* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    --bg-app: #f5f5f5;
    --bg-card: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #888888;
    --border: rgba(0,0,0,0.08);
    --shadow: rgba(0,0,0,0.06);
    --header-shadow: rgba(0,0,0,0.05);

    --accent-red: #e84040;
    --accent-blue: #4a90e2;
    --accent-yellow: #f5a623;
    --accent-green: #2ecc71;
    --accent-purple: #9b59b6;
}

[data-theme="dark"] {
    --bg-app: #1a1a1a;
    --bg-card: #2a2a2a;
    --text-primary: #f0f0f0;
    --text-secondary: #666666;
    --border: rgba(255,255,255,0.08);
    --shadow: rgba(0,0,0,0.3);
    --header-shadow:rgba(255, 255, 255, 0.1);
}

/* COLOR CATEGORY */
.category[data-color="red"] {border-left: 4px solid var(--accent-red); }
.category[data-color="blue"] {border-left: 4px solid var(--accent-blue); }
.category[data-color="yellow"] {border-left: 4px solid var(--accent-yellow); }
.category[data-color="green"] {border-left: 4px solid var(--accent-green); }
.category[data-color="purple"] {border-left: 4px solid var(--accent-purple); }

.category[data-color="red"] .category-name {color: var(--accent-red); }
.category[data-color="blue"] .category-name {color: var(--accent-blue); }
.category[data-color="yellow"] .category-name{color: var(--accent-yellow); }
.category[data-color="green"] .category-name{color: var(--accent-green); }
.category[data-color="purple"] .category-name{color: var(--accent-purple); }

.category[data-color="red"]    .progress-bar-fill { background-color: var(--accent-red); }
.category[data-color="blue"]   .progress-bar-fill { background-color: var(--accent-blue); }
.category[data-color="yellow"] .progress-bar-fill { background-color: var(--accent-yellow); }
.category[data-color="green"]  .progress-bar-fill { background-color: var(--accent-green); }
.category[data-color="purple"] .progress-bar-fill { background-color: var(--accent-purple); }

.category[data-color="red"]    .add-habit-btn { color: var(--accent-red); }
.category[data-color="blue"]   .add-habit-btn { color: var(--accent-blue); }
.category[data-color="yellow"] .add-habit-btn { color: var(--accent-yellow); }
.category[data-color="green"]  .add-habit-btn { color: var(--accent-green); }
.category[data-color="purple"] .add-habit-btn { color: var(--accent-purple); }

.category[data-color="red"] .habit-checkbox:checked { background-color: var(--accent-red); }
.category[data-color="blue"] .habit-checkbox:checked { background-color: var(--accent-blue); }
.category[data-color="yellow"] .habit-checkbox:checked { background-color: var(--accent-yellow); }
.category[data-color="green"] .habit-checkbox:checked { background-color: var(--accent-green); }
.category[data-color="purple"] .habit-checkbox:checked { background-color: var(--accent-purple); }
/* GENERAL */
body {
    background-color: var(--bg-app);
    color: var(--text-primary);
    min-height: 100vh;
    transition: background-color 0.2s ease;
    -webkit-font-smoothing: antialiased;
    font-family: 'Outfit', sans-serif;
}

#app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    padding: 12px;
}

#board {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: 860px; 
    margin: 0 auto;
    width: 100%;
    padding: 0 24px;
    margin-top: 16px;
}

.empty-state {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-top: 168px;
}

/* HEADER */
#header {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
    border-bottom: 1px solid var(--border);
    background: var(--bg-card);
    border-radius: 8px;
    box-shadow: 0px 8px 12px var(--header-shadow);
    transition: box-shadow 0.3s ease;
}

#header-title {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: color 0.2s;
}

#header-category {
    background: linear-gradient(
        to right,
         rgba(232, 64, 64, 0.85),   
        rgba(46, 204, 113, 0.85),  
        rgba(74, 144, 226, 0.85),  
        rgba(155, 89, 182, 0.85),   
        rgba(245, 166, 35, 0.85)
    );
    background-size: 100% 100%;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 16px;
    font-family: 'Outfit', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: filter 0.2s, transform 0.1s;
}

