/* ═══════════════════════════════════════════════════════════
   MyPeptideApp — Landing Pages Shared Styles
   Design tokens, navbar, footer, animations, and responsive.
   Used by: landing.php, changelog.php, and future static pages.
   ═══════════════════════════════════════════════════════════ */

/* ─── Design Tokens (matching app variables.css) ─────── */
:root {
    --color-primary: #000000;
    --color-primary-hover: #1a1a1a;
    --color-bg: #ffffff;
    --color-bg-secondary: #F9FAFB;
    --color-bg-tertiary: #F3F4F6;
    --color-border: #E5E7EB;
    --color-border-light: #F3F4F6;
    --color-text-primary: #111827;
    --color-text-secondary: #6B7280;
    --color-text-tertiary: #9CA3AF;
    --color-text-inverse: #FFFFFF;
    --color-success: #10B981;
    --color-info: #3B82F6;
    --color-warning: #F59E0B;

    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-full: 9999px;

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 8px 10px -6px rgba(0,0,0,0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(0,0,0,0.15);
}

/* ─── Reset & Base ───────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; scroll-behavior: smooth; -webkit-font-smoothing: antialiased; color-scheme: light; }
body {
    font-family: var(--font-sans);
    color: var(--color-text-primary);
    background: var(--color-bg);
    line-height: 1.6;
    overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { display: block; max-width: 100%; }
::selection { background: var(--color-primary); color: var(--color-text-inverse); }

/* ─── Navbar ─────────────────────────────────────────── */
.lp-nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    background: rgba(255,255,255,0.75);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    transition: background 0.2s, backdrop-filter 0.2s;
}
.lp-nav-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
    position: relative;
    z-index: 4; /* stays above backdrop and mobile menu overlay */
}
.lp-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.125rem;
    letter-spacing: -0.02em;
}
.lp-logo-icon {
    width: 32px; height: 32px;
    background: var(--color-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-inverse);
}
.lp-nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}
.lp-nav-link {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: color 0.15s;
}
.lp-nav-link:hover { color: var(--color-text-primary); }
.lp-nav-cta {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text-inverse);
    background: var(--color-primary);
    padding: 10px 24px;
    border-radius: var(--radius-full);
    transition: background 0.15s, transform 0.15s;
}
.lp-nav-cta:hover { background: var(--color-primary-hover); transform: translateY(-1px); }

/* ─── Animated hamburger (3 bars → X) ───── */
.lp-hamburger {
    display: none;
    background: none; border: none;
    cursor: pointer; padding: 8px;
    color: var(--color-text-primary);
    position: relative;
    width: 40px;
    height: 40px;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    border-radius: var(--radius-sm);
    transition: background 0.15s;
    -webkit-tap-highlight-color: transparent;
}
.hamburger-bar {
    display: block;
    width: 20px;
    height: 2px;
    background: currentColor;
    border-radius: 1px;
    transition: transform 0.3s cubic-bezier(0.77,0,0.18,1),
                opacity 0.2s ease;
    transform-origin: center;
}
/* Animate to X when open */
.lp-nav.menu-open .hamburger-bar:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.lp-nav.menu-open .hamburger-bar:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}
.lp-nav.menu-open .hamburger-bar:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ─── Mobile menu (full-height overlay) ─── */
.lp-mobile-menu {
    display: none;
    position: fixed;
    top: 72px; left: 0; right: 0;
    bottom: 0;
    background: var(--color-bg);
    z-index: 2;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
}
.lp-mobile-menu.open {
    display: flex;
    flex-direction: column;
    animation: mobileMenuIn 0.3s cubic-bezier(0.16,1,0.3,1) forwards;
}
@keyframes mobileMenuIn {
    from { opacity: 0; transform: translateY(-12px); }
    to   { opacity: 1; transform: translateY(0); }
}
.lp-mobile-menu-content {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    flex: 1;
    padding: 12px 24px 32px;
}
.lp-mobile-menu-links {
    display: flex;
    flex-direction: column;
    gap: 0;
    border-bottom: 1px solid var(--color-border-light);
}
.lp-mobile-menu-links a {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 18px 4px;
    font-size: 1.0625rem;
    font-weight: 400;
    color: var(--color-text-primary);
    border-top: 1px solid var(--color-border-light);
    transition: color 0.15s;
    -webkit-tap-highlight-color: transparent;
    opacity: 0;
    transform: translateY(8px);
}
.lp-mobile-menu-links a:active { color: var(--color-text-secondary); }

