/* =============================================
   ADVANCED MRI — V2 Base Styles
   Premium / Apple-inspired design
   ============================================= */

:root {
    --font-heading: 'Sora', -apple-system, sans-serif;
    --font-body: 'Manrope', -apple-system, sans-serif;
    --nav-height: 64px;
    --container: 1120px;
    --radius: 16px;
    --radius-sm: 10px;
    --radius-pill: 9999px;
}

/* === Reset === */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0; padding: 0;
    font-family: var(--font-body);
    font-size: 17px;
    line-height: 1.65;
    color: var(--text);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background 0.4s ease, color 0.4s ease;
}
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--text);
    margin: 0 0 16px;
    font-weight: 700;
    line-height: 1.15;
    transition: color 0.4s ease;
}
p { margin: 0 0 16px; color: var(--text-secondary); transition: color 0.4s ease; }
a { color: var(--accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--accent-dark); }
img { max-width: 100%; height: auto; display: block; }
::selection { background: rgba(39,131,183,0.2); }
.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* === Skip Link === */
.skip-link {
    position: absolute; left: -9999px; top: 0; z-index: 10000;
    padding: 8px 16px; background: var(--accent); color: #fff;
    font-weight: 600; border-radius: 0 0 8px 8px;
}
.skip-link:focus { left: 50%; transform: translateX(-50%); }

/* === Buttons === */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    gap: 8px; padding: 14px 32px;
    font-family: var(--font-body); font-size: 15px; font-weight: 700;
    border-radius: var(--radius-pill); border: none;
    cursor: pointer; transition: all 0.25s ease;
    text-decoration: none; line-height: 1;
}
.btn i { font-size: 13px; }
.btn-primary {
    background: linear-gradient(135deg, #2f3087, #2783b7);
    color: #ffffff;
    box-shadow: 0 4px 16px rgba(39,131,183,0.25);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 28px rgba(39,131,183,0.35);
    color: #ffffff;
}
.btn-secondary {
    background: var(--btn-secondary-bg);
    color: var(--text);
    border: 1.5px solid var(--border);
}
.btn-secondary:hover {
    border-color: var(--accent);
    color: var(--accent);
}
.btn-sm { padding: 10px 22px; font-size: 13px; }
.btn-lg { padding: 18px 40px; font-size: 16px; }

/* === Header === */
.site-header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    height: var(--nav-height);
    background: var(--header-bg);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid var(--border-light);
    transition: all 0.3s ease;
}
.site-header .container {
    display: flex; align-items: center; justify-content: space-between;
    height: 100%;
}
.site-header-logo img { height: 32px; }
.site-header-nav {
    display: flex; align-items: center; gap: 4px;
    list-style: none; margin: 0; padding: 0;
}
.site-header-nav a {
    font-family: var(--font-body); font-size: 13px; font-weight: 600;
    color: var(--text-secondary); text-decoration: none;
    padding: 8px 16px; border-radius: var(--radius-pill);
    transition: all 0.2s ease;
}
.site-header-nav a:hover { color: var(--text); background: var(--bg-alt); }
.site-header-actions { display: flex; align-items: center; gap: 12px; }

/* Mobile nav */
.site-header-toggle {
    display: none; width: 28px; height: 28px;
    flex-direction: column; justify-content: center; gap: 5px;
    background: none; border: none; cursor: pointer; padding: 0;
}
.site-header-toggle span {
    display: block; width: 100%; height: 2px;
    background: var(--text); border-radius: 1px; transition: all 0.3s;
}
.mobile-nav {
    display: none; position: fixed; top: var(--nav-height); left: 0; right: 0; bottom: 0;
    background: var(--bg); padding: 24px; z-index: 999; overflow-y: auto;
}
.mobile-nav.open { display: block; }
.mobile-nav a {
    display: block; font-size: 18px; font-weight: 600; color: var(--text);
    padding: 14px 0; border-bottom: 1px solid var(--border-light); text-decoration: none;
}

/* === Footer === */
.site-footer {
    background: var(--bg-alt); border-top: 1px solid var(--border-light);
    padding: 60px 0 0;
}
.site-footer p { font-size: 14px; line-height: 1.8; }
.site-footer .footer-logo img { height: 32px; margin-bottom: 16px; }
.site-footer .widget-title {
    font-family: var(--font-heading); font-size: 14px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.06em;
    color: var(--text); margin-bottom: 14px;
}
.site-footer ul { list-style: none; padding: 0; margin: 0; }
.site-footer ul li { margin-bottom: 6px; }
.site-footer ul li a { color: var(--text-secondary); font-size: 14px; }
.site-footer ul li a:hover { color: var(--accent); }
.footer-bottom {
    margin-top: 40px; padding: 20px 0;
    border-top: 1px solid var(--border-light);
    display: flex; align-items: center; justify-content: space-between;
    font-size: 13px; color: var(--text-secondary);
}

/* Logo swap */
[data-theme="light"] .logo-for-dark, :root .logo-for-dark { display: none; }
[data-theme="light"] .logo-for-light, :root .logo-for-light { display: inline; }
[data-theme="dark"] .logo-for-dark { display: inline !important; }
[data-theme="dark"] .logo-for-light { display: none !important; }

/* === Responsive === */
@media (max-width: 991px) {
    .site-header-nav { display: none; }
    .site-header-toggle { display: flex; }
}
@media (max-width: 767px) {
    .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
}