:root {
    --bg-color: #f4f5f7;
    --text-color: #172b4d;
    --card-bg: #ffffff;
    --column-bg: #ebecf0;
    --header-bg: #ffffff;
    --shadow-sm: 0 1px 2px rgba(9, 30, 66, 0.25);
    
    /* Column accents */
    --col-backlog: #42526e;
    --col-todo: #0052cc;
    --col-inprogress: #00b8d9;
    --col-done: #36b37e;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    line-height: 1.5;
}

.board-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
}

header {
    background: var(--header-bg);
    padding: 1rem 2rem;
    border-bottom: 1px solid #dfe1e6;
    display: flex;
    align-items: center;
    gap: 1rem;
}

header h1 {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 600;
}

header p {
    margin: 0;
    color: #5e6c84;
    font-size: 0.9rem;
}

.board {
    display: flex;
    overflow-x: auto;
    padding: 1.5rem;
    gap: 1.5rem;
    height: 100%;
    align-items: flex-start;
}

.column {
    background-color: var(--column-bg);
    border-radius: 8px; /* Slightly more rounded */
    min-width: 300px;
    max-width: 300px;
    display: flex;
    flex-direction: column;
    max-height: calc(100vh - 100px);
}

.column h2 {
    font-size: 0.95rem;
    font-weight: 600;
    margin: 0;
    padding: 1rem 1rem 0.5rem;
    color: var(--text-color);
    border-top: 3px solid transparent;
}

/* Specific column styling */
.column.backlog h2 { border-color: var(--col-backlog); }
.column.todo h2 { border-color: var(--col-todo); }
.column.inprogress h2 { border-color: var(--col-inprogress); }
.column.done h2 { border-color: var(--col-done); }

.task-list {
    padding: 0.5rem 0.5rem;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.card {
    background: var(--card-bg);
    padding: 0.75rem;
    border-radius: 6px; /* Matching rounded corners */
    box-shadow: var(--shadow-sm);
    font-size: 0.9rem;
    transition: transform 0.1s, box-shadow 0.1s;
    cursor: default;
    border: 1px solid transparent;
}

.card:hover {
    background-color: #fafbfc;
    border-color: #dfe1e6;
}