/* www/styles.css — homepage + shared styling.
 *
 * Refactored at F4.C2.3: every literal hex colour was replaced with a
 * brand token from www/brand.css (loaded before this file). The CTA
 * border-on-dark uses an `rgba()` overlay (a CSS feature, not a brand
 * decision) so it stays alpha-blended over the parent surface; the
 * brand-token allowlist permits `rgba()` literals. No bare `#...`
 * literal appears below this comment (enforced by
 * tests/check-brand-assets.sh — BR4.C2.1).
 */

/* ---- Reset & Base ---- */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--brand-font-family);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background: var(--brand-bg-page);
}

/* ---- Header ---- */

header {
    position: absolute;
    top: 0;
    width: 100%;
    z-index: 100;
    padding: 1.5rem 2rem;
}

nav {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.125rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.85);
    text-decoration: none;
    letter-spacing: -0.01em;
}

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

.nav-logged-out,
.nav-logged-in {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-user {
    color: rgba(255, 255, 255, 0.65);
    font-size: 0.875rem;
    margin-right: 0.25rem;
}

.btn-nav-login {
    background: transparent;
    color: rgba(255, 255, 255, 0.75);
    border: none;
    padding: 0.5rem 0.875rem;
    font-size: 0.875rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    border-radius: 6px;
    transition: color 0.15s;
}

.btn-nav-login:hover {
    color: rgba(255, 255, 255, 0.95);
}

.btn-nav-signup {
    background: rgba(255, 255, 255, 0.12);
    color: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(255, 255, 255, 0.15);
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    border-radius: 6px;
    transition: background 0.15s, border-color 0.15s;
}

.btn-nav-signup:hover {
    background: rgba(255, 255, 255, 0.18);
    border-color: rgba(255, 255, 255, 0.25);
}

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

.hero {
    min-height: 100vh;
    background: var(--brand-bg-page);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    overflow: hidden;
}

/* Stars */
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        radial-gradient(1px 1px at 12% 22%, rgba(255, 255, 255, 0.6), transparent),
        radial-gradient(1.5px 1.5px at 28% 68%, rgba(255, 255, 255, 0.4), transparent),
        radial-gradient(1px 1px at 45% 12%, rgba(255, 255, 255, 0.7), transparent),
        radial-gradient(1px 1px at 62% 38%, rgba(255, 255, 255, 0.35), transparent),
        radial-gradient(1.5px 1.5px at 78% 55%, rgba(255, 255, 255, 0.5), transparent),
        radial-gradient(1px 1px at 8% 82%, rgba(255, 255, 255, 0.25), transparent),
        radial-gradient(1px 1px at 35% 48%, rgba(255, 255, 255, 0.45), transparent),
        radial-gradient(1px 1px at 55% 78%, rgba(255, 255, 255, 0.3), transparent),
        radial-gradient(1.5px 1.5px at 88% 18%, rgba(255, 255, 255, 0.55), transparent),
        radial-gradient(1px 1px at 92% 72%, rgba(255, 255, 255, 0.3), transparent),
        radial-gradient(1px 1px at 18% 42%, rgba(255, 255, 255, 0.5), transparent),
        radial-gradient(1px 1px at 72% 85%, rgba(255, 255, 255, 0.2), transparent);
    animation: twinkle 4s ease-in-out infinite alternate;
}

/* Faint dawn glow at horizon */
.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 35%;
    background: radial-gradient(ellipse 100% 100% at 50% 100%, rgba(30, 16, 64, 0.4), transparent);
    pointer-events: none;
}

.hero-content {
    text-align: center;
    padding: 2rem;
    position: relative;
    z-index: 1;
}

.hero-content h1 {
    font-size: clamp(2.5rem, 5vw + 1rem, 4rem);
    font-weight: 700;
    color: rgba(255, 255, 255, 0.95);
    letter-spacing: -0.03em;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.hero-content p {
    font-size: clamp(1rem, 1.5vw + 0.5rem, 1.25rem);
    color: rgba(255, 255, 255, 0.5);
    max-width: 460px;
    margin: 0 auto;
    line-height: 1.6;
}

/* Scroll indicator */
.scroll-hint {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    z-index: 1;
    animation: bob 2.5s ease-in-out infinite;
}

.scroll-hint::before {
    content: '';
    display: block;
    width: 16px;
    height: 16px;
    border-right: 1.5px solid rgba(255, 255, 255, 0.2);
    border-bottom: 1.5px solid rgba(255, 255, 255, 0.2);
    transform: rotate(45deg);
}

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

.features {
    background: linear-gradient(180deg, var(--brand-night-1) 0%, var(--brand-night-2) 100%);
    padding: 8rem 2rem;
}

.container {
    max-width: 960px;
    margin: 0 auto;
}

.features h2 {
    font-size: clamp(1.5rem, 3vw + 0.5rem, 2.25rem);
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    text-align: center;
    margin-bottom: 4rem;
    letter-spacing: -0.02em;
}