#header-buttons {
    display: flex;
    align-items: center;
    gap: 8px;
}

#header-category:hover {
    filter: brightness(1.1);
    transform: translateY(-3px);
    
}

#header-category:active {
    transform: scale(0.97);
}

 /*THEME TOGGLE */

 .theme-switch {
    position: relative;
    width: 44px;
    height: 24px;
    cursor: pointer;
 }

 .theme-switch input {
    opacity: 0;
    width: 0;
    height: 0;
 }

 .slider {
    position: absolute; 
    inset: 0;
    background-color: var(--border);
    border-radius: 99px;
    transition: background-color 0.3s ease;
 }

 .slider-icon-light {
    position: absolute;
    left: 4px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 12px;
    opacity: 1;
    transition: opacity 0.2s;
 }

 .slider-icon-dark {
    position: absolute;
    right: 4px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 12px;
    opacity: 0;
    transition: opacity 0.01s;
}

#theme-toggle:checked ~ .slider .slider-icon-light {
    opacity: 0;
}

#theme-toggle:checked ~ .slider .slider-icon-dark {
    opacity: 1;
}

.slider::before {
    content: "";
    position: absolute;
    width: 18px;
    height: 18px;
    left: 3px;
    top: 3px;
    background: white;
    border-radius: 50%;
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

#theme-toggle:checked + .slider {
    background-color: #1a1a1a;
}

#theme-toggle:checked + .slider::before {
    transform: translateX(20px);
}

/* CATEGORY CARD */
.category {
    background: var(--bg-card);
    border-radius: 8px;
    box-shadow: 0 2px 6px var(--shadow);
    overflow: hidden;
    padding: 16px;
    width: 100%;
}

.category-header {
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    padding: 6px;
    align-items: center;
}

.category-name {
    font-weight: 600;
    font-size: 1.2rem;
}

.add-habit-btn {
    border: none;
    width: 100%;
    text-align: left;
    padding: 6px;
    background: transparent;
}

/* PROGRESS BAR */

.progress-bar-track {
    height: 5px;
    background: var(--border);
    border-radius: 99px;
    margin: 2px;
    overflow: hidden;
}

.progress-bar-fill {
    border-radius: 99px;
    transition: width 0.3s ease;
    height: 100%;
}

/* HABIT ROWS */

.habit-list {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 6px 0px;
    border-bottom: 1px solid var(--border);
}

.habit-row:last-child { border-bottom: none; }

.habit-row {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 0px;
    border-bottom: 1px solid var(--border);
}

.habit-name {
    flex: 1;
}

.habit-checkbox {
    appearance: none;
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 4px;
    border: 1.5px solid var(--border);
    flex-shrink: 0;
    cursor: pointer;
    transition: background-color 0.2s, border-color 0.2s;
}

.habit-checkbox:checked::after {
    content: "✓";
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 12px;
    width: 100%;
    height: 100%;
}

.habit-checkbox.checked {
    border: none;
}

.add-habit-btn {
    border: none;
    width: 100%;
    text-align: left;
    padding: 6px;
    background: transparent;
    font-family: 'Outfit', sans-serif;
}

.empty-habits {
    font-size:0.9rem;
    margin-top: 8px;
    opacity: 0.6;
}


/* MODAL */

#modal-overlay, #confirm-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.4);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
}

#modal {
    background: var(--bg-card);
    border-radius: 18px;
    padding: 32px;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

#modal-heading {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

#modal-cancel {
    background: var(--bg-app);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 8px 16px;
    font-family: 'Outfit', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

#modal-save {
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 16px;
    font-family: 'Outfit', sans-serif;
    font-size: 0.85rem;
    cursor: pointer;
    transition: opacity 0.2s;
}

#modal-buttons, #confirm-buttons {
    display: flex;
    justify-content: flex-end;
    gap: 16px;
}

#modal-input {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--bg-app);
    color: var(--text-primary);
    font-family: 'Outfit', sans-serif;
    font-size: 0.9rem;
    outline: none;
    transition: border-color 0.2s;
}

