/* Hmmmm Design System — Clean/Refresh */
/* Evolutionary update: GOV.UK transparency + branded teal identity */
/* See design-system.md for full documentation */

/* === Reset === */
*, *::before, *::after {
    box-sizing: border-box;
}

* {
    margin: 0;
}

/* === Accessibility === */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* === CSS Variables === */
:root {
    /* Brand */
    --color-brand: #1B5E4B;
    --color-brand-dark: #164D3E;
    --color-brand-light: #e8f0ed;

    /* Text */
    --color-text: #0b0c0c;
    --color-text-secondary: #505a5f;
    --color-text-inverse: #ffffff;

    /* Links — teal family */
    --color-link: #1A6B5A;
    --color-link-hover: #134D3E;
    --color-link-visited: #4a7c6e;

    /* States */
    --color-focus: #ffdd00;
    --color-error: #d4351c;
    --color-success: #00703c;

    /* Neutrals */
    --color-border: #b1b4b6;
    --color-input-border: #0b0c0c;
    --color-bg-grey: #f3f2f1;

    /* Spacing (5px base) */
    --space-1: 5px;
    --space-2: 10px;
    --space-3: 15px;
    --space-4: 20px;
    --space-5: 25px;
    --space-6: 30px;
    --space-7: 40px;
    --space-8: 50px;
    --space-9: 60px;

    /* Layout */
    --max-width: 1020px;

    /* Typography */
    --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                  Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
}


/* === Base === */

html {
    font-size: 19px;
    line-height: 25px;
}

body {
    font-family: var(--font-stack);
    color: var(--color-text);
    background-color: #fff;
    -webkit-font-smoothing: antialiased;
    padding: 0 var(--space-3);
}

img, picture, video, canvas, svg {
    display: block;
    max-width: 100%;
}

input, button, textarea, select {
    font: inherit;
}

p, h1, h2, h3, h4, h5, h6 {
    overflow-wrap: break-word;
}

p {
    text-wrap: pretty;
}

h1, h2, h3, h4, h5, h6 {
    text-wrap: balance;
}


/* === Typography (mobile first) === */

h1 {
    font-size: 32px;
    line-height: 35px;
    font-weight: 700;
    margin-bottom: var(--space-6);
}

h2 {
    font-size: 21px;
    line-height: 25px;
    font-weight: 700;
    margin-bottom: var(--space-3);
}

h3 {
    font-size: 19px;
    line-height: 25px;
    font-weight: 700;
    margin-bottom: var(--space-2);
}

small {
    font-size: 16px;
    line-height: 20px;
}

/* Large screens type scale */
@media (min-width: 641px) {
    h1 {
        font-size: 48px;
        line-height: 50px;
    }

    h2 {
        font-size: 24px;
        line-height: 30px;
    }
}


/* === Links — teal palette === */

a {
    color: var(--color-link);
    text-decoration: underline;
    text-decoration-thickness: max(1px, .0625rem);
    text-underline-offset: .1578em;
}

a:visited {
    color: var(--color-link-visited);
}

a:hover {
    color: var(--color-link-hover);
    text-decoration-thickness: max(3px, .1875rem);
}

a:focus {
    outline: 3px solid var(--color-focus);
    outline-offset: 0;
    background-color: var(--color-focus);
    color: var(--color-text);
    text-decoration: none;
}


/* === Focus (global) === */

:focus-visible {
    outline: 3px solid var(--color-focus);
    outline-offset: 0;
}


/* === Layout === */

#main {
    display: flex;
    flex-direction: column;
    margin: 0 auto;
    min-height: 100vh;
    max-width: var(--max-width);
}

/* === Header — full-width teal bar, compact content === */

#header {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    background-color: var(--color-brand);
    padding: var(--space-3) var(--space-3);
    margin-bottom: var(--space-6);

    /* Break out of #main max-width and body padding */
    margin-left: calc(-1 * var(--space-3));
    margin-right: calc(-1 * var(--space-3));
}

