/* ========================================
   StudyFlow — Student Productivity Dashboard
   Styles
   ======================================== */

/* ── CSS Custom Properties ── */
:root {
  /* Core palette */
  --bg-gradient-start: #0f0c29;
  --bg-gradient-mid: #302b63;
  --bg-gradient-end: #24243e;
  --accent: #7c5cfc;
  --accent-light: #a78bfa;
  --accent-glow: rgba(124, 92, 252, 0.35);
  --success: #34d399;
  --success-dark: #059669;
  --warning: #fbbf24;
  --danger: #f87171;

  /* Glass card */
  --card-bg: rgba(255, 255, 255, 0.06);
  --card-border: rgba(255, 255, 255, 0.12);
  --card-shadow: 0 8px 32px rgba(0, 0, 0, 0.35);
  --card-blur: 16px;

  /* Text */
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  /* Misc */
  --radius: 16px;
  --radius-sm: 10px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'Inter', system-ui, -apple-system, sans-serif;
}

/* ── Dark-mode overrides ── */
body.dark-mode {
  --bg-gradient-start: #050510;
  --bg-gradient-mid: #1a1640;
  --bg-gradient-end: #0e0e1a;
  --card-bg: rgba(255, 255, 255, 0.03);
  --card-border: rgba(255, 255, 255, 0.07);
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-mid), var(--bg-gradient-end));
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
  overflow-x: hidden;
}

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

/* ========================================
   HEADER
   ======================================== */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 2rem;
  backdrop-filter: blur(12px);
  background: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid var(--card-border);
  position: sticky;
  top: 0;
  z-index: 100;
  animation: fadeSlideDown 0.6s ease;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.logo {
  font-size: 1.75rem;
}

.app-header h1 {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.5px;
}

.accent {
  color: var(--accent-light);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.greeting {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* Dark-mode toggle */
.btn-icon {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 50%;
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.15rem;
  transition: var(--transition);
  position: relative;
}

.btn-icon:hover {
  background: var(--accent-glow);
  border-color: var(--accent);
  transform: rotate(20deg) scale(1.1);
}

.icon-moon {
  display: none;
}
body.dark-mode .icon-sun {
  display: none;
}
body.dark-mode .icon-moon {
  display: inline;
}

/* ========================================
   DASHBOARD GRID
   ======================================== */
.dashboard {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  padding: 2rem;
  max-width: 1400px;
  margin: 0 auto;
  animation: fadeIn 0.8s ease;
}

/* ── Glass Card ── */
.card {
  background: var(--card-bg);
  backdrop-filter: blur(var(--card-blur));
  -webkit-backdrop-filter: blur(var(--card-blur));
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--card-shadow);
  transition: transform var(--transition), box-shadow var(--transition);
  animation: fadeSlideUp 0.6s ease both;
}

.card:nth-child(1) { animation-delay: 0.05s; }
.card:nth-child(2) { animation-delay: 0.10s; }
.card:nth-child(3) { animation-delay: 0.15s; }
.card:nth-child(4) { animation-delay: 0.20s; }
.card:nth-child(5) { animation-delay: 0.25s; }
.card:nth-child(6) { animation-delay: 0.30s; }

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.45), 0 0 20px var(--accent-glow);
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
}

.card-header h2 {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: -0.3px;
}

/* ── Badges ── */
.badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.25rem 0.6rem;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-pending {
  background: rgba(251, 191, 36, 0.15);
  color: var(--warning);
}

.badge-done {
  background: rgba(52, 211, 153, 0.15);
  color: var(--success);
}

.badge-session {
  background: rgba(124, 92, 252, 0.18);
  color: var(--accent-light);
}

.task-counters {
  display: flex;
  gap: 0.5rem;
}

/* ========================================
   TO-DO LIST
   ======================================== */
.todo-input-group {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.todo-input-group input {
  flex: 1;
}

input[type="text"],
input[type="number"] {
  background: rgba(255, 255, 255, 0.07);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-sm);
  padding: 0.65rem 1rem;
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 0.9rem;
  outline: none;
  transition: var(--transition);
}

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

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

/* Buttons */
.btn {
  border: none;
  border-radius: var(--radius-sm);
  padding: 0.65rem 1.2rem;
  font-family: var(--font);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
}

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

.btn-primary {
  background: linear-gradient(135deg, var(--accent), #6340e0);
  color: #fff;
}
.btn-primary:hover {
  box-shadow: 0 4px 20px var(--accent-glow);
  filter: brightness(1.15);
}

.btn-success {
  background: linear-gradient(135deg, var(--success), var(--success-dark));
  color: #fff;
}
.btn-success:hover {
  box-shadow: 0 4px 20px rgba(52, 211, 153, 0.35);
  filter: brightness(1.15);
}

.btn-warning {
  background: linear-gradient(135deg, var(--warning), #d97706);
  color: #1a1a2e;
}
.btn-warning:hover {
  filter: brightness(1.15);
}

.btn-danger {
  background: linear-gradient(135deg, var(--danger), #dc2626);
  color: #fff;
}
.btn-danger:hover {
  filter: brightness(1.15);
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  filter: none;
}

/* Task list */
.task-list {
  list-style: none;
  max-height: 260px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.task-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.6rem 0.75rem;
  background: rgba(255, 255, 255, 0.04);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  animation: fadeSlideUp 0.3s ease;
}

