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

:root {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-card: #16213e;
  --bg-input: #1e2a45;
  --bg-hover: #1e2d50;
  --text-primary: #e0e0e0;
  --text-secondary: #8892b0;
  --text-muted: #5a6480;
  --accent: #00d4aa;
  --accent-hover: #00f0c0;
  --success: #2ecc71;
  --danger: #ff6b6b;
  --warning: #ffd93d;
  --border: #2a2a4a;
  --radius: 10px;
  --shadow: 0 4px 20px rgba(0,0,0,0.3);
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, sans-serif;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-size: 15px;
  line-height: 1.5;
}

/* ─── Login Page ───────────────────────────────────────────────────────────── */
.login-container {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
  background: linear-gradient(135deg, #0f0f1a 0%, #1a1a2e 50%, #16213e 100%);
}

.login-card {
  background: var(--bg-secondary);
  border-radius: 16px;
  padding: 40px;
  width: 100%;
  max-width: 400px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.login-header {
  text-align: center;
  margin-bottom: 30px;
}

.login-icon {
  font-size: 48px;
  margin-bottom: 10px;
}

.login-header h1 {
  font-size: 24px;
  color: var(--accent);
  margin-bottom: 6px;
}

.login-subtitle {
  color: var(--text-secondary);
  font-size: 14px;
}

.login-form {
  margin-bottom: 20px;
}

.login-footer {
  text-align: center;
  color: var(--text-muted);
  font-size: 12px;
}

.login-footer strong {
  color: var(--text-secondary);
}

/* ─── App Layout ───────────────────────────────────────────────────────────── */
.app-container {
  display: flex;
  flex-direction: column;
  height: 100vh;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 16px;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.header-left h1 {
  font-size: 20px;
  font-weight: 600;
  color: var(--accent);
}

.header-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.user-info {
  color: var(--text-secondary);
  font-size: 13px;
  padding: 4px 10px;
  background: var(--bg-card);
  border-radius: 6px;
}

/* ─── Task Area ────────────────────────────────────────────────────────────── */
.task-area {
  flex: 1;
  overflow-y: auto;
  padding: 16px 0;
}

.task-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.loading, .empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 40px;
}

/* ─── Task Table ──────────────────────────────────────────────────────────── */
.task-table {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.task-table-header {
  display: flex;
  align-items: center;
  padding: 10px 16px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.task-table-header .sortable {
  cursor: pointer;
  user-select: none;
  transition: color 0.15s;
}

.task-table-header .sortable:hover {
  color: var(--accent);
}

.task-table-row {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  transition: background 0.15s;
}

.task-table-row:last-child {
  border-bottom: none;
}

.task-table-row:hover {
  background: var(--bg-hover);
}

.task-table-row.row-overdue {
  background: rgba(255,107,107,0.05);
}

.task-table-row.row-done {
  opacity: 0.5;
}

.tt-col {
  flex-shrink: 0;
}

.col-select {
  width: 40px;
}

.col-select input[type="checkbox"] {
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

.col-title {
  flex: 1;
  min-width: 0;
}

.tt-title-text {
  font-weight: 500;
  font-size: 14px;
  display: block;
  word-break: break-word;
}

.tt-title-text.tt-done {
  text-decoration: line-through;
  color: var(--text-muted);
}

.tt-assignee {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 2px;
  display: inline-block;
}

.col-date {
  width: 130px;
  font-size: 13px;
  color: var(--text-secondary);
}

.col-priority {
  width: 110px;
}

.col-deadline {
  width: 130px;
  font-size: 13px;
  color: var(--text-secondary);
}

.col-deadline.tt-overdue {
  color: var(--danger);
  font-weight: 600;
}

.col-actions {
  width: 50px;
  text-align: center;
}

.p-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
}

.p-badge.priority-high {
  background: rgba(255,107,107,0.15);
  color: #ff6b6b;
}

.p-badge.priority-mid {
  background: rgba(255,217,61,0.15);
  color: #ffd93d;
}

.p-badge.priority-low {
  background: rgba(107,203,255,0.15);
  color: #6bcbff;
}

@media (max-width: 700px) {
  .col-date { width: 90px; font-size: 12px; }
  .col-priority { width: 90px; }
  .col-deadline { width: 90px; font-size: 12px; }
}

@media (max-width: 550px) {
  .task-table-header { display: none; }
  .col-date, .col-deadline, .col-priority { font-size: 11px; }
  .task-table-row { flex-wrap: wrap; gap: 4px; padding: 10px 12px; }
  .col-select { width: 32px; }
  .col-title { width: calc(100% - 82px); flex: none; }
  .col-priority { width: auto; }
  .col-date { width: auto; }
  .col-deadline { width: auto; }
  .col-actions { width: 32px; }
}