#header a {
    color: var(--color-text-inverse);
    text-decoration: none;
}

#header a:visited {
    color: var(--color-text-inverse);
}

#header a:hover {
    text-decoration: underline;
    color: var(--color-text-inverse);
}

#header a:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
}

/* Emoji home link */
.brand {
    font-size: 28px;
    line-height: 1;
    text-decoration: none;
    flex-shrink: 0;
}

.brand:visited {
    color: inherit;
}

/* Breadcrumb navigation inline with emoji */
#header nav {
    font-size: 16px;
    line-height: 20px;
}

#header nav a {
    color: rgba(255, 255, 255, 0.85);
}

#header nav a:hover {
    color: var(--color-text-inverse);
}

#header nav h2 {
    font-size: 19px;
    line-height: 25px;
    font-weight: 700;
    margin-bottom: 0;
    color: var(--color-text-inverse);
}

#header nav h2 a {
    color: rgba(255, 255, 255, 0.85);
}

/* Header h1 (for index.html landing) */
#header h1 {
    font-size: 24px;
    line-height: 30px;
    font-weight: 700;
    margin-bottom: 0;
    color: var(--color-text-inverse);
}

#header h2 {
    font-size: 16px;
    line-height: 20px;
    font-weight: 400;
    margin-bottom: 0;
    color: rgba(255, 255, 255, 0.85);
}

#content {
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

#primary {
    max-width: 75ch;
}

.hero-headline {
    font-size: 1.6rem;
    line-height: 1.2;
    margin-bottom: var(--space-5);
}

.hero-cta {
    margin-top: var(--space-5);
    margin-bottom: var(--space-7);
}

.hero-cta p {
    color: var(--color-text-secondary);
    margin-bottom: var(--space-3);
}

.hero-cta small {
    display: block;
    margin-top: var(--space-2);
}

#secondary {
    margin-top: var(--space-7);
    padding: var(--space-5);
    background-color: var(--color-bg-grey);
    border-radius: 10px;
    max-width: 75ch;
}

#secondary > h1 {
    font-size: 24px;
    line-height: 30px;
    margin-bottom: var(--space-4);
}

#secondary a {
    color: var(--color-link);
}

#secondary a.start {
    color: #fff;
}

#secondary a.thought {
    color: var(--color-text);
}

#secondary a.tool {
    color: var(--color-text-secondary);
}

#secondary #chain + div {
    text-align: center;
}

#footer {
    margin-top: auto;
    padding: var(--space-5) 0;
}

/* Two-column on larger screens */
@media (min-width: 641px) {
    body {
        padding: 0 var(--space-6);
    }

    #header {
        margin-left: calc(-1 * var(--space-6));
        margin-right: calc(-1 * var(--space-6));
        padding-left: var(--space-6);
        padding-right: var(--space-6);
    }

    #content {
        flex-direction: row;
        gap: var(--space-7);
    }

    #primary {
        flex: 55;
        min-width: 0;
    }

    .hero-headline {
        font-size: 2.2rem;
    }

    #secondary {
        flex: 45;
        margin-top: 0;
        min-width: 0;
        padding-right: var(--space-7);
    }

    #secondary > h1 {
        font-size: 36px;
        line-height: 40px;
    }

    #continue {
        text-align: left;
    }
}


/* === Paragraphs & descriptions === */

p, .desc {
    margin-bottom: var(--space-4);
    max-width: 75ch;
}

.desc ul, .desc ol {
    padding-left: var(--space-4);
    margin-top: var(--space-2);
    margin-bottom: var(--space-4);
}

.desc li {
    margin-bottom: var(--space-1);
}

.empty {
    color: var(--color-text-secondary);
    padding: var(--space-5) 0;
}

/* Form-only desc blocks sit inline */
#primary > .desc:has(> form:only-child) {
    display: inline-block;
    margin-right: var(--space-3);
}


/* === Menu items — teal with chevron === */

.menu-item {
    display: flex;
    align-items: center;
    padding: var(--space-3) var(--space-4);
    margin-bottom: 0;
    border-bottom: 1px solid #e0dedd;
    text-decoration: none;
    color: var(--color-link);
    font-weight: 700;
}

