:root {
    --primary-color: #007bff;
    --border-color: #ddd;
    --background-color: #f4f7f6;
    --column-background: #e9ecef;
    --card-background: #fff;
    --text-color: #333;
    --text-muted: #888;
    --success-color: #4CAF50;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --flagged-background: #fff3cd;
}

body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif; 
    margin: 0; 
    background-color: var(--background-color);
    color: var(--text-color);
}

/* --- Navigation --- */
nav { background: var(--card-background); padding: 0.8em 2em; box-shadow: 0 2px 4px rgba(0,0,0,0.05); display: flex; justify-content: space-between; align-items: center; }
.nav-brand { font-weight: bold; font-size: 1.2em; color: var(--primary-color); text-decoration: none; }
.nav-user { display: flex; align-items: center; gap: 1em; }
.nav-user span { color: var(--text-muted); }
.nav-user a { color: var(--primary-color); text-decoration: none; }
.admin-link { font-weight: bold; border: 1px solid var(--warning-color); padding: 5px 10px; border-radius: 5px; }
.admin-link:hover { background-color: #fff9e8; }

/* --- Main Layout & Board --- */
.centered-column { max-width: 1400px; margin: 2em auto; padding: 0 1em; }
.board-container { display: flex; gap: 20px; align-items: flex-start; }
.board-column { flex: 1; background-color: var(--column-background); border-radius: 8px; padding: 15px; min-width: 300px; }
.board-column h2 { margin-top: 0; padding-bottom: 10px; border-bottom: 2px solid #ccc; font-size: 1.2em; }
.task-list { min-height: 100px; display: flex; flex-direction: column; gap: 10px; }

/* --- General Input Styling --- */
input[type="text"], input[type="password"], input[type="number"], select, .form-control {
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 5px;
    font-size: 0.9em;
    transition: border-color 0.2s;
}
input:focus, select:focus { outline: none; border-color: var(--primary-color); }

/* --- Filter Controls --- */
.filter-controls { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 15px; align-items: center; }
.filter-controls input[type="text"] { flex-grow: 1; }
.filter-checkbox { display: flex; align-items: center; gap: 5px; font-size: 0.9em; color: var(--text-muted); }

/* --- Task Card --- */
.task-card { background-color: var(--card-background); border: 1px solid var(--border-color); border-radius: 8px; padding: 12px; display: flex; flex-direction: column; gap: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.05); }
.task-flagged { background-color: var(--flagged-background); border-left: 5px solid var(--warning-color); }
.task-header { display: flex; justify-content: space-between; align-items: center; font-size: 0.9em; color: var(--text-muted); }
.task-content p { margin: 0; word-break: break-word; }
.task-content small { color: var(--text-muted); font-size: 0.8em; }

/* --- Task Card Footer & Actions --- */
.task-footer { display: flex; justify-content: space-between; align-items: center; border-top: 1px solid #eee; padding-top: 8px; margin-top: 8px; flex-wrap: wrap; gap: 10px; }
.task-owner-info { display: flex; flex-direction: column; gap: 4px; font-size: 0.85em; }
.task-owner-info a { color: var(--primary-color); text-decoration: none; }
.claimed-by { font-weight: bold; color: var(--danger-color); }
.task-action-wrapper { text-align: right; }
.task-action-wrapper form { display: flex; gap: 8px; align-items: center; justify-content: flex-end; }
.task-action-wrapper form:not(:first-child) { margin-top: 8px; }

/* --- Buttons & Forms --- */
button { background-color: var(--primary-color); color: white; border: none; padding: 8px 12px; border-radius: 5px; cursor: pointer; font-size: 0.9em; white-space: nowrap; transition: background-color 0.2s; }
button:disabled { background-color: #a0a0a0; cursor: not-allowed; }
button:hover:not(:disabled) { background-color: #0056b3; }
.btn-secondary { background-color: #6c757d; }
.btn-secondary:hover:not(:disabled) { background-color: #5a6268; }
.btn-danger { background-color: var(--danger-color); }
.btn-danger:hover { background-color: #c82333; }
.btn-delete-task { background: none; border: none; color: var(--text-muted); font-size: 1.5em; font-weight: bold; cursor: pointer; padding: 0 5px; line-height: 1; }
.btn-delete-task:hover { color: var(--danger-color); }
.complete-form input[type="file"] { font-size: 0.85em; max-width: 150px; }
.upload-status { font-size: 0.9em; color: var(--primary-color); }
.no-proof-form { display: inline-block; }

/* --- Notes Section --- */
.notes-details { margin-top: 10px; font-size: 0.9em; }
.notes-details summary { cursor: pointer; font-weight: bold; color: var(--text-muted); }
.notes-textarea { width: 100%; box-sizing: border-box; margin-top: 5px; padding: 8px; border: 1px solid #ddd; border-radius: 5px; min-height: 80px; font-family: inherit; resize: vertical; }

/* --- Flash Messages --- */
.flash { padding: 1em; margin-bottom: 1em; border-radius: 5px; background-color: #e0f7fa; border: 1px solid #b2ebf2; }

/* --- Admin & Login --- */
.admin-section, .login-form { background-color: var(--card-background); padding: 2em; border-radius: 8px; border: 1px solid var(--border-color); margin-bottom: 2em; }
.user-list { display: flex; flex-direction: column; gap: 10px; }
.user-item { display: flex; justify-content: space-between; align-items: center; }
.create-user-form { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.login-form .form-group { display: flex; flex-direction: column; margin-bottom: 1em; }
.create-user-form input[type="text"], .create-user-form input[type="password"],
.login-form input { flex-grow: 1; width: 100%; box-sizing: border-box; }

.notification-controls {
    margin-bottom: 1em;
    padding: 1em;
    background-color: var(--card-background);
    border-radius: 8px;
    text-align: center;
}

/* Toast Notification for in-page feedback */
.toast-notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: #28a745;
    color: white;
    padding: 15px 20px;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    z-index: 1000;
    opacity: 0;
    transform: translateY(-20px);
    transition: all 0.3s ease-in-out;
}
.toast-notification.show {
    opacity: 1;
    transform: translateY(0);
}