/* || Root Variables */

:root {
    --font-h1: 3rem;
    --font-subtitle: 1.4rem;
    --font-nav-logo: 1.65rem;
    --font-nav-link: 1.2rem;
    --font-section-h2: 2.25rem;
    --font-section-p: 1.25rem;
    --font-card: 1.25rem;

    --line-tight: 1.2;
    --line-normal: 1.5;
    --line-relaxed: 1.65;

    --landing-colour-taster: #FFB350;
    --landing-colour-taster-hover: #FFA500;
    --landing-gradient-start: rgba(162, 226, 159, 0.5);
    --landing-gradient-end: rgba(21, 182, 13, 0.5);
    --landing-gradient-start-hover: rgba(162, 226, 159, 0.7);
    --landing-gradient-end-hover: rgba(21, 182, 13, 0.7);
    --landing-card-method-bg: #C5EDFF;
    --landing-card-use-lingual-bg: #FFDFC5;
    --landing-section-why-lingual-bg: #fff0e4;
    --landing-section-use-lingual-bg: #e8f5ef;
    --landing-section-cta-bg: #eef5ff;
}

#body {
    width: 100%;
}

/* || Navigation */

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--auth-colour-accent-soft);
    height: var(--nav-height);
    padding: 0 2rem;
    box-sizing: border-box;
    box-shadow: 0 2px 4px var(--colour-overlay-medium);
    position: fixed;
    width: 100%;
    top: 0;
    left: 0;
    z-index: var(--z-index-nav);
}

nav a#logo {
    font-size: var(--font-nav-logo);
    font-weight: 700;
    margin: 0;
    text-decoration: none;
    color: var(--colour-text-primary);
    letter-spacing: -0.02em;
}

nav #nav-menu {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 2.5rem;
    margin-left: auto;
}

nav ul#nav-links {
    list-style: none;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2.5rem;
    padding: 0;
    margin: 0;
    font-weight: 500;
}

nav ul#nav-links li a {
    font-size: var(--font-nav-link);
    text-decoration: none;
    color: var(--colour-text-primary);
    transition: color 0.2s ease;
}

nav ul#nav-links li a:hover {
    color: var(--auth-colour-link-hover);
    cursor: pointer;
}

nav ul#nav-links li a:focus-visible,
nav ul#nav-links li.taster a:focus-visible,
nav a#get-started-btn:focus-visible,
nav #nav-toggle:focus-visible {
    outline: 2px solid var(--colour-focus);
    outline-offset: 2px;
}

nav ul#nav-links li.taster a {
    background: var(--landing-colour-taster);
    padding: 0.5rem 1rem;
    border-radius: 1.5rem;
    color: var(--colour-text-primary);
    transition: background-color 0.2s ease, transform 0.2s ease;
}

nav ul#nav-links li.taster a:hover {
    background: var(--landing-colour-taster-hover);
    transform: scale(1.05);
}

nav a#get-started-btn {
    background: linear-gradient(90deg, var(--landing-gradient-start), var(--landing-gradient-end));
    padding: 0.625rem 1.25rem;
    border-radius: 0.5rem;
    font-size: var(--font-nav-link);
    text-align: center;
    text-decoration: none;
    color: var(--colour-text-primary);
    font-weight: 600;
    transition: background 0.2s ease, transform 0.2s ease;
}

nav a#get-started-btn:hover {
    background: linear-gradient(90deg, var(--landing-gradient-start-hover), var(--landing-gradient-end-hover));
    transform: scale(1.05);
}

nav #nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    height: 2.5rem;
    padding: 0.25rem;
    border: none;
    border-radius: 999px;
    background-color: var(--colour-overlay-light);
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

nav #nav-toggle:hover {
    background-color: var(--colour-overlay-light-strong);
    transform: scale(1.05);
}

nav #nav-toggle svg {
    width: 1.5rem;
    height: 1.5rem;
}

nav.nav-collapsed #nav-menu {
    display: none;
}

nav.nav-collapsed #nav-toggle {
    display: inline-flex;
}

nav.nav-collapsed.nav-open #nav-menu {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
    position: absolute;
    top: calc(var(--nav-height) + 0.5rem);
    right: 1rem;
    left: 1rem;
    padding: 0.75rem;
    background: var(--auth-colour-accent-soft);
    border: 1px solid var(--colour-border-overlay);
    border-radius: 1rem;
    box-shadow: 0 8px 20px var(--colour-overlay-medium);
    z-index: calc(var(--z-index-nav) + 1);
}

nav.nav-collapsed.nav-open ul#nav-links {
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
}

nav.nav-collapsed.nav-open ul#nav-links li a {
    display: block;
    width: 100%;
    padding: 0.5rem 0.75rem;
    border-radius: 0.75rem;
}

nav.nav-collapsed.nav-open a#get-started-btn {
    width: 100%;
    max-width: none;
}

