/* ===================================================== */
/* ROOT VARIABLES */
/* ===================================================== */

:root {

    --bg-primary: #0b1120;
    --bg-secondary: #111827;
    --bg-tertiary: #172033;

    --border-color: #263247;

    --accent-blue: #3b82f6;
    --accent-hover: #2563eb;

    --text-primary: #f3f4f6;
    --text-secondary: #c4ccd8;
    --text-muted: #93a0b5;

    --success: #10b981;

    --radius-sm: 10px;
    --radius-md: 16px;
    --radius-lg: 24px;

    --shadow-soft:
        0 10px 30px rgba(0, 0, 0, 0.22);

    --container-width: 1240px;
    --container-narrow: 900px;
}

/* ===================================================== */
/* RESET */
/* ===================================================== */

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

html {
    scroll-behavior: smooth;
}

body {

    background: var(--bg-primary);

    color: var(--text-primary);

    font-family:
        Inter,
        "Segoe UI",
        sans-serif;

    line-height: 1.7;

    overflow-x: hidden;
}

/* ===================================================== */
/* GLOBAL */
/* ===================================================== */

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
}

.container {

    width: 92%;

    max-width: var(--container-width);

    margin: 0 auto;
}

.narrow-container {
    max-width: var(--container-narrow);
}

.section-block {
    padding: 7rem 0;
}

.alternate-section {
    background: var(--bg-secondary);
}

.center-align {
    text-align: center;
}

/* ===================================================== */
/* TYPOGRAPHY */
/* ===================================================== */

h1,
h2,
h3,
h4 {

    line-height: 1.2;

    letter-spacing: -0.02em;
}

p {
    color: var(--text-secondary);
}

.section-label {

    display: inline-block;

    color: var(--accent-blue);

    font-size: 0.85rem;

    font-weight: 700;

    text-transform: uppercase;

    letter-spacing: 1.5px;

    margin-bottom: 1rem;
}

.section-heading {
    margin-bottom: 4rem;
}

.section-heading h2 {

    font-size: 2.6rem;

    max-width: 820px;

    font-weight: 700;
}

/* ===================================================== */
/* HEADER */
/* ===================================================== */

.site-header {

    position: sticky;

    top: 0;

    z-index: 1000;

    background:
        rgba(11, 17, 32, 0.92);

    backdrop-filter: blur(14px);

    border-bottom:
        1px solid rgba(255, 255, 255, 0.05);
}

.header-container {

    height: 90px;

    display: flex;

    align-items: center;

    justify-content: space-between;
}

/* ===================================================== */
/* BRANDING */
/* ===================================================== */

.header-brand {

    display: flex;

    align-items: center;

    gap: 14px;

    text-decoration: none;
}

.site-logo {

    width: 58px;

    height: 58px;

    object-fit: contain;

    display: block;

    flex-shrink: 0;
}

.brand-text {

    display: flex;

    flex-direction: column;

    justify-content: center;
}

.header-brand-main {

    font-size: 2rem;

    font-weight: 900;

    line-height: 1;

    letter-spacing: 0.08em;

    background:
        linear-gradient(
            135deg,
            #ff6b35 0%,
            #ff3d54 45%,
            #3b82f6 100%
        );

    -webkit-background-clip: text;

    -webkit-text-fill-color: transparent;

    background-clip: text;
}

.header-brand-sub {

    font-size: 0.78rem;

    color: rgba(255,255,255,0.82);

    font-weight: 700;

    margin-top: 0.32rem;

    line-height: 1.4;

    max-width: 420px;

    letter-spacing: 0.02em;
}

/* ===================================================== */
/* NAVIGATION */
/* ===================================================== */

.main-navigation {

    display: flex;

    align-items: center;

    gap: 2rem;
}

.main-navigation a {

    color: var(--text-secondary);

    font-size: 0.95rem;

    transition: 0.25s ease;
}

.main-navigation a:hover,
.active-nav {

    color: var(--text-primary);
}

.mobile-menu-btn {

    display: none;

    background: none;

    border: none;

    color: var(--text-primary);

    font-size: 1.8rem;

    cursor: pointer;
}

/* ===================================================== */
/* HERO */
/* ===================================================== */

