgba(88, 166, 255, 0.15);
  --settings-bg: rgba(27, 31, 35, 0.05);
  --mode-btn-active: rgba(27, 31, 35, 0.08);
  
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
  --shadow-lg: 0 8px 20px rgba(0,0,0,0.08);
}

/* --- Global Reset & Basics --- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--font-base);
  background-color: var(--bg-color);
  background-image: 
    radial-gradient(circle at top right, var(--bg-gradient-1), transparent 40%),
    radial-gradient(circle at bottom left, var(--bg-gradient-2), transparent 40%);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 2rem;
  line-height: 1.5;
  transition: background-color 0.4s ease, color 0.4s ease;
  overflow-x: hidden;
}

/* --- Global Controls (Theme & Language) --- */
.global-controls {
  position: absolute;
  top: 1.5rem;
  right: 2rem;
  display: flex;
  gap: 0.75rem;
  z-index: 100;
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.btn-glass {
  background: var(--pane-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--pane-border);
  color: var(--text-main);
  font-weight: 600;
  font-size: 0.85rem;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.btn-glass:hover {
  transform: translateY(-2px) scale(1.05);
  border-color: var(--primary-color);
  box-shadow: 0 4px 12px rgba(88, 166, 255, 0.2);
}

.btn-glass:active {
  transform: translateY(0) scale(0.95);
}

/* --- Layout --- */
.app-container {
  width: 100%;
  max-width: 900px;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.app-header {
  text-align: center;
}

.app-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  background: linear-gradient(to right, var(--primary-color), var(--pomodoro-color));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  letter-spacing: -0.5px;
}

.app-header p {
  color: var(--text-muted);
  font-size: 1rem;
  margin-top: 0.25rem;
}

.main-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: flex-start;
}

/* Responsive */
@media (max-width: 768px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

/* --- Glassmorphism Panes --- */
.pane {
  background: var(--pane-bg);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  border: 1px solid var(--pane-border);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: var(--shadow-lg);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.hidden {
  display: none !important;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--pane-border);
  padding-bottom: 0.75rem;
}

.section-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
}

.badge {
  background-color: var(--pane-border);
  color: var(--text-main);
  padding: 0.15rem 0.6rem;
  border-radius: 12px;
  font-size: 0.85rem;
  font-weight: 500;
  transition: all 0.3s;
}

/* --- Buttons & Inputs --- */
.btn {
  font-family: inherit;
  cursor: pointer;
  border: none;
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  font-size: 0.95rem;
}

.btn:active {
  transform: scale(0.95);
}

.btn-scale:hover {
  transform: scale(1.03);
}

.btn-bounce:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background-color: var(--primary-color);
  color: #fff;
  box-shadow: 0 2px 8px rgba(88, 166, 255, 0.3);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  box-shadow: 0 4px 12px rgba(88, 166, 255, 0.4);
}

.btn-secondary {
  background-color: transparent;
  border: 1px solid var(--pane-border);
  color: var(--text-main);
}

.btn-secondary:hover {
  background-color: var(--pane-border-hover);
  border-color: var(--text-muted);
}

.btn-large {
  padding: 0.75rem 2rem;
  font-size: 1.1rem;
  border-radius: 12px;
}

.btn-sm {
  padding: 0.35rem 0.75rem;
  font-size: 0.85rem;
}

.btn-icon {
  background: transparent;
  color: var(--text-muted);
  padding: 0.5rem;
  border: 1px solid transparent;
}

.btn-icon:hover {
  color: var(--text-main);
  background-color: var(--pane-border-hover);
  border-radius: 8px;
}

/* --- Tasks Section --- */
.task-form {
  display: flex;
  gap: 0.5rem;
}

#task-input {
  flex: 1;
  background-color: var(--input-bg);
  border: 1px solid var(--pane-border);
  border-radius: 8px;
  padding: 0.5rem 1rem;
  color: var(--text-main);
  font-family: inherit;
  font-size: 0.95rem;
  outline: none;
  transition: border-color 0.3s, box-shadow 0.3s, background-color 0.4s;
}

#task-input::placeholder {
  color: var(--text-muted);
  opacity: 0.7;
}

#task-input:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.15);
}

.task-list-container {
  max-height: 350px;
  overflow-y: auto;
  overflow-x: hidden;
  padding-right: 0.25rem;
}

/* Custom Scrollbar */
.task-list-container::-webkit-scrollbar {
  width: 6px;
}
.task-list-container::-webkit-scrollbar-thumb {
  background-color: var(--pane-border-hover);
  border-radius: 4px;
}

.task-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* Task Animations */
.task-enter {
  animation: slideIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.task-leave {
  animation: shrinkOut 0.3s ease forwards;
}

