:root {
    --color-bg: #f3f6ff;
    --color-fg: #0f172a;
    --color-muted: #6b7a99;
    --color-on-primary: #ffffff;
    --color-primary: #2f66ff;
    --color-primary-strong: #1f4ae0;
    --color-secondary-bg: #eef3ff;
    --color-danger: #e54848;
    --color-danger-strong: #c73737;
    --color-danger-border: #f6b3b3;
    --color-danger-soft: rgba(229, 72, 72, 0.12);
    --color-surface: #ffffff;
    --color-surface-muted: #f2f5ff;
    --color-border: #dfe7f5;
    --color-border-subtle: #e7edfa;
    --gradient-bg: linear-gradient(180deg, #f3f6ff 0%, #f8faff 45%, #ffffff 100%);
    --header-bg: #ffffff;
    --header-border: #e4ebf9;
    --nav-active-bg: #e6efff;
    --kanban-column-bg: #f4f7ff;
    --kanban-task-bg: #ffffff;
    --kanban-task-border: #e1e8f6;
    --table-header-bg: #e9f0ff;
    --table-row-alt: #f4f7ff;
    --table-row-hover: #e9f0ff;
    --shadow-sm: 0 8px 18px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 20px 40px rgba(15, 23, 42, 0.12);
    --shadow-primary: 0 12px 18px rgba(47, 102, 255, 0.25);
    --radius-sm: 0.6rem;
    --radius-md: 0.85rem;
    --radius-lg: 1rem;
    --radius-xl: 1.25rem;
    --radius-pill: 999px;
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.5rem;
    --space-6: 2rem;
    --space-7: 2.5rem;
    --font-sans: 'Plus Jakarta Sans', 'Segoe UI', sans-serif;
    --transition-fast: 0.2s ease;
    --focus-ring: 0 0 0 3px rgba(47, 102, 255, 0.25);
}

html[data-theme='dark'] {
    --color-bg: #0b1220;
    --color-fg: #e2e8f0;
    --color-muted: #94a3b8;
    --color-surface: rgba(15, 23, 42, 0.92);
    --color-surface-muted: rgba(30, 41, 59, 0.6);
    --color-border: rgba(148, 163, 184, 0.2);
    --color-border-subtle: rgba(148, 163, 184, 0.2);
    --color-danger-border: rgba(248, 113, 113, 0.4);
    --color-danger-soft: rgba(244, 63, 94, 0.18);
    --gradient-bg: linear-gradient(180deg, #0b1220 0%, #0f172a 45%, #101827 100%);
    --header-bg: rgba(15, 23, 42, 0.9);
    --header-border: rgba(148, 163, 184, 0.2);
    --nav-active-bg: rgba(47, 102, 255, 0.2);
    --kanban-column-bg: rgba(15, 23, 42, 0.8);
    --kanban-task-bg: rgba(15, 23, 42, 0.95);
    --table-header-bg: rgba(148, 163, 184, 0.12);
    --table-row-alt: rgba(47, 102, 255, 0.08);
    --table-row-hover: rgba(148, 163, 184, 0.16);
    --shadow-lg: 0 25px 45px rgba(2, 6, 23, 0.35);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    background-image: var(--gradient-bg);
    background-size: 100% 100%;
    color: var(--color-fg);
}

a {
    color: inherit;
    text-decoration: none;
}

.sr-only {
    border: 0;
    clip: rect(0 0 0 0);
    height: 1px;
    margin: -1px;
    overflow: hidden;
    padding: 0;
    position: absolute;
    width: 1px;
}

.text-muted {
    color: var(--color-muted);
}

.app-shell {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.app-header {
    padding: 0.9rem var(--space-6);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--header-bg);
    border-bottom: 1px solid var(--header-border);
}

.app-header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.app-brand {
    font-weight: 700;
    letter-spacing: 0.01em;
    font-size: 1.1rem;
    color: var(--color-primary);
}

.app-nav {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-size: 0.9rem;
}

.nav-link {
    padding: 0.25rem 0;
    border-radius: 0;
    font-weight: 500;
    transition: background var(--transition-fast), color var(--transition-fast);
    color: var(--color-muted);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
}

