/*
    The mobile site, on top of weaver's dark theme (style-dark.css, with
    Bootstrap 3). Mobile first: the wide-screen rules are at the end.
    The code editor's colours are in editors/codemirror/editor.js; keep the
    two in step.
*/

:root {
    --bg: #060818;
    --surface: #11152a;
    --surface-raised: #1b1e35;
    --border: #3b3f5c;
    --text: #e0e2ec;
    --muted: #8a90ad;
    --accent: #1ab394;
    --accent-strong: #23d1ad;
    --danger: #ff6b76;
    --danger-bg: #2a1219;
    --success-bg: #0d2620;
    --bar-height: 56px;
    --mono: Menlo, Consolas, "DejaVu Sans Mono", monospace;
}

html {
    -webkit-text-size-adjust: 100%;
}

/* Bootstrap's .btn and others would show a [hidden] element anyway. */
[hidden] {
    display: none !important;
}

body,
#page-wrapper,
.gray-bg {
    background-color: var(--bg);
}

body {
    color: var(--text);
    font-size: 16px;
    line-height: 1.55;
}

/* Weaver's page frame. Its overflow-x: hidden would make #wrapper a scroll
   container, and the course bar would then not stick to the top; clip
   cuts off the same overflow without that. */
#wrapper {
    overflow-x: clip;
}

/* Tightened for a phone. */
.wrapper-content {
    padding: 16px 0 32px;
}

@media (max-width: 767px) {
    #page-wrapper {
        padding-left: 0;
        padding-right: 0;
    }

    #page-wrapper > .row.border-bottom {
        margin-left: 0;
        margin-right: 0;
    }
}

#app {
    min-height: 60vh;
}

#app a:not(.btn) {
    color: var(--accent-strong);
}

/* The navigation bar: bigger targets in the phone menu. */
.top-navigation .navbar-nav > li > a,
.top-navigation .navbar-top-links > li > a {
    font-size: 16px;
}

.top-navigation .navbar-collapse.in .nav > li > a,
.top-navigation .navbar-collapse.collapsing .nav > li > a {
    padding: 14px 20px;
}

@media (max-width: 767px) {
    /* Lined up with the left-hand entries, as .navbar-nav does. */
    .top-navigation .navbar-top-links {
        margin: 0 -15px 7px;
        padding: 0;
        float: none !important;
    }

    .top-navigation .navbar-top-links > li {
        display: block;
    }

    .top-navigation .navbar-top-links > li > a {
        padding: 14px 20px;
        min-height: 0;
    }
}

.nav-label .fa {
    margin-right: 6px;
}

/* Pages */

.page {
    max-width: 760px;
    margin: 0 auto;
}

.page-title {
    font-size: 28px;
    font-weight: 600;
    color: var(--text);
    margin: 4px 0 18px;
}

.page p,
.lead-text {
    color: var(--text);
}

.loading {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--muted);
    padding: 24px 0;
}

.spinner {
    width: 18px;
    height: 18px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: manabase-spin 0.8s linear infinite;
}

@keyframes manabase-spin {
    to { transform: rotate(360deg); }
}

.card-box,
.course-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
    margin-bottom: 16px;
}

.card-box p:last-of-type {
    margin-bottom: 12px;
}

.course-card-title,
.course-card-title:hover,
.course-card-title:focus {
    text-decoration: none;
}

.course-card-title h2 {
    font-size: 21px;
    font-weight: 600;
    margin: 0 0 8px;
    color: var(--accent-strong);
}

.course-card-description {
    color: var(--muted);
    font-size: 15px;
    cursor: pointer;
}

/* A long description shows its first lines until tapped. */
.course-card-description.clamped {
    display: -webkit-box;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 4;
    overflow: hidden;
}

.course-card-progress {
    margin: 12px 0;
}

.course-card-revision {
    margin-top: 14px;
    padding-top: 12px;
    border-top: 1px solid var(--border);
}

