:root {
    --bg: #f4f6f2;
    --ink: #1f2a24;
    --muted: #68746d;
    --line: #cbd5cc;
    --panel: #ffffff;
    --center: #fff3c4;
    --accent: #247a69;
    --accent-dark: #155f51;
    --danger: #a33a32;
    --shadow: 0 18px 50px rgba(31, 42, 36, 0.12);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    min-height: 100vh;
    color: var(--ink);
    background:
        linear-gradient(135deg, rgba(36, 122, 105, 0.12), transparent 42%),
        var(--bg);
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.app-shell {
    width: min(1080px, calc(100vw - 32px));
    margin: 0 auto;
    padding: 32px 0;
}

.app-header {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 16px;
    margin-bottom: 18px;
}

.brand-title {
    margin: 0;
    color: var(--accent);
    font-size: 1.25rem;
    font-weight: 800;
    letter-spacing: 0;
    text-transform: uppercase;
}

.save-form {
    margin: 0;
}

.editor-form,
.hidden-form {
    margin: 0;
}

.hidden-form {
    display: none;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.save-button,
.secondary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    min-width: 108px;
    min-height: 44px;
    border: 0;
    border-radius: 8px;
    color: #fff;
    background: var(--accent);
    box-shadow: 0 8px 18px rgba(36, 122, 105, 0.22);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
}

.save-button:hover,
.save-button:focus-visible,
.secondary-button:hover,
.secondary-button:focus-visible {
    background: var(--accent-dark);
}

.logout-button,
.danger-button,
.back-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 108px;
    min-height: 44px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: rgba(255, 255, 255, 0.76);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
}

.logout-button:hover,
.logout-button:focus-visible,
.danger-button:hover,
.danger-button:focus-visible,
.back-button:hover,
.back-button:focus-visible {
    border-color: var(--accent);
}

.danger-button {
    color: var(--danger);
}

.danger-button:hover,
.danger-button:focus-visible {
    border-color: rgba(163, 58, 50, 0.56);
    background: rgba(163, 58, 50, 0.08);
}

.notice {
    margin: 0 0 14px;
    padding: 10px 12px;
    border-radius: 8px;
    font-weight: 700;
}

.success {
    color: var(--accent-dark);
    background: rgba(36, 122, 105, 0.1);
}

.error {
    color: var(--danger);
    background: rgba(163, 58, 50, 0.1);
}

.breadcrumb {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 0 0 14px;
}

.breadcrumb a {
    display: inline-flex;
    align-items: center;
    min-height: 34px;
    max-width: 220px;
    padding: 7px 10px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: rgba(255, 255, 255, 0.7);
    font-size: 0.88rem;
    font-weight: 700;
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.breadcrumb a::after {
    content: ">";
    margin-left: 8px;
    color: var(--muted);
}

.breadcrumb a:last-child {
    border-color: var(--accent);
    color: var(--accent-dark);
}

.breadcrumb a:last-child::after {
    content: "";
    margin-left: 0;
}

.login-shell {
    display: grid;
    min-height: 100vh;
    place-items: center;
}

.login-panel {
    width: min(420px, 100%);
    padding: 28px;
    border: 1px solid rgba(203, 213, 204, 0.8);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.84);
    box-shadow: var(--shadow);
}

.login-form {
    display: grid;
    gap: 14px;
    margin-top: 22px;
}

.login-form label {
    display: grid;
    gap: 8px;
    color: var(--muted);
    font-size: 0.9rem;
    font-weight: 700;
}

.password-input {
    width: 100%;
    min-height: 46px;
    padding: 10px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: #fff;
    font: inherit;
    outline: none;
}

.password-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(36, 122, 105, 0.18);
}

.manager,
.board-tools {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 14px;
}

.board-tools {
    padding: 12px;
    border: 1px solid rgba(203, 213, 204, 0.8);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.5);
}

.board-switcher {
    display: flex;
    flex: 1;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 2px;
}

.board-tab {
    display: inline-flex;
    align-items: center;
    min-height: 38px;
    max-width: 220px;
    padding: 8px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: rgba(255, 255, 255, 0.8);
    font-size: 0.92rem;
    font-weight: 700;
    text-decoration: none;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.board-tab.is-active {
    border-color: var(--accent);
    color: #fff;
    background: var(--accent);
}

.create-form,
.delete-form {
    display: flex;
    gap: 8px;
    margin: 0;
}

.title-field {
    display: grid;
    flex: 1;
    gap: 6px;
    color: var(--muted);
    font-size: 0.85rem;
    font-weight: 700;
}

.title-input {
    width: 100%;
    min-height: 44px;
    padding: 10px 12px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: #fff;
    font: inherit;
    outline: none;
}

.create-form .title-input {
    width: min(260px, 32vw);
}

.title-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(36, 122, 105, 0.18);
}