.nav-link.active {
    border-bottom: 2px solid var(--color-primary);
}

.nav-link-primary {
    background: var(--color-primary);
    box-shadow: var(--shadow-primary);
    color: var(--color-on-primary);
}

.nav-link-secondary {
    padding: 0.25rem 0.6rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    color: var(--color-primary);
}

.theme-toggle {
    border: none;
    background: var(--color-surface);
    border-radius: var(--radius-sm);
    padding: 0.45rem 0.85rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: transform var(--transition-fast), background var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.theme-toggle:hover {
    transform: translateY(-2px);
}

.app-content {
    flex: 1;
    padding: var(--space-7) clamp(1rem, 3vw, 3rem);
    max-width: 1440px;
    width: 100%;
    margin: 0 auto;
}

.page-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-4);
    margin-bottom: var(--space-5);
}

.page-header > div:first-child {
    flex: 1;
}

.page-header h1 {
    margin: 0;
    font-size: clamp(1.9rem, 4vw, 2.6rem);
    font-weight: 700;
    letter-spacing: -0.02em;
}

.page-header p {
    margin: 0.35rem 0 0;
    color: var(--color-muted);
}

.page-header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.action-links {
    display: inline-flex;
    gap: var(--space-3);
    align-items: baseline;
    flex-wrap: wrap;
}

.action-links a {
    font-weight: 600;
    color: var(--color-primary);
    transition: color var(--transition-fast);
}

.action-links a:hover {
    color: var(--color-primary-strong);
}

.list-footer {
    display: flex;
    justify-content: flex-end;
    margin-top: var(--space-5);
}

.list-footer a {
    text-decoration: none;
    font-weight: 600;
}

.link-primary {
    font-weight: 600;
    color: var(--color-on-primary);
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0.55rem 1rem;
    border-radius: var(--radius-md);
    background: var(--color-primary);
    box-shadow: var(--shadow-primary);
}

.emoji-plus {
    color: var(--color-on-primary);
    font-variant-emoji: text;
    font-family: "Plus Jakarta Sans", sans-serif;
}

.link-primary:hover {
    color: var(--color-on-primary);
    background: var(--color-primary-strong);
    text-decoration: none;
}

.link-danger {
    font-weight: 600;
    color: var(--color-danger);
    transition: color var(--transition-fast);
}

.link-danger:hover {
    color: var(--color-danger-strong);
}

.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--space-5);
    box-shadow: var(--shadow-sm);
}

.card + .card {
    margin-top: var(--space-4);
}

.alert {
    border-radius: var(--radius-md);
    padding: var(--space-3) var(--space-4);
}

.alert-danger {
    border: 1px solid var(--color-danger-border);
    background: var(--color-danger-soft);
    color: var(--color-danger-strong);
    margin-bottom: var(--space-4);
}

.badge,
.tag {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.35rem 0.75rem;
    border-radius: var(--radius-pill);
    background: #e8efff;
    color: var(--color-primary);
}

.kanban-board {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--space-4);
}

.kanban-column {
    border-radius: var(--radius-lg);
    padding: var(--space-4);
    min-height: 180px;
    background: var(--kanban-column-bg);
    border: 1px solid var(--color-border-subtle);
    box-shadow: var(--shadow-sm);
}

.kanban-column h3 {
    margin-top: 0;
    margin-bottom: var(--space-3);
    font-size: 1rem;
}

.kanban-task {
    border-radius: 0.85rem;
    padding: 0.8rem;
    margin-bottom: 0.65rem;
    background: var(--kanban-task-bg);
    border: 1px solid var(--kanban-task-border);
    cursor: grab;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), background var(--transition-fast);
    color: var(--color-fg);
}

.kanban-task:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(15, 23, 42, 0.15);
}

.kanban-task.dragging {
    opacity: 0.55;
}

.btn {
    border: none;
    border-radius: var(--radius-md);
    padding: 0.65rem 1.25rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform var(--transition-fast), background var(--transition-fast), color var(--transition-fast);
}

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

.btn-secondary {
    background: var(--color-secondary-bg);
    color: var(--color-fg);
    border: 1px solid var(--color-border);
}

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

.btn-danger:hover {
    background: var(--color-danger-strong);
}

.btn:focus-visible {
    outline: 2px solid rgba(56, 189, 248, 0.5);
    outline-offset: 2px;
}

