/* Reset */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
:root {
  --bg: #a8dcff;
  --card: #ffffff;
  --muted: #eef3f6;
  --accent: #06b85b;
  --soft: #f4f7fa;
  --shadow: rgba(20, 40, 60, 0.12);
  --pill-shadow: rgba(6, 184, 91, 0.25);
  --radius: 20px;
  --radius-lg: 28px;
  --text: #111827;
}
body {
  font-family: "Segoe UI", Roboto, system-ui, -apple-system, "Noto Sans",
    sans-serif;
  background: linear-gradient(180deg, var(--bg), #9fd3ff 60%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
}

/* card */
.card {
  width: 900px;
  max-width: 92%;
  background: var(--card);
  border-radius: 28px;
  padding: 36px 56px 22px;
  box-shadow: 0 12px 30px var(--shadow);
  position: relative;
}

/* header */
.title {
  text-align: center;
  font-size: 36px;
  letter-spacing: 0.6px;
  margin-bottom: 28px;
  color: var(--text);
  font-weight: 800;
}

/* input row */
.add-row {
  display: flex;
  align-items: center;
  gap: 18px;
  background: var(--muted);
  padding: 5px 22px;
  border-radius: 60px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.6);
}

.add-row input {
  flex: 1;
  border: 0;
  background: transparent;
  font-size: 18px;
  padding: 6px 8px;
  outline: none;
  color: var(--text);
}

/* green round button */
.add-btn {
  width: 55px;
  height: 55px;
  border-radius: 50%;
  border: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(180deg, #19c55d, #0ea04b);
  box-shadow: 0 10px 18px var(--pill-shadow), 0 2px 6px rgba(0, 0, 0, 0.08);
  cursor: pointer;
  transition: transform 0.12s ease;
}
.add-btn:active {
  transform: scale(0.98);
}

/* tasks list */
.tasks {
  margin-top: 26px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 0 6px;
}

/* single task */
.task-item {
  background: var(--soft);
  padding: 10px 18px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.02);
}

/* left content */
.left {
  display: flex;
  gap: 14px;
  align-items: center;
  flex: 1;
}

/* custom checkbox */
.checkbox {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  background: white;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px solid #e6eef2;
  cursor: pointer;
}
.checkbox.checked {
  background: linear-gradient(180deg, #c6ffc6, #78e08b);
  border: 2px solid #06b85b;
  box-shadow: 0 6px 14px rgba(6, 184, 91, 0.14),
    0 0 0 6px rgba(6, 184, 91, 0.06);
}

/* task text */
.task-text {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

/* completed */
.task-text.completed {
  text-decoration: line-through;
  color: #94a3b8;
  font-weight: 600;
}

/* action buttons */
.actions {
  display: flex;
  gap: 10px;
  align-items: center;
  margin-left: 12px;
}
.action-btn {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  border: 0;
  background: white;
  box-shadow: 0 4px 10px rgba(2, 6, 23, 0.06);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 26px;
}

/* bottom row */
.bottom-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 18px;
}
.count {
  color: #6b7280;
  font-size: 14px;
}
.filters {
  display: flex;
  gap: 8px;
  align-items: center;
}
.filter {
  border-radius: 999px;
  border: 0;
  background: #fff;
  padding: 8px 12px;
  box-shadow: 0 2px 6px rgba(2, 6, 23, 0.04);
  cursor: pointer;
  font-size: 14px;
}
.filter.active {
  background: #fff;
  border: 2px solid #000;
  padding: 6px 10px;
}

/* small screens */
@media (max-width: 700px) {
  .card {
    padding: 22px 20px;
  }
  .title {
    font-size: 26px;
  }
  .add-btn {
    width: 56px;
    height: 56px;
  }
}