.progress-text {
    color: var(--muted);
    font-size: 14px;
    margin-bottom: 8px;
}

.progress {
    height: 8px;
    margin-bottom: 6px;
    background: var(--surface-raised);
    border-radius: 4px;
    box-shadow: none;
}

.progress-bar {
    background: var(--accent);
}

/* Buttons and forms: thumb-sized. */

.btn {
    border-radius: 8px;
    min-height: 44px;
    font-size: 16px;
}

.btn-sm {
    min-height: 36px;
    font-size: 14px;
}

.btn-lg {
    min-height: 52px;
    font-size: 17px;
}

.btn-default,
.btn-default:focus {
    background: var(--surface-raised);
    border-color: var(--border);
    color: var(--text);
}

.btn-default:hover,
.btn-default:active,
.btn-default.active {
    background: #262a4a;
    border-color: #4b5078;
    color: #fff;
}

.btn-primary[disabled],
.btn-default[disabled] {
    opacity: 0.55;
}

.btn-link {
    color: var(--muted);
}

.form-control {
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 8px;
    font-size: 16px; /* smaller makes iOS zoom in on focus */
    height: auto;
    padding: 12px 14px;
}

.form-control:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(26, 179, 148, 0.25);
}

.account-form {
    display: grid;
    gap: 12px;
    margin: 18px 0;
}

.account-switch {
    margin-top: 20px;
    color: var(--muted);
}

.form-feedback:empty {
    display: none;
}

.form-feedback .btn {
    margin-top: 8px;
}

#app .btn-block + .btn-block,
#app .btn + .form-feedback {
    margin-top: 12px;
}

/* Alerts, which the light theme draws in pastels. */

.alert {
    border-radius: 8px;
    border-width: 1px;
}

.alert-success {
    background: var(--success-bg);
    border-color: #1a5c4c;
    color: #8ff0d6;
}

.alert-danger {
    background: var(--danger-bg);
    border-color: #6b2630;
    color: #ffb3ba;
}

.alert .rich-text p:last-child {
    margin-bottom: 0;
}

/* Problem text */

.rich-text p {
    white-space: pre-line; /* list items keep their own lines */
    overflow-wrap: anywhere;
}

.code-block {
    margin: 0 0 14px;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    background: var(--surface);
}

/* Until the editor script loads, and if it never does. */
.code-block > pre,
.code-editor > pre {
    margin: 0;
    padding: 10px 12px;
    border: 0;
    border-radius: 0;
    background: var(--surface);
    color: var(--text);
    font-family: var(--mono);
    font-size: 14px;
    line-height: 20px;
    white-space: pre;
    overflow-x: auto;
}

/* The course screen */

body.on-course .wrapper-content {
    padding-top: 0;
    padding-bottom: calc(80px + env(safe-area-inset-bottom));
}

.course-bar {
    position: sticky;
    top: 0;
    z-index: 30;
    display: flex;
    align-items: center;
    gap: 10px;
    height: var(--bar-height);
    margin: 0 -15px 16px;
    padding: 0 15px;
    background: rgba(6, 8, 24, 0.94);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(6px);
}

.course-bar-toggle {
    flex: none;
    min-height: 40px;
    padding: 6px 12px;
}

.course-bar-title {
    flex: 1;
    min-width: 0;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.course-bar-count {
    flex: none;
    color: var(--muted);
    font-size: 14px;
    font-variant-numeric: tabular-nums;
}

.revision-mode .course-bar-count::before {
    content: "\21BB  ";
    color: #f8ac59;
}

/* The drawer: off the left edge until opened. */

.course-drawer {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    z-index: 1050;
    width: min(86vw, 340px);
    overflow-y: auto;
    overscroll-behavior: contain;
    background: var(--surface);
    border-right: 1px solid var(--border);
    transform: translateX(-102%);
    transition: transform 0.22s ease-out;
    padding-bottom: env(safe-area-inset-bottom);
}

