:root {
    color-scheme: light;
    --bg: #f6f7f9;
    --surface: #ffffff;
    --surface-muted: #eef1f5;
    --surface-hover: #fbfcfd;
    --text-primary: #17191c;
    --text-secondary: #59616b;
    --text-muted: #7d8792;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-light: #eaf1ff;
    --border: #d9dee5;
    --border-light: #e8ebef;
    --border-strong: #b8c0ca;
    --shadow-sm: 0 1px 2px rgb(0 0 0 / 0.04);
    --shadow: 0 5px 14px rgb(0 0 0 / 0.07);
    --radius-sm: 6px;
    --radius: 8px;
    --radius-lg: 12px;
    --max-width: 1120px;
    --transition: 160ms ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text-primary);
    line-height: 1.55;
    min-height: 100vh;
}

button,
a {
    -webkit-tap-highlight-color: transparent;
}

.container {
    width: min(100% - 2rem, var(--max-width));
    margin: 0 auto;
}

.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;
}

/* Navigation: solid and compact, not glassy */
.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 58px;
}

.nav-logo {
    color: var(--text-primary);
    font-size: 1.05rem;
    font-weight: 750;
    letter-spacing: -0.025em;
    text-decoration: none;
}

.nav-logo span,
.footer-brand span {
    color: var(--accent);
}

.nav-links {
    display: none;
    align-items: center;
    gap: 1.5rem;
}

.nav-links a,
.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
}

.nav-links a {
    font-size: 0.875rem;
    font-weight: 550;
}

.nav-links a:hover,
.footer-links a:hover {
    color: var(--text-primary);
}

.nav-account {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.btn-icon {
    width: 34px;
    height: 34px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-secondary);
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
}

.btn-icon:hover {
    background: var(--surface-muted);
    color: var(--text-primary);
    border-color: var(--border-strong);
}

.mobile-menu-btn {
    display: inline-flex;
}

.mobile-menu {
    position: fixed;
    inset: 0;
    z-index: 200;
    display: flex;
    flex-direction: column;
    gap: 0;
    padding: 1rem;
    background: var(--surface);
    transform: translateX(100%);
    transition: transform 220ms ease;
}

.mobile-menu.open {
    transform: translateX(0);
}

.mobile-menu-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}

.mobile-menu a {
    padding: 0.9rem 0;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.45rem;
    min-height: 40px;
    padding: 0.55rem 0.9rem;
    border: 1px solid transparent;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 650;
    text-decoration: none;
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition), color var(--transition), transform var(--transition);
}

.btn-primary {
    background: var(--accent);
    color: #fff;
}

.btn-primary:hover {
    background: var(--accent-hover);
}

.btn-secondary {
    background: var(--surface);
    border-color: var(--border);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--surface-muted);
}

.btn-lg {
    min-height: 44px;
    padding: 0.65rem 1rem;
}

/* Hero: more like a useful homepage, less like a product launch */
.hero {
    padding: 3.25rem 0 2.75rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}

.hero-label {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    margin-bottom: 1rem;
    color: var(--accent);
    font-size: 0.78rem;
    font-weight: 700;
}

.hero h1 {
    max-width: 720px;
    font-size: clamp(2.7rem, 7vw, 5rem);
    font-weight: 800;
    line-height: 0.98;
    letter-spacing: -0.055em;
    margin-bottom: 0.8rem;
}

.hero h1 .period {
    color: var(--accent);
}

.hero-tagline {
    margin-bottom: 0.7rem;
    color: var(--text-primary);
    font-size: clamp(1.05rem, 2vw, 1.25rem);
    font-weight: 650;
}

.hero-desc {
    max-width: 650px;
    margin-bottom: 1.35rem;
    color: var(--text-secondary);
    font-size: 0.98rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

/* Toolbox */
.toolbox {
    padding: 2.5rem 0 3.5rem;
}

.section-header {
    margin-bottom: 1rem;
}

.section-header h2 {
    margin-bottom: 0.2rem;
    font-size: 1.25rem;
    line-height: 1.2;
    font-weight: 750;
    letter-spacing: -0.02em;
}

.section-header p {
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.tools-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.65rem;
}

.tool-card {
    position: relative;
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    column-gap: 0.85rem;
    min-height: 92px;
    padding: 0.9rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    cursor: pointer;
    transition: border-color var(--transition), background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.tool-card::before {
    display: none;
}

