/* =====================================================
   LUMEN WEBSITE
   Landing page styles. The browser app (app.html) keeps
   using style.css and is not affected by anything here.
===================================================== */

/* Fonts (Fraunces + Inter, the same pair the app uses) are loaded from index.html. */

/* -----------------------------------------------------
   Tokens
----------------------------------------------------- */

:root {
    color-scheme: light;

    /* Colour: taken from the Lumen logo and the app */
    --paper: #f7f7fc;
    --surface: #ffffff;
    --tint: #eceefb;
    --line: #d5d8ea;
    --ink: #171a3f;
    --ink-soft: #464b6b;
    --brand: #5658aa;        /* text-safe brand indigo (6.2:1 on white) */
    --navy: #262a70;         /* buttons, dark band (12.8:1 on white) */
    --navy-deep: #1a1d55;
    --highlight: #a7afe8;    /* the app's active-button colour */
    --sky: #8fb0e6;          /* top of the logo gradient */

    /* Type */
    --font-display: "Fraunces", Georgia, "Times New Roman", serif;
    --font-body: "Inter", "Segoe UI", system-ui, -apple-system, Arial, sans-serif;

    --text-base: 1.0625rem;
    --text-small: 0.9375rem;
    --text-h3: 1.25rem;
    --text-h2: clamp(1.9rem, 1.35rem + 2vw, 2.9rem);
    --text-h1: clamp(2.3rem, 1.4rem + 3.8vw, 4.1rem);

    /* Shape and space */
    --radius-s: 12px;
    --radius-m: 18px;
    --container: 72rem;
    --gutter: 1.25rem;
    --section-space: clamp(4rem, 3rem + 5vw, 7.5rem);
    --header-height: 4.25rem;
}

/* -----------------------------------------------------
   Base
----------------------------------------------------- */

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

html {
    scroll-padding-top: calc(var(--header-height) + 1rem);
    -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}

body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.65;
    text-rendering: optimizeLegibility;
}

img {
    max-width: 100%;
    height: auto;
}

h1,
h2,
h3 {
    margin: 0;
    font-family: var(--font-display);
    font-weight: 600;
    letter-spacing: -0.015em;
    color: inherit;
}

h1 {
    font-size: var(--text-h1);
    line-height: 1.06;
}

h2 {
    font-size: var(--text-h2);
    line-height: 1.12;
}

h3 {
    font-size: var(--text-h3);
    line-height: 1.25;
}

p {
    margin: 0;
}

a {
    color: var(--brand);
    text-underline-offset: 0.2em;
}

a:hover {
    color: var(--navy);
}

:focus-visible {
    outline: 3px solid var(--navy);
    outline-offset: 3px;
    border-radius: 4px;
}

.band-dark :focus-visible {
    outline-color: #ffffff;
}

.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;
}

.skip-link {
    position: absolute;
    left: 1rem;
    top: -4rem;
    z-index: 100;
    padding: 0.75rem 1.25rem;
    background: var(--navy);
    color: #ffffff;
    font-weight: 600;
    border-radius: var(--radius-s);
    text-decoration: none;
}

.skip-link:focus {
    top: 1rem;
    color: #ffffff;
}

/* -----------------------------------------------------
   Layout helpers
----------------------------------------------------- */

.container {
    width: min(var(--container), 100% - (var(--gutter) * 2));
    margin-inline: auto;
}

.section {
    padding-block: var(--section-space);
}

.band-tint {
    background: var(--tint);
}

.band-white {
    background: var(--surface);
}

.band-dark {
    background: var(--navy);
    color: #ffffff;
}

.measure {
    max-width: 38rem;
}

.lead {
    font-size: 1.1875rem;
    color: var(--ink-soft);
}

.band-dark .lead {
    color: #dfe1f7;
}

.stack > * + * {
    margin-top: 1.25rem;
}

.split {
    display: grid;
    gap: 2.5rem;
}

@media (min-width: 60rem) {
    .split {
        grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
        gap: 5rem;
        align-items: start;
    }
}