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

.feature {
    padding: 2rem;
    border-radius: var(--brand-radius-card);
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid rgba(255, 255, 255, 0.06);
    transition: background 0.2s;
}

.feature:hover {
    background: rgba(255, 255, 255, 0.06);
}

.feature h3 {
    font-size: 1.125rem;
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 0.75rem;
    letter-spacing: -0.01em;
}

.feature p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 0.95rem;
    line-height: 1.65;
}

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

.mission {
    background: linear-gradient(180deg, var(--brand-night-2) 0%, var(--brand-night-3) 50%, var(--brand-violet) 100%);
    padding: 8rem 2rem;
    text-align: center;
}

.mission h2 {
    font-size: clamp(1.5rem, 3vw + 0.5rem, 2.25rem);
    font-weight: 600;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 2rem;
    letter-spacing: -0.02em;
}

.mission p {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.6);
    max-width: 540px;
    margin: 0 auto 1rem;
    line-height: 1.7;
}

.mission strong {
    color: rgba(255, 255, 255, 0.85);
}

/* ---- CTA ---- */

.cta {
    background: linear-gradient(180deg, var(--brand-violet) 0%, var(--brand-rust) 100%);
    padding: 8rem 2rem;
    text-align: center;
}

.cta h2 {
    font-size: clamp(1.5rem, 3vw + 0.5rem, 2.25rem);
    font-weight: 600;
    color: rgba(255, 255, 255, 0.95);
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.cta p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
}

.cta-buttons {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    flex-wrap: wrap;
}

.cta-welcome {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.1rem;
}

.btn-cta-signup {
    padding: 0.875rem 1.75rem;
    background: rgba(255, 255, 255, 0.93);
    color: var(--brand-rust);
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    font-family: inherit;
    cursor: pointer;
    transition: transform 0.15s, background 0.15s;
}

.btn-cta-signup:hover {
    transform: translateY(-1px);
    background: var(--brand-fg-on-warm);
}

.btn-cta-signup:active {
    transform: translateY(0);
}

.btn-cta-login {
    padding: 0.875rem 1.75rem;
    background: transparent;
    color: rgba(255, 255, 255, 0.85);
    border: 1.5px solid rgba(255, 255, 255, 0.25);
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: transform 0.15s, border-color 0.15s;
}

.btn-cta-login:hover {
    transform: translateY(-1px);
    border-color: rgba(255, 255, 255, 0.45);
}

.btn-cta-login:active {
    transform: translateY(0);
}

/* ---- Sunrise gradient ---- */

.sunrise {
    height: 30vh;
    min-height: 150px;
    max-height: 300px;
    background: linear-gradient(180deg,
        var(--brand-rust)   0%,
        var(--brand-dawn-1) 30%,
        var(--brand-dawn-2) 55%,
        var(--brand-dawn-3) 80%,
        var(--brand-accent) 100%);
}

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

footer {
    background: var(--brand-accent);
    padding: 2.5rem 2rem;
    text-align: center;
}

footer p {
    color: rgba(69, 26, 3, 0.45);
    font-size: 0.875rem;
}

/* ---- Scroll reveal ---- */

.fade-in {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.feature.fade-in:nth-child(2) {
    transition-delay: 0.1s;
}

.feature.fade-in:nth-child(3) {
    transition-delay: 0.2s;
}

/* ---- Toast notification ---- */

.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(16px);
    background: rgba(0, 0, 0, 0.85);
    color: white;
    padding: 0.875rem 1.5rem;
    border-radius: 8px;
    font-size: 0.925rem;
    font-family: inherit;
    opacity: 0;
    transition: opacity 0.3s, transform 0.3s;
    z-index: 1000;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.toast.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ---- Animations ---- */

@keyframes twinkle {
    from { opacity: 0.5; }
    to { opacity: 1; }
}

@keyframes bob {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* ---- Accessibility ---- */

@media (prefers-reduced-motion: reduce) {
    .fade-in {
        opacity: 1;
        transform: none;
        transition: none;
    }

    .hero::before {
        animation: none;
        opacity: 0.8;
    }

    .scroll-hint {
        animation: none;
    }
}

/* ---- Responsive ---- */

@media (max-width: 768px) {
    header {
        padding: 1.25rem 1.5rem;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 1.25rem;
    }

    .feature.fade-in:nth-child(2),
    .feature.fade-in:nth-child(3) {
        transition-delay: 0s;
    }

    .features,
    .mission,
    .cta {
        padding: 5rem 1.5rem;
    }
}

@media (max-width: 480px) {
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn-cta-signup,
    .btn-cta-login {
        width: 100%;
        max-width: 280px;
    }

    .nav-auth {
        gap: 0.25rem;
    }

    .btn-nav-login {
        padding: 0.4rem 0.5rem;
        font-size: 0.8rem;
    }

    .btn-nav-signup {
        padding: 0.4rem 0.75rem;
        font-size: 0.8rem;
    }
}