.menu-item::after {
    content: "\203A"; /* › right single angle quotation */
    margin-left: auto;
    font-size: 24px;
    line-height: 1;
    color: var(--color-border);
    padding-left: var(--space-3);
}

.menu-item:visited {
    color: var(--color-link);
}

.menu-item:hover {
    background-color: var(--color-bg-grey);
    color: var(--color-link-hover);
}

.menu-item:hover::after {
    color: var(--color-link-hover);
}

.menu-item:focus {
    background-color: var(--color-focus);
    color: var(--color-text);
    outline: 3px solid var(--color-focus);
}

.menu-item:focus::after {
    color: var(--color-text);
}


/* === List items (thoughts, chains) === */

#thoughts, #sessions, #chains {
    margin: var(--space-5) 0;
}

#thoughts > .item, #chains > .item {
    display: flex;
    align-items: center;
    border-bottom: 1px solid #e0dedd;
}

.title {
    flex-grow: 1;
    padding: var(--space-2) var(--space-3);
    color: var(--color-link);
    text-decoration: underline;
}

.title:visited {
    color: var(--color-link-visited);
}

.edit, .delete {
    padding: var(--space-2) var(--space-1);
    color: var(--color-text-secondary);
    font-size: 22px;
    text-decoration: none;
}

.edit-title {
    font-size: 0.8em;
    text-decoration: none;
    color: var(--color-text-secondary);
    margin-right: 0.15em;
}
.edit-title:hover {
    color: var(--color-link-hover);
}

@media (min-width: 641px) {
    .edit, .delete {
        font-size: 16px;
    }
}

.edit:hover, .delete:hover {
    color: var(--color-link-hover);
}

.unlinked {
    border-left: 4px solid var(--color-border);
    background-color: var(--color-bg-grey);
}


/* === Chain (the core UI) === */

#chain {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    margin: var(--space-4) 0;
}

#tools {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: -20px;
    position: relative;
}

#children, #parents {
    display: flex;
    flex-direction: column;
    align-items: stretch;
}

#continue {
    margin-top: var(--space-5);
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-2);
}

#add {
    text-align: center;
}

#add form {
    justify-content: center;
}

/* Overlapping cards — each card sits on top of the one above */
#chain > .thought,
#chain > .tool,
#children > .thought,
#parents > .thought,
#tools > .tool,
#add > .thought {
    margin-top: -10px;
    position: relative;
}

/* First card in chain/parents has no negative margin */
#chain > :first-child,
#parents > :first-child {
    margin-top: 0;
}

/* Navigation link above chain (extend upward / cancel) */
.chain-nav {
    text-align: center;
    margin-bottom: var(--space-3);
}

/* When chain follows tools (extend-upward view), overlap into tools */
#tools + #chain {
    margin-top: -10px;
}

/* Extra bottom padding on parent cards so tool label stays visible above overlap */
#parents > .thought {
    padding-bottom: calc(var(--space-4) + 20px);
}


/* Thought cards — soft, elevated, overlapping cards */
.thought {
    display: block;
    padding: var(--space-4) var(--space-5);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    background-color: #fff;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.06);
    text-align: center;
    color: var(--color-text);
    text-decoration: none;
    position: relative;
}

.thought:visited {
    color: var(--color-text);
}

.thought:hover {
    background-color: var(--color-bg-grey);
    color: var(--color-text);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12), 0 2px 4px rgba(0, 0, 0, 0.08);
}

.thought:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
    text-decoration: none;
}


/* Tool cards — secondary, softer, overlapping */
.tool {
    display: block;
    padding: var(--space-3) var(--space-4) var(--space-4);
    border: 1px solid #e0dedd;
    border-radius: 8px;
    background-color: var(--color-bg-grey);
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.06);
    text-align: center;
    font-size: 16px;
    line-height: 20px;
    color: var(--color-text-secondary);
    text-decoration: none;
    align-self: center;
    width: 60%;
    position: relative;
}

