/* ============================================================
   MAIN STYLES - Современный минималистичный дизайн
   ============================================================ */

/* ============================================================
   CSS Reset
   ============================================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ============================================================
   CSS Variables - Design System
   ============================================================ */
:root {
    /* Основные цвета */
    --primary: #2196F3;
    --primary-dark: #1976D2;
    --primary-light: #BBDEFB;
    --success: #4CAF50;
    --warning: #FF9800;
    --danger: #f44336;

    /* Приоритеты */
    --priority-low: #4CAF50;
    --priority-medium: #FF9800;
    --priority-high: #f44336;

    /* Нейтральные цвета */
    --gray-50: #FAFAFA;
    --gray-100: #F5F5F5;
    --gray-200: #EEEEEE;
    --gray-300: #E0E0E0;
    --gray-400: #BDBDBD;
    --gray-500: #9E9E9E;
    --gray-600: #757575;
    --gray-700: #616161;
    --gray-800: #424242;
    --gray-900: #212121;

    /* Фоны */
    --bg-body: #FAFAFA;
    --bg-column: #FFFFFF;
    --bg-card: #FFFFFF;
    --bg-header: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);

    /* Текст */
    --text-primary: #212121;
    --text-secondary: #757575;
    --text-disabled: #BDBDBD;
    --text-on-primary: #FFFFFF;

    /* Границы */
    --border-light: #F5F5F5;
    --border-medium: #E0E0E0;
    --border-dark: #BDBDBD;

    /* Тени */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 2px 4px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 4px 8px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 8px 16px rgba(0, 0, 0, 0.15);

    /* Spacing система (8px grid) */
    --space-xs: 0.25rem;   /* 4px */
    --space-sm: 0.5rem;    /* 8px */
    --space-md: 1rem;      /* 16px */
    --space-lg: 1.5rem;    /* 24px */
    --space-xl: 2rem;      /* 32px */
    --space-2xl: 3rem;     /* 48px */

    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    /* Z-index система */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
    --z-popover: 1060;
    --z-tooltip: 1070;
}

/* ============================================================
   Typography
   ============================================================ */
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    font-size: 18px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-body);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
}

/* ============================================================
   Utilities
   ============================================================ */
.hidden {
    display: none !important;
}

/* ============================================================
   Header - Минималистичный
   ============================================================ */
header {
    background: var(--bg-header);
    color: var(--text-on-primary);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-lg) var(--space-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.header-title {
    flex: 0 1 auto;
}

.header-title h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--space-xs);
    letter-spacing: -0.02em;
}

.subtitle {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 400;
}

.header-actions {
    display: flex;
    gap: var(--space-md);
    align-items: center;
    flex-wrap: wrap;
}

/* ============================================================
   Board Layout
   ============================================================ */
.board-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-xl) var(--space-md);
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-lg);
    align-items: start;
}

/* ============================================================
   Column - Минималистичный дизайн
   ============================================================ */
.column {
    background-color: var(--bg-column);
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-light);
    transition: box-shadow var(--transition-base);
    min-height: 400px;
    display: flex;
    flex-direction: column;
}

.column:hover {
    box-shadow: var(--shadow-md);
}

.column-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-md);
    border-bottom: 2px solid var(--gray-100);
}

.column-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.card-count {
    background-color: var(--primary);
    color: var(--text-on-primary);
    padding: var(--space-xs) var(--space-sm);
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 700;
    min-width: 24px;
    text-align: center;
}

/* ============================================================
   Cards Container
   ============================================================ */
.cards-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
    min-height: 200px;
    max-height: calc(100vh - 400px);
    overflow-y: auto;
    padding: var(--space-xs);
    margin: 0 calc(-1 * var(--space-xs));
}

/* Custom scrollbar */
.cards-container::-webkit-scrollbar {
    width: 8px;
}

.cards-container::-webkit-scrollbar-track {
    background: transparent;
}

.cards-container::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: var(--radius-full);
}

.cards-container::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}

/* ============================================================
   Card - Минималистичный дизайн
   ============================================================ */
.card {
    background-color: var(--bg-card);
    border-radius: var(--radius-md);
    padding: var(--space-md);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-medium);
    transition: all var(--transition-base);
    position: relative;
}

.card:hover {
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.card-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    line-height: 1.4;
    word-wrap: break-word;
}

.card-description {
    font-size: 1rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
    line-height: 1.5;
    word-wrap: break-word;
}

.card-description:empty {
    display: none;
}

.card-actions {
    display: flex;
    gap: var(--space-sm);
    flex-wrap: wrap;
    margin-top: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--border-light);
}

.card-btn {
    padding: var(--space-xs) var(--space-md);
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.938rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.card-btn:hover {
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

.card-btn:active {
    transform: translateY(0);
}

.btn-edit {
    background-color: var(--primary);
    color: var(--text-on-primary);
}

.btn-edit:hover {
    background-color: var(--primary-dark);
}

.btn-delete {
    background-color: var(--danger);
    color: var(--text-on-primary);
}

.btn-delete:hover {
    background-color: #d32f2f;
}

/* ============================================================
   Add Card Button
   ============================================================ */
.add-card-btn {
    width: 100%;
    padding: var(--space-md);
    background-color: transparent;
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
    margin-top: var(--space-md);
}

.add-card-btn:hover {
    background-color: var(--gray-50);
    border-color: var(--primary);
    color: var(--primary);
    border-style: solid;
}

.add-card-btn span {
    font-size: 1.25rem;
    font-weight: 600;
    margin-right: var(--space-xs);
}

/* ============================================================
   Modal - Чистый дизайн
   ============================================================ */
.modal-overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: var(--z-modal-backdrop);
    animation: fadeIn var(--transition-base);
}

.modal {
    background-color: var(--bg-card);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 540px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    animation: slideUp var(--transition-slow);
}

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

.modal-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.close-btn:hover {
    background-color: var(--gray-100);
    color: var(--text-primary);
}

/* ============================================================
   Form
   ============================================================ */
#card-form {
    padding: var(--space-xl);
}

.form-group {
    margin-bottom: var(--space-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--space-sm);
    font-weight: 500;
    color: var(--text-primary);
    font-size: 1rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: var(--space-md);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: inherit;
    color: var(--text-primary);
    background-color: var(--bg-card);
    transition: all var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

/* Modal Actions */
.modal-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: flex-end;
    padding-top: var(--space-lg);
    margin-top: var(--space-lg);
    border-top: 1px solid var(--border-light);
}

.btn {
    padding: var(--space-md) var(--space-xl);
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.btn-outline:hover {
    background-color: var(--gray-50);
}

.btn-cancel {
    background-color: var(--gray-100);
    color: var(--text-primary);
}

.btn-cancel:hover {
    background-color: var(--gray-200);
}

.btn-primary {
    background-color: var(--primary);
    color: var(--text-on-primary);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: scale(0.98);
}

/* ============================================================
   Animations
   ============================================================ */
@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        transform: translateY(32px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Плавные появления элементов */
.card {
    animation: fadeIn var(--transition-base);
}