.hero-section {

    padding:
        8rem 0 7rem;

    position: relative;

    overflow: hidden;
}

.hero-container {

    display: flex;

    flex-direction: column;

    align-items: center;

    text-align: center;
}

.hero-badge {

    background:
        rgba(59, 130, 246, 0.1);

    border:
        1px solid rgba(59, 130, 246, 0.25);

    color: var(--accent-blue);

    padding:
        0.7rem 1.2rem;

    border-radius: 999px;

    font-size: 0.82rem;

    margin-bottom: 2rem;
}

.hero-title {

    font-size: 7rem;

    font-weight: 900;

    letter-spacing: 8px;

    margin-bottom: 1rem;

    line-height: 1;
}

.hero-full-form {

    font-size: 1.25rem;

    color: var(--text-secondary);

    max-width: 900px;

    margin-bottom: 2rem;
}

.hero-description {

    max-width: 860px;

    font-size: 1.12rem;

    color: var(--text-secondary);

    margin-bottom: 3rem;
}

.hero-buttons {

    display: flex;

    gap: 1rem;

    margin-bottom: 2rem;
}

.hero-note {

    color: var(--text-muted);

    font-size: 0.92rem;
}

/* ===================================================== */
/* BUTTONS */
/* ===================================================== */

.primary-button,
.secondary-button {

    display: inline-flex;

    align-items: center;

    justify-content: center;

    min-height: 52px;

    padding:
        0 1.6rem;

    border-radius: var(--radius-sm);

    font-weight: 600;

    transition: 0.25s ease;
}

.primary-button {

    background: var(--accent-blue);

    color: white;
}

.primary-button:hover {

    background: var(--accent-hover);

    transform: translateY(-2px);
}

.secondary-button {

    border:
        1px solid var(--border-color);

    color: var(--text-primary);
}

.secondary-button:hover {

    background:
        rgba(255, 255, 255, 0.04);
}

/* ===================================================== */
/* CONTENT */
/* ===================================================== */

.content-paragraphs {

    display: flex;

    flex-direction: column;

    gap: 1.5rem;
}

.content-paragraphs p {

    font-size: 1.04rem;
}

/* ===================================================== */
/* RESEARCH GRID */
/* ===================================================== */

.research-grid {

    display: grid;

    grid-template-columns:
        repeat(auto-fit, minmax(280px, 1fr));

    gap: 1.5rem;
}

.research-card {

    background: var(--bg-tertiary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-md);

    padding: 2rem;

    transition: 0.3s ease;
}

.research-card:hover {

    transform: translateY(-5px);

    border-color:
        rgba(59, 130, 246, 0.4);
}

.research-card h3 {

    margin-bottom: 1rem;

    font-size: 1.2rem;
}

.research-card p {

    color: var(--text-secondary);

    font-size: 0.96rem;
}

/* ===================================================== */
/* WORKFLOW */
/* ===================================================== */

.workflow-grid {

    display: grid;

    grid-template-columns:
        repeat(auto-fit, minmax(240px, 1fr));

    gap: 1.5rem;
}

.workflow-item {

    background: var(--bg-secondary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-md);

    padding: 2rem;
}

.workflow-item span {

    display: inline-flex;

    align-items: center;

    justify-content: center;

    width: 54px;
    height: 54px;

    border-radius: 50%;

    background:
        rgba(59, 130, 246, 0.12);

    color: var(--accent-blue);

    font-weight: 700;

    margin-bottom: 1.5rem;
}

.workflow-item h3 {

    margin-bottom: 1rem;

    font-size: 1.15rem;
}

/* ===================================================== */
/* PRICING */
/* ===================================================== */