.tool:visited {
    color: var(--color-text-secondary);
}

.tool:hover {
    background-color: #e8e6e3;
    color: var(--color-text);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.tool:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
}

@media (min-width: 641px) {
    .tool {
        width: 45%;
    }
}


/* === Buttons === */

/* Primary action — brand teal, solid, high contrast */
.start {
    display: inline-block;
    padding: var(--space-2) var(--space-5);
    background-color: var(--color-brand);
    color: var(--color-text-inverse);
    font-weight: 700;
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: 6px;
    cursor: pointer;
}

.start:visited {
    color: var(--color-text-inverse);
}

.start:hover {
    background-color: var(--color-brand-dark);
    color: var(--color-text-inverse);
}

.start:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
}

.start-outline {
    display: inline-block;
    padding: var(--space-2) var(--space-5);
    background-color: #fff;
    color: var(--color-brand);
    font-weight: 700;
    text-decoration: none;
    border: 2px solid var(--color-brand);
    border-radius: 6px;
    cursor: pointer;
}
.start-outline:visited { color: var(--color-brand); }
.start-outline:hover { background-color: var(--color-brand); color: var(--color-text-inverse); }
.start-outline:focus { outline: 3px solid var(--color-focus); background-color: var(--color-focus); color: var(--color-text); }

/* Action (form submit) — brand teal */
.action {
    display: inline-block;
    padding: var(--space-2) var(--space-4);
    background-color: var(--color-brand);
    color: var(--color-text-inverse);
    font-weight: 700;
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: 6px;
    cursor: pointer;
}

.action:hover {
    background-color: var(--color-brand-dark);
}

.action:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
}

/* Secondary — grey background */
.button {
    display: inline-block;
    padding: var(--space-2) var(--space-4);
    background-color: var(--color-bg-grey);
    color: var(--color-text);
    text-decoration: none;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    cursor: pointer;
}

.button:hover {
    background-color: #e0dedd;
}

/* Move/cancel — plain underlined link */
.move {
    color: var(--color-link);
    text-decoration: underline;
    background: none;
    border: none;
    padding: var(--space-2) 0;
    margin-right: var(--space-3);
    cursor: pointer;
}

/* Warning — neutral button style, not scary */
.warning {
    display: inline-block;
    padding: var(--space-2) var(--space-4);
    background-color: var(--color-bg-grey);
    color: var(--color-text-secondary);
    text-decoration: none;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    cursor: pointer;
}

.warning:visited {
    color: var(--color-text-secondary);
}

.warning:hover {
    background-color: #e0dedd;
    color: var(--color-text);
}

/* Form actions — Cancel+Save left, Delete right */
.form-actions {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: var(--space-2);
}

/* Danger — red, only on confirmations */
.danger,
input[type=submit].danger,
button.danger {
    display: inline-block;
    padding: var(--space-2) var(--space-4);
    background-color: var(--color-error);
    color: #fff;
    font-weight: 700;
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: 6px;
    cursor: pointer;
}

.danger:hover,
input[type=submit].danger:hover,
button.danger:hover {
    background-color: #aa2a16;
    color: #fff;
}

.danger:focus,
input[type=submit].danger:focus,
button.danger:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
}

.isolated {
    margin-top: var(--space-7);
}

/* Delete button spaced from primary actions (e.g. confirm delete page) */
form > .warning {
    margin-left: var(--space-7);
}

/* Center break chain button within #continue */
#continue form {
    margin-left: 0;
    text-align: center;
}
#continue form > .warning {
    margin-left: 0;
}

/* Generic submit / button */
input[type=submit], button {
    padding: var(--space-2) var(--space-4);
    cursor: pointer;
    border: 1px solid var(--color-border);
    border-radius: 6px;
    background-color: var(--color-bg-grey);
    color: var(--color-text);
}

input[type=submit]:hover, button:hover {
    background-color: #e0dedd;
}

input[type=submit]:focus, button:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
    color: var(--color-text);
}


