/* ============================================
   RESET & BASE STYLES
   ============================================ */

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

   :root{
    --primary-color: #3B82F6;
    --success-color: #10B981;
    --danger-color: #EF4444;
    --bg-color: #F3F4F6;
    --card-bg: #FFFFFF;
    --text-primary: #1F2937;
    --text-secondary: #6B7280;
    --border-color: #E5E7EB;
    --shadow: 0 10px 30px rgba(0,0,0,0.1);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.15);

    /* spacing  */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* radius  */
    --radius-sm: 0.375rem;
    --radius-md:0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* transition  */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
   }

   body{
    font-family: 'Segoe UI', Tahoma, Verdana, Geneva, sans-serif;
    background: var(--bg-color);
    min-height: 100vh;
    padding: var(--spacing-md);
    color: var(--text-primary);
    transition: var(--transition);
   }

   /* ============================================
   CONTAINER
   ============================================ */
   .container{
    max-width: 1200px;
    margin: 0 auto;
    animation: fadeIn 0.6s ease;
   }

   @keyframes fadeIn{
    from{

        opacity: 0;
        transform: translateY(20px);
    } to{
        opacity: 1;
        transform: translateY(0);
    }
   }

   /* ============================================
   HEADER
   ============================================ */

   header{
    text-align: center;
    margin-bottom: var(--spacing-lg);
   }

   header h1{
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-xs);
   }

   .subtitle{
    color: var(--text-secondary);
    font-size: 1.1rem;
   }

   /* ============================================
   TABS NAVIGATION
   ============================================ */
   .tabs{
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
    background: var(--card-bg);
    padding: var(--spacing-xs);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
   }

   .tab-btn{
    flex:1;
    padding: var(--spacing-sm) var(--spacing-md);
    background: transparent;
    border: none;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    font-size: 0.95rem;
    font-weight: 600;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-xs);
   }

   .tab-btn:hover{
    background: var(--bg-color);
    color: var(--text-primary);
   }

   .tab-btn.active{
    background: var(--primary-color);
    color: #FFFFFF;
   }

   /* ============================================
   MODE CONTENT
   ============================================ */
   .mode-content{
    display: none;
    animation: slideIn 0.4s ease;
   }

   .mode-content.active{
    display: block;
   }

   @keyframes slideIn {
    from{
        opacity: 0;
        transform: translateX(-20px);
    }
    to{
        opacity: 1;
        transform: translateX(0);
    }
   }

   /* ============================================
   SINGLE COLOR MODE
   ============================================ */
   .color-display{
    background: var(--bg-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-lg);
    transition: var(--transition);
   }

   .color-info{
    text-align: center;
    padding: var(--spacing-xl) 0;
   }

   .color-name{
    font-size: 2.5rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
   }

   .color-codes{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
   }

   .code-item{
    background: var(--bg-color);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
   }

   .code-item label{
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
   }

   .code-value{
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-sm);
   }

   .code-value span{
    font-family: 'Courier New', monospace;
    font-size: 1.1rem;
    color: var(--text-primary);
    font-weight: 600;
   }

   .copy-btn{
    background: var(--primary-color);
    color: #FFFFFF;
    border: none;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
   }

   .copy-btn:hover{
    background: #2563Eb;
    transform: scale(1.05);
   }

   /* ============================================
   ACTIONS
   ============================================ */
   .actions{
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
   }

   .btn{
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
   }

   .btn-primary{
    background: var(--primary-color);
    color: #FFFFFF;
   }

   .btn-primary:hover{
    background: #2563EB;
    transform: translateY(-2px);
    box-shadow: var(--shadow);
   }

   .btn-success{
    background: var(--success-color);
    color: #FFFFFF;
   }

   .btn-success:hover{
    background: #059669;
    transform: translateY(-2px);
   }

   .btn-secondary{
    background: var(--text-secondary);
    color: #FFFFFF;
   }

   .btn-secondary:hover{
    background: #4B5563;
    transform: translateY(-2px);
   }

   .btn-danger{
    background: var(--danger-color);
    color: #FFFFFF;
   }

   .btn-danger:hover{
    background: #DC2626;
    transform: translateY(-2px);
   }

   /* ============================================
   SHADES & TINTS
   ============================================ */
   .shades-section{
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-lg);
    border-top: 2px solid var(--border-color);
   }

   .shades-section h3{
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
   }

   .shades-grid{
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(80px, 1fr));
    gap: var(--spacing-sm);
   }

   .shade-box{
    aspect-ratio: 1;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
   }

   .shade-box:hover{
    transform: scale(1.05);
    box-shadow: var(--shadow);
   }

   .shade-box::after{
    content: attr(data-color);
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.7);
    color: #FFFFFF;
    padding: var(--spacing-xs);
    font-size: 0.7rem;
    text-align: center;
    opacity: 0;
    transition: var(--transition);
   }

   .shade-box::after:hover{
    opacity: 1;
   }

   /* ============================================
   PALETTE MODE
   ============================================ */

   .palette-controls{
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
    align-items: flex-end;
   }

