:root {
  --bg: #121212;
  --surface: #1e1e1e;
  --surface-2: #272727;
  --text: #f5f5f5;
  --text-muted: #b3b3b3;
  --accent: #e11d48;
  --accent-hover: #be123c;
  --border: #3a3a3a;
  --shadow: rgba(0, 0, 0, 0.4);
  --radius: 10px;
  --success-bg: #163b2c;
  --success-text: #7fe0ab;
  --warning-bg: #4a3a10;
  --warning-text: #f5cf6b;
  --danger-bg: #4a1620;
  --danger-text: #f5919f;
}

[data-theme="light"] {
  --bg: #f4f4f6;
  --surface: #ffffff;
  --surface-2: #f0f0f3;
  --text: #1a1a1a;
  --text-muted: #5a5a60;
  --accent: #e11d48;
  --accent-hover: #be123c;
  --border: #e0e0e5;
  --shadow: rgba(0, 0, 0, 0.1);
  --success-bg: #e2f5e9;
  --success-text: #196a3f;
  --warning-bg: #fdf1d6;
  --warning-text: #8a6410;
  --danger-bg: #fbe3e7;
  --danger-text: #99223a;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100%;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  transition: background-color 0.2s ease, color 0.2s ease;
}

a {
  color: inherit;
}

button {
  font-family: inherit;
}

/* Navbar */

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 10px 20px;
  background-color: var(--surface);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 8px var(--shadow);
  position: sticky;
  top: 0;
  z-index: 10;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 600;
  text-decoration: none;
  color: var(--text);
  white-space: nowrap;
}

.navbar-brand i {
  color: var(--accent);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text);
  font-size: 20px;
  padding: 6px 10px;
  border-radius: var(--radius);
  cursor: pointer;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: var(--radius);
  color: var(--text-muted);
  text-decoration: none;
  font-size: 15px;
  transition: background-color 0.2s, color 0.2s;
}

.nav-link:hover {
  background-color: var(--surface-2);
  color: var(--text);
}

.nav-link.active {
  background-color: var(--accent);
  color: #fff;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  margin-left: 6px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background-color: var(--surface-2);
  color: var(--text);
  cursor: pointer;
  transition: background-color 0.2s, box-shadow 0.2s;
}

.theme-toggle:hover {
  background-color: var(--border);
}

@media screen and (max-width: 780px) {
  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background-color: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 8px 16px var(--shadow);
    padding: 8px;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-link {
    justify-content: flex-start;
  }

  .theme-toggle {
    margin: 6px 0 0 0;
    align-self: flex-start;
  }
}

/* Layout */

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 30px 16px 60px;
  gap: 20px;
}

.card {
  width: 100%;
  max-width: 480px;
  padding: 24px;
  border-radius: var(--radius);
  background-color: var(--surface);
  border: 1px solid var(--border);
  box-shadow: 0 4px 12px var(--shadow);
}

.card h2 {
  margin: 0 0 16px;
  text-align: center;
}

/* Home page */

.hero {
  max-width: 640px;
  text-align: center;
  margin-bottom: 10px;
}

.hero h1 {
  margin-bottom: 8px;
}

.hero p {
  color: var(--text-muted);
  font-size: 16px;
  line-height: 1.5;
}

.tool-boxes {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  width: 100%;
  max-width: 1000px;
}

.tool-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 8px;
  padding: 28px 20px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 4px 12px var(--shadow);
  text-decoration: none;
  color: var(--text);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.tool-box:hover,
.tool-box:focus-visible {
  transform: translateY(-4px);
  box-shadow: 0 10px 24px var(--shadow);
  border-color: var(--accent);
}

.tool-box i {
  font-size: 28px;
  color: var(--accent);
  margin-bottom: 6px;
}

.tool-box h2 {
  margin: 0;
  font-size: 18px;
}

.tool-box p {
  margin: 0;
  color: var(--text-muted);
  font-size: 14px;
}

/* Forms (shared) */

form {
  display: flex;
  flex-direction: column;
}

label {
  margin-bottom: 6px;
  color: var(--text-muted);
  font-size: 14px;
}

input[type="text"],
input[type="date"],
input[type="number"],
select,
textarea {
  margin-bottom: 14px;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background-color: var(--surface-2);
  color: var(--text);
  font-size: 15px;
}

input:focus,
select:focus,
textarea:focus,
button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.btn,
button[type="submit"] {
  padding: 10px 20px;
  background-color: var(--accent);
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 15px;
  transition: background-color 0.2s, box-shadow 0.2s;
}

.btn:hover,
button[type="submit"]:hover {
  background-color: var(--accent-hover);
  box-shadow: 0 6px 14px var(--shadow);
}

.btn-secondary {
  background-color: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover {
  background-color: var(--border);
}

.form-actions {
  display: flex;
  gap: 10px;
  justify-content: center;
}

/* Task manager */

.task-form,
.task-list {
  width: 100%;
  max-width: 480px;
}

.task-form form {
  align-items: stretch;
}

.task-list {
  text-align: center;
}

.task-list h2 {
  margin-bottom: 12px;
}

.empty-state {
  color: var(--text-muted);
  font-size: 14px;
}

.task-list ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.task-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background-color: var(--surface-2);
  color: var(--text);
  text-align: left;
}

.task-list li .task-text {
  flex: 1;
}

.task-list li.done .task-text {
  text-decoration: line-through;
  color: var(--text-muted);
}

