/* css/style.css — Expense & Budget Visualizer */

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

:root {
  --color-bg: #f5f7fa;
  --color-surface: #ffffff;
  --color-border: #e2e8f0;
  --color-text: #1a202c;
  --color-text-muted: #718096;
  --color-accent: #4f46e5;
  --color-accent-hover: #4338ca;
  --color-danger: #e53e3e;
  --color-danger-hover: #c53030;
  --color-error-bg: #fff5f5;
  --color-error-border: #fc8181;
  --color-warning-bg: #fffbeb;
  --color-warning-border: #f6ad55;
  --color-focus-ring: rgba(79, 70, 229, 0.35);

  /* Category colors matching chart */
  --color-food: #FF6384;
  --color-transport: #36A2EB;
  --color-fun: #FFCE56;

  --radius: 8px;
  --radius-sm: 4px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.05);
  --font: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

/* ── Dark Mode ────────────────────────────────────────────────────────────── */
[data-theme="dark"] {
  --color-bg: #0f1117;
  --color-surface: #1a1d27;
  --color-border: #2d3148;
  --color-text: #e2e8f0;
  --color-text-muted: #8892a4;
  --color-accent: #6366f1;
  --color-accent-hover: #818cf8;
  --color-error-bg: #2d1515;
  --color-warning-bg: #2a1f0a;
  --color-warning-border: #b7791f;
  --color-focus-ring: rgba(99, 102, 241, 0.4);
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.5);
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  min-height: 100vh;
  transition: background-color 0.2s, color 0.2s;
}

/* ── Header ───────────────────────────────────────────────────────────────── */
header {
  background-color: var(--color-accent);
  color: #ffffff;
  padding: 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  text-align: center;
  box-shadow: var(--shadow-md);
}

header h1 {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

#balance-display {
  font-size: 2rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

/* Theme toggle button */
#theme-toggle {
  background: rgba(255,255,255,0.15);
  border: 1.5px solid rgba(255,255,255,0.4);
  border-radius: 999px;
  color: #fff;
  cursor: pointer;
  font-size: 1.1rem;
  line-height: 1;
  padding: 0.3em 0.6em;
  transition: background 0.15s;
  flex-shrink: 0;
}

#theme-toggle:hover {
  background: rgba(255,255,255,0.25);
}

/* ── Main Layout ──────────────────────────────────────────────────────────── */
main {
  max-width: 720px;
  margin: 0 auto;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ── Storage Warning Banner ───────────────────────────────────────────────── */
#storage-warning,
#storage-warning-banner {
  background-color: var(--color-warning-bg);
  border: 1px solid var(--color-warning-border);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.875rem;
  color: #7b4f12;
}

#storage-warning p,
#storage-warning-banner p {
  flex: 1;
}

#storage-warning button,
#storage-warning-banner button {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  line-height: 1;
  color: #7b4f12;
  padding: 0;
  flex-shrink: 0;
  opacity: 0.7;
  transition: opacity 0.15s;
}

#storage-warning button:hover,
#storage-warning-banner button:hover {
  opacity: 1;
}

/* ── Card Surface ─────────────────────────────────────────────────────────── */
section {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: var(--shadow);
}

/* ── Input Form ───────────────────────────────────────────────────────────── */
#transaction-form {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

#transaction-form input,
#transaction-form select {
  width: 100%;
  padding: 0.625rem 0.75rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9375rem;
  color: var(--color-text);
  background-color: var(--color-surface);
  transition: border-color 0.15s, box-shadow 0.15s;
  appearance: none;
  -webkit-appearance: none;
}

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

#transaction-form input:focus,
#transaction-form select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-focus-ring);
}

/* Error state on inputs */
#transaction-form input.input-error,
#transaction-form select.input-error {
  border-color: var(--color-danger);
  background-color: var(--color-error-bg);
}

#transaction-form input.input-error:focus,
#transaction-form select.input-error:focus {
  box-shadow: 0 0 0 3px rgba(229, 62, 62, 0.25);
}

/* Select arrow */
#item-category {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%23718096' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2.25rem;
  cursor: pointer;
}

/* Submit button */
#transaction-form button[type="submit"] {
  padding: 0.625rem 1.25rem;
  background-color: var(--color-accent);
  color: #ffffff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s, transform 0.1s;
  align-self: flex-start;
}

#transaction-form button[type="submit"]:hover {
  background-color: var(--color-accent-hover);
}

#transaction-form button[type="submit"]:active {
  transform: scale(0.98);
}

#transaction-form button[type="submit"]:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--color-focus-ring);
}

/* Form error messages */
#form-errors {
  font-size: 0.8125rem;
  color: var(--color-danger);
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

#form-errors:empty {
  display: none;
}

.error-message {
  display: flex;
  align-items: center;
  gap: 0.375rem;
}

.error-message::before {
  content: "⚠";
  font-size: 0.75rem;
}

/* ── Chart Section ────────────────────────────────────────────────────────── */
#chart-section {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

#pie-chart {
  max-width: 100%;
  height: auto;
  display: block;
}

#chart-placeholder {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  text-align: center;
  padding: 1.5rem 0;
}

/* ── Transaction List ─────────────────────────────────────────────────────── */
#list-section {
  padding: 0;
  overflow: hidden;
}

#transaction-list {
  list-style: none;
  overflow-y: auto;
  max-height: 300px;
  padding: 0;
}