@keyframes slideIn {
  from { opacity: 0; transform: translateX(-20px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes shrinkOut {
  from { opacity: 1; transform: scale(1); height: auto; }
  to { opacity: 0; transform: scale(0.9); height: 0; padding: 0; margin: 0; border: none; }
}

.task-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1rem;
  background-color: var(--task-bg);
  border: 1px solid var(--pane-border);
  border-radius: 8px;
  transition: all 0.25s ease;
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.task-item:hover {
  background-color: var(--task-bg-hover);
  border-color: var(--pane-border-hover);
  transform: translateX(2px);
}

.task-item.active {
  border-color: var(--primary-color);
  background-color: var(--task-active-bg);
  box-shadow: 0 2px 8px rgba(88, 166, 255, 0.1);
}

.task-item.active::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background-color: var(--primary-color);
  border-radius: 3px 0 0 3px;
}

.task-item.completed {
  opacity: 0.7;
}

.task-item.completed .task-text {
  text-decoration: line-through;
  color: var(--text-muted);
}

.task-content {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex: 1;
}

.task-checkbox {
  appearance: none;
  min-width: 18px;
  width: 18px;
  height: 18px;
  border: 2px solid var(--text-muted);
  border-radius: 4px;
  cursor: pointer;
  position: relative;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  background-color: transparent;
}

.task-checkbox:hover {
  border-color: var(--success-color);
}

.task-checkbox:checked {
  background-color: var(--success-color);
  border-color: var(--success-color);
  animation: popIn 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes popIn {
  0% { transform: scale(0.8); }
  50% { transform: scale(1.1); }
  100% { transform: scale(1); }
}

.task-checkbox:checked::after {
  content: '';
  position: absolute;
  width: 4px;
  height: 8px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
  left: 5px;
  top: 1px;
}

.task-text {
  font-size: 0.95rem;
  transition: color 0.2s;
  word-break: break-word;
}

.task-actions-btns {
  display: flex;
  gap: 0.25rem;
  opacity: 0;
  transform: translateX(10px);
  transition: all 0.2s ease;
}

.task-item:hover .task-actions-btns {
  opacity: 1;
  transform: translateX(0);
}

.delete-btn {
  color: var(--danger-color);
  padding: 0.4rem;
}

.delete-btn:hover {
  background-color: rgba(248, 81, 73, 0.1);
  color: var(--danger-color);
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem 0;
  font-style: italic;
  font-size: 0.9rem;
  animation: fadeIn 0.4s;
}

/* --- Timer Section --- */
.timer-section {
  align-items: center;
  justify-content: space-between;
}

.active-task-display {
  text-align: center;
  width: 100%;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--pane-border);
  transition: border-color 0.4s;
}

.active-task-display .label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.active-task-display h3 {
  font-size: 1.1rem;
  margin-top: 0.25rem;
  color: var(--primary-color);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  transition: color 0.4s;
}

.timer-display {
  position: relative;
  width: 240px;
  height: 240px;
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 1.5rem 0;
}

.timer-ring {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.timer-ring-bg {
  fill: none;
  stroke: var(--pane-border);
  stroke-width: 8;
  transition: stroke 0.4s;
}

.timer-ring-progress {
  fill: none;
  stroke: var(--pomodoro-color);
  stroke-width: 8;
  stroke-linecap: round;
  stroke-dasharray: 691; /* 2 * PI * 110 */
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 1s linear, stroke 0.5s ease;
}

/* Dynamic Timer Colors based on Mode */
.mode-pomodoro .timer-ring-progress { stroke: var(--pomodoro-color); }
.mode-shortBreak .timer-ring-progress { stroke: var(--short-break-color); }
.mode-longBreak .timer-ring-progress { stroke: var(--long-break-color); }

.timer-text {
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 10;
}

#time-left {
  font-size: 3.8rem;
  font-weight: 700;
  letter-spacing: -2px;
  font-variant-numeric: tabular-nums;
  line-height: 1;
  text-shadow: 0 4px 12px rgba(0,0,0,0.1);
  transition: text-shadow 0.4s;
}

body.light-mode #time-left {
  text-shadow: none;
}

.mode-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 2px;
  margin-top: 0.5rem;
  font-weight: 500;
}

.timer-controls {
  display: flex;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1rem;
}

/* Adjust primary button color based on mode */
.mode-pomodoro #btn-start { background-color: var(--pomodoro-color); box-shadow: 0 4px 12px rgba(255, 90, 95, 0.3); }
.mode-pomodoro #btn-start:hover { background-color: var(--pomodoro-hover); }

