:root {
    --bg-color: #121212;
    --container-bg: rgba(30, 30, 30, 0.6);
    --border-color: rgba(255, 255, 255, 0.1);
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --success-color: #10b981;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, #0f172a, #1e1b4b);
}

.container {
    background: var(--container-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 2.5rem;
    width: 100%;
    max-width: 500px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

h1 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    background: linear-gradient(to right, #818cf8, #c084fc);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

header p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.task-form {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

input[type="text"] {
    flex: 1;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.875rem 1.25rem;
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: all 0.3s ease;
}

input[type="text"]:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(99, 102, 241, 0.2);
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 12px;
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.1s ease;
}

.btn-primary:hover {
    background: var(--primary-hover);
}

.btn-primary:active {
    transform: scale(0.98);
}

.task-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.task-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem 1.25rem;
    transition: all 0.3s ease;
}

.task-item:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.2);
}

.task-content {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex: 1;
}

.task-checkbox {
    appearance: none;
    width: 1.25rem;
    height: 1.25rem;
    border: 2px solid var(--text-secondary);
    border-radius: 6px;
    cursor: pointer;
    position: relative;
    transition: all 0.2s ease;
}

.task-checkbox:checked {
    background-color: var(--success-color);
    border-color: var(--success-color);
}

.task-checkbox:checked::after {
    content: '';
    position: absolute;
    left: 5px;
    top: 2px;
    width: 4px;
    height: 8px;
    border: solid white;
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.task-title {
    font-size: 1rem;
    transition: color 0.3s ease;
}

.task-item.completed .task-title {
    text-decoration: line-through;
    color: var(--text-secondary);
}

.btn-delete {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-delete:hover {
    color: var(--danger-color);
    background: rgba(239, 68, 68, 0.1);
}

.disclaimer {
    position: fixed;
    bottom: 1.5rem;
    left: 0;
    right: 0;
    text-align: center;
    padding: 0 1rem;
    pointer-events: none;
    z-index: 10;
}

.disclaimer p {
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.4);
    letter-spacing: 0.5px;
}

.disclaimer strong {
    color: rgba(255, 255, 255, 0.6);
    font-weight: 500;
}