/* Scrollbar styling (Webkit) */
#transaction-list::-webkit-scrollbar {
  width: 6px;
}

#transaction-list::-webkit-scrollbar-track {
  background: var(--color-bg);
}

#transaction-list::-webkit-scrollbar-thumb {
  background-color: var(--color-border);
  border-radius: 3px;
}

/* Transaction list items */
#transaction-list li {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  padding: 0.75rem 1rem;
  border-bottom: 1px solid var(--color-border);
  transition: background-color 0.1s;
}

#transaction-list li:last-child {
  border-bottom: none;
}

#transaction-list li:hover {
  background-color: var(--color-bg);
}

/* Transaction name */
.txn-name {
  flex: 1;
  font-size: 0.9375rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}

/* Transaction amount */
.txn-amount {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-text);
  white-space: nowrap;
  flex-shrink: 0;
}

/* Category badge */
.txn-category {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2em 0.55em;
  border-radius: 999px;
  white-space: nowrap;
  flex-shrink: 0;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.txn-category[data-category="Food"] {
  background-color: rgba(255, 99, 132, 0.15);
  color: #c0143c;
}

.txn-category[data-category="Transport"] {
  background-color: rgba(54, 162, 235, 0.15);
  color: #1565a8;
}

.txn-category[data-category="Fun"] {
  background-color: rgba(255, 206, 86, 0.2);
  color: #7a5c00;
}

/* Delete button */
.delete-btn {
  background-color: transparent;
  border: 1.5px solid var(--color-danger);
  color: var(--color-danger);
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2em 0.5em;
  cursor: pointer;
  flex-shrink: 0;
  transition: background-color 0.15s, color 0.15s;
  line-height: 1.4;
}

.delete-btn:hover {
  background-color: var(--color-danger);
  color: #ffffff;
}

.delete-btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px rgba(229, 62, 62, 0.3);
}

/* ── Responsive: tablet and up ────────────────────────────────────────────── */
@media (min-width: 540px) {
  header {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    text-align: left;
    padding: 1rem 1.5rem;
  }

  header h1 { font-size: 1.375rem; }
  #balance-display { font-size: 1.75rem; }

  #transaction-form {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-areas:
      "name   amount"
      "cat    submit"
      "errors errors";
    gap: 0.625rem;
  }

  #item-name     { grid-area: name; }
  #item-amount   { grid-area: amount; }
  #item-category { grid-area: cat; }

  #transaction-form button[type="submit"] {
    grid-area: submit;
    align-self: stretch;
    width: 100%;
  }

  #form-errors {
    grid-area: errors;
  }
}

@media (min-width: 720px) {
  main {
    padding: 1.5rem;
    gap: 1.25rem;
  }

  header {
    padding: 1.125rem 2rem;
  }

  #balance-display {
    font-size: 2rem;
  }
}

/* ── Wide desktop ─────────────────────────────────────────────────────────── */
@media (min-width: 1024px) {
  main {
    display: grid;
    grid-template-columns: 1fr 1fr;
    grid-template-areas:
      "budget budget"
      "form   chart"
      "list   list"
      "summary summary";
    align-items: start;
  }

  #budget-section  { grid-area: budget; }
  #form-section    { grid-area: form; }
  #chart-section   { grid-area: chart; }
  #list-section    { grid-area: list; }
  #summary-section { grid-area: summary; }
}

/* ── Budget Section ───────────────────────────────────────────────────────── */
#budget-section label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--color-text-muted);
}

#budget-row {
  display: flex;
  gap: 0.5rem;
}

#budget-limit {
  flex: 1;
  padding: 0.5rem 0.75rem;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9375rem;
  color: var(--color-text);
  background-color: var(--color-surface);
  transition: border-color 0.15s;
}

#budget-limit:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-focus-ring);
}

#budget-save {
  padding: 0.5rem 1rem;
  background-color: var(--color-accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.15s;
}

#budget-save:hover { background-color: var(--color-accent-hover); }

#budget-status {
  margin-top: 0.5rem;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.6rem;
}

#budget-status:empty { display: none; }

.budget-ok {
  background-color: rgba(72, 187, 120, 0.12);
  color: #276749;
}

[data-theme="dark"] .budget-ok {
  background-color: rgba(72, 187, 120, 0.15);
  color: #68d391;
}

.budget-over {
  background-color: rgba(229, 62, 62, 0.1);
  color: var(--color-danger);
  font-weight: 700;
}

/* ── Monthly Summary ──────────────────────────────────────────────────────── */
#summary-section h2 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

#month-nav {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

#month-nav button {
  background: var(--color-surface);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  cursor: pointer;
  font-size: 1.25rem;
  line-height: 1;
  padding: 0.15em 0.5em;
  transition: background 0.15s;
}

#month-nav button:hover { background: var(--color-bg); }

#month-label {
  font-weight: 600;
  font-size: 0.9375rem;
  flex: 1;
  text-align: center;
}

.summary-empty {
  color: var(--color-text-muted);
  font-size: 0.9rem;
}

.summary-total {
  font-size: 0.9375rem;
  margin-bottom: 0.5rem;
}

.summary-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.summary-list li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.summary-pct {
  color: var(--color-text-muted);
  font-size: 0.8rem;
}

/* ── Responsive updates for new sections ─────────────────────────────────── */
@media (min-width: 1024px) {
  #summary-section { grid-column: 1 / -1; }
}