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

:root {
  --bg: #1a1410;
  --surface: #231c16;
  --surface-raised: #2d241d;
  --surface-hover: #352b23;
  --border: #3d3026;
  --border-light: #4d3d30;
  --primary: #e89040;
  --primary-light: #f0a860;
  --primary-dim: #d47830;
  --primary-glow: rgba(232, 144, 64, 0.12);
  --break: #60a8c0;
  --break-light: #80c0d4;
  --break-glow: rgba(96, 168, 192, 0.12);
  --longbreak: #7a8ab0;
  --text: #e8ddd0;
  --text-secondary: #9a8a78;
  --text-muted: #6b5f53;
  --success: #7aab7a;
  --danger: #c46060;
  --font-display: 'Fraunces', Georgia, serif;
  --font-body: 'Plus Jakarta Sans', -apple-system, sans-serif;
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --transition: 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
  position: relative;
}

/* Grain texture overlay */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  z-index: 9999;
  pointer-events: none;
  opacity: 0.025;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 200px 200px;
}

/* ===== Navigation ===== */
.top-nav {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  position: sticky;
  top: 0;
  z-index: 100;
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
}

.nav-inner {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 24px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-back {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: color var(--transition);
}

.nav-back:hover {
  color: var(--primary);
}

.nav-brand {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.02em;
}

/* ===== Layout ===== */
.app {
  max-width: 540px;
  margin: 0 auto;
  padding: 32px 24px 64px;
}

.section {
  margin-top: 40px;
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.section-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text);
  letter-spacing: 0.01em;
}

.section-badge {
  background: var(--surface-raised);
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 10px;
  border-radius: 99px;
  border: 1px solid var(--border);
}

/* ===== Timer ===== */
.timer-section {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.timer-ring-wrap {
  position: relative;
  width: 260px;
  height: 260px;
  margin-bottom: 28px;
  animation: fadeSlideUp 0.6s ease-out;
}

.timer-ring {
  width: 100%;
  height: 100%;
  display: block;
  filter: drop-shadow(0 0 30px var(--primary-glow));
  transition: filter var(--transition);
}

.timer-ring-wrap.running .timer-ring {
  filter: drop-shadow(0 0 40px var(--primary-glow)) drop-shadow(0 0 80px rgba(232, 144, 64, 0.08));
}

.timer-ring-wrap.break-mode .timer-ring {
  filter: drop-shadow(0 0 30px var(--break-glow));
}

.timer-ring-wrap.break-mode.running .timer-ring {
  filter: drop-shadow(0 0 40px var(--break-glow)) drop-shadow(0 0 80px rgba(96, 168, 192, 0.08));
}

.ring-track {
  fill: none;
  stroke: var(--border);
  stroke-width: 4;
}

.ring-progress {
  fill: none;
  stroke-width: 4;
  transition: stroke-dashoffset 0.5s linear;
}

.ring-inner {
  fill: none;
  stroke: var(--surface-raised);
  stroke-width: 1;
  opacity: 0.6;
}

.timer-center {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  user-select: none;
}

.timer-time {
  font-family: var(--font-display);
  font-size: 3.5rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  line-height: 1;
  letter-spacing: 0.02em;
  transition: color var(--transition);
}

.break-mode .timer-time {
  color: var(--break-light);
}

.timer-mode-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-top: 8px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.timer-status {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 4px;
  letter-spacing: 0.05em;
}

/* ===== Mode Tabs ===== */
.mode-tabs {
  display: flex;
  gap: 4px;
  background: var(--surface);
  padding: 3px;
  border-radius: 99px;
  border: 1px solid var(--border);
  margin-bottom: 28px;
}

.mode-tab {
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 8px 20px;
  border: none;
  border-radius: 99px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  position: relative;
  white-space: nowrap;
}

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

.mode-tab.active {
  background: var(--surface-raised);
  color: var(--primary);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.mode-tab[data-mode="shortBreak"].active {
  color: var(--break);
}

.mode-tab[data-mode="longBreak"].active {
  color: var(--longbreak);
}

/* ===== Controls ===== */
.controls {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}

.btn {
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  padding: 10px 28px;
  border: none;
  border-radius: 99px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
}

.btn:active {
  transform: scale(0.96);
}

.btn-icon {
  font-size: 0.8rem;
  line-height: 1;
}

.btn-primary {
  background: var(--primary);
  color: #1a1410;
  box-shadow: 0 4px 16px rgba(232, 144, 64, 0.25);
}

