:root {
    --app-bg: #050815;
    --app-bg-alt: #0b1220;
    --glass-bg: rgba(15, 23, 42, 0.55);
    --glass-hover: rgba(30, 41, 59, 0.68);
    --glass-border: rgba(148, 163, 184, 0.22);
    --glass-border-strong: rgba(148, 163, 184, 0.4);
    --text-primary: #e2e8f0;
    --text-secondary: #94a3b8;
    --accent-purple: #8b5cf6;
    --accent-cyan: #22d3ee;
    --accent-rose: #f472b6;
    --accent-green: #34d399;
    --task-bg: rgba(148, 163, 184, 0.1);
    --task-border: rgba(99, 102, 241, 0.55);
    --drag-over: rgba(79, 70, 229, 0.25);
    --input-bg: rgba(15, 23, 42, 0.7);
    --input-border: rgba(148, 163, 184, 0.35);
    --shadow-strong: rgba(2, 8, 33, 0.75);
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

html,
body {
    height: 100%;
}

.app-body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, var(--app-bg), var(--app-bg-alt));
    color: var(--text-primary);
    margin: 0;
    min-height: 100%;
    padding: clamp(1.5rem, 5vw, 4rem) clamp(1rem, 4vw, 3rem);
    position: relative;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    overflow-x: hidden;
}

.app-body::before {
    content: '';
    position: fixed;
    inset: -20%;
    background:
        radial-gradient(circle at 20% 15%, rgba(139, 92, 246, 0.55), transparent 60%),
        radial-gradient(circle at 80% 0%, rgba(56, 189, 248, 0.4), transparent 55%),
        radial-gradient(circle at 50% 95%, rgba(236, 72, 153, 0.35), transparent 62%);
    opacity: 0.75;
    transform: translate3d(0, 0, 0) scale(1);
    animation: auroraDrift 28s ease-in-out infinite alternate;
    pointer-events: none;
    z-index: -2;
}

.app-body::after {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(circle at 18% 32%, rgba(255, 255, 255, 0.08), transparent 35%),
        radial-gradient(circle at 82% 72%, rgba(148, 163, 184, 0.08), transparent 40%);
    opacity: 0.45;
    mix-blend-mode: screen;
    animation: pulseGlow 16s ease-in-out infinite alternate;
    pointer-events: none;
    z-index: -1;
}

@keyframes auroraDrift {
    0% {
        transform: translate3d(-3%, -2%, 0) scale(1.05);
    }
    50% {
        transform: translate3d(3%, 2%, 0) scale(1.08);
    }
    100% {
        transform: translate3d(-2%, 4%, 0) scale(1.03);
    }
}

@keyframes pulseGlow {
    0% {
        opacity: 0.28;
        transform: scale(1);
    }
    50% {
        opacity: 0.55;
        transform: scale(1.06);
    }
    100% {
        opacity: 0.38;
        transform: scale(1.1);
    }
}

.app-shell {
    width: min(1100px, 100%);
    display: flex;
    flex-direction: column;
    gap: clamp(1.25rem, 3vw, 2.5rem);
    position: relative;
    z-index: 1;
}

.glass-panel {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 1.2rem;
    box-shadow: 0 25px 45px -35px var(--shadow-strong);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    transition: transform 0.35s ease, box-shadow 0.35s ease, background 0.35s ease, border-color 0.35s ease;
}

.glass-panel:hover {
    background: var(--glass-hover);
    border-color: var(--glass-border-strong);
    transform: translateY(-4px);
    box-shadow: 0 30px 60px -30px rgba(2, 8, 33, 0.85);
}

.app-header {
    text-align: center;
    padding: clamp(1.75rem, 4vw, 2.75rem);
    position: relative;
    overflow: hidden;
}

.app-header::after {
    content: '';
    position: absolute;
    inset: 1.5px;
    border-radius: inherit;
    border: 1px solid rgba(148, 163, 184, 0.2);
    pointer-events: none;
}

.app-header.glass-panel:hover {
    transform: none;
    box-shadow: 0 25px 45px -35px var(--shadow-strong);
}

.app-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    letter-spacing: 0.08em;
    margin: 0;
}

.app-subtitle {
    margin: 0.9rem auto 0;
    color: var(--text-secondary);
    max-width: 32rem;
    line-height: 1.6;
}

.task-form {
    padding: clamp(1.5rem, 4vw, 2.5rem);
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.form-heading {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.section-title {
    margin: 0;
    font-size: clamp(1.25rem, 3vw, 1.5rem);
}

.section-subtitle {
    margin: 0;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.input-label {
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 0.25rem;
}

.task-input {
    width: 100%;
    border: 1px solid var(--input-border);
    background: var(--input-bg);
    color: var(--text-primary);
    padding: 0.95rem 1rem;
    border-radius: 0.9rem;
    transition: border-color 0.3s ease, box-shadow 0.3s ease, background 0.3s ease;
}

