* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background: #0f0f1a;
  color: #fff;
  min-height: 100vh;
}

.hidden {
  display: none !important;
}

/* AUTH SCREEN */
#authScreen {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.auth-box {
  background: #1a1a2e;
  padding: 40px;
  border-radius: 16px;
  width: 320px;
  text-align: center;
  box-shadow: 0 8px 24px rgba(0,0,0,0.4);
}

.auth-box h1 {
  margin-bottom: 4px;
}

.subtitle {
  color: #999;
  margin-bottom: 24px;
  font-size: 0.9rem;
}

.auth-box input {
  width: 100%;
  padding: 12px;
  margin-bottom: 12px;
  border-radius: 8px;
  border: none;
  background: #2a2a40;
  color: #fff;
  font-size: 0.95rem;
}

.auth-box input::placeholder {
  color: #888;
}

.auth-box button {
  width: 100%;
  padding: 12px;
  margin-top: 6px;
  border-radius: 8px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  font-size: 0.95rem;
}

#loginBtn {
  background: #FF6B6B;
  color: #fff;
}

#signupBtn {
  background: #2a2a40;
  color: #fff;
}

.error {
  color: #ff8080;
  font-size: 0.85rem;
  margin-top: 10px;
}

/* APP HEADER */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 30px;
  background: #1a1a2e;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 0.85rem;
  color: #aaa;
}

#logoutBtn {
  background: #2a2a40;
  color: #fff;
  border: none;
  padding: 8px 16px;
  border-radius: 8px;
  cursor: pointer;
}

/* TABS */
.tabs {
  display: flex;
  justify-content: center;
  gap: 10px;
  padding: 20px 0 0;
}

.tab {
  background: none;
  border: none;
  color: #999;
  padding: 10px 20px;
  font-size: 1rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
}

.tab.active {
  color: #FF6B6B;
  border-bottom: 2px solid #FF6B6B;
}

.tab-content {
  max-width: 500px;
  margin: 40px auto;
  padding: 0 20px;
  text-align: center;
}

/* TIMER */
.timer-circle {
  width: 240px;
  height: 240px;
  border-radius: 50%;
  border: 6px solid #FF6B6B;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 20px;
  background: #1a1a2e;
}

#timeDisplay {
  font-size: 3rem;
  font-weight: 700;
}

#modeLabel {
  color: #aaa;
  margin-bottom: 20px;
}

.timer-controls {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.timer-controls button {
  padding: 12px 24px;
  border-radius: 8px;
  border: none;
  font-weight: 600;
  cursor: pointer;
  background: #2a2a40;
  color: #fff;
}

#startBtn {
  background: #FF6B6B;
}

/* TASKS */
.task-input {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

.task-input input {
  flex: 1;
  padding: 12px;
  border-radius: 8px;
  border: none;
  background: #2a2a40;
  color: #fff;
}

.task-input button {
  padding: 12px 20px;
  border-radius: 8px;
  border: none;
  background: #FF6B6B;
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}

#taskList {
  list-style: none;
  text-align: left;
}

#taskList li {
  background: #1a1a2e;
  padding: 14px 16px;
  border-radius: 10px;
  margin-bottom: 10px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#taskList li.completed span {
  text-decoration: line-through;
  color: #777;
}

.task-actions button {
  background: none;
  border: none;
  color: #999;
  cursor: pointer;
  font-size: 1rem;
  margin-left: 8px;
}

/* STATS */
.stats-summary {
  display: flex;
  gap: 16px;
  justify-content: center;
  margin-bottom: 30px;
}

.stat-card {
  background: #1a1a2e;
  padding: 24px;
  border-radius: 12px;
  flex: 1;
}

.stat-card span {
  font-size: 2rem;
  font-weight: 700;
  color: #FF6B6B;
}

.stat-card p {
  color: #999;
  font-size: 0.85rem;
  margin-top: 6px;
}

#chartContainer {
  background: #1a1a2e;
  border-radius: 12px;
  padding: 20px;
}