.small-note {
    font-size: var(--text-small);
    color: var(--ink-soft);
}

/* -----------------------------------------------------
   Buttons
----------------------------------------------------- */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 3rem;
    padding: 0.7rem 1.6rem;

    border: 2px solid var(--navy);
    border-radius: 999px;

    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    line-height: 1.2;
    text-align: center;
    text-decoration: none;

    cursor: pointer;
    transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn-primary {
    background: var(--navy);
    color: #ffffff;
}

.btn-primary:hover {
    background: var(--navy-deep);
    border-color: var(--navy-deep);
    color: #ffffff;
}

.btn-secondary {
    background: transparent;
    color: var(--navy);
}

.btn-secondary:hover {
    background: var(--tint);
    color: var(--navy);
}

.button-row {
    display: flex;
    flex-wrap: wrap;
    gap: 0.875rem;
}

@media (max-width: 30rem) {
    .button-row .btn {
        width: 100%;
    }
}

/* Links that are not set up yet stay out of the way. */
[hidden] {
    display: none !important;
}

/* -----------------------------------------------------
   Header and navigation
----------------------------------------------------- */

.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem 1.5rem;
    min-height: var(--header-height);
}

.brand-link {
    display: inline-flex;
    align-items: center;
    padding-block: 0.5rem;
}

.brand-link img {
    display: block;
    height: 2.25rem;
    width: auto;
}

.site-nav ul {
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 1.5rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.site-nav a {
    display: inline-block;
    padding: 0.5rem 0.125rem;

    color: var(--ink);
    font-size: var(--text-small);
    font-weight: 500;
    text-decoration: none;

    border-bottom: 3px solid transparent;
}

.site-nav a:hover {
    color: var(--brand);
    border-bottom-color: var(--line);
}

/* Current section: underline plus heavier weight, not colour alone */
.site-nav a[aria-current] {
    font-weight: 700;
    border-bottom-color: var(--navy);
}

.nav-toggle {
    display: none;
    min-height: 2.75rem;
    padding: 0.5rem 1.1rem;

    background: transparent;
    color: var(--navy);
    border: 2px solid var(--navy);
    border-radius: 999px;

    font-family: var(--font-body);
    font-size: var(--text-small);
    font-weight: 600;
    cursor: pointer;
}

@media (max-width: 55rem) {

    .js .nav-toggle {
        display: inline-flex;
        align-items: center;
    }

    .js .site-nav {
        display: none;
        flex-basis: 100%;
        padding-bottom: 0.75rem;
    }

    .js .site-nav.is-open {
        display: block;
    }

    .js .site-nav ul {
        flex-direction: column;
        gap: 0;
    }

    .js .site-nav a {
        display: block;
        padding: 0.85rem 0.25rem;
        border-bottom: 1px solid var(--line);
        font-size: 1.0625rem;
    }

    .js .site-nav a[aria-current] {
        border-bottom-color: var(--navy);
    }
}

/* -----------------------------------------------------
   Hero
----------------------------------------------------- */

.hero {
    padding-block: clamp(2.5rem, 1.5rem + 5vw, 5.5rem) var(--section-space);
}

.hero-grid {
    display: grid;
    gap: 3rem;
    align-items: center;
}

@media (min-width: 60rem) {
    .hero-grid {
        grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
        gap: 4.5rem;
    }
}

.hero-copy h1 {
    max-width: 17ch;
}

.hero-copy .lead {
    max-width: 34rem;
    margin-top: 1.5rem;
}

.hero-copy .button-row {
    margin-top: 2rem;
}

.hero-copy .small-note {
    margin-top: 1.25rem;
}

/* -----------------------------------------------------
   Board illustration (hero)
   A simplified drawing of the real Lumen board, using
   the app's own words, order and colours.
----------------------------------------------------- */

.demo {
    width: 100%;
    max-width: 26rem;
    margin-inline: auto;
}

@media (min-width: 60rem) {
    .demo {
        margin-inline: 0 0;
        justify-self: end;
    }
}

