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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
    min-height: 100vh;
    padding: 20px;
    color: #e2e8f0;
    user-select: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    color: #f7fafc;
    font-size: 2.5rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.input-section {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    justify-content: center;
}

#noteInput {
    padding: 12px 20px;
    border: none;
    border-radius: 25px;
    width: 300px;
    font-size: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    background: rgba(255, 255, 255, 0.9);
}

#addNoteBtn {
    padding: 12px 25px;
    background: #e53e3e;
    color: white;
    border: none;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    box-shadow: 0 4px 6px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
}

#addNoteBtn:hover {
    background: #c53030;
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(0,0,0,0.3);
}

.categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
}

.category {
    background: rgba(45, 55, 72, 0.8);
    border-radius: 15px;
    padding: 20px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    min-height: 300px;
    transition: all 0.3s ease;
}

.category h2 {
    text-align: center;
    margin-bottom: 20px;
    color: #f7fafc;
    font-size: 1.5rem;
}

.notes-list {
    min-height: 200px;
}

.note {
    background: rgba(26, 32, 44, 0.8);
    border-radius: 10px;
    padding: 15px;
    margin-bottom: 15px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    transition: all 0.3s ease;
    position: relative;
    border-left: 4px solid #63b3ed;
    cursor: grab;
    transform: translate(0, 0);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.note:active {
    cursor: grabbing;
    transform: scale(1.02);
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

.note:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

.note-text {
    margin-bottom: 10px;
    word-wrap: break-word;
}

.note-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
}

.btn {
    padding: 6px 12px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.2s ease;
}

.btn-delete {
    background: #e53e3e;
    color: white;
}

.btn-delete:hover {
    background: #c53030;
    transform: scale(1.05);
}

#todo .note {
    border-left-color: #4fd1c5;
}

#doing .note {
    border-left-color: #f6e05e;
}

#finished .note {
    border-left-color: #68d391;
}

.dragging {
    opacity: 0.8;
    transform: rotate(3deg) scale(1.03);
    transition: transform 0.2s ease, opacity 0.2s ease;
    z-index: 1000;
    box-shadow: 0 8px 20px rgba(0,0,0,0.4);
}

.drag-over {
    background: rgba(74, 85, 104, 0.8);
    border-radius: 10px;
    transform: scale(1.02);
}

.drag-placeholder {
    background: rgba(74, 85, 104, 0.5);
    border: 2px dashed #a0aec0;
    border-radius: 10px;
    height: 60px;
    margin-bottom: 15px;
}

.drag-mirror {
    position: fixed;
    top: 0;
    left: 0;
    pointer-events: none;
    z-index: 9999;
    filter: drop-shadow(0 8px 20px rgba(0,0,0,0.4));
    opacity: 0.95;
    transform: translate3d(0,0,0);
    transition: none;
}

.drag-mirror .note {
    transform: rotate(3deg) scale(1.03);
}