/* Chevron arrow */
.lp-mobile-menu-links a::after {
    content: '';
    width: 7px;
    height: 7px;
    border-right: 1.5px solid var(--color-text-tertiary);
    border-bottom: 1.5px solid var(--color-text-tertiary);
    transform: rotate(-45deg);
    flex-shrink: 0;
    margin-left: 12px;
    transition: transform 0.15s;
}
.lp-mobile-menu-links a:active::after {
    transform: rotate(-45deg) translate(1px, 1px);
}

/* stagger animation — triggered via .animating class from JS */
.lp-mobile-menu-links a.animating {
    animation: menuItemIn 0.4s cubic-bezier(0.16,1,0.3,1) both;
}
.lp-mobile-menu-links a.animating:nth-child(1) { animation-delay: 0.03s; }
.lp-mobile-menu-links a.animating:nth-child(2) { animation-delay: 0.07s; }
.lp-mobile-menu-links a.animating:nth-child(3) { animation-delay: 0.11s; }
@keyframes menuItemIn {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

.lp-mobile-menu-footer {
    padding: 0;
}
.lp-mobile-menu-footer .lp-nav-cta {
    display: block;
    text-align: center;
    padding: 16px 24px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    opacity: 0;
    transform: translateY(8px);
}
.lp-mobile-menu-footer .lp-nav-cta.animating {
    animation: menuItemIn 0.4s cubic-bezier(0.16,1,0.3,1) 0.1s both;
}

/* Dim overlay behind mobile menu */
.lp-menu-backdrop {
    display: none;
    position: fixed;
    top: 72px; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.25);
    z-index: 1;
    opacity: 0;
    transition: opacity 0.3s;
}
.lp-menu-backdrop.open {
    display: block;
    opacity: 1;
}

/* Nav solid background when mobile menu is open */
.lp-nav.menu-open {
    background: var(--color-bg);
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
}

/* Lock body scroll when menu is open */
body.menu-locked {
    overflow: hidden;
}

/* ─── Shared Button ──────────────────────────────────── */
.lp-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 16px 32px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    border: none;
    cursor: pointer;
    transition: all 0.2s;
}
.lp-btn-primary {
    background: var(--color-primary);
    color: var(--color-text-inverse);
    box-shadow: var(--shadow-lg);
}
.lp-btn-primary:hover {
    background: var(--color-primary-hover);
    box-shadow: var(--shadow-xl);
    transform: translateY(-2px);
}
.lp-btn-secondary {
    background: var(--color-bg);
    color: var(--color-text-primary);
    border: 1px solid var(--color-border);
}
.lp-btn-secondary:hover {
    border-color: var(--color-primary);
    background: var(--color-bg-secondary);
}

/* ─── Footer ─────────────────────────────────────────── */
.lp-footer {
    padding: 40px 24px;
    border-top: 1px solid var(--color-border-light);
}
.lp-footer-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 16px;
}
.lp-footer-links {
    display: flex;
    gap: 24px;
}
.lp-footer-links a {
    font-size: 0.8125rem;
    color: var(--color-text-tertiary);
    transition: color 0.15s;
}
.lp-footer-links a:hover { color: var(--color-text-primary); }
.lp-footer-copy {
    font-size: 0.8125rem;
    color: var(--color-text-tertiary);
}

/* ─── Animations ─────────────────────────────────────── */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s cubic-bezier(0.16,1,0.3,1),
                transform 0.6s cubic-bezier(0.16,1,0.3,1);
}
.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}
.reveal-delay-1 { transition-delay: 80ms; }
.reveal-delay-2 { transition-delay: 160ms; }
.reveal-delay-3 { transition-delay: 240ms; }

/* ─── Shared Responsive ──────────────────────────────── */
@media (max-width: 768px) {
    .lp-nav-links { display: none; }
    .lp-hamburger { display: flex; align-items: center; justify-content: center; }
    .lp-btn { padding: 14px 28px; font-size: 0.9375rem; width: 100%; }

    /* Footer mobile: centered stack with 2×2 link grid */
    .lp-footer {
        padding: 32px 24px;
    }
    .lp-footer-inner {
        flex-direction: column;
        align-items: center;
        text-align: center;
        gap: 20px;
    }
    .lp-footer-links {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: 12px 32px;
        justify-items: center;
        width: auto;
        max-width: none;
    }
    .lp-footer-links a {
        font-size: 0.875rem;
        white-space: nowrap;
    }
}