   .control-group{
    flex: 1;
    min-width: 200px;
   }

   .control-group label{
    display: block;
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
    color: var(--text-primary);
   }

   .select-input{
    width: 100%;
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    background: var(--card-bg);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
   }

   .select-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.palette-display {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.color-card {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.color-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.color-box {
    height: 200px;
    position: relative;
    transition: var(--transition);
}

.lock-btn {
    position: absolute;
    top: var(--spacing-sm);
    right: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.9);
    border: none;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.lock-btn:hover {
    background: white;
    transform: scale(1.1);
}

.lock-btn.locked {
    background: var(--primary-color);
    color: white;
}

.color-card-info {
    padding: var(--spacing-sm);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.color-hex {
    font-family: 'Courier New', monospace;
    font-weight: 600;
    color: var(--text-primary);
}

.copy-btn-small {
    background: var(--bg-color);
    border: none;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
}

.copy-btn-small:hover {
    background: var(--primary-color);
    color: white;
}

.palette-info {
    margin-top: var(--spacing-lg);
}

.info-card {
    background: #EEF2FF;
    border-left: 4px solid var(--primary-color);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    display: flex;
    gap: var(--spacing-sm);
    align-items: flex-start;
}

.info-card i {
    color: var(--primary-color);
    margin-top: 0.2rem;
}

kbd {
    background: var(--card-bg);
    padding: 0.2rem 0.5rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    font-family: monospace;
    font-size: 0.9rem;
}

/* ============================================
   GRADIENT MODE
   ============================================ */
.gradient-display {
    background: var(--card-bg);
    border-radius: var(--radius-xl);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow);
}

.gradient-preview {
    height: 300px;
    border-radius: var(--radius-lg);
    background: linear-gradient(to right, #3B82F6, #8B5CF6, #EC4899);
    transition: var(--transition);
}

.gradient-controls {
    background: var(--card-bg);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow);
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.gradient-color-inputs {
    display: flex;
    gap: var(--spacing-sm);
}

.gradient-color-inputs input[type="color"] {
    width: 60px;
    height: 60px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
}

.gradient-code {
    background: var(--card-bg);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
}

.gradient-code label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--text-primary);
}

.code-display {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #1F2937;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    gap: var(--spacing-sm);
}

.code-display code {
    color: #10B981;
    font-family: 'Courier New', monospace;
    flex: 1;
    overflow-x: auto;
}

/* ============================================
   FAVORITES MODE
   ============================================ */
.favorites-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.favorites-header h2 {
    color: var(--text-primary);
}

.favorites-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: var(--spacing-md);
}

.favorite-item {
    aspect-ratio: 1;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    box-shadow: var(--shadow);
}

.favorite-item:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-lg);
}

.favorite-item::after {
    content: attr(data-color);
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: rgba(0, 0, 0, 0.8);
    color: white;
    padding: var(--spacing-xs);
    font-size: 0.8rem;
    text-align: center;
    font-family: 'Courier New', monospace;
    opacity: 0;
    transition: var(--transition);
}

.favorite-item:hover::after {
opacity: 1;
}
.empty-message {
text-align: center;
color: var(--text-secondary);
padding: var(--spacing-xl);
font-style: italic;
grid-column: 1 / -1;
}
/* ============================================
TOAST NOTIFICATION
============================================ */
.toast {
position: fixed;
bottom: 2rem;
right: 2rem;
background: var(--text-primary);
color: white;
padding: var(--spacing-md) var(--spacing-lg);
border-radius: var(--radius-lg);
box-shadow: var(--shadow-lg);
display: flex;
align-items: center;
gap: var(--spacing-sm);
transform: translateY(150%);
transition: transform 0.3s ease;
z-index: 1000;
}
.toast.show {
transform: translateY(0);
}
.toast i {
color: var(--success-color);
}
/* ============================================
FOOTER
============================================ */
footer {
text-align: center;
margin-top: var(--spacing-xl);
color: var(--text-secondary);
font-size: 0.9rem;
}
footer a {
color: var(--primary-color);
text-decoration: none;
font-weight: 600;
}
footer a:hover {
text-decoration: underline;
}
.shortcuts {
margin-top: var(--spacing-sm);
font-size: 0.85rem;
}
/* ============================================
RESPONSIVE DESIGN
============================================ */
@media (max-width: 768px) {
header h1 {
font-size: 2rem;
}
.tabs {
    flex-wrap: wrap;
}

.tab-btn {
    flex: 1 1 45%;
}

.actions {
    flex-direction: column;
}

.btn {
    width: 100%;
    justify-content: center;
}

.palette-controls {
    flex-direction: column;
}

.palette-display {
    grid-template-columns: repeat(auto-fit, minmax(100px, 1fr));
}

.toast {
    bottom: 1rem;
    right: 1rem;
    left: 1rem;
}
}
@media (max-width: 480px) {
.color-name {
font-size: 2rem;
}
.color-codes {
    grid-template-columns: 1fr;
}

.shades-grid {
    grid-template-columns: repeat(auto-fit, minmax(60px, 1fr));
}
}