.tool-card:hover {
    border-color: #b8c0ca;
    background: #fbfcfd;
    box-shadow: var(--shadow-sm);
    transform: translateY(-1px);
}

.tool-card:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.tool-icon {
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface-muted);
    font-size: 1.15rem;
}

.tool-card h3 {
    margin-bottom: 0.12rem;
    font-size: 0.96rem;
    font-weight: 700;
}

.tool-card p {
    color: var(--text-secondary);
    font-size: 0.82rem;
    line-height: 1.4;
}

.tool-arrow {
    color: var(--text-muted);
    opacity: 1;
    transform: none;
    transition: color var(--transition), transform var(--transition);
}

.tool-card:hover .tool-arrow {
    color: var(--accent);
    transform: translateX(2px);
}

/* Workflow */
.workflow {
    padding: 2.75rem 0;
    background: var(--surface-muted);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.workflow h2 {
    margin-bottom: 0.35rem;
    text-align: center;
    font-size: 1.25rem;
    font-weight: 750;
}

.workflow-sub {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    text-align: center;
    font-size: 0.875rem;
}

.workflow-steps {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.35rem;
    max-width: 620px;
    margin: 0 auto;
}

.workflow-step {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    width: 100%;
    max-width: 330px;
    padding: 0.65rem 0.8rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
}

.step-number {
    width: 24px;
    height: 24px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    border-radius: 50%;
    background: var(--text-primary);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 750;
}

.step-text {
    font-size: 0.9rem;
    font-weight: 650;
}

.workflow-arrow {
    color: var(--text-muted);
    font-size: 1rem;
    line-height: 1;
}

/* About / feature section */
.feature {
    padding: 3rem 0;
}

.feature-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.feature-item {
    padding: 0 0 1.35rem;
    border-bottom: 1px solid var(--border);
}

.feature-item:last-child {
    border-bottom: 0;
}

.feature-item h3 {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.4rem;
    font-size: 0.98rem;
    font-weight: 700;
}

.feature-item p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    line-height: 1.6;
}

/* Resources */
.resources {
    padding: 2.75rem 0;
    background: var(--surface);
    border-top: 1px solid var(--border);
}

.resources-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0;
    margin-top: 1rem;
    border-top: 1px solid var(--border);
}

.resource-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 0.85rem 0.2rem;
    border-bottom: 1px solid var(--border);
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition), padding var(--transition);
}

.resource-card:hover {
    padding-left: 0.45rem;
    padding-right: 0.45rem;
    color: var(--accent);
    background: transparent;
}

.resource-card span:first-child {
    font-size: 0.9rem;
    font-weight: 550;
}

.resource-card span:last-child {
    color: var(--text-muted);
    font-size: 1rem;
}

/* Footer */
.footer {
    padding: 2.5rem 0 1.5rem;
    background: var(--bg);
    border-top: 1px solid var(--border);
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.75rem;
}

.footer-brand {
    margin-bottom: 0.35rem;
    font-size: 1rem;
    font-weight: 750;
}

.footer-tagline {
    color: var(--text-muted);
    font-size: 0.82rem;
}

.footer-links h4 {
    margin-bottom: 0.45rem;
    color: var(--text-muted);
    font-size: 0.7rem;
    font-weight: 750;
    letter-spacing: 0.07em;
    text-transform: uppercase;
}

.footer-links a {
    display: block;
    padding: 0.22rem 0;
    font-size: 0.82rem;
}

.footer-bottom {
    margin-top: 1.75rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.72rem;
}

/* Tool window */
.tool-overlay {
    position: fixed;
    inset: 0;
    z-index: 300;
    display: flex;
    flex-direction: column;
    background: var(--bg);
    transform: translateY(100%);
    transition: transform 220ms ease;
}

.tool-overlay.open {
    transform: translateY(0);
}

.tool-overlay-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.8rem 1rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface);
}

.tool-overlay-header h3 {
    font-size: 0.98rem;
    font-weight: 750;
}

.tool-overlay-body {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    text-align: center;
}

.tool-placeholder-icon {
    margin-bottom: 0.75rem;
    font-size: 2.5rem;
    opacity: 0.55;
}

