@import url("https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@500;700&family=Manrope:wght@400;600;700&display=swap");

:root {
  color-scheme: light;
  --bg-a: #f3f7ff;
  --bg-b: #eaf7f0;
  --card: rgba(255, 255, 255, 0.84);
  --text: #10243f;
  --muted: #5c6b82;
  --primary: #0f6fff;
  --primary-hover: #005be0;
  --danger: #d12f4d;
  --danger-bg: #ffe6ec;
  --border: rgba(16, 36, 63, 0.11);
  --ring: rgba(15, 111, 255, 0.22);
  --shadow-lg: 0 22px 50px rgba(27, 53, 92, 0.16);
  --shadow-sm: 0 6px 18px rgba(27, 53, 92, 0.08);
  --input-bg: rgba(255, 255, 255, 0.75);
  --item-bg: rgba(255, 255, 255, 0.8);
  --empty-bg: rgba(255, 255, 255, 0.55);
  --toggle-bg: #eef2ff;
  --toggle-text: #223354;
  --toggle-border: rgba(35, 51, 84, 0.15);
  --radius-lg: 20px;
  --radius-md: 12px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg-a: #0b1222;
  --bg-b: #0a1a1d;
  --card: rgba(11, 19, 35, 0.86);
  --text: #e6eefc;
  --muted: #a7b6d6;
  --primary: #4b8dff;
  --primary-hover: #2e73f8;
  --danger: #ff7b98;
  --danger-bg: rgba(255, 123, 152, 0.16);
  --border: rgba(158, 184, 226, 0.2);
  --ring: rgba(75, 141, 255, 0.3);
  --shadow-lg: 0 22px 50px rgba(0, 0, 0, 0.45);
  --shadow-sm: 0 10px 24px rgba(0, 0, 0, 0.32);
  --input-bg: rgba(12, 27, 45, 0.9);
  --item-bg: rgba(16, 31, 52, 0.85);
  --empty-bg: rgba(12, 27, 45, 0.65);
  --toggle-bg: rgba(75, 141, 255, 0.15);
  --toggle-text: #dbe8ff;
  --toggle-border: rgba(175, 202, 255, 0.35);
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  padding: 1rem;
  color: var(--text);
  font-family: "Manrope", "Segoe UI", Tahoma, sans-serif;
  background:
    radial-gradient(circle at 10% 16%, rgba(98, 148, 255, 0.52) 0%, transparent 45%),
    radial-gradient(circle at 90% 84%, rgba(86, 201, 160, 0.46) 0%, transparent 42%),
    radial-gradient(circle at 62% 8%, rgba(165, 126, 255, 0.22) 0%, transparent 36%),
    radial-gradient(circle at 22% 88%, rgba(95, 143, 255, 0.24) 0%, transparent 32%),
    linear-gradient(140deg, var(--bg-a), var(--bg-b));
  display: grid;
  place-items: center;
  transition: background 250ms ease, color 250ms ease;
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
}

body::before {
  background:
    radial-gradient(circle at 16% 24%, rgba(82, 133, 255, 0.32), transparent 40%),
    radial-gradient(circle at 84% 72%, rgba(58, 187, 147, 0.28), transparent 40%),
    linear-gradient(120deg, rgba(76, 132, 255, 0.2), transparent 38%),
    linear-gradient(-120deg, rgba(38, 190, 145, 0.18), transparent 34%),
    repeating-linear-gradient(
      32deg,
      rgba(16, 36, 63, 0.03) 0,
      rgba(16, 36, 63, 0.03) 2px,
      transparent 2px,
      transparent 18px
    ),
    repeating-linear-gradient(
      135deg,
      rgba(16, 36, 63, 0.04) 0,
      rgba(16, 36, 63, 0.04) 1px,
      transparent 1px,
      transparent 10px
    );
  opacity: 1;
}

body::after {
  background:
    radial-gradient(circle at 20% 25%, rgba(255, 255, 255, 0.86), transparent 44%),
    radial-gradient(circle at 78% 78%, rgba(255, 255, 255, 0.72), transparent 46%),
    radial-gradient(circle at 52% 84%, rgba(255, 255, 255, 0.44), transparent 38%),
    radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.2), transparent 55%);
  mix-blend-mode: soft-light;
  opacity: 0.92;
}

:root[data-theme="dark"] body::before,
:root[data-theme="dark"] body::after {
  opacity: 0;
}

.app {
  width: 100%;
  max-width: 680px;
  max-height: min(90vh, 52rem);
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(8px);
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  animation: fadeUp 320ms ease;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1rem;
}

h1 {
  margin: 0;
  font-family: "Space Grotesk", "Manrope", sans-serif;
  font-size: clamp(1.5rem, 2.6vw, 2rem);
  letter-spacing: 0.2px;
}

.theme-toggle {
  border: 1px solid var(--toggle-border);
  border-radius: 999px;
  background: var(--toggle-bg);
  color: var(--toggle-text);
  font-size: 1rem;
  line-height: 1;
  width: 2.7rem;
  height: 2.2rem;
  display: inline-grid;
  place-items: center;
  padding: 0;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: transform 150ms ease, background 150ms ease, border-color 150ms ease;
}