/* === Forms === */

form {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    gap: var(--space-3);
    align-items: center;
    justify-content: center;
}

form input[type=text], form input[type=email], form textarea {
    width: 100%;
}

input[type=text], input[type=email] {
    display: block;
    width: 100%;
    padding: var(--space-2);
    border: 2px solid var(--color-input-border);
    border-radius: 4px;
    background-color: #fff;
}

input[type=text]:focus, input[type=email]:focus {
    outline: 3px solid var(--color-focus);
    outline-offset: 0;
}

textarea {
    display: block;
    width: 100%;
    padding: var(--space-2);
    border: 2px solid var(--color-input-border);
    border-radius: 4px;
    min-height: 100px;
}

textarea:focus {
    outline: 3px solid var(--color-focus);
    outline-offset: 0;
}


/* === Floating buttons === */

#floating_home_button {
    position: fixed;
    bottom: var(--space-3);
    right: var(--space-3);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 1px solid var(--color-border);
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
    font-size: 1.5rem;
    text-decoration: none;
    color: var(--color-text);
}

#floating_home_button:hover {
    background-color: var(--color-bg-grey);
}

#floating_home_button:focus {
    outline: 3px solid var(--color-focus);
    background-color: var(--color-focus);
}

#up_button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: 1px solid var(--color-border);
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.15);
    text-decoration: none;
    color: var(--color-text);
    margin-bottom: var(--space-3);
}


/* === Utility === */

q {
    font-style: italic;
}

/* === Session Graph === */

.graph-key {
    padding: 4px 16px;
    display: flex;
    gap: 18px;
    align-items: center;
    flex-wrap: wrap;
}

.graph-key .dot {
    width: 18px;
    height: 14px;
    border-radius: 7px;
    border: 1.5px solid;
    flex-shrink: 0;
}

.graph-key span {
    font-size: 12px;
    color: var(--color-text-secondary);
}

.graph-key .dot-root { background: #DBEAFE; border-color: #2563EB; }
.graph-key .dot-thought { background: #fff; border-color: #94A3B8; }
.graph-key .dot-leaf { background: #FEF9C3; border-color: #CA8A04; }
.graph-key .dot-orphan { background: #F3E8FF; border-color: #7C3AED; }

/* Tool selection page */
.tool-list {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.tool-toggle {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.6rem 0;
    border-bottom: 1px solid var(--color-border);
}

.tool-toggle form {
    margin: 0;
    display: inline;
}

.tool-link {
    color: inherit;
    text-decoration: none;
}

.tool-link:hover {
    text-decoration: underline;
}

.tool-active {
    color: var(--color-text);
}

.tool-disabled {
    color: var(--color-text-secondary);
}

.slide-toggle {
    position: relative;
    width: 44px;
    height: 24px;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    flex-shrink: 0;
    padding: 0;
}

.slide-toggle::after {
    content: '';
    position: absolute;
    top: 2px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #fff;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.slide-toggle-on {
    background: var(--color-success);
}

.slide-toggle-on::after {
    left: 22px;
}

.slide-toggle-off {
    background: #ccc;
}

.slide-toggle-off::after {
    left: 2px;
}

.graph-legend {
    padding: 4px 16px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 4px;
}

.graph-legend .label {
    font-size: 12px;
    color: var(--color-text-secondary);
    margin-right: 8px;
    font-weight: 600;
}

.graph-legend .tool-item {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    margin-right: 12px;
}

.graph-legend .tool-bar {
    width: 16px;
    height: 3px;
    border-radius: 2px;
    display: inline-block;
}

.graph-legend .tool-name {
    font-size: 12px;
    color: #555;
}

.graph-container {
    overflow: auto;
    width: 100%;
    max-width: 100vw;
    -webkit-overflow-scrolling: touch;
}

.graph-container svg {
    max-width: none;
}

.graph-container svg text {
    pointer-events: none;
}

.graph-container svg a:hover rect {
    filter: brightness(0.93);
}

#main:has(.graph-page) {
    max-width: 100%;
}

.graph-page {
    width: 100%;
}

.graph-page h1 {
    padding: 0 16px;
    margin-bottom: 4px;
}

.graph-meta {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    padding: 0 16px 4px;
}