.tool-placeholder h4 {
    margin-bottom: 0.35rem;
    font-size: 1.1rem;
    font-weight: 750;
}

.tool-placeholder p {
    max-width: 340px;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

/* Animations are deliberately subtle */
@keyframes fadeUp {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-in {
    animation: fadeUp 260ms ease-out both;
}

.delay-1 { animation-delay: 50ms; }
.delay-2 { animation-delay: 90ms; }
.delay-3 { animation-delay: 130ms; }
.delay-4 { animation-delay: 170ms; }

@media (min-width: 640px) {
    .tools-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .resources-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        column-gap: 2rem;
        border-top: 0;
    }

    .resource-card {
        border-top: 1px solid var(--border);
    }

    .feature-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
        gap: 1.5rem;
    }

    .feature-item {
        padding: 0 1.5rem 0 0;
        border-bottom: 0;
        border-right: 1px solid var(--border);
    }

    .feature-item:last-child {
        border-right: 0;
        padding-right: 0;
    }

    .footer-grid {
        grid-template-columns: 2fr 1fr 1fr 1fr;
    }
}

@media (min-width: 900px) {
    .container {
        width: min(100% - 3rem, var(--max-width));
    }

    .nav-inner {
        min-height: 62px;
    }

    .nav-links {
        display: flex;
    }

    .mobile-menu-btn {
        display: none;
    }

    .hero {
        padding: 5rem 0 4rem;
    }

    .hero-desc {
        font-size: 1rem;
    }

    .tools-grid {
        grid-template-columns: repeat(4, minmax(0, 1fr));
    }

    .tool-card {
        display: block;
        min-height: 170px;
        padding: 1.1rem;
    }

    .tool-icon {
        margin-bottom: 1rem;
    }

    .tool-arrow {
        position: absolute;
        right: 1rem;
        bottom: 1rem;
    }

    .workflow-steps {
        flex-direction: row;
        justify-content: center;
        max-width: none;
        gap: 0.45rem;
    }

    .workflow-step {
        width: auto;
        max-width: none;
        min-width: 135px;
    }

    .workflow-arrow {
        transform: none;
    }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}


/* Follow the operating system/browser appearance automatically. */
@media (prefers-color-scheme: dark) {
    :root {
        color-scheme: dark;
        --bg: #101318;
        --surface: #191e26;
        --surface-muted: #222a35;
        --surface-hover: #202833;
        --text-primary: #edf1f7;
        --text-secondary: #b2bdca;
        --text-muted: #8794a4;
        --accent: #79a7ff;
        --accent-hover: #9bbcff;
        --accent-light: #243653;
        --border: #343e4b;
        --border-light: #2a333f;
        --border-strong: #526174;
        --shadow-sm: 0 1px 3px rgb(0 0 0 / 0.28);
        --shadow: 0 8px 22px rgb(0 0 0 / 0.32);
    }