.mode-shortBreak #btn-start { background-color: var(--short-break-color); box-shadow: 0 4px 12px rgba(46, 160, 67, 0.3); }
.mode-shortBreak #btn-start:hover { background-color: #268938; }

.mode-longBreak #btn-start { background-color: var(--long-break-color); box-shadow: 0 4px 12px rgba(137, 87, 229, 0.3); }
.mode-longBreak #btn-start:hover { background-color: #794bc4; }

.pomodoro-settings {
  display: flex;
  gap: 0.5rem;
  background-color: var(--settings-bg);
  padding: 0.35rem;
  border-radius: 12px;
  transition: background-color 0.4s;
}

.mode-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 0.4rem 0.8rem;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.mode-btn:hover {
  color: var(--text-main);
}

.mode-btn.active {
  background-color: var(--mode-btn-active);
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
}

/* --- Zen Mode & Pomodoro Dots --- */
body.zen-active .app-header,
body.zen-active .tasks-section {
  display: none !important;
}

body.zen-active .main-content {
  grid-template-columns: 1fr;
  max-width: 500px;
  margin: 0 auto;
}

body.zen-active {
  background-image: none;
  background-color: #000;
}

body.zen-active .pane {
  border-color: transparent;
  background: transparent;
  box-shadow: none;
  transform: scale(1.1);
}

body.zen-active .global-controls {
  opacity: 0.1;
}

body.zen-active .global-controls:hover {
  opacity: 1;
}

.pomodoro-dots {
  display: flex;
  gap: 4px;
  justify-content: center;
  margin-top: 8px;
  min-height: 12px;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--pane-border-hover);
  transition: background-color 0.3s, transform 0.3s;
}

.dot.filled {
  background-color: var(--pomodoro-color);
  box-shadow: 0 0 5px var(--pomodoro-color);
  transform: scale(1.1);
}

.mode-shortBreak .dot.filled {
  background-color: var(--short-break-color);
  box-shadow: 0 0 5px var(--short-break-color);
}
.mode-longBreak .dot.filled {
  background-color: var(--long-break-color);
  box-shadow: 0 0 5px var(--long-break-color);
}

/* --- Ambient Canvas (Zen Mode) --- */
#ambient-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
  opacity: 0;
  transition: opacity 1s ease;
}

body.zen-active #ambient-canvas {
  opacity: 1;
}

/* --- Analytics & Constellation Section --- */
.analytics-section {
  grid-column: 1 / -1;
  margin-top: 1rem;
}

.analytics-kpis {
  display: flex;
  gap: 1rem;
  justify-content: space-between;
  margin-bottom: 1.5rem;
}

@media (max-width: 600px) {
  .analytics-kpis {
    flex-direction: column;
  }
}

.kpi-card {
  flex: 1;
  background: var(--task-bg);
  border: 1px solid var(--pane-border);
  border-radius: 12px;
  padding: 1.25rem;
  text-align: center;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: all 0.3s ease;
}

.kpi-card:hover {
  transform: translateY(-2px);
  border-color: var(--primary-color);
  background: var(--task-bg-hover);
}

.kpi-value {
  font-size: 2rem;
  font-weight: 700;
  color: var(--primary-color);
  line-height: 1;
}

.kpi-label {
  font-size: 0.8rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.constellation-header {
  margin-bottom: 0.5rem;
  color: var(--text-muted);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.constellation-container {
  min-height: 180px;
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid var(--pane-border);
  border-radius: 12px;
  position: relative;
  overflow: hidden;
  padding: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  align-content: flex-start;
}

body.light-mode .constellation-container {
  background: rgba(255, 255, 255, 0.5);
}

/* Star Nodes */
.star-node {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--task-bg);
  padding: 8px 12px;
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 10px rgba(88, 166, 255, 0.2);
  animation: floatNode 3s ease-in-out infinite alternate;
  transform-origin: center;
  cursor: help;
  transition: all 0.3s;
}

body.light-mode .star-node {
  border: 1px solid rgba(0, 0, 0, 0.1);
  box-shadow: 0 0 10px rgba(88, 166, 255, 0.3);
}

.star-node:hover {
  transform: scale(1.05);
  box-shadow: 0 0 15px var(--primary-color);
  z-index: 10;
}

.star-icon {
  width: 12px;
  height: 12px;
  background: var(--primary-color);
  border-radius: 50%;
  box-shadow: 0 0 8px var(--primary-color);
}

.star-text {
  font-size: 0.85rem;
  font-weight: 500;
  white-space: nowrap;
}

@keyframes floatNode {
  0% { transform: translateY(0px); }
  100% { transform: translateY(-5px); }
}