.btn:disabled {
    cursor: not-allowed;
    opacity: 0.6;
    box-shadow: none;
}

.form-card {
    padding: var(--space-6);
    border-radius: var(--radius-xl);
    background: var(--color-surface);
    box-shadow: var(--shadow-sm);
}

.form-stack {
    display: grid;
    gap: var(--space-4);
}

.form-field {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.form-input-wrapper {
    width: 100%;
}

.form-input-wrapper > * {
    width: 100%;
}

.form-field--inline {
    flex-direction: row;
    align-items: center;
    gap: var(--space-2);
}

.form-field label {
    font-weight: 600;
    color: var(--color-muted);
}

.form-field input,
.form-field textarea,
.form-field select {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 0.75rem 1rem;
    background: var(--color-surface);
    color: var(--color-fg);
    font-family: inherit;
    font-size: 1rem;
    transition: border var(--transition-fast), box-shadow var(--transition-fast);
}

.form-field input:focus,
.form-field textarea:focus,
.form-field select:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: var(--focus-ring);
}

.form-field textarea {
    min-height: 140px;
    resize: vertical;
}

.form-field select {
    appearance: none;
    background-image: linear-gradient(45deg, transparent 50%, currentColor 50%),
                      linear-gradient(135deg, currentColor 50%, transparent 50%);
    background-position: calc(100% - 1.5rem) 50%, calc(100% - 1rem) 50%;
    background-size: 7px 7px, 7px 7px;
    background-repeat: no-repeat;
    padding-right: 2.75rem;
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: var(--space-3);
}

.form-help {
    margin: 0;
    color: var(--color-muted);
    font-size: 0.85rem;
}

.form-errors {
    margin: 0;
    color: #f87171;
    font-size: 0.85rem;
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin-bottom: var(--space-4);
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--color-border);
    background: var(--color-surface);
    box-shadow: var(--shadow-sm);
}

table th,
table td {
    padding: var(--space-2) var(--space-4);
    text-align: left;
    border-bottom: 1px solid var(--color-border);
    font-size: 0.9rem;
}

table th {
    background-color: var(--table-header-bg);
    color: var(--color-fg);
    font-weight: 600;
}

table tr:last-child td {
    border-bottom: none;
}

table tr {
    cursor: default;
}

table tbody tr:nth-child(odd) {
    background-color: var(--table-row-alt);
}

table tbody tr:nth-child(odd):hover {
    background-color: var(--table-row-hover);
}

table tbody tr:hover {
    background-color: var(--table-row-hover);
}

@media (max-width: 768px) {
    .app-header {
        flex-direction: column;
        gap: var(--space-3);
    }

    .app-header-actions {
        width: 100%;
        justify-content: space-between;
    }

    .app-nav {
        flex-wrap: wrap;
        justify-content: center;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .page-header-actions {
        width: 100%;
        justify-content: flex-start;
    }
}

@media (min-width: 1440px) {
    .kanban-board {
        grid-template-columns: repeat(5, minmax(0, 1fr));
    }
}

@media (max-width: 820px) {
    table thead {
        display: none;
    }

    table,
    table tbody,
    table tr,
    table th,
    table td {
        display: block;
        width: 100%;
    }

    table tr {
        margin-bottom: var(--space-4);
        border: 1px solid var(--color-border);
        border-radius: var(--radius-lg);
        overflow: hidden;
        background: var(--color-surface);
        box-shadow: var(--shadow-sm);
    }

    table tbody tr:nth-child(odd),
    table tbody tr:nth-child(odd):hover,
    table tbody tr:hover {
        background: var(--color-surface);
    }

    table th,
    table td {
        border-bottom: 1px dashed var(--color-border-subtle);
        padding: var(--space-3) var(--space-4);
        display: flex;
        justify-content: space-between;
        align-items: center;
        gap: var(--space-3);
        background: transparent;
        cursor: default;
    }

    table th::before,
    table td::before {
        content: attr(data-label);
        font-weight: 600;
        color: var(--color-muted);
    }

    table tr:last-child td,
    table tr:last-child th {
        border-bottom: none;
    }
}