.drawer-open .course-drawer {
    transform: none;
    box-shadow: 8px 0 32px rgba(0, 0, 0, 0.5);
}

.drawer-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1040;
    background: rgba(0, 0, 0, 0.55);
}

.drawer-open .drawer-backdrop {
    display: block;
}

body.drawer-open {
    overflow: hidden;
}

.drawer-head {
    display: flex;
    align-items: center;
    padding: 12px 8px 4px 16px;
}

.drawer-title {
    flex: 1;
    margin: 0;
    font-size: 18px;
    font-weight: 600;
    color: var(--text);
}

.drawer-close {
    font-size: 22px;
    min-width: 44px;
}

.revision-box {
    margin: 8px 12px 12px;
    padding: 12px;
    background: var(--surface-raised);
    border-radius: 8px;
}

.revision-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.revision-help-toggle {
    font-size: 20px;
    min-height: 36px;
    padding: 0 6px;
}

.revision-help {
    font-size: 14px;
    color: var(--muted);
    margin-top: 8px;
}

.revision-status {
    color: var(--muted);
    font-size: 14px;
    margin: 6px 0;
}

.revision-box .btn {
    margin-top: 4px;
}

/* A switch for revision mode, made of a checkbox. */
.switch {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin: 0;
    font-weight: 600;
    cursor: pointer;
    min-height: 36px;
}

.switch input {
    position: absolute;
    opacity: 0;
    width: 1px;
    height: 1px;
}

.switch-track {
    position: relative;
    width: 44px;
    height: 26px;
    border-radius: 13px;
    background: var(--border);
    transition: background 0.15s;
}

.switch-track::after {
    content: "";
    position: absolute;
    top: 3px;
    left: 3px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #fff;
    transition: transform 0.15s;
}

.switch input:checked + .switch-track {
    background: var(--accent);
}

.switch input:checked + .switch-track::after {
    transform: translateX(18px);
}

.switch input:focus-visible + .switch-track {
    outline: 2px solid var(--accent-strong);
    outline-offset: 2px;
}

.switch input:disabled + .switch-track {
    opacity: 0.5;
}

/* The problem tree */

.problem-tree ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.problem-tree ul ul {
    padding-left: 14px;
}

.problem-tree summary,
.tree-problem {
    display: flex;
    align-items: baseline;
    gap: 8px;
    padding: 10px 16px;
    min-height: 44px;
    color: var(--text);
}

.problem-tree summary {
    cursor: pointer;
    font-weight: 600;
    list-style: none;
}

.problem-tree summary::-webkit-details-marker {
    display: none;
}

.problem-tree summary::after {
    content: "\25B8";
    color: var(--muted);
    margin-left: 4px;
    transition: transform 0.15s;
}

.problem-tree details[open] > summary::after {
    transform: rotate(90deg);
}

#app a.tree-problem {
    color: var(--text);
    text-decoration: none;
    border-left: 3px solid transparent;
}

.tree-problem.current {
    background: rgba(26, 179, 148, 0.12);
    border-left-color: var(--accent) !important;
}

.problem-tree .tree-mark {
    flex: none;
    width: 1em;
    color: var(--muted);
}

.problem-tree .solved > .tree-mark {
    color: var(--accent-strong);
}

.tree-title {
    flex: 1;
    min-width: 0;
}

.problem-tree .count,
.problem-tree .times {
    flex: none;
    color: var(--muted);
    font-size: 13px;
    font-weight: normal;
    font-variant-numeric: tabular-nums;
}

/* The problem */

.problem {
    max-width: 760px;
    margin: 0 auto;
    min-width: 0;
}

.problem-title {
    font-size: 26px;
    font-weight: 600;
    color: var(--text);
    margin: 0 0 14px;
    line-height: 1.25;
}