.task-list li.low {
  background-color: var(--success-bg);
  color: var(--success-text);
}

.task-list li.medium {
  background-color: var(--warning-bg);
  color: var(--warning-text);
}

.task-list li.high {
  background-color: var(--danger-bg);
  color: var(--danger-text);
}

.task-list li button {
  padding: 6px 10px;
  font-size: 13px;
  background-color: rgba(0, 0, 0, 0.2);
  border: none;
  border-radius: 6px;
  color: inherit;
  cursor: pointer;
  transition: background-color 0.2s;
}

.task-list li button:hover {
  background-color: rgba(0, 0, 0, 0.35);
}

.task-list li input[type="checkbox"] {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* Notepad */

.notepad-wrap {
  width: 100%;
  max-width: 900px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.notepad-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.save-status {
  color: var(--text-muted);
  font-size: 13px;
}

#notepad {
  width: 100%;
  height: calc(100vh - 220px);
  min-height: 300px;
  margin-bottom: 0;
  padding: 16px 20px;
  border-radius: var(--radius);
  background-color: var(--surface);
  font-size: 16px;
  line-height: 24px;
  color: var(--text);
  resize: vertical;
  outline: none;
}

/* Calculator */

.calculator {
  width: 100%;
  max-width: 340px;
  padding: 20px;
  background-color: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 4px 12px var(--shadow);
}

.result-display {
  width: 100%;
  margin-bottom: 14px;
  padding: 16px 14px;
  font-size: 26px;
  text-align: right;
  border: 1px solid var(--border);
  background-color: var(--surface-2);
  color: var(--text);
  border-radius: 8px;
}

.calc-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
}

.calc-button {
  padding: 16px 0;
  font-size: 18px;
  color: var(--text);
  background-color: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.2s, box-shadow 0.2s;
}

.calc-button:hover {
  background-color: var(--border);
}

.calc-button:active {
  box-shadow: inset 0 2px 4px var(--shadow);
}

.calc-button.calc-op {
  background-color: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.calc-button.calc-op:hover {
  background-color: var(--accent-hover);
}

.calc-button.calc-equals {
  background-color: var(--accent);
  color: #fff;
  border-color: var(--accent);
  grid-column: span 2;
}

.calc-button.calc-equals:hover {
  background-color: var(--accent-hover);
}

.calc-button.calc-zero {
  grid-column: span 1;
}

/* Unit converter */

.unit-converter {
  width: 100%;
  max-width: 480px;
}

.unit-converter .row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.unit-converter .swap {
  align-self: center;
  justify-self: center;
  margin: 4px 0 14px;
  width: 40px;
  height: 40px;
  border-radius: 50%;
}

.unit-converter .result {
  margin-top: 8px;
  padding: 14px;
  text-align: center;
  font-size: 18px;
  background-color: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
}

/* Color picker */

.color-picker {
  width: 100%;
  max-width: 480px;
}

.color-picker .swatch-preview {
  width: 100%;
  height: 100px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  margin-bottom: 16px;
}

.color-picker input[type="color"] {
  width: 100%;
  height: 48px;
  padding: 4px;
  margin-bottom: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background-color: var(--surface-2);
  cursor: pointer;
}

.color-values {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.color-value {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  background-color: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  font-family: "Consolas", "Courier New", monospace;
}

.color-value button {
  padding: 4px 10px;
  font-size: 12px;
  background-color: var(--border);
  color: var(--text);
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

.palette {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}

.palette button {
  height: 48px;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  padding: 0;
}

/* Markdown previewer */

.markdown-previewer {
  width: 100%;
  max-width: 1000px;
}

.markdown-panes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.markdown-panes h3 {
  margin: 0 0 8px;
  font-size: 14px;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

#markdown-input {
  width: 100%;
  height: 420px;
  margin-bottom: 0;
  padding: 14px;
  border-radius: 8px;
  background-color: var(--surface-2);
  color: var(--text);
  font-family: "Consolas", "Courier New", monospace;
  font-size: 14px;
  resize: vertical;
}

#markdown-output {
  height: 420px;
  overflow-y: auto;
  padding: 14px;
  border-radius: 8px;
  background-color: var(--surface-2);
  border: 1px solid var(--border);
  line-height: 1.5;
}

#markdown-output img {
  max-width: 100%;
}

#markdown-output pre {
  background-color: var(--surface);
  padding: 10px;
  border-radius: 6px;
  overflow-x: auto;
}

#markdown-output code {
  background-color: var(--surface);
  padding: 2px 5px;
  border-radius: 4px;
}

@media screen and (max-width: 720px) {
  .markdown-panes {
    grid-template-columns: 1fr;
  }
}

/* Pomodoro */

.pomodoro {
  width: 100%;
  max-width: 420px;
  text-align: center;
}

.pomodoro .mode-switch {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.pomodoro .mode-switch button {
  padding: 8px 14px;
  font-size: 13px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background-color: var(--surface-2);
  color: var(--text-muted);
  cursor: pointer;
}

.pomodoro .mode-switch button.active {
  background-color: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.pomodoro .time-display {
  font-size: 64px;
  font-weight: 700;
  margin: 10px 0 24px;
  font-variant-numeric: tabular-nums;
}

.pomodoro .controls {
  display: flex;
  gap: 10px;
  justify-content: center;
}