.demo-frame {
    padding: 1.1rem;
    background: var(--tint);
    border: 1px solid var(--line);
    border-radius: var(--radius-m);
}

.demo-screen {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 2.9rem;
    margin-bottom: 0.75rem;

    background: #0d0f26;
    color: #ffffff;
    border-radius: var(--radius-s);

    font-size: 1.125rem;
    font-weight: 500;
}

.demo-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.6rem;
}

.demo-cell {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 3.4rem;
    padding: 0.5rem 0.25rem;

    background: var(--surface);
    color: var(--ink);
    border: 2px solid var(--line);
    border-radius: var(--radius-s);

    font-size: clamp(0.8rem, 0.55rem + 1.2vw, 0.95rem);
    font-weight: 600;
    text-align: center;
    line-height: 1.2;

    transition: background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

/* The highlight that steps across the board */
.demo-cell.is-scanned {
    background: var(--highlight);
    border-color: var(--navy);
}

/* The button chosen by the gesture */
.demo-cell.is-selected {
    background: var(--navy);
    border-color: var(--navy);
    color: #ffffff;
}

.demo-spoken {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    min-height: 2.5rem;
    margin-top: 0.75rem;
    padding-inline: 0.25rem;

    color: var(--ink);
    font-size: var(--text-small);
    font-weight: 600;
}

.demo-spoken svg {
    flex: none;
    color: var(--navy);
}

.demo-spoken[data-visible="false"] {
    visibility: hidden;
}

.demo-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
    margin-top: 0.875rem;
}

.demo-toggle {
    min-height: 2.75rem;
    padding: 0.4rem 1.1rem;

    background: transparent;
    color: var(--navy);
    border: 2px solid var(--navy);
    border-radius: 999px;

    font-family: var(--font-body);
    font-size: var(--text-small);
    font-weight: 600;
    cursor: pointer;
}

.demo-toggle:hover {
    background: var(--tint);
}

.demo .small-note {
    max-width: 22rem;
}

/* -----------------------------------------------------
   Problem
----------------------------------------------------- */

.problem-copy {
    display: grid;
    gap: 1.25rem;
    font-size: 1.125rem;
}

.problem-copy p {
    max-width: 36rem;
}

/* -----------------------------------------------------
   How it works
----------------------------------------------------- */

.section-head {
    max-width: 44rem;
    margin-bottom: clamp(2.5rem, 2rem + 2vw, 4rem);
}

.section-head .lead {
    margin-top: 1rem;
}

.steps {
    display: grid;
    gap: 2.25rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

@media (min-width: 40rem) {
    .steps {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 2.5rem 2rem;
    }
}

@media (min-width: 64rem) {
    .steps {
        grid-template-columns: repeat(4, minmax(0, 1fr));
        gap: 2rem;
    }
}

.step {
    padding-top: 1.25rem;
    border-top: 3px solid var(--navy);
}

.step-number {
    display: block;
    margin-bottom: 0.5rem;

    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 500;
    line-height: 1;
    color: var(--brand);
}

.step h3 {
    margin-bottom: 0.6rem;
}

.step p {
    color: var(--ink-soft);
}

.steps-footnote {
    margin-top: 2.5rem;
}

/* -----------------------------------------------------
   Features
----------------------------------------------------- */

.feature-list {
    display: grid;
    gap: 2.25rem 3rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

@media (min-width: 42rem) {
    .feature-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (min-width: 64rem) {
    .feature-list {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

.feature {
    padding-top: 1.1rem;
    border-top: 1px solid var(--ink);
}

.feature h3 {
    margin-bottom: 0.5rem;
}

.feature p {
    color: var(--ink-soft);
}

/* -----------------------------------------------------
   Try / Download
----------------------------------------------------- */

.expect-list {
    display: grid;
    gap: 1rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.expect-list li {
    display: grid;
    grid-template-columns: 1.5rem minmax(0, 1fr);
    gap: 0.75rem;
}

.expect-list svg {
    margin-top: 0.3rem;
    color: var(--navy);
}

.panel {
    padding: clamp(1.5rem, 1rem + 2vw, 2.25rem);
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-m);
}