/* || Landing Section */

section#welcome {
    background: var(--auth-colour-bg-accent-1);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
    padding: 4.5rem 10%;
    min-height: calc(100vh - var(--nav-height));
    box-sizing: border-box;
    position: relative;
    margin-top: var(--nav-height);
}

section#welcome h1 {
    font-size: var(--font-h1);
    line-height: var(--line-tight);
    margin: 0;
    color: var(--colour-text-primary);
    font-weight: 700;
}

section#welcome p.subtitle {
    font-family: "Hannari";
    font-size: var(--font-subtitle);
    line-height: var(--line-normal);
    max-width: 800px;
    margin-top: 1.5rem;
    color: var(--colour-text-secondary);
}

section#welcome .cards {
    display: flex;
    flex-direction: row;
    justify-content: flex-start;
    align-items: center;
    gap: 1.75rem;
    margin-top: 3rem;
    width: 100%;
    box-sizing: border-box;
}

section#welcome .cards .card {
    width: 14rem;
    height: 5rem;
    border-radius: 1rem;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: var(--font-card);
    font-weight: 600;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    text-align: center;
    cursor: pointer;
    color: var(--colour-text-primary);
    box-shadow: 0 2px 8px var(--colour-overlay-soft);
}

section#welcome .cards .card.method {
    background: var(--landing-card-method-bg);
}

section#welcome .cards .card.use-lingual {
    background: var(--landing-card-use-lingual-bg);
}

section#welcome .cards .card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 16px var(--colour-overlay-medium);
}

/* || Shared Section Styles */

.info-section {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-sizing: border-box;
    padding: 5rem 10%;
    min-height: 100vh;
}

.info-section h2 {
    font-size: var(--font-section-h2);
    margin: 0;
    color: var(--colour-text-primary);
    font-weight: 700;
    text-align: center;
}

.info-section p {
    font-size: var(--font-section-p);
    max-width: 800px;
    line-height: var(--line-relaxed);
    margin-top: 1.5rem;
    color: var(--colour-text-secondary);
    text-align: center;
}

/* || Individual Sections */

#purpose {
    background: var(--auth-colour-soft-purple);
}

#why-lingual {
    background: var(--landing-section-why-lingual-bg);
}

#use-lingual {
    background: var(--landing-section-use-lingual-bg);
}

#final-cta {
    background: var(--landing-section-cta-bg);
}

.feature-grid {
    width: 100%;
    max-width: 1000px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.8rem;
    margin-top: 2rem;
}

.feature-grid .feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 1rem;
    padding: 1.1rem;
    box-shadow: 0 1px 4px var(--colour-overlay-soft);
}

.feature-grid .feature-card h3 {
    margin: 0;
    color: var(--colour-text-primary);
}

.feature-grid .feature-card p {
    margin-top: 0.7rem;
}

.cta-btn {
    margin-top: 2rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.4rem;
    border-radius: 999px;
    background: linear-gradient(90deg, var(--landing-gradient-start), var(--landing-gradient-end));
    color: var(--colour-text-primary);
    text-decoration: none;
    font-weight: 700;
    transition: background 0.2s ease, transform 0.2s ease;
}

.cta-btn:hover {
    background: linear-gradient(90deg, var(--landing-gradient-start-hover), var(--landing-gradient-end-hover));
    transform: translateY(-1px);
}

.cta-btn:focus-visible,
section#welcome .cards .card:focus-visible {
    outline: 2px solid var(--colour-focus);
    outline-offset: 2px;
}

/* || Responsive Breakpoints */

@media (max-width: 1024px) {
    section#welcome {
        padding: 4rem 8%;
        align-items: center;
        text-align: center;
    }

    section#welcome p.subtitle {
        max-width: 100%;
    }

    section#welcome .cards {
        justify-content: center;
        flex-wrap: wrap;
    }
}

@media (max-width: 900px) {
    nav {
        padding: 1rem 1.25rem;
    }

    nav #nav-menu {
        gap: 1.5rem;
    }

    section#welcome {
        min-height: auto;
        padding: 3.5rem 6% 4rem;
    }

    section#welcome h1 {
        font-size: 2.4rem;
    }

    section#welcome .cards {
        flex-direction: column;
        align-items: center;
        margin-top: 2rem;
    }

    section#welcome .cards .card {
        width: 100%;
        max-width: 20rem;
        height: auto;
        padding: 1rem;
    }

    .info-section {
        padding: 3.5rem 6%;
        min-height: auto;
    }
}

@media (max-width: 600px) {
    section#welcome h1 {
        font-size: 2rem;
    }

    section#welcome p.subtitle {
        font-size: 1.1rem;
    }

    .info-section h2 {
        font-size: 1.8rem;
    }

    .info-section p {
        font-size: 1.1rem;
    }
}