.task-item:hover {
  background: rgba(255, 255, 255, 0.08);
}

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

.task-checkbox {
  width: 20px;
  height: 20px;
  border-radius: 6px;
  border: 2px solid var(--accent);
  background: transparent;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: var(--transition);
  font-size: 0.7rem;
  color: transparent;
}

.task-item.completed .task-checkbox {
  background: var(--accent);
  color: #fff;
}

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

.task-actions {
  display: flex;
  gap: 0.3rem;
}

.task-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  opacity: 0.5;
  transition: var(--transition);
  padding: 0.2rem;
  border-radius: 4px;
}

.task-btn:hover {
  opacity: 1;
  background: rgba(255, 255, 255, 0.1);
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  padding: 1.5rem 0;
}

/* ========================================
   POMODORO TIMER
   ======================================== */
.timer-display {
  display: flex;
  justify-content: center;
  margin-bottom: 1.25rem;
}

.timer-ring {
  position: relative;
  width: 180px;
  height: 180px;
}

.timer-ring svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.ring-bg {
  fill: none;
  stroke: rgba(255, 255, 255, 0.06);
  stroke-width: 8;
}

.ring-progress {
  fill: none;
  stroke: var(--accent);
  stroke-width: 8;
  stroke-linecap: round;
  stroke-dasharray: 565.48;  /* 2 * π * 90 */
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 1s linear, stroke 0.3s;
  filter: drop-shadow(0 0 6px var(--accent-glow));
}

.ring-progress.break-mode {
  stroke: var(--success);
  filter: drop-shadow(0 0 6px rgba(52, 211, 153, 0.4));
}

.timer-text {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.timer-digits {
  font-size: 2.4rem;
  font-weight: 800;
  letter-spacing: 2px;
  font-variant-numeric: tabular-nums;
}

.timer-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-top: 0.15rem;
}

.timer-controls {
  display: flex;
  gap: 0.5rem;
  justify-content: center;
  margin-bottom: 1rem;
}

.timer-controls .btn {
  padding: 0.55rem 1rem;
  font-size: 0.8rem;
}

.session-info {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ========================================
   DAILY GOALS
   ======================================== */
.goal-setting,
.log-time-section {
  margin-bottom: 1.25rem;
}

.goal-setting label,
.log-time-section label {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-bottom: 0.4rem;
  font-weight: 500;
}

.goal-input-group {
  display: flex;
  gap: 0.5rem;
}

.goal-input-group input {
  width: 80px;
}

.progress-section {
  margin-bottom: 1.25rem;
}

.progress-header {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  margin-bottom: 0.5rem;
}

.progress-pct {
  font-weight: 700;
  color: var(--accent-light);
}

.progress-bar-track {
  width: 100%;
  height: 12px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 6px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--success));
  border-radius: 6px;
  transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.progress-bar-fill::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
  animation: shimmer 2s infinite;
}

.progress-detail {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
}

/* ========================================
   STUDY CHART
   ======================================== */
.chart-container {
  position: relative;
  width: 100%;
  height: 220px;
}

.chart-container canvas {
  width: 100% !important;
  height: 100% !important;
}

/* ========================================
   STREAK TRACKER
   ======================================== */
.streak-display {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.streak-flame {
  font-size: 2.5rem;
  animation: flamePulse 1.5s ease-in-out infinite;
}

.streak-number {
  font-size: 3rem;
  font-weight: 800;
  background: linear-gradient(135deg, #f97316, #ef4444, #fbbf24);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.streak-label {
  font-size: 1rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.streak-msg {
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ========================================
   MOTIVATIONAL QUOTES
   ======================================== */
.quote-display {
  text-align: center;
  padding: 0.5rem 0;
}

.quote-text {
  font-size: 1.05rem;
  font-style: italic;
  color: var(--text-primary);
  line-height: 1.7;
  margin-bottom: 0.75rem;
  min-height: 3.5rem;
  transition: opacity 0.5s ease;
}

.quote-author {
  font-size: 0.8rem;
  color: var(--accent-light);
  font-weight: 600;
}

/* ========================================
   FOOTER
   ======================================== */
.app-footer {
  text-align: center;
  padding: 1.5rem;
  color: var(--text-muted);
  font-size: 0.8rem;
  border-top: 1px solid var(--card-border);
  margin-top: 1rem;
}

/* ========================================
   ANIMATIONS
   ======================================== */
@keyframes fadeIn {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes fadeSlideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

@keyframes shimmer {
  0%   { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@keyframes flamePulse {
  0%, 100% { transform: scale(1); }
  50%      { transform: scale(1.15); }
}

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 1024px) {
  .dashboard {
    grid-template-columns: repeat(2, 1fr);
    padding: 1.25rem;
  }
}

@media (max-width: 640px) {
  .dashboard {
    grid-template-columns: 1fr;
    padding: 1rem;
    gap: 1rem;
  }

  .app-header {
    padding: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
  }

  .app-header h1 {
    font-size: 1.2rem;
  }

  .greeting {
    display: none;
  }

  .timer-ring {
    width: 150px;
    height: 150px;
  }

  .timer-digits {
    font-size: 2rem;
  }
}