/* --- Core Variables and Global Reset --- */
:root {
    --primary: #2563eb;
    --secondary: #1d4ed8;
    --background: #0f172a;
    --text: #f8fafc;
    --text-secondary: #cbd5e1;
    --success: #10b981;
    --radius: 12px;
    --shadow: 0 10px 25px -5px rgba(0,0,0,0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--background); 
    color: var(--text);
    line-height: 1.6;
}

.container { max-width:1200px; margin:0 auto; padding:0 1rem; }

/* Skip link */
.skip-link {
    position:absolute; top:-40px; left:6px;
    background:var(--primary); color:var(--text);
    padding:.5rem 1rem; border-radius:var(--radius);
    z-index:3000; transition:top .2s;
}
.skip-link:focus { top:6px; }

header { background:var(--background); padding:1rem 0; position:sticky; top:0; z-index:100; }
nav { display:flex; justify-content:space-between; align-items:center; }
.logo img { height:40px; width:auto; }
.logo-fallback { display:none; color:var(--text); font-size:1.5rem; font-weight:bold; }
.nav-links a { color:var(--text); text-decoration:none; margin-left:1.5rem; font-weight:500; }
.nav-links a:hover { color:var(--primary); }

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 0;
}
.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text);
    border-radius: 2px;
    transition: all 0.3s;
}
.hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.hamburger.active span:nth-child(2) { opacity: 0; }
.hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(7px, -6px); }

.hero { padding:4rem 0; text-align:center; }
.hero-content h1 { font-size:2.5rem; margin-bottom:1rem; }
.hero-content p { color:var(--text-secondary); max-width:600px; margin:0 auto 2rem; }

.button {
    padding:.75rem 1.5rem; border-radius:var(--radius); font-weight:600;
    cursor:pointer; transition:background-color .3s, box-shadow .3s, transform .3s; 
    display:inline-flex; align-items:center; justify-content:center;
    text-decoration:none;
    min-height: 44px;
}
.button:focus { outline:2px solid var(--primary); outline-offset:2px; }
.primary-cta { background:var(--primary); color:var(--text); border:none; }
.primary-cta:hover { 
    background:var(--secondary); 
    box-shadow: 0 0 10px rgba(37,99,235,0.5);
}
.primary-cta:disabled { background:#64748b; cursor:not-allowed; }
.secondary-cta { background:transparent; border:2px solid var(--primary); color:var(--primary); }
.secondary-cta:hover { 
    background:var(--primary); color:var(--text); 
    box-shadow: 0 0 10px rgba(37,99,235,0.5);
}

.donation-tiers, .features-grid {
    display:grid; grid-template-columns:repeat(auto-fit,minmax(300px,1fr));
    gap:2rem; margin:2rem 0;
}
.tier-card, .feature-card {
    background:#1e293b; padding:1.5rem; border-radius:var(--radius);
    box-shadow:var(--shadow); text-align:center;
    transition: all 0.3s ease;
}
.tier-card:hover, .feature-card:hover {
    transform: translateY(-3px);
}
.feature-icon { font-size:2rem; margin-bottom:1rem; }

.consulting-option {
    background:#1e293b; padding:2rem; border-radius:var(--radius);
    text-align:center; margin-top:2rem; border:2px solid var(--primary);
}

.demo-container { max-width:600px; margin:0 auto; }
.demo-input {
    width:100%; padding:.75rem; border-radius:var(--radius);
    border:1px solid var(--text-secondary); margin-bottom:1rem;
    background:var(--background); color:var(--text);
}
.demo-response { margin-top:1rem; color:var(--text); }

.section-description { text-align:center; color:var(--text-secondary); margin-bottom:2rem; }
.max-width-800 { max-width:800px; margin-left:auto; margin-right:auto; }
.consulting-details-grid {
    display:grid; grid-template-columns:repeat(auto-fit,minmax(250px,1fr));
    gap:1.5rem; margin-bottom:2rem;
}
.list-unstyled { list-style:none; text-align:left; color:var(--text-secondary); padding:0; margin:0; }
.mt-1 { margin-top:1rem; }
.mb-1-5 { margin-bottom:1.5rem; }
.mb-0-5 { margin-bottom:.5rem; }

.visually-hidden {
    position:absolute; width:1px; height:1px; padding:0; margin:-1px;
    overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0;
}

/* Modal */
.modal {
    position:fixed; inset:0; background:rgba(0,0,0,.5);
    display:flex; align-items:center; justify-content:center; z-index:1000;
}
.modal-content {
    background:var(--background); padding:2rem; border-radius:var(--radius);
    color:var(--text); max-width:500px; text-align:center;
}
.modal-close {
    background:var(--primary); color:var(--text); padding:.5rem 1rem;
    border:none; border-radius:var(--radius); cursor:pointer; margin-top:1rem;
    min-height: 44px;
}
.modal-close:hover { background:var(--secondary); }

/* Loading spinner */
#loading-spinner {
    position:fixed; inset:0; background:var(--background);
    display:flex; align-items:center; justify-content:center;
    z-index:2000; opacity:1; transition:opacity .4s ease;
}
.spinner {
    width:40px; height:40px; border:4px solid var(--primary);
    border-top:4px solid transparent; border-radius:50%;
    animation:spin 1s linear infinite;
}
@keyframes spin { to { transform:rotate(360deg); } }

/* Small Loading Spinner for Buttons */
.loading-spinner-small {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--text);
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite; 
    vertical-align: middle;
    margin-right: 8px;
}

/* Contact section */
.contact-section {
    background:#1e293b; padding:3rem 0; text-align:center;
}
.contact-section h2 { margin-bottom:1rem; }
.contact-section p { color:var(--text-secondary); margin-bottom:1.5rem; }
.contact-links a { color:var(--primary); text-decoration:underline; }

footer { padding:2rem 0; text-align:center; background:#1e293b; }
.social-links a { color:var(--text); margin:0 1rem; font-size:1.2rem; text-decoration:none; }
.social-links a:hover { color:var(--primary); }

.footer-links { margin-top:1rem; }
.footer-links a {
    color:var(--text-secondary); text-decoration:none; margin:0 .5rem;
}
.footer-links a:hover { text-decoration:underline; }

/* Mobile Responsive */
@media (max-width: 768px) {
    .hamburger { display:flex; }
    .nav-links {
        position:fixed; top:0; right:-100%; width:80%; max-width:300px;
        height:100vh; background:var(--background);
        flex-direction:column; align-items:center; justify-content:center;
        transition:right .4s ease; z-index:999; padding:2rem 0;
    }
    .nav-links.active { right:0; }
    .nav-links a { margin:1rem 0; font-size:1.2rem; }
    .nav-overlay {
        display:none; position:fixed; inset:0; background:rgba(0,0,0,.7); z-index:998;
    }
    .nav-overlay.active { display:block; }
}

@media (max-width:600px) {
    .consulting-details-grid,
    .donation-tiers,
    .features-grid { grid-template-columns:1fr; }
    .hero-content h1 { font-size:1.8rem; }
}