body {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #0f172a;
    font-family: 'Inter', Arial, sans-serif;
    color: #e2e8f0;
}
.back {
    position: absolute;
    top: 1.25rem; left: 1.25rem;
    color: #64ffda;
    font-family: 'JetBrains Mono', monospace;
    font-size: .85rem;
    text-decoration: none;
}
.back:hover { text-decoration: underline; }

.todo-container {
    background-color: #1e293b;
    padding: 24px;
    border-radius: 12px;
    border: 1px solid #334155;
    box-shadow: 0 10px 30px -10px rgba(0,0,0,.6);
    width: 400px;
    max-width: calc(100% - 2rem);
}
h1 {
    text-align: center;
    font-size: 22px;
    margin: 0 0 20px;
    color: #e2e8f0;
    letter-spacing: -.01em;
}
.input-section {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}
#taskInput {
    flex: 1;
    padding: 12px;
    font-size: 15px;
    background: #0f172a;
    color: #e2e8f0;
    border: 1px solid #334155;
    border-radius: 8px;
    outline: none;
    transition: border-color .2s;
}
#taskInput:focus { border-color: #64ffda; }
#taskInput::placeholder { color: #64748b; }

#addTaskBtn {
    padding: 12px 20px;
    font-size: 15px;
    font-weight: 600;
    background-color: #64ffda;
    color: #0f172a;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color .2s;
}
#addTaskBtn:hover { background-color: #4de0c0; }

.task-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.task-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px;
    border-radius: 8px;
    background: #0f172a;
    margin-bottom: 8px;
    border: 1px solid transparent;
    transition: border-color .2s;
}
.task-item:hover { border-color: #334155; }

.task-item.completed span {
    text-decoration: line-through;
    color: #64748b;
}
.task-item input[type="checkbox"] {
    accent-color: #64ffda;
    width: 18px; height: 18px;
    cursor: pointer;
    flex-shrink: 0;
}
.task-item span {
    flex: 1;
    font-size: 15px;
    word-break: break-word;
}
.task-item button {
    padding: 6px 12px;
    background-color: transparent;
    color: #f87171;
    border: 1px solid #f87171;
    border-radius: 6px;
    cursor: pointer;
    font-size: 13px;
    transition: all .2s;
    flex-shrink: 0;
}
.task-item button:hover {
    background-color: #f87171;
    color: #0f172a;
}

.task-count {
    text-align: center;
    font-size: 13px;
    color: #64748b;
    margin: 12px 0 0;
    font-family: 'JetBrains Mono', monospace;
    min-height: 1em;
}