    .btn-primary {
        color: #101318;
    }

    .tool-card:hover {
        background: var(--surface-hover);
    }

    .role-picker-card {
        box-shadow: 0 24px 80px rgb(0 0 0 / 0.55);
    }
}

/* First-visit role picker */
.role-picker[hidden] { display: none !important; }
.role-picker {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: grid;
    place-items: center;
    padding: 24px;
    background: rgb(15 23 42 / 58%);
    backdrop-filter: blur(5px);
    overflow-y: auto;
    animation: rolePickerFadeIn 180ms ease-out;
}
.role-picker-card {
    width: min(100%, 520px);
    padding: clamp(24px, 5vw, 40px);
    border: 1px solid var(--border);
    border-radius: 18px;
    background: var(--surface);
    box-shadow: 0 24px 80px rgb(0 0 0 / 0.24);
}
.role-picker-brand {
    margin-bottom: 30px;
    color: var(--text-primary);
    font-size: 1.15rem;
    font-weight: 800;
    letter-spacing: -0.04em;
}
.role-picker-brand span { color: var(--accent); }
.role-picker-eyebrow {
    margin-bottom: 8px;
    color: var(--accent);
    font-size: 0.72rem;
    font-weight: 800;
    letter-spacing: 0.12em;
}
.role-picker-card h2 {
    color: var(--text-primary);
    font-size: clamp(1.6rem, 5vw, 2rem);
    line-height: 1.18;
    letter-spacing: -0.045em;
}
.role-picker-description {
    margin-top: 12px;
    margin-bottom: 24px;
    color: var(--text-secondary);
    font-size: 0.96rem;
}
.role-picker-options { display: grid; gap: 12px; }
.role-option {
    display: flex;
    align-items: center;
    gap: 14px;
    width: 100%;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: 12px;
    background: var(--surface);
    color: var(--text-primary);
    text-align: left;
    cursor: pointer;
    transition: border-color var(--transition), background var(--transition), transform var(--transition), box-shadow var(--transition);
}
.role-option:hover, .role-option:focus-visible {
    border-color: var(--accent);
    background: var(--accent-light);
    box-shadow: 0 0 0 3px rgb(37 99 235 / 10%);
    outline: none;
}
.role-option:active { transform: scale(0.99); }
.role-option-icon {
    display: grid;
    flex: 0 0 46px;
    width: 46px;
    height: 46px;
    place-items: center;
    border-radius: 12px;
    background: var(--surface-muted);
    font-size: 1.5rem;
}
.role-option-copy { display: grid; flex: 1; gap: 3px; }
.role-option-copy strong { font-size: 1rem; }
.role-option-copy span { color: var(--text-secondary); font-size: 0.83rem; line-height: 1.45; }
.role-option-arrow { color: var(--accent); font-size: 1.3rem; }
.role-picker-note { margin-top: 18px; color: var(--text-muted); font-size: 0.78rem; text-align: center; }
body.role-picker-open { overflow: hidden; }
@keyframes rolePickerFadeIn { from { opacity: 0; } to { opacity: 1; } }
@media (max-width: 420px) {
    .role-picker { padding: 14px; }
    .role-picker-card { padding: 24px 18px; }
    .role-option { gap: 10px; padding: 13px; }
    .role-option-icon { flex-basis: 40px; width: 40px; height: 40px; }
}
@media (prefers-reduced-motion: reduce) {
    .role-picker { animation: none; }
    .role-option { transition: none; }
}


/* Role-specific toolbox cards */
[data-role-section] {
    display: none;
}

html[data-user-role="teacher"] [data-role-section="teacher"],
html[data-user-role="student"] [data-role-section="student"] {
    display: grid;
}

.pangram-tool-card,
.quizpaste-tool-card {
    color: inherit;
    text-decoration: none;
}

.pangram-tool-card .external-tool-label,
.quizpaste-tool-card .external-tool-label {
    display: inline-block;
    margin-left: 0.25rem;
    padding: 0.12rem 0.35rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-muted);
    font-size: 0.62rem;
    font-weight: 650;
    letter-spacing: 0.02em;
    vertical-align: 0.12em;
}

.pangram-tool-card .tool-disclaimer,
.quizpaste-tool-card .tool-disclaimer {
    margin-top: 0.45rem;
    color: var(--text-muted);
    font-size: 0.7rem;
    line-height: 1.4;
}

@media (min-width: 900px) {
    html[data-user-role="teacher"] .tools-grid [data-role-section="teacher"],
    html[data-user-role="student"] .tools-grid [data-role-section="student"] {
        display: block;
    }
}


