:root {
  --font-family-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: var(--font-family-primary);
}

body {
    background: #dfe6fb;
    line-height: 1.6;
}

header {
    background: #4a53fe;
    color: #fff;
    padding: 20px 0;
    text-align: left;
    width: 100%;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.task {
    background: #ffffff;
    padding: 20px;
    border-radius: 10px;
    margin: 30px 0;
    max-width: 500px;
    display: inline-block;
}

.input-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.task_title {
    font-size: 1.5rem;
    margin-bottom: 15px;
    font-weight: 600;
    color: #333;
}

.task_input {
    flex: 1;
    padding: 12px 15px;
    border: 1px solid #ccc;
    border-radius: 8px;
    font-size: 16px;
}

.task_input::placeholder {
    color: #999;
}

.task_button {
    padding: 12px 20px;
    background: #4a53fe;
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
}

.task_button:hover {
    background: #3b44cc;
    transform: scale(1.05);
    transition: 0.3s;
}

.board_container {
    display: flex;
    gap: 20px;
    margin: 30px 0;
    width: 100%;
}

.backlog_column, .progress_column, .ready_column, .del_column {
    flex: 1;
    border-radius: 10px;
}

.backlog_column h3, .progress_column h3, .ready_column h3, .del_column h3 {
    display: inline-block;
    margin: 0 0 15px 0;
    padding: 12px 20px;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
}

.task-list {
    list-style: none;
    padding-left: 0;
    margin: 0 0 10px 0;
    min-height: 100px;
}

.task_card {
    background-color: #ffffff;
    padding: 12px 15px;
    margin: 8px 0;
    border-radius: 8px;
    border-left: 4px solid #e0e0e0;
    cursor: pointer;
    transition: 0.3s;
    font-size: 18px;
    font-weight: 500;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.task_card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.backlog_column h3 { 
    background-color: #b0b0b0; 
    color: #333;
}

.backlog_column .task_card { 
    border-left: 4px solid #b0b0b0;
}

.progress_column h3 { 
    background-color: #8fa1fd;
    color: #0021c2;
}

.progress_column .task_card { 
    border-left: 4px solid #8fa1fd;
}

.ready_column h3 { 
    background-color: #adfac4;
    color: #009f3a;
}

.ready_column .task_card { 
    border-left: 4px solid #adfac4;
}

.del_column h3 { 
    background-color: #ff8b8b;
    color: #b60000;
}

.del_column .task_card { 
    border-left: 4px solid #ff8b8b;
}

.del_column button {
    background-color: #fd2525;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 16px 20px;
    font-size: 16px;
    cursor: pointer;
    width: 100%;
    display: block;
    min-width: 300px;
}

.del_column button:hover {
    transform: scale(1.05);
    transition: 0.5s;
}

header h1 {
    font-size: 2rem;
    margin: 0;
}