.theme-toggle:hover {
  transform: translateY(-1px);
  border-color: var(--primary);
}

.theme-icon {
  position: absolute;
  transition: transform 220ms ease, opacity 220ms ease;
}

.theme-icon-sun {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.theme-icon-moon {
  opacity: 0;
  transform: translateY(8px) scale(0.88);
}

:root[data-theme="dark"] .theme-icon-sun {
  opacity: 0;
  transform: translateY(-8px) scale(0.88);
}

:root[data-theme="dark"] .theme-icon-moon {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.todo-form {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.7rem;
  margin-bottom: 0.3rem;
}

.todo-form input {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--input-bg);
  color: var(--text);
  padding: 0.82rem 0.95rem;
  font-size: 0.98rem;
  outline: none;
  transition: border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

.todo-form input::placeholder {
  color: #7b8798;
}

.todo-form input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--ring);
  transform: translateY(-1px);
}

.todo-form button {
  border: 0;
  border-radius: var(--radius-md);
  background: linear-gradient(180deg, #2a85ff, var(--primary));
  color: #fff;
  padding: 0.8rem 1.15rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
  box-shadow: 0 8px 18px rgba(15, 111, 255, 0.32);
}

.todo-form button:hover {
  background: linear-gradient(180deg, #1575f8, var(--primary-hover));
  transform: translateY(-1px);
}

.todo-form button:active {
  transform: translateY(0);
}

.message {
  min-height: 1.2rem;
  margin: 0.65rem 0 0.9rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.message.error {
  color: var(--danger);
}

.toast-container {
  position: fixed;
  top: 1rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 20;
  display: grid;
  gap: 0.5rem;
  width: min(20rem, calc(100vw - 2rem));
}

.toast {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--card);
  color: var(--text);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(8px);
  padding: 0.68rem 0.85rem;
  font-size: 0.88rem;
  font-weight: 700;
  text-align: center;
  transform: translateY(-8px);
  opacity: 0;
  transition: transform 220ms ease, opacity 220ms ease;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.toast-success {
  border-color: color-mix(in srgb, #1fa16b 45%, var(--border));
}

.toast-error {
  border-color: color-mix(in srgb, var(--danger) 48%, var(--border));
}

.toast-info {
  border-color: color-mix(in srgb, var(--primary) 40%, var(--border));
}

.todo-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.62rem;
  flex: 1;
  min-height: 0;
  overflow-y: hidden;
  padding-right: 0.3rem;
}

.todo-list.is-scrollable {
  overflow-y: auto;
}

.todo-list::-webkit-scrollbar {
  width: 8px;
}

.todo-list::-webkit-scrollbar-track {
  background: transparent;
}

.todo-list::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--muted) 34%, transparent);
  border-radius: 999px;
}

.todo-list::-webkit-scrollbar-thumb:hover {
  background: color-mix(in srgb, var(--muted) 54%, transparent);
}

.todo-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--item-bg);
  padding: 0.75rem 0.75rem 0.75rem 0.68rem;
  box-shadow: var(--shadow-sm);
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 0.7rem;
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
  animation: fadeInItem 260ms ease both;
  animation-delay: calc(var(--i, 0) * 45ms);
}

.todo-item:hover {
  transform: translateY(-1px);
  border-color: rgba(15, 111, 255, 0.25);
  box-shadow: 0 10px 24px rgba(27, 53, 92, 0.12);
}

.todo-item label {
  display: flex;
  align-items: center;
}

.todo-item input[type="checkbox"] {
  width: 1rem;
  height: 1rem;
  accent-color: var(--primary);
  cursor: pointer;
}

.todo-title {
  overflow-wrap: anywhere;
  line-height: 1.45;
  font-weight: 600;
}

.todo-item.completed .todo-title {
  text-decoration: line-through;
  color: var(--muted);
  opacity: 0.78;
}

.delete-btn {
  border: 1px solid transparent;
  border-radius: 10px;
  background: var(--danger-bg);
  color: var(--danger);
  cursor: pointer;
  padding: 0.44rem 0.7rem;
  font-size: 0.84rem;
  font-weight: 700;
  transition: transform 150ms ease, background 150ms ease, border-color 150ms ease;
}

.delete-btn:hover {
  background: color-mix(in srgb, var(--danger-bg) 72%, white 28%);
  border-color: color-mix(in srgb, var(--danger) 30%, transparent);
  transform: translateY(-1px);
}

.empty {
  border: 1px dashed var(--border);
  border-radius: var(--radius-md);
  text-align: center;
  color: var(--muted);
  padding: 1.1rem;
  background: var(--empty-bg);
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(9px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInItem {
  from {
    opacity: 0;
    transform: translateY(6px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 560px) {
  body {
    padding: 0.75rem;
  }

  .app {
    padding: 1rem;
    border-radius: 16px;
    max-height: 94vh;
  }

  .app-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.6rem;
  }

  .todo-form {
    grid-template-columns: 1fr;
  }

  .todo-form button {
    width: 100%;
  }

  .toast-container {
    top: 0.7rem;
    left: 50%;
  }
}