.panel h3 {
    margin-bottom: 1.25rem;
}

.facts {
    display: grid;
    gap: 0;
    margin: 0;
}

.facts div {
    display: grid;
    grid-template-columns: 7rem minmax(0, 1fr);
    gap: 1rem;
    padding-block: 0.85rem;
    border-bottom: 1px solid var(--line);
}

.facts div:first-child {
    border-top: 1px solid var(--line);
}

.facts dt {
    color: var(--ink-soft);
    font-size: var(--text-small);
}

.facts dd {
    margin: 0;
    font-weight: 600;
    overflow-wrap: anywhere;
}

.panel .button-row,
.panel .pending-note {
    margin-top: 1.5rem;
}

.pending-note {
    padding: 0.85rem 1rem;
    background: var(--tint);
    border-left: 4px solid var(--navy);
    border-radius: 0 var(--radius-s) var(--radius-s) 0;
    font-size: var(--text-small);
}

/* -----------------------------------------------------
   Mission
----------------------------------------------------- */

.mission {
    text-align: left;
}

.mission h2 {
    max-width: 22ch;
    font-size: clamp(2.1rem, 1.4rem + 3.2vw, 3.9rem);
    line-height: 1.08;
}

.mission .lead {
    margin-top: 1.5rem;
    max-width: 34rem;
}

.motto {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 2.5rem;

    font-family: var(--font-display);
    font-size: 1.25rem;
    font-weight: 500;
}

.motto img {
    width: 2rem;
    height: auto;
    filter: brightness(1.9) saturate(0.7);   /* the star is decorative; lift it off the navy */
}

/* -----------------------------------------------------
   About
----------------------------------------------------- */

.details {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-m);
}

.details summary {
    padding: 1.1rem 1.5rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: var(--radius-m);
}

.details[open] summary {
    border-bottom: 1px solid var(--line);
    border-radius: var(--radius-m) var(--radius-m) 0 0;
}

.tech-list {
    display: grid;
    gap: 1.1rem;
    margin: 0;
    padding: 1.25rem 1.5rem 1.5rem;
}

.tech-list dt {
    font-weight: 600;
}

.tech-list dd {
    margin: 0.15rem 0 0;
    color: var(--ink-soft);
    font-size: var(--text-small);
}

.tech-credit {
    padding: 0 1.5rem 1.5rem;
}

/* -----------------------------------------------------
   Feedback
----------------------------------------------------- */

.feedback-list {
    display: grid;
    gap: 0.6rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.feedback-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--line);
    font-weight: 500;
}

.feedback-list li:first-child {
    border-top: 1px solid var(--line);
}

/* -----------------------------------------------------
   Footer
----------------------------------------------------- */

.site-footer {
    padding-block: 3.5rem 2.5rem;
    background: var(--surface);
    border-top: 1px solid var(--line);
    font-size: var(--text-small);
}

.footer-grid {
    display: grid;
    gap: 2.5rem;
}

@media (min-width: 48rem) {
    .footer-grid {
        grid-template-columns: minmax(0, 1.3fr) repeat(2, minmax(0, 1fr));
    }
}

.footer-brand img {
    display: block;
    height: 2.25rem;
    width: auto;
    margin-bottom: 1rem;
}

.footer-brand p {
    max-width: 22rem;
    color: var(--ink-soft);
}

.site-footer h2 {
    margin-bottom: 0.75rem;
    font-family: var(--font-body);
    font-size: var(--text-small);
    font-weight: 700;
    letter-spacing: 0;
}

.footer-links {
    display: grid;
    gap: 0.25rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.footer-links a {
    display: inline-block;
    padding-block: 0.3rem;
    color: var(--ink);
}

.footer-links a:hover {
    color: var(--brand);
}

.footer-legal {
    margin-top: 2.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--line);
    color: var(--ink-soft);
}

/* -----------------------------------------------------
   Reduced motion
   The board illustration stays still (see site.js) and
   colour changes happen instantly.
----------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}