.pricing-box {

    background: var(--bg-tertiary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-lg);

    padding: 3rem;

    text-align: center;
}

.pricing-row {

    display: flex;

    justify-content: center;

    align-items: center;

    gap: 1rem;

    margin-bottom: 1rem;
}

.old-price {

    font-size: 1.5rem;

    color: var(--text-muted);

    text-decoration: line-through;
}

.new-price {

    font-size: 3rem;

    font-weight: 800;

    color: var(--text-primary);
}

.pricing-validity {

    margin-bottom: 2rem;

    color: var(--text-muted);
}

.pricing-note-box {

    max-width: 700px;

    margin: 0 auto;

    display: flex;

    flex-direction: column;

    gap: 1rem;
}

/* ===================================================== */
/* ETHICS */
/* ===================================================== */

.ethics-grid {

    display: grid;

    grid-template-columns:
        repeat(auto-fit, minmax(260px, 1fr));

    gap: 1.5rem;
}

.ethics-card {

    background: var(--bg-secondary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-md);

    padding: 2rem;
}

.ethics-card h3 {

    margin-bottom: 1rem;

    font-size: 1.15rem;
}

/* ===================================================== */
/* NOTICE */
/* ===================================================== */

.notice-box {

    background: var(--bg-tertiary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-lg);

    padding: 3rem;

    text-align: center;
}

.notice-box h2 {

    margin-bottom: 1.5rem;

    font-size: 2rem;
}

.notice-box p {

    margin-bottom: 1rem;
}

/* ===================================================== */
/* CTA */
/* ===================================================== */

.cta-section {

    padding: 7rem 0;

    text-align: center;
}

.cta-section h2 {

    font-size: 2.4rem;

    margin-bottom: 1rem;
}

.cta-section p {

    max-width: 700px;

    margin:
        0 auto 2rem;
}

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

.site-footer {

    background: #070c17;

    border-top:
        1px solid rgba(255, 255, 255, 0.06);

    padding-top: 5rem;
}

.footer-grid {

    display: grid;

    grid-template-columns:
        1.5fr 1fr 1fr 1fr;

    gap: 3rem;

    padding-bottom: 4rem;
}

.footer-column {

    display: flex;

    flex-direction: column;

    gap: 0.9rem;
}

.footer-brand {

    font-size: 2rem;

    font-weight: 800;

    letter-spacing: 3px;
}

.footer-brand-full {

    color: var(--text-secondary);

    margin-bottom: 1rem;
}

.footer-small-text {

    color: var(--text-muted);

    font-size: 0.92rem;
}

.footer-column h4 {

    margin-bottom: 1rem;

    font-size: 1rem;
}

.footer-column a {

    color: var(--text-secondary);

    transition: 0.25s ease;
}

.footer-column a:hover {

    color: var(--text-primary);
}

.footer-bottom {

    border-top:
        1px solid rgba(255, 255, 255, 0.06);

    padding:
        2rem 0;

    text-align: center;
}

.footer-bottom p {

    color: var(--text-muted);

    font-size: 0.9rem;

    margin-bottom: 0.7rem;
}

.footer-powered {

    font-size: 0.82rem;
}

/* ===================================================== */
/* RESPONSIVE */
/* ===================================================== */

@media (max-width: 1024px) {

    .hero-title {
        font-size: 5rem;
    }

    .footer-grid {

        grid-template-columns:
            repeat(2, 1fr);
    }
}

@media (max-width: 768px) {

    .section-block {
        padding: 5rem 0;
    }

    .header-container {
        height: 82px;
    }

    .mobile-menu-btn {
        display: block;
    }

    .main-navigation {

        position: absolute;

        top: 82px;

        left: 0;

        width: 100%;

        background: var(--bg-secondary);

        border-top:
            1px solid rgba(255,255,255,0.05);

        display: none;

        flex-direction: column;

        align-items: flex-start;

        padding: 1.5rem;
    }

    .main-navigation.active {
        display: flex;
    }

    .hero-section {

        padding:
            6rem 0 5rem;
    }

    .hero-title {

        font-size: 3.8rem;

