:root {
    /* Dark Theme */
    --bg-dark: #0F1219;
    --bg-panel: #161A23;
    --bg-input: #0B0D12;
    --bg-hover: rgba(255, 255, 255, 0.05);
    --border: #2A2E39;

    --primary: #6366F1;
    --primary-hover: #4F46E5;
    --accent: #22D3EE;

    --text-main: #F3F4F6;
    --text-muted: #9CA3AF;

    --radius: 12px;
    --radius-sm: 8px;
    --transition: 200ms ease;
    --glass-bg: rgba(22, 26, 35, 0.7);
}

.theme-light {
    --bg-dark: #F9FAFB;
    --bg-panel: #FFFFFF;
    --bg-input: #F3F4F6;
    --bg-hover: rgba(0, 0, 0, 0.05);
    --border: #E5E7EB;

    --text-main: #111827;
    --text-muted: #6B7280;
    --glass-bg: rgba(255, 255, 255, 0.8);
}

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

body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    height: 100vh;
    overflow: hidden;
    transition: background-color var(--transition), color var(--transition);
}

.hidden {
    display: none !important;
}

/* Layout */
.app-container {
    display: flex;
    height: 100vh;
    width: 100vw;
}

/* --- Sidebar --- */
.sidebar {
    width: 320px;
    background: var(--bg-panel);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    padding: 1.5rem;
    z-index: 10;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.1);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-main);
    margin-bottom: 2rem;
}

.logo svg {
    color: var(--primary);
}

h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.control-group {
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.control-group label {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.divider {
    border: 0;
    height: 1px;
    background: var(--border);
    margin: 0.5rem 0 1.5rem 0;
}

/* Inputs */
.select-wrapper {
    position: relative;
}

.select-wrapper::after {
    content: "▼";
    font-size: 0.6rem;
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    pointer-events: none;
}

select {
    width: 100%;
    appearance: none;
    background: var(--bg-input);
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-family: 'Inter', sans-serif;
    font-size: 0.9rem;
    outline: none;
    cursor: pointer;
}

select:focus {
    border-color: var(--primary);
}

input[type="range"] {
    appearance: none;
    width: 100%;
    height: 6px;
    background: var(--bg-input);
    border-radius: 4px;
    outline: none;
    margin: 0.5rem 0;
}

input[type="range"]::-webkit-slider-thumb {
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary);
    cursor: pointer;
    transition: transform 0.1s;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.range-labels {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: 'JetBrains Mono', monospace;
}

.image-dropzone {
    border: 2px dashed var(--border);
    border-radius: var(--radius-sm);
    padding: 2rem 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition);
    text-align: center;
    background: var(--bg-input);
}

.image-dropzone:hover,
.image-dropzone.drag-over {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(99, 102, 241, 0.05);
}

.sidebar-actions {
    margin-top: auto;
    display: grid;
    grid-template-columns: 1fr 1fr auto;
    gap: 0.5rem;
}

/* --- Buttons --- */
.btn {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
    font-family: 'Inter', sans-serif;
    cursor: pointer;
    border: none;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.btn.primary {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
}

.btn.primary:hover {
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.4);
    transform: translateY(-1px);
}

.btn.secondary {
    background: var(--bg-input);
    color: var(--text-main);
}

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

.btn.outline {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-muted);
}

.btn.outline:hover {
    border-color: var(--text-main);
    color: var(--text-main);
}

.btn.full-width {
    width: 100%;
}

.btn.icon-only {
    width: 42px;
    padding: 0;
}

/* --- Palette Display --- */
.palette-display {
    flex: 1;
    display: flex;
    flex-direction: row;
    transition: background 0.5s ease;
}

.color-column {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    position: relative;
    cursor: pointer;
    transition: flex-grow 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.color-column:hover {
    flex-grow: 1.2;
}

/* Dynamic classes added via JS to adjust text color based on background luminance */
.color-column.dark-text {
    color: #000 !important;
}

.color-column.light-text {
    color: #fff !important;
}

.color-column.dark-text .color-controls button {
    color: rgba(0, 0, 0, 0.6);
}