/* ─── Task Card ────────────────────────────────────────────────────────────── */
.task-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px 16px;
  transition: all 0.2s;
  position: relative;
}

.task-card:hover {
  background: var(--bg-hover);
  border-color: var(--accent);
}

.task-card.overdue {
  border-color: var(--danger);
  box-shadow: 0 0 0 1px var(--danger);
}

.task-card.done {
  opacity: 0.55;
}

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

/* Checkbox */
.task-check {
  flex-shrink: 0;
  margin-top: 2px;
}

.task-check input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--accent);
  cursor: pointer;
}

/* Task body */
.task-body {
  flex: 1;
  min-width: 0;
}

.task-title {
  font-weight: 500;
  font-size: 15px;
  margin-bottom: 6px;
  word-break: break-word;
}

.task-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary);
}

.task-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: 4px;
  background: var(--bg-input);
}

.task-meta-item.priority-high {
  background: rgba(255,107,107,0.15);
  color: #ff6b6b;
}

.task-meta-item.priority-mid {
  background: rgba(255,217,61,0.15);
  color: #ffd93d;
}

.task-meta-item.priority-low {
  background: rgba(107,203,255,0.15);
  color: #6bcbff;
}

.task-meta-item.overdue-icon {
  background: rgba(255,107,107,0.2);
  color: var(--danger);
  font-weight: 600;
}

/* Task actions */
.task-actions {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ─── Footer (bottom actions) ──────────────────────────────────────────────── */
.app-footer {
  display: flex;
  gap: 10px;
  padding: 16px 0;
  border-top: 1px solid var(--border);
  flex-shrink: 0;
}

.app-footer .btn {
  flex: 1;
}

/* ─── Buttons ──────────────────────────────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 8px 16px;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  font-family: var(--font);
  text-decoration: none;
}

.btn-primary {
  background: var(--accent);
  color: #0f0f1a;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
}

.btn-success {
  background: var(--success);
  color: #0f0f1a;
}

.btn-success:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

.btn-danger {
  background: var(--danger);
  color: #fff;
}

.btn-danger:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.btn-outline:hover {
  background: rgba(0,212,170,0.1);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  color: var(--text-primary);
  background: var(--bg-card);
}

.btn-icon {
  background: transparent;
  color: var(--text-secondary);
  padding: 6px 8px;
  font-size: 16px;
  border-radius: 6px;
}

.btn-icon:hover {
  color: var(--accent);
  background: var(--bg-card);
}

.btn-full {
  width: 100%;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

/* ─── Forms ─────────────────────────────────────────────────────────────────── */
.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 6px;
  font-weight: 500;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 10px 14px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 14px;
  font-family: var(--font);
  outline: none;
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--accent);
}

.form-group input::placeholder {
  color: var(--text-muted);
}

.form-group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%238892b0' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.form-row {
  display: flex;
  gap: 12px;
}

.form-row .form-group {
  flex: 1;
}

/* ─── Alert ─────────────────────────────────────────────────────────────────── */
.alert {
  padding: 12px 16px;
  border-radius: 8px;
  font-size: 13px;
  margin-bottom: 16px;
}

.alert-error {
  background: rgba(255,107,107,0.15);
  color: var(--danger);
  border: 1px solid rgba(255,107,107,0.3);
}

/* ─── Modal ─────────────────────────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 20px;
  backdrop-filter: blur(4px);
}

.modal-card {
  background: var(--bg-secondary);
  border-radius: 16px;
  padding: 28px;
  width: 100%;
  max-width: 480px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.5);
  border: 1px solid var(--border);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}

.modal-header h2 {
  font-size: 18px;
  color: var(--text-primary);
}

.modal-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  margin-top: 8px;
}

.modal-actions .btn {
  min-width: 100px;
}

/* ─── Scrollbar ────────────────────────────────────────────────────────────── */
.task-area::-webkit-scrollbar {
  width: 6px;
}

.task-area::-webkit-scrollbar-track {
  background: transparent;
}

.task-area::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

.task-area::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* ─── Responsive ───────────────────────────────────────────────────────────── */
@media (max-width: 600px) {
  .app-container {
    padding: 0 12px;
  }

  .app-header {
    flex-direction: column;
    gap: 10px;
    align-items: flex-start;
  }

  .header-right {
    width: 100%;
    justify-content: flex-end;
  }

  .form-row {
    flex-direction: column;
    gap: 0;
  }

  .modal-card {
    padding: 20px;
  }

  .app-footer {
    flex-direction: column;
  }
}