.board-wrap {
    padding: clamp(12px, 3vw, 24px);
    border: 1px solid rgba(203, 213, 204, 0.8);
    border-radius: 8px;
    background: rgba(255, 255, 255, 0.72);
    box-shadow: var(--shadow);
}

.board {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(8px, 1.6vw, 14px);
}

.cell {
    position: relative;
    display: block;
    min-height: clamp(130px, 23vw, 210px);
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--panel);
    overflow: hidden;
}

.cell.is-center {
    border-color: #d7b53a;
    background: var(--center);
}

.cell.has-child-content {
    border-color: rgba(36, 122, 105, 0.7);
    background: #e3f4ef;
}

.cell-number {
    position: absolute;
    top: 10px;
    left: 12px;
    z-index: 1;
    color: var(--muted);
    font-size: 0.78rem;
    font-weight: 800;
}

textarea {
    display: block;
    width: 100%;
    height: 100%;
    min-height: inherit;
    padding: 34px 14px 50px;
    border: 0;
    color: var(--ink);
    background: transparent;
    font: inherit;
    font-size: clamp(0.95rem, 2vw, 1.1rem);
    line-height: 1.5;
    resize: none;
    outline: none;
}

textarea[readonly] {
    color: var(--accent-dark);
    font-weight: 700;
    cursor: default;
}

textarea:focus {
    box-shadow: inset 0 0 0 3px rgba(36, 122, 105, 0.24);
}

.cell-open-button {
    position: absolute;
    right: 10px;
    bottom: 10px;
    z-index: 2;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 64px;
    min-height: 32px;
    border: 1px solid var(--line);
    border-radius: 8px;
    color: var(--ink);
    background: rgba(255, 255, 255, 0.88);
    font-size: 0.86rem;
    font-weight: 700;
    cursor: pointer;
}

.cell-open-button:hover,
.cell-open-button:focus-visible {
    border-color: var(--accent);
    color: var(--accent-dark);
}

textarea::placeholder {
    color: #9aa49e;
}

.app-footer {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    margin-top: 16px;
    color: var(--muted);
    font-size: 0.92rem;
}

@media (max-width: 640px) {
    .app-shell {
        width: min(100vw - 20px, 560px);
        padding: 10px 0 16px;
    }

    .app-header {
        align-items: center;
        flex-direction: row;
        margin-bottom: 8px;
    }

    .header-actions {
        width: auto;
        align-items: center;
        flex-direction: row;
        gap: 6px;
    }

    .brand-title {
        font-size: 1rem;
    }

    .notice {
        margin-bottom: 8px;
        padding: 8px 10px;
        font-size: 0.88rem;
    }

    .manager {
        align-items: center;
        gap: 8px;
        margin-bottom: 8px;
    }

    .board-tools {
        display: grid;
        grid-template-columns: minmax(0, 1fr) auto auto auto;
        align-items: end;
        gap: 6px;
        margin-bottom: 8px;
        padding: 8px;
    }

    .create-form,
    .delete-form {
        width: auto;
        flex: 0 0 auto;
        gap: 6px;
    }

    .create-form .title-input {
        width: 9.5rem;
    }

    .secondary-button,
    .danger-button,
    .back-button {
        width: auto;
    }

    .save-button,
    .secondary-button,
    .logout-button,
    .danger-button,
    .back-button {
        min-width: 0;
        min-height: 38px;
        padding: 0 10px;
        font-size: 0.88rem;
    }

    .save-form {
        width: auto;
    }

    .logout-button {
        width: auto;
    }

    .board-switcher {
        min-width: 0;
        gap: 6px;
    }

    .board-tab {
        min-height: 34px;
        max-width: 150px;
        padding: 6px 9px;
        font-size: 0.84rem;
    }

    .breadcrumb {
        flex-wrap: nowrap;
        gap: 6px;
        margin-bottom: 8px;
        overflow-x: auto;
        padding-bottom: 2px;
    }

    .breadcrumb a {
        min-height: 30px;
        max-width: 150px;
        padding: 5px 8px;
        font-size: 0.8rem;
    }

    .title-field {
        min-width: 0;
        gap: 4px;
        font-size: 0.74rem;
    }

    .title-input {
        min-height: 38px;
        padding: 8px 9px;
        font-size: 0.88rem;
    }

    .board-wrap {
        padding: 8px;
    }

    .board {
        gap: 6px;
    }

    .cell {
        min-height: 106px;
    }

    textarea {
        padding: 30px 10px 46px;
        font-size: 0.9rem;
    }

    .cell-open-button {
        right: 8px;
        bottom: 8px;
        min-width: 56px;
    }

    .app-footer {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 6px;
        margin-top: 8px;
        font-size: 0.78rem;
    }
}