.task-input::placeholder {
    color: rgba(148, 163, 184, 0.65);
}

.task-input:focus {
    outline: none;
    border-color: rgba(129, 140, 248, 0.55);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.25);
    background: rgba(15, 23, 42, 0.85);
}

.error-message {
    color: #fb7185;
    font-size: 0.85rem;
    margin-top: -0.35rem;
}

.add-task-btn {
    border: none;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.9), rgba(168, 85, 247, 0.95));
    color: var(--text-primary);
    font-weight: 600;
    padding: 0.95rem 1rem;
    border-radius: 0.9rem;
    cursor: pointer;
    transition: transform 0.25s ease, box-shadow 0.25s ease, filter 0.25s ease;
    box-shadow: 0 17px 35px -22px rgba(129, 140, 248, 0.9);
}

.add-task-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 20px 40px -20px rgba(129, 140, 248, 0.95);
    filter: brightness(1.05);
}

.add-task-btn:active {
    transform: translateY(0);
    filter: brightness(0.95);
}

.add-task-btn:focus-visible {
    outline: 2px solid rgba(56, 189, 248, 0.85);
    outline-offset: 3px;
}

.kanban-board {
    display: grid;
    gap: clamp(1rem, 2.5vw, 1.75rem);
}

@media (min-width: 768px) {
    .kanban-board {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.kanban-column {
    padding: clamp(1.25rem, 3vw, 2rem);
    display: flex;
    flex-direction: column;
    min-height: 420px;
    position: relative;
}

.kanban-column::before {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    border: 1px solid rgba(148, 163, 184, 0.12);
    pointer-events: none;
}

.kanban-column:hover::before {
    border-color: rgba(148, 163, 184, 0.25);
}

.column-title {
    margin: 0 0 1.5rem;
    font-size: 1.1rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--text-secondary);
}

.column-title--todo {
    color: rgba(129, 140, 248, 0.95);
}

.column-title--progress {
    color: rgba(56, 189, 248, 0.9);
}

.column-title--done {
    color: rgba(34, 197, 94, 0.9);
}

.kanban-column ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.85rem;
    flex: 1;
}

.task-card {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 0.75rem;
    padding: 1rem 1.15rem;
    background: var(--task-bg);
    border-radius: 1rem;
    border: 1px solid rgba(148, 163, 184, 0.18);
    border-left: 4px solid var(--task-border);
    transition: transform 0.25s ease, box-shadow 0.3s ease, border-color 0.3s ease, background 0.3s ease;
    cursor: grab;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.task-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 25px 40px -28px rgba(15, 23, 42, 0.85);
    border-color: rgba(129, 140, 248, 0.8);
    background: rgba(148, 163, 184, 0.16);
}

.task-card:active {
    cursor: grabbing;
    transform: scale(0.98);
}

.task-text {
    flex: 1;
    line-height: 1.5;
}

.delete-btn {
    border: none;
    background: rgba(15, 23, 42, 0.45);
    color: rgba(248, 250, 252, 0.72);
    border-radius: 50%;
    width: 2.25rem;
    height: 2.25rem;
    display: grid;
    place-items: center;
    font-size: 1.2rem;
    cursor: pointer;
    transition: background 0.25s ease, color 0.25s ease, transform 0.25s ease;
}

.delete-btn:hover {
    background: rgba(239, 68, 68, 0.22);
    color: #f87171;
    transform: scale(1.05);
}

.delete-btn:focus-visible {
    outline: 2px solid rgba(248, 113, 113, 0.6);
    outline-offset: 2px;
}

.task-moving {
    animation: task-move 0.3s ease;
}

@keyframes task-move {
    from {
        transform: translateY(-12px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.dragging {
    opacity: 0.55;
}

.drag-over {
    border-color: rgba(129, 140, 248, 0.45);
    box-shadow: inset 0 0 0 1px rgba(129, 140, 248, 0.25);
    background: var(--drag-over);
}

.rose-gold-accent {
    border-left-color: rgba(251, 191, 183, 0.9);
}

.done-column .task-card {
    border-left-color: rgba(74, 222, 128, 0.7);
    background: rgba(34, 197, 94, 0.12);
}

.done-column .task-card:hover {
    border-color: rgba(74, 222, 128, 0.85);
    background: rgba(34, 197, 94, 0.18);
}

@media (max-width: 768px) {
    .app-body {
        padding: clamp(1.25rem, 5vw, 2rem) clamp(0.75rem, 4vw, 1.5rem);
    }

    .glass-panel:hover {
        transform: none;
        box-shadow: 0 25px 45px -35px var(--shadow-strong);
    }

    .task-card:hover {
        transform: translateY(-2px);
    }
}

@media (prefers-reduced-motion: reduce) {
    .app-body::before,
    .app-body::after {
        animation: none;
    }

    .glass-panel,
    .task-card,
    .add-task-btn {
        transition: none;
    }

    .task-moving {
        animation: none;
    }
}

@supports not ((backdrop-filter: blur(18px)) or (-webkit-backdrop-filter: blur(18px))) {
    .glass-panel,
    .task-card {
        background: rgba(15, 23, 42, 0.88);
    }
}