.btn-primary:hover {
  background: var(--primary-light);
  box-shadow: 0 6px 24px rgba(232, 144, 64, 0.35);
  transform: translateY(-1px);
}

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

.btn-ghost:hover {
  background: var(--surface-hover);
  color: var(--text);
  border-color: var(--border-light);
}

.btn-square {
  width: 40px;
  height: 40px;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  flex-shrink: 0;
}

/* ===== Session Counter ===== */
.session-counter {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.session-counter strong {
  color: var(--primary);
  font-weight: 700;
}

/* ===== Task Section ===== */
.task-input-row {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.input {
  flex: 1;
  font-family: var(--font-body);
  font-size: 0.9rem;
  padding: 10px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--text);
  outline: none;
  transition: border-color var(--transition);
}

.input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

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

.task-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.task-empty {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 20px 0;
}

.task-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  animation: fadeSlideIn 0.3s ease-out;
}

.task-item:hover {
  background: var(--surface-raised);
  border-color: var(--border-light);
}

.task-check {
  appearance: none;
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-light);
  border-radius: 50%;
  cursor: pointer;
  position: relative;
  flex-shrink: 0;
  transition: all var(--transition);
}

.task-check:checked {
  background: var(--success);
  border-color: var(--success);
}

.task-check:checked::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 6px;
  width: 5px;
  height: 9px;
  border: solid #1a1410;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.task-text {
  flex: 1;
  font-size: 0.9rem;
  color: var(--text);
  transition: color var(--transition);
  word-break: break-word;
}

.task-check:checked ~ .task-text {
  text-decoration: line-through;
  color: var(--text-muted);
}

.task-delete {
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 1.1rem;
  cursor: pointer;
  padding: 4px;
  line-height: 1;
  border-radius: 4px;
  transition: all var(--transition);
  opacity: 0;
}

.task-item:hover .task-delete {
  opacity: 1;
}

.task-delete:hover {
  color: var(--danger);
  background: rgba(196, 96, 96, 0.1);
}

/* ===== Stats ===== */
.chart-wrap {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px 16px 12px;
  margin-bottom: 16px;
}

#statsChart {
  width: 100%;
  display: block;
  aspect-ratio: 600 / 180;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

.stat-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px 12px;
  text-align: center;
  transition: border-color var(--transition);
}

.stat-card:hover {
  border-color: var(--border-light);
}

.stat-value {
  display: block;
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.2;
}

.stat-card:nth-child(2) .stat-value {
  color: var(--break);
}

.stat-card:nth-child(3) .stat-value {
  color: var(--longbreak);
}

.stat-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 4px;
  font-weight: 500;
}

/* ===== Notification ===== */
.notification {
  position: fixed;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--surface-raised);
  border: 1px solid var(--border-light);
  padding: 12px 24px;
  border-radius: var(--radius);
  font-size: 0.9rem;
  color: var(--text);
  box-shadow: 0 8px 32px rgba(0,0,0,0.4);
  z-index: 1000;
  animation: notifIn 0.4s ease-out;
  text-align: center;
  max-width: 90%;
}

.notification.fade-out {
  animation: notifOut 0.3s ease-in forwards;
}

/* ===== Animations ===== */
@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes notifIn {
  from { opacity: 0; transform: translateX(-50%) translateY(16px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

@keyframes notifOut {
  from { opacity: 1; transform: translateX(-50%) translateY(0); }
  to { opacity: 0; transform: translateX(-50%) translateY(16px); }
}

/* Timer ring pulse */
.timer-ring-wrap.running .ring-inner {
  animation: pulseRing 4s ease-in-out infinite;
}

@keyframes pulseRing {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 0.8; }
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .app { padding: 20px 16px 48px; }

  .timer-ring-wrap {
    width: 220px;
    height: 220px;
    margin-bottom: 24px;
  }

  .timer-time {
    font-size: 2.8rem;
  }

  .mode-tab {
    font-size: 0.75rem;
    padding: 6px 14px;
  }

  .controls {
    gap: 10px;
  }

  .btn {
    font-size: 0.85rem;
    padding: 9px 22px;
  }

  .stats-grid {
    gap: 6px;
  }

  .stat-value {
    font-size: 1.5rem;
  }
}

@media (max-width: 400px) {
  .timer-ring-wrap {
    width: 190px;
    height: 190px;
  }

  .timer-time {
    font-size: 2.2rem;
  }

  .mode-tabs {
    gap: 2px;
    padding: 2px;
  }

  .mode-tab {
    font-size: 0.7rem;
    padding: 5px 10px;
  }
}