/* =========================
   GLOBAL VARIABLES
========================= */
:root {
    /* Fonts */
    --font-body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Liberation Sans", sans-serif;
    --font-heading: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    --font-footer: "Segoe UI", Arial, sans-serif;
    /* Colors */
    --color-white: #fff;
    --color-black: #000;
    --color-text: #1f2937;
    --color-text-muted: #6b7280;
    --color-muted-light: #cbd5e1;
    --color-border-light: #e5e7eb;
    --color-primary: #0b74b5;
    --color-primary-hover: #095f93;
    --color-accent: #f59e0b;
    --color-orange-bg: #f59e0b;
    --color-footer-bg: #001b2a;
    /* Navigation colors */
    --color-nav-link: #111827;
    --color-nav-hover: var(--color-primary);
    --color-nav-active: var(--color-accent);
    /* Layout sizes */
    --logo-height: 50px;
    --flag-width: 18px;
    --container-max: 900px;
    /* Typography scale */
    --body-font-size: 16px;
    --body-line-height: 1.7;
    --h1-size: 26px;
    --h1-size-mobile: 20px;
    --h2-size: 1.6rem;
    --nav-font-size: 15px;
    --nav-font-size-mobile: 14px;
    --nav-font-weight: 600;
    --nav-icon-size: 12px;
    --lang-font-size: 13px;
    --footer-heading-size: 16px;
    --footer-text-size: 13px;
    /* Spacing */
    --space-0: 0;
    --space-3: 3px;
    --space-5: 5px;
    --space-8: 8px;
    --space-10: 10px;
    --space-12: 12px;
    --space-15: 15px;
    --space-18: 18px;
    --space-20: 20px;
    --space-24: 24px;
    --space-30: 30px;
    --space-40: 40px;
    --space-50: 50px;
    /* Border radius */
    --radius-sm: 6px;
    /* Buttons */
    --btn-padding-y: 10px;
    --btn-padding-x: 16px;
    --btn-padding-x-sm: 12px;
    /* Inputs */
    --input-height: 45px;
    --input-padding-left: 20px;
    /* Effects */
    --footer-divider: rgba(255, 255, 255, 0.12);
    /* Footer */
    --scrollup-size: 18px;
    /* Layout gaps */
    --gap-nav: 22px;
    --gap-actions: 14px;
    --gap-lang: 10px;
    /* Lists */
    --li-margin-bottom: 12px;
    --ul-padding-left: 22px;
    /* Motion */
    --transition-fast: 160ms ease;
    --transition-med: 220ms ease;
}

/* =========================
   BASE TYPOGRAPHY
========================= */
html {
    font-size: var(--body-font-size);
}

body {
    font-family: var(--font-body);
    margin: var(--space-0);
    color: var(--color-text);
    line-height: var(--body-line-height);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    min-height: 100vh; /* footer sticks to bottom */
}

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    color: var(--color-text);
    letter-spacing: -0.2px;
}

p {
    margin: auto;
}

a {
    color: var(--color-primary);
    text-decoration-thickness: 2px;
    text-underline-offset: 3px;
}

/* =========================
   HEADER / NAV
========================= */
.main-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-12) var(--space-24);
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border-light);
}

.logo {
    display: flex;
    align-items: center;
}

    .logo img {
        height: var(--logo-height);
    }

.nav-menu ul {
    list-style: none;
    display: flex;
    align-items: center;
    gap: var(--gap-nav);
    margin: var(--space-0);
    padding: var(--space-0);
}

    .nav-menu ul li a {
        position: relative;
        text-decoration: none;
        color: var(--color-nav-link);
        font-size: var(--nav-font-size);
        font-weight: var(--nav-font-weight);
        padding: 10px 2px;
        transition: color var(--transition-fast);
    }

        .nav-menu ul li a::after {
            content: "";
            position: absolute;
            left: 0;
            bottom: 4px;
            width: 0%;
            height: 2px;
            background: var(--color-nav-hover);
            transition: width var(--transition-med);
        }

        .nav-menu ul li a:hover {
            color: var(--color-nav-hover);
        }

            .nav-menu ul li a:hover::after {
                width: 100%;
            }

        .nav-menu ul li a.active {
            color: var(--color-nav-active);
        }

            .nav-menu ul li a.active::after {
                width: 100%;
                background: var(--color-nav-active);
            }

        .nav-menu ul li a:focus-visible {
            outline: 3px solid rgba(11, 116, 181, 0.25);
            outline-offset: 4px;
            border-radius: 6px;
        }

.nav-menu i {
    font-size: var(--nav-icon-size);
    margin-left: var(--space-5);
    opacity: 0.9;
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--gap-actions);
}

.submit-btn {
    background-color: var(--color-primary);
    color: var(--color-white);
    padding: var(--btn-padding-y) var(--btn-padding-x);
    border-radius: var(--radius-sm);
    text-decoration: none;
    font-weight: 700;
    font-size: 14px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast), transform var(--transition-fast);
}

    .submit-btn:hover {
        background-color: var(--color-primary-hover);
        transform: translateY(-1px);
    }

.search-btn {
    background: #111827;
    color: var(--color-white);
    border: none;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}

    .search-btn:hover {
        transform: translateY(-1px);
        opacity: 0.95;
    }