        letter-spacing: 4px;
    }

    .hero-full-form {

        font-size: 1rem;
    }

    .hero-description {

        font-size: 1rem;
    }

    .hero-buttons {

        width: 100%;

        flex-direction: column;
    }

    .primary-button,
    .secondary-button {

        width: 100%;
    }

    .section-heading h2 {

        font-size: 2rem;
    }

    .pricing-box,
    .notice-box {

        padding: 2rem;
    }

    .footer-grid {

        grid-template-columns: 1fr;
    }

    .site-logo {

        width: 48px;

        height: 48px;
    }

    .header-brand-main {

        font-size: 1.4rem;
    }

    .header-brand-sub {

        font-size: 0.65rem;

        max-width: 220px;
    }
}

@media (max-width: 480px) {

    .hero-title {

        font-size: 3rem;
    }

    .section-heading h2 {

        font-size: 1.7rem;
    }

    .new-price {

        font-size: 2.2rem;
    }

    .workflow-grid,
    .research-grid,
    .ethics-grid {

        grid-template-columns: 1fr;
    }
}

/* ===================================================== */
/* ARCHIVE PAGE */
/* ===================================================== */

.archive-hero {

    padding-bottom: 5rem;
}

.archive-title {

    font-size: 5.5rem;
}

.paper-entry {

    background: var(--bg-secondary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-lg);

    padding: 2.5rem;

    margin-bottom: 2rem;

    transition: 0.3s ease;
}

.paper-entry:hover {

    border-color:
        rgba(59, 130, 246, 0.35);

    transform: translateY(-4px);
}

.paper-meta-top {

    display: flex;

    justify-content: space-between;

    align-items: center;

    gap: 1rem;

    margin-bottom: 1.5rem;

    flex-wrap: wrap;
}

.paper-id {

    display: inline-flex;

    align-items: center;

    justify-content: center;

    background:
        rgba(59, 130, 246, 0.12);

    color: var(--accent-blue);

    border:
        1px solid rgba(59, 130, 246, 0.2);

    border-radius: 999px;

    padding:
        0.5rem 1rem;

    font-size: 0.85rem;

    font-weight: 700;

    letter-spacing: 0.5px;
}

.paper-date {

    color: var(--text-muted);

    font-size: 0.92rem;
}

.paper-title {

    font-size: 1.8rem;

    line-height: 1.4;

    margin-bottom: 1rem;
}

.paper-title a {

    color: var(--text-primary);

    transition: 0.25s ease;
}

.paper-title a:hover {

    color: var(--accent-blue);
}

.paper-authors {

    color: var(--text-muted);

    margin-bottom: 1.5rem;

    font-size: 0.96rem;
}

.paper-abstract {

    margin-bottom: 1.8rem;

    font-size: 1rem;

    color: var(--text-secondary);
}

.paper-keywords {

    display: flex;

    flex-wrap: wrap;

    gap: 0.8rem;

    margin-bottom: 2rem;
}

.paper-keywords span {

    background:
        rgba(255,255,255,0.04);

    border:
        1px solid rgba(255,255,255,0.08);

    color: var(--text-secondary);

    border-radius: 999px;

    padding:
        0.55rem 1rem;

    font-size: 0.82rem;
}

.paper-actions {

    display: flex;

    align-items: center;

    gap: 1rem;
}

/* ===================================================== */
/* PDF DOWNLOAD SECTION */
/* ===================================================== */

.pdf-download-box {

    background: var(--bg-secondary);

    border:
        1px solid var(--border-color);

    border-radius: var(--radius-lg);

    padding: 4rem 3rem;

    text-align: center;
}

.pdf-download-box h2 {

    margin-bottom: 1rem;

    font-size: 2rem;
}

.pdf-download-box p {

    color: var(--text-secondary);

    margin-bottom: 2rem;
}

.large-button {

    min-width: 280px;

    justify-content: center;
}