#modal-input:focus {
    border-color: var(--focus-color);
    box-shadow: 0 0 0 4px color-mix(in srgb, var(--focus-color) 20%, transparent);
}


#confirm-modal {
    background: var(--bg-card);
    border-radius:18px;
    padding: 24px;
    max-width: 400px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

#confirm-heading {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

#confirm-cancel {
    background: var(--bg-app);
    color: var(--text-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 8px 16px;
    font-family: 'Outfit', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

#confirm-delete {
    background: #dc2626;
    color: white;
    border: none;
    border-radius: 8px;
    padding: 8px 16px;
    font-family: 'Outfit', sans-serif;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

#confirm-message {
    font-size: 0.85rem;
    color: var(--text-primary);
}

/* BUTTON */

.delete-btn, .delete-habit-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.85rem;
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.2s;
}

.delete-btn svg {
    width: 18px;
    height: 18px;
}

.category:hover .delete-btn,
.habit-row:hover .delete-habit-btn {
    opacity: 0.7;
}


.hidden {
    display: none !important;
}

/* ANIMATION */

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-16px);
    } 
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes overlayFadeIn {
    from {background: rgba(0,0,0,0); }
    to { background: rgba(0,0,0,0.4); }
}

@keyframes modalAppear {
    from {opacity: 0; transform: scale(0.96) translateY(-8px); }
    to {opacity: 1; transform: scale(1) translateY(0); }
}

@keyframes elementFadeIn {
    from {opacity: 0; transform: translateY(6px); }
    to {opacity: 1; transform: translateY(0); }
}

@keyframes overlayFadeOut {
    from { background: rgba(0,0,0,0.4); }
    to { background: rgba(0,0,0,0); }
}

@keyframes modalSink {
    from {opacity: 1; transform: scale(1) translateY(0); }
    to {opacity: 0; transform: scale(0.96) translateY(-8px); }
}

/* POP ANIMATION */

@keyframes popIn {
    0% { transform: scale(0.8); opacity: 0; }
    60% { transform: scale(1.04); opacity: 1; }
    100% { transform: scale(1); opacity: 1;}
}

@keyframes popOut {
    0% { transform: scale(1); opacity: 1; }
    30% { transform: scale(1.04); }
    100% { transform: scale(0.8); opacity: 0; }
}

.pop-in {
    animation: popIn 0.3s cubic-bezier(0.34,1.56,0.64,1) forwards !important;
}

.pop-out {
    animation: popOut 0.25s ease forwards !important;
}

/* FOR MODAL ANIMATION*/
#modal-overlay.open {
    animation: overlayFadeIn 0.2s ease forwards;
}

#modal-overlay.open #modal {
    animation: modalAppear 0.25s ease 0.2s both;
}

#modal-overlay.open #modal > * {
    animation: elementFadeIn 0.2s ease both;
}

#modal-overlay.open #modal > *:nth-child(1) {animation-delay: 0.26s; }
#modal-overlay.open #modal > *:nth-child(2) {animation-delay: 0.32s; }
#modal-overlay.open #modal > *:nth-child(3) {animation-delay: 0.40s; }

#modal-overlay.closing {
    animation: overlayFadeOut 0.3s ease forwards;
}

#modal-overlay.closing #modal {
    animation: modalSink 0.25s ease forwards;
}


/* CONFIRM ANIMATION */
#confirm-overlay.open {
    animation: overlayFadeIn 0.5s ease forwards;
}

#confirm-overlay.open #confirm-modal {
    animation: modalAppear 0.25s ease 0.1s both;
}

#confirm-overlay.open #confirm-modal > * {
    animation: elementFadeIn 0.2s ease both;
}

#confirm-overlay.open #confirm-modal > *:nth-child(1) { animation-delay: 0.26s; }
#confirm-overlay.open #confirm-modal > *:nth-child(2) { animation-delay: 0.32s; }
#confirm-overlay.open #confirm-modal > *:nth-child(3) { animation-delay: 0.40s; }

#confirm-overlay.closing {
    animation: overlayFadeOut 0.3s ease forwards;
}

#confirm-overlay.closing #confirm-modal {
    animation: modalSink 0.25s ease forwards;
}