.problem-title .solved-mark {
    display: none;
}

.problem-title.solved {
    color: var(--accent-strong);
}

.problem-title.solved .solved-mark {
    display: inline;
}

.problem-question p {
    font-weight: 600;
}

.choices {
    display: grid;
    gap: 10px;
    margin: 6px 0 16px;
}

.choice {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    margin: 0;
    padding: 14px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 10px;
    font-weight: normal;
    cursor: pointer;
    -webkit-tap-highlight-color: transparent;
}

.choice input {
    flex: none;
    width: 20px;
    height: 20px;
    margin: 2px 0 0;
    accent-color: var(--accent);
}

.choice-text {
    flex: 1;
    min-width: 0;
    overflow-wrap: anywhere;
}

.choice:has(input:checked) {
    border-color: var(--accent);
    background: rgba(26, 179, 148, 0.1);
}

.code-editor {
    height: max(240px, 45vh);
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
    background: #0b0e1c;
}

.code-editor-local {
    height: auto;
    max-height: 45vh;
    overflow: auto;
}

.code-fallback {
    width: 100%;
    height: 100%;
    border: 0;
    padding: 10px;
    background: #0b0e1c;
    color: var(--text);
    font-family: var(--mono);
    font-size: 16px;
    resize: none;
}

/* The keys a phone keyboard hides. A mouse and keyboard need none. */
.key-bar {
    display: flex;
    gap: 6px;
    overflow-x: auto;
    padding: 8px 0 4px;
    margin-bottom: 8px;
    scrollbar-width: none;
}

.key-bar::-webkit-scrollbar {
    display: none;
}

.key-bar .btn {
    flex: none;
    min-width: 40px;
    min-height: 40px;
    padding: 4px 10px;
    font-family: var(--mono);
}

@media (hover: hover) and (pointer: fine) {
    .key-bar {
        display: none;
    }

    .code-editor {
        margin-bottom: 12px;
    }
}

.button-row {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 10px;
    margin-bottom: 12px;
}

.run-output {
    margin: 0 0 16px;
    padding: 10px 12px;
    max-height: 50vh;
    overflow: auto;
    background: #0b0e1c;
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 8px;
    font-family: var(--mono);
    font-size: 14px;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
}

.paste-label {
    display: block;
    margin: 16px 0 6px;
}

.paste-box {
    font-family: var(--mono);
    margin-bottom: 12px;
}

.feedback {
    margin-top: 16px;
    scroll-margin-bottom: calc(80px + env(safe-area-inset-bottom));
}

/* Previous and Next, along the bottom. */

.problem-nav {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 30;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background: var(--border);
    border-top: 1px solid var(--border);
    padding-bottom: env(safe-area-inset-bottom);
}

.problem-nav a {
    display: flex;
    align-items: center;
    min-height: 56px;
    padding: 8px 14px;
    background: var(--surface);
    font-size: 15px;
    text-decoration: none;
    min-width: 0;
}

#app .problem-nav a {
    color: var(--text);
}

#app .problem-nav a.disabled {
    color: var(--border);
    pointer-events: none;
}

.problem-nav-next {
    justify-content: flex-end;
    text-align: right;
}

.problem-nav-inner {
    display: flex;
    align-items: center;
    gap: 6px;
    min-width: 0;
}

.problem-nav-title {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Wide screens: the tree is a column beside the problem. */

@media (min-width: 992px) {
    .course-layout {
        display: grid;
        grid-template-columns: 300px minmax(0, 1fr);
        gap: 28px;
        align-items: start;
    }

    .course-drawer {
        position: sticky;
        top: calc(var(--bar-height) + 16px);
        z-index: auto;
        width: auto;
        max-height: calc(100vh - var(--bar-height) - 112px);
        transform: none;
        transition: none;
        border: 1px solid var(--border);
        border-radius: 10px;
    }

    .course-bar-toggle,
    .drawer-close,
    .drawer-backdrop,
    .drawer-open .drawer-backdrop {
        display: none;
    }

    body.drawer-open {
        overflow: auto;
    }

    .problem {
        margin: 0;
    }
}