/* Word counter and QR generator */
.utility-tool {
    width: min(100%, 820px);
    margin: 0 auto;
    color: var(--text-primary);
}
.utility-intro { margin-bottom: 1.35rem; }
.utility-intro h4 { margin-bottom: 0.35rem; font-size: 1.2rem; font-weight: 750; }
.utility-intro p { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.55; }
.utility-label {
    display: block;
    margin-bottom: 0.45rem;
    color: var(--text-primary);
    font-size: 0.88rem;
    font-weight: 650;
}
.utility-textarea {
    display: block;
    width: 100%;
    min-height: 180px;
    padding: 0.9rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    color: var(--text-primary);
    font: inherit;
    line-height: 1.55;
    resize: vertical;
}
.utility-textarea:focus, .utility-select:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
.word-counter-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.65rem;
    margin-top: 0.85rem;
}
.word-counter-stat {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
    padding: 0.8rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
}
.word-counter-stat strong { font-size: clamp(1.15rem, 4vw, 1.65rem); line-height: 1.2; }
.word-counter-stat span { color: var(--text-secondary); font-size: 0.75rem; }
.utility-actions { display: flex; flex-wrap: wrap; gap: 0.55rem; margin-top: 0.85rem; }
.utility-status { min-height: 1.4em; margin-top: 0.65rem; color: var(--text-secondary); font-size: 0.82rem; }
.qr-input { min-height: 110px; }
.qr-controls {
    display: flex;
    align-items: end;
    flex-wrap: wrap;
    gap: 0.7rem;
    margin-top: 0.9rem;
}
.qr-controls .utility-label { margin: 0 0 0.45rem; }
.utility-select {
    min-height: 40px;
    padding: 0.5rem 0.65rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-primary);
    font: inherit;
}
.qr-result {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.85rem;
    width: fit-content;
    max-width: 100%;
    margin: 1rem auto 0;
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: #fff;
}
.qr-result[hidden] { display: none !important; }
.qr-code-canvas { display: grid; place-items: center; max-width: 100%; overflow: auto; }
.qr-code-canvas canvas, .qr-code-canvas img { display: block; max-width: 100%; height: auto; }
@media (max-width: 480px) {
    .word-counter-stats { grid-template-columns: 1fr 1fr; }
    .word-counter-stat:last-child { grid-column: 1 / -1; }
    .qr-controls { align-items: stretch; flex-direction: column; }
    .qr-controls .btn { width: 100%; }
}

/* Word Counter document import */
.word-counter-upload {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
    margin: 0 0 0.5rem;
    padding: 1rem;
    border: 1px dashed var(--border-strong);
    border-radius: var(--radius);
    background: var(--surface);
}
.word-counter-upload strong { display: block; margin-bottom: 0.2rem; color: var(--text-primary); font-size: 0.9rem; }
.word-counter-upload p { color: var(--text-secondary); font-size: 0.8rem; line-height: 1.45; }
.word-counter-upload label { cursor: pointer; }


/* Consistent navigation back to the toolbox from every tool. */
.tool-overlay-header {
    gap: 1rem;
}
.tool-overlay-header h3 {
    flex: 1;
    min-width: 0;
    text-align: center;
}
.tool-back {
    flex: 0 0 auto;
    white-space: nowrap;
}
.tool-back svg {
    flex: 0 0 auto;
}
@media (max-width: 480px) {
    .tool-overlay-header {
        gap: 0.55rem;
        padding: 0.7rem;
    }
    .tool-back {
        min-height: 38px;
        padding: 0.45rem 0.55rem;
        font-size: 0.78rem;
    }
    .tool-back svg {
        width: 14px;
        height: 14px;
    }
    .tool-overlay-header h3 {
        font-size: 0.88rem;
    }
}


/* Grade calculator and text formatter utilities */
.utility-number-input {
    display: block;
    width: 100%;
    min-height: 44px;
    margin: 0 0 1rem;
    padding: 0.65rem 0.75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface);
    color: var(--text-primary);
    font: inherit;
}
.utility-number-input:focus {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
.grade-calculator-fields {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    max-width: 520px;
}
.grade-calculator-fields .btn {
    justify-self: start;
}
.grade-result {
    margin-top: 1rem;
    padding: 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--surface);
    color: var(--text-primary);
    line-height: 1.5;
}
.grade-result strong {
    display: block;
    margin-bottom: 0.25rem;
    font-size: 1.8rem;
}
.grade-result.is-success { border-color: #22a06b; }
.grade-result.is-error { border-color: #d97706; }
.formatter-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.75rem;
}
.formatter-actions .btn { flex: 1 1 auto; }

/* Additional local utility tools */
.utility-select{width:100%;min-height:44px;padding:.65rem .75rem;border:1px solid var(--border);border-radius:10px;background:var(--surface);color:var(--text-primary);font:inherit;margin-bottom:.85rem}
.unit-converter-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.85rem}
.study-timer-presets{display:flex;flex-wrap:wrap;gap:.5rem;margin-bottom:1rem}
.study-timer-display{margin:1.25rem 0;text-align:center;font-size:clamp(3.5rem,12vw,6rem);font-weight:750;line-height:1.1;letter-spacing:-.06em;font-variant-numeric:tabular-nums;color:var(--text-primary)}
@media(max-width:560px){.unit-converter-grid{grid-template-columns:1fr;gap:0}.study-timer-presets .btn{flex:1 1 calc(50% - .5rem)}}