:root {
    /* Color Palette */
    --color-primary: #E11D48;
    --color-primary-hover: #BE123C;
    --color-secondary: #FB7185;
    --color-accent: #FFE4E6;
    --color-background: #1A0A10;
    --color-surface: #271217;
    --color-text-main: #FFFFFF;
    --color-text-muted: #CBD5E1;

    --color-card-bg: rgba(255, 255, 255, 0.03);
    --color-card-border: rgba(255, 255, 255, 0.08);
    --color-card-hover: rgba(255, 255, 255, 0.06);

    --color-input-bg: rgba(0, 0, 0, 0.2);
    --color-input-border: rgba(255, 255, 255, 0.1);

    /* Layout */
    --border-radius: 12px;
    --border-radius-sm: 8px;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Column Colors */
    --col-went-well: #10B981;
    --col-to-improve: #F59E0B;
    --col-action: #3B82F6;

    /* Transitions */
    --transition-speed: 0.2s;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

[data-theme="light"] {
    --color-background: #F8FAFC;
    --color-surface: #FFFFFF;
    --color-text-main: #0F172A;
    --color-text-muted: #64748B;

    --color-card-bg: #FFFFFF;
    --color-card-border: #E2E8F0;
    --color-card-hover: #F1F5F9;

    --color-input-bg: #F1F5F9;
    --color-input-border: #E2E8F0;
}

/* Reset & Base */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--color-background);
    color: var(--color-text-main);
    line-height: 1.5;
    transition: background-color var(--transition-speed), color var(--transition-speed);
    height: 100vh;
    overflow: hidden; /* App-like feel */
}

/* Layout */
.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 1600px;
    margin: 0 auto;
}

/* Header */
.app-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(26, 10, 16, 0.5); /* Semi-transparent */
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-card-border);
    z-index: 10;
}

[data-theme="light"] .app-header {
    background: rgba(255, 255, 255, 0.8);
}

.logo-area {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-primary);
}

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
}

.app-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-main);
}

.controls-area {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* Timer */
.timer-control {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-sm);
}

.timer-display {
    font-family: monospace;
    font-size: 1rem;
    font-weight: 600;
    min-width: 3.5rem;
    text-align: center;
}

/* Buttons */
button {
    cursor: pointer;
    border: none;
    background: none;
    color: inherit;
    font-family: inherit;
    transition: all var(--transition-speed);
}

.icon-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xs);
    border-radius: var(--border-radius-sm);
    color: var(--color-text-muted);
}

.icon-btn:hover {
    background-color: var(--color-card-hover);
    color: var(--color-text-main);
}

.secondary-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius-sm);
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    font-size: 0.875rem;
    font-weight: 500;
}

.secondary-btn:hover {
    background-color: var(--color-card-hover);
    border-color: var(--color-text-muted);
}

/* Board Grid */
.board-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-lg);
    flex: 1;
    overflow: hidden; /* Allow columns to scroll independently */
}

/* Columns */
.column {
    display: flex;
    flex-direction: column;
    background-color: var(--color-surface);
    border-radius: var(--border-radius);
    border: 1px solid var(--color-card-border);
    overflow: hidden;
    height: 100%;
}

.column-header {
    padding: var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--color-card-border);
}

.column-header h2 {
    font-size: 1rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

/* Indicators */
.column-header h2::before {
    content: '';
    display: block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.went-well-header h2::before { background-color: var(--col-went-well); }
.to-improve-header h2::before { background-color: var(--col-to-improve); }
.action-items-header h2::before { background-color: var(--col-action); }

.card-count {
    background-color: var(--color-card-bg);
    padding: 0.125rem 0.5rem;
    border-radius: 999px;
    font-size: 0.75rem;
    color: var(--color-text-muted);
    border: 1px solid var(--color-card-border);
}

/* Input Area */
.card-input-area {
    padding: var(--spacing-md);
    display: flex;
    gap: var(--spacing-sm);
    border-bottom: 1px solid var(--color-card-border);
    background-color: var(--color-background); /* Slight contrast */
}

.card-input-area textarea {
    flex: 1;
    background-color: var(--color-input-bg);
    border: 1px solid var(--color-input-border);
    border-radius: var(--border-radius-sm);
    padding: var(--spacing-sm);
    color: var(--color-text-main);
    font-family: inherit;
    resize: none;
    height: 40px; /* Compact */
    transition: height 0.2s, border-color 0.2s;
}

.card-input-area textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    height: 80px; /* Expand on focus */
}

.add-card-btn {
    align-self: flex-end;
    background-color: var(--color-primary);
    color: white;
    width: 32px;
    height: 32px;
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.add-card-btn:hover {
    background-color: var(--color-primary-hover);
}

/* Cards Container */
.cards-container {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* Card */
.retro-card {
    background-color: var(--color-card-bg);
    border: 1px solid var(--color-card-border);
    border-radius: var(--border-radius-sm);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s, box-shadow 0.2s;
    animation: slideIn 0.3s ease-out;
    position: relative;
    cursor: grab;
}

.retro-card:active {
    cursor: grabbing;
}

.retro-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: rgba(255, 255, 255, 0.2);
}

[data-theme="light"] .retro-card:hover {
    border-color: var(--color-primary);
}

.retro-card.dragging {
    opacity: 0.5;
    border: 2px dashed var(--color-primary);
}

.card-content {
    font-size: 0.9375rem;
    margin-bottom: var(--spacing-md);
    word-break: break-word;
    white-space: pre-wrap;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.vote-controls {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    background-color: var(--color-input-bg);
    padding: 2px 4px;
    border-radius: var(--border-radius-sm);
}

.vote-btn {
    padding: 4px;
    border-radius: 4px;
    color: var(--color-text-muted);
}

.vote-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--color-primary);
}

.vote-count {
    font-size: 0.875rem;
    font-weight: 600;
    min-width: 1.5rem;
    text-align: center;
}

.card-actions {
    display: flex;
    gap: var(--spacing-xs);
    opacity: 0; /* Hidden by default */
    transition: opacity 0.2s;
}

.retro-card:hover .card-actions {
    opacity: 1;
}

.card-action-btn {
    color: var(--color-text-muted);
    padding: 4px;
    border-radius: 4px;
}

.card-action-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--color-primary);
}

.delete-btn:hover {
    color: #EF4444; /* Red */
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: scale(0.9);
    }
}

.hidden {
    display: none !important;
}

/* Toast */
.toast-container {
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    background-color: var(--color-surface);
    color: var(--color-text-main);
    border: 1px solid var(--color-primary);
    padding: 12px 20px;
    border-radius: var(--border-radius-sm);
    box-shadow: var(--shadow-md);
    animation: slideIn 0.3s ease-out;
}

/* Responsive */
@media (max-width: 1024px) {
    .board-grid {
        overflow-x: auto;
        padding-bottom: var(--spacing-md);
    }

    .column {
        min-width: 300px;
    }
}

@media (max-width: 768px) {
    .app-header {
        flex-direction: column;
        gap: var(--spacing-md);
        align-items: stretch;
    }

    .logo-area {
        justify-content: center;
    }

    .controls-area {
        justify-content: space-between;
    }

    .board-grid {
        grid-template-columns: 1fr;
        overflow-y: auto;
        padding: var(--spacing-sm);
    }

    .column {
        height: auto;
        max-height: 500px;
        min-width: auto;
    }

    body {
        overflow: auto; /* Allow body scroll on mobile */
        height: auto;
    }

    .app-container {
        height: auto;
    }
}