:root {
    color-scheme: light dark;
    --bg: #0f172a;
    --bg-elevated: #111c37;
    --surface: #1e293b;
    --surface-soft: #334155;
    --text: #e2e8f0;
    --text-muted: #94a3b8;
    --accent: #38bdf8;
    --accent-contrast: #082f49;
    --danger: #f87171;
    --shadow: 0 16px 40px rgba(2, 6, 23, 0.35);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: radial-gradient(circle at top left, #1d4ed8 0%, var(--bg) 45%);
    color: var(--text);
}

.app {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1rem 2.5rem;
}

.app__header {
    display: flex;
    gap: 1rem;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.eyebrow {
    margin: 0;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    font-size: 0.75rem;
    font-weight: 700;
}

h1 {
    margin: 0.2rem 0 0.4rem;
    font-size: clamp(1.6rem, 3vw, 2.2rem);
}

.subtitle {
    margin: 0;
    color: var(--text-muted);
    max-width: 50ch;
    font-size: 0.95rem;
}

.task-form {
    display: flex;
    gap: 0.6rem;
    width: min(450px, 100%);
}

.task-form input {
    flex: 1;
    border: 1px solid transparent;
    border-radius: 0.8rem;
    padding: 0.8rem 0.95rem;
    background: rgba(148, 163, 184, 0.15);
    color: var(--text);
    outline: none;
    transition: border-color 0.2s ease, background 0.2s ease;
}

.task-form input:focus {
    border-color: var(--accent);
    background: rgba(148, 163, 184, 0.2);
}

.task-form button {
    border: 0;
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    border-radius: 0.8rem;
    padding: 0.8rem 1rem;
    background: linear-gradient(135deg, #0ea5e9, #2563eb);
    color: white;
    font-weight: 600;
    cursor: pointer;
}

.kanban {
    display: grid;
    grid-template-columns: repeat(3, minmax(240px, 1fr));
    gap: 1rem;
}

.column {
    background: rgba(15, 23, 42, 0.55);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(148, 163, 184, 0.2);
    border-radius: 1rem;
    padding: 0.85rem;
    box-shadow: var(--shadow);
    min-height: 420px;
    display: flex;
    flex-direction: column;
}

.column__header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.8rem;
}

.column h2 {
    margin: 0;
    font-size: 1rem;
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
}

.column h2 .bi {
    color: var(--accent);
}


.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 1.8rem;
    padding: 0.2rem 0.5rem;
    border-radius: 999px;
    background: var(--surface-soft);
    color: var(--text);
    font-size: 0.75rem;
    font-weight: 600;
}

.task-list {
    display: grid;
    gap: 0.65rem;
    min-height: 300px;
    align-content: start;
    padding-bottom: 0.25rem;
}

.task {
    background: var(--surface);
    border-radius: 0.8rem;
    border: 1px solid transparent;
    display: flex;
    gap: 0.6rem;
    justify-content: space-between;
    align-items: flex-start;
    padding: 0.75rem 0.8rem;
    cursor: grab;
}

.task.dragging {
    opacity: 0.35;
    border-color: var(--accent);
}

.task__text {
    margin: 0;
    line-height: 1.35;
    word-break: break-word;
}

.task__delete {
    border: 0;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1;
    cursor: pointer;
}

.task__delete:hover {
    color: var(--danger);
}

.column.dropzone {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.25), var(--shadow);
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

@media (max-width: 900px) {
    .kanban {
        grid-template-columns: 1fr;
    }

    .column {
        min-height: 240px;
    }
}