.color-column.light-text .color-controls button {
    color: rgba(255, 255, 255, 0.8);
}

.color-column.dark-text .color-controls button:hover {
    color: #000;
    background: rgba(0, 0, 0, 0.1);
}

.color-column.light-text .color-controls button:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.2);
}

.color-details {
    padding: 2rem 1rem;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
}

.color-column:hover .color-details {
    opacity: 1;
    transform: translateY(0);
}

.color-hex {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    font-weight: 700;
    cursor: pointer;
    text-transform: uppercase;
}

.color-hex:hover {
    transform: scale(1.1);
}

.color-rgb {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    opacity: 0.7;
}

.accessibility-badge {
    font-size: 0.75rem;
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-weight: 600;
    border: 1px solid currentColor;
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    opacity: 0.8;
    margin-top: 0.5rem;
}

.color-controls {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    display: flex;
    flex-direction: column;
    gap: 1rem;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.color-column:hover .color-controls {
    opacity: 1;
}

.color-controls button {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.lock-btn.locked {
    opacity: 1;
}

/* override hover */

/* --- Modals --- */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal {
    background: var(--bg-panel);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    width: 600px;
    max-width: 90vw;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
}

.modal-body {
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.modal-footer {
    padding: 1.25rem 1.5rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: flex-end;
}

.export-tabs {
    display: flex;
    gap: 0.5rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1rem;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    padding: 0.5rem 1rem;
    cursor: pointer;
    font-weight: 500;
    border-bottom: 2px solid transparent;
    transition: all var(--transition);
    margin-bottom: -1px;
}

.tab-btn.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

#export-textarea {
    width: 100%;
    height: 250px;
    background: var(--bg-input);
    border: 1px solid var(--border);
    color: var(--text-main);
    padding: 1rem;
    border-radius: var(--radius-sm);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.85rem;
    resize: none;
}

/* --- History Drawer --- */
.drawer {
    position: fixed;
    top: 0;
    right: 0;
    width: 350px;
    height: 100vh;
    background: var(--bg-panel);
    border-left: 1px solid var(--border);
    z-index: 50;
    display: flex;
    flex-direction: column;
    box-shadow: -4px 0 20px rgba(0, 0, 0, 0.2);
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.drawer:not(.hidden) {
    transform: translateX(0);
}

.drawer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
}

.drawer-body {
    flex: 1;
    overflow-y: auto;
    padding: 1rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.drawer-footer {
    padding: 1rem;
    border-top: 1px solid var(--border);
}

.history-item {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    background: var(--bg-input);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    cursor: pointer;
    transition: border-color var(--transition);
}

.history-item:hover {
    border-color: var(--primary);
}

.history-swatches {
    display: flex;
    height: 30px;
    border-radius: 4px;
    overflow: hidden;
}

.history-swatch {
    flex: 1;
}

.history-meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* --- Toast --- */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(0);
    background: var(--text-main);
    color: var(--bg-dark);
    padding: 0.75rem 1.5rem;
    border-radius: 99px;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    z-index: 1000;
    transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.toast.hidden {
    opacity: 0;
    transform: translateX(-50%) translateY(30px);
    pointer-events: none;
}

/* Responsive */
@media (max-width: 768px) {
    .app-container {
        flex-direction: column-reverse;
    }

    .sidebar {
        width: 100%;
        height: 35vh;
        overflow-y: auto;
        border-right: none;
        border-top: 1px solid var(--border);
        padding: 1rem;
    }

    .palette-display {
        height: 65vh;
        flex-direction: column;
    }

    .color-column {
        flex-direction: row;
        align-items: center;
        padding: 0 1rem;
    }

    .color-column:hover {
        flex-grow: 1;
    }

    /* disable grow on mobile */
    .color-details {
        padding: 0;
        flex-direction: row;
        transform: none;
        opacity: 1;
        width: 100%;
        justify-content: space-between;
    }

    .color-controls {
        position: static;
        transform: none;
        opacity: 1;
        flex-direction: row;
        margin-left: auto;
    }

    .accessibility-badge {
        display: none;
    }
}