.lang-selector {
    display: flex;
    gap: var(--gap-lang);
    font-size: var(--lang-font-size);
    font-weight: 700;
    color: var(--color-text);
}

.lang-item {
    display: inline-flex;
    align-items: center;
    gap: var(--space-5);
    padding: 6px 8px;
    border-radius: 999px;
}

    .lang-item img {
        width: var(--flag-width);
    }

/* =========================
   BANNER / BREADCRUMB
========================= */
.orange-bg {
    background-color: var(--color-orange-bg) !important;
    width: 100%;
    display: block !important;
    padding: 10px 15px;
}

.banner-section {
    color: var(--color-white) !important;
}

    .banner-section h1 {
        font-family: var(--font-heading);
        font-size: 30px;
        font-weight: 600 !important;
        letter-spacing: -0.3px;
    }

.breadcrumb-text {
    opacity: 0.95;
    font-weight: 600;
}

/* =========================
   CONTENT AREA
========================= */
.journal-title {
    font-style: italic;
    font-weight: 600;
}

h2 {
    font-size: var(--h2-size);
    font-weight: 800;
    margin-top: var(--space-30);
    margin-bottom: var(--space-20);
}

ul {
    list-style-type: disc;
    padding-left: var(--ul-padding-left);
}

li {
    margin-bottom: var(--li-margin-bottom);
    margin: auto;
}

/* =========================
   FOOTER FIXED
========================= */

.main-footer {
    background-color: var(--color-footer-bg);
    color: var(--color-white);
    font-family: var(--font-footer);
    margin-top: auto;
    padding: var(--space-20) 40px var(--space-10) 40px;
    display: flex;
    flex-direction: column;
    gap: var(--space-20);
    width: 100%;
    box-sizing: border-box;
}

.footer-top {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-30);
}

.footer-logo {
    font-size: 25px;
    font-weight: 800;
    margin-bottom: var(--space-5);
}

.journal-info {
    font-size: var(--footer-text-size);
    color: var(--color-muted-light);
    margin-bottom: var(--space-10);
}

.open-access {
    font-size: 14px;
}

.footer-heading {
    font-weight: 800;
    margin-bottom: var(--space-15);
    font-size: var(--footer-heading-size);
    color: var(--color-white); /* FIXED: heading color white */
}

.footer-links {
    list-style: none;
    padding: var(--space-0);
    margin: var(--space-0);
}

    .footer-links li {
        margin-bottom: 6px;
    }

    .footer-links a {
        color: var(--color-white);
        text-decoration: none;
        font-size: 18px;
        opacity: 0.92;
        transition: opacity var(--transition-fast), text-decoration var(--transition-fast);
    }

        .footer-links a:hover {
            opacity: 1;
            text-decoration: underline;
            text-underline-offset: 4px;
        }

/* Newsletter Inputs */
.newsletter-row {
    display: flex;
    gap: var(--space-10);
    flex-wrap: wrap;
    margin-top: var(--space-15);
}

.custom-field {
    background-color: var(--color-white) !important;
    border: 1px solid #e5e7eb !important;
    height: var(--input-height);
    padding-left: var(--input-padding-left) !important;
    font-size: 14px;
    color: var(--color-text) !important;
    flex: 1 1 auto;
    min-width: 150px;
}

.subscribe-btn {
    background-color: var(--color-primary) !important;
    color: var(--color-white) !important;
    font-weight: 800;
    height: var(--input-height);
    border: none;
    letter-spacing: 0.6px;
    cursor: pointer;
    transition: background var(--transition-fast), transform var(--transition-fast);
}

    .subscribe-btn:hover {
        background-color: var(--color-primary-hover) !important;
        transform: translateY(-1px);
    }

.footer-bottom {
    border-top: 1px solid var(--footer-divider);
    margin-top: var(--space-20);
    padding-top: var(--space-10);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    position: relative;
}

.copyright-text {
    font-size: var(--footer-text-size);
    color: var(--color-muted-light);
}

.scroll-up-btn {
    color: var(--color-primary);
    font-size: var(--scrollup-size);
    cursor: pointer;
}

/* =========================
   RESPONSIVE
========================= */
@media screen and (max-width: 768px) {
    .main-header {
        flex-direction: column;
        gap: var(--space-15);
        text-align: center;
        padding: var(--space-15);
    }

    .nav-menu ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--space-10);
    }

    .header-actions {
        flex-direction: column;
        width: 100%;
        gap: var(--space-10);
    }

    .submit-btn {
        width: 100%;
        text-align: center;
    }

    .container {
        padding: 0 var(--space-15);
    }

    .custom-field, .subscribe-btn {
        width: 100% !important;
        margin-bottom: var(--space-10);
    }

    .main-footer {
        padding-left: var(--space-20);
        padding-right: var(--space-20);
    }

    .footer-top {
        flex-direction: column;
        gap: var(--space-15);
    }

    .newsletter-row {
        flex-direction: column;
    }

    .subscribe-btn {
        margin-left: 0;
        width: 100%;
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
        gap: var(--space-10);
    }
}

@media screen and (max-width: 480px) {
    .nav-menu ul li a {
        font-size: var(--nav-font-size-mobile);
    }

    .footer-links a {
        font-size: 16px;
    }
}