/* ========================================
   ROOT VARIABLES & GLOBAL STYLES
   ======================================== */

:root {
    --color-brown: rgb(153, 102, 0);
    --color-dark-blue: rgb(0, 51, 102);
    --color-white: white;
    --color-light-gray: #f8f9fa;
    --color-border: #e0e0e0;
    --color-light-brown: rgba(153, 102, 0, 0.05);
    --color-dark-blue-light: rgba(0, 51, 102, 0.05);
    --spacing-unit: 1rem;
    --transition: all 0.3s ease;
    --box-shadow-subtle: 0 2px 8px rgba(0, 0, 0, 0.08);
    --box-shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.12);
    --box-shadow-prominent: 0 8px 20px rgba(0, 0, 0, 0.15);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: var(--color-white);
}

/* ========================================
   ACCESSIBILITY & SKIP LINK
   ======================================== */

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-dark-blue);
    color: var(--color-white);
    padding: 8px;
    text-decoration: none;
    z-index: 100;
    font-weight: 600;
}

.skip-link:focus {
    top: 0;
}

/* ========================================
   CONTAINER & LAYOUT
   ======================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-unit);
}

.row {
    display: flex;
    flex-wrap: wrap;
    gap: 2rem;
    align-items: center;
}

.col {
    flex: 1;
    min-width: 280px;
}

.col-md-6 {
    flex-basis: calc(50% - 1rem);
}

@media (max-width: 768px) {
    .col-md-6 {
        flex-basis: 100%;
    }

    .row {
        gap: 1.5rem;
    }
}

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

.navbar {
    background-color: var(--color-dark-blue);
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: var(--box-shadow-subtle);
}

.nav-list {
    list-style: none;
    display: flex;
    gap: 2rem;
    padding: 1rem 0;
}

.nav-link {
    color: var(--color-white);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-bottom: 3px solid transparent;
    transition: var(--transition);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-brown);
    border-bottom-color: var(--color-brown);
}

@media (max-width: 768px) {
    .nav-list {
        flex-direction: column;
        gap: 0.5rem;
        padding: 0.75rem 0;
    }

    .nav-link {
        padding: 0.5rem 0;
    }
}

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

.header {
    background: linear-gradient(135deg, var(--color-dark-blue) 0%, rgba(0, 51, 102, 0.9) 100%);
    color: var(--color-white);
    padding: 4rem var(--spacing-unit);
    text-align: center;
    box-shadow: var(--box-shadow-prominent);
}

.header-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.site-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: -0.5px;
}

.site-subtitle {
    font-size: 1.1rem;
    font-weight: 300;
    margin: 0.25rem 0;
    opacity: 0.95;
}

@media (max-width: 768px) {
    .site-title {
        font-size: 2rem;
    }

    .site-subtitle {
        font-size: 0.95rem;
    }

    .header {
        padding: 2rem var(--spacing-unit);
    }
}

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

.main-content {
    padding: 3rem 0;
    min-height: calc(100vh - 200px);
}

.content-section {
    padding: 3rem 0;
    border-bottom: 1px solid var(--color-border);
}

.content-section:last-child {
    border-bottom: none;
}

/* ========================================
   SECTION HEADERS
   ======================================== */

.page-header {
    margin-bottom: 2.5rem;
    padding-bottom: 1rem;
    border-bottom: 3px solid var(--color-brown);
}

.page-header h2 {
    font-size: 2rem;
    color: var(--color-dark-blue);
    font-weight: 700;
}

/* ========================================
   ABOUT SECTION
   ======================================== */

.about-text p {
    margin-bottom: 1rem;
    line-height: 1.8;
    color: #444;
}

.lead {
    font-size: 1.15rem;
    font-weight: 500;
    color: var(--color-dark-blue);
    margin-bottom: 1.5rem;
}

.about-text ul {
    list-style-position: inside;
    margin-left: 1rem;
}

.about-text li {
    margin-bottom: 0.5rem;
    color: #555;
}

.mt-4 {
    margin-top: 2rem;
}

.about-image-container {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.about-image {
    width: 100%;
    max-width: 350px;
    border-radius: 8px;
    box-shadow: var(--box-shadow-prominent);
    border: 4px solid var(--color-brown);
}

.image-caption {
    margin-top: 1rem;
    font-size: 0.9rem;
    color: #777;
    font-style: italic;
}

/* ========================================
   EDUCATION SECTION
   ======================================== */

.education-timeline {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.education-item {
    display: flex;
    gap: 2rem;
    padding: 1.5rem;
    background-color: var(--color-light-gray);
    border-left: 4px solid var(--color-brown);
    border-radius: 4px;
    transition: var(--transition);
}

.education-item:hover {
    box-shadow: var(--box-shadow-medium);
    transform: translateX(4px);
}

.education-degree h3 {
    font-size: 1.3rem;
    color: var(--color-dark-blue);
    margin-bottom: 0.5rem;
}

.education-period {
    color: var(--color-brown);
    font-weight: 600;
    font-size: 0.95rem;
}

.education-major {
    font-size: 1rem;
    color: #555;
    margin-bottom: 0.5rem;
}

.education-university {
    color: #666;
    font-size: 0.95rem;
}

@media (max-width: 768px) {
    .education-item {
        flex-direction: column;
        gap: 1rem;
    }
}

/* ========================================
   RESEARCH SECTION (INDEX)
   ======================================== */

.research-item {
    padding: 2rem;
    margin-bottom: 2rem;
    background-color: var(--color-light-gray);
    border-radius: 6px;
    border-left: 4px solid var(--color-dark-blue);
    transition: var(--transition);
}

.research-item:hover {
    box-shadow: var(--box-shadow-medium);
    transform: translateY(-2px);
}

.research-title {
    font-size: 1.2rem;
    color: var(--color-dark-blue);
    font-weight: 600;
    margin-bottom: 0.75rem;
    line-height: 1.6;
}

.research-authors {
    color: #666;
    font-style: italic;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.research-status {
    display: inline-block;
    padding: 0.4rem 0.8rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-top: 0.5rem;
}

.research-status.published {
    background-color: var(--color-brown);
    color: var(--color-white);
}

.research-status.under-review {
    background-color: #ff9800;
    color: var(--color-white);
}

.research-status.in-progress {
    background-color: #2196F3;
    color: var(--color-white);
}

/* ========================================
   ABSTRACTS PAGE STYLING
   ======================================== */

.abstract-item {
    background: var(--color-white);
    border: 2px solid var(--color-border);
    border-left: 6px solid var(--color-brown);
    border-radius: 8px;
    padding: 2.5rem;
    margin: 0 auto 2.5rem auto;
    max-width: 900px;
    box-shadow: var(--box-shadow-subtle);
    transition: var(--transition);
}

.abstract-item:hover {
    box-shadow: var(--box-shadow-medium);
    border-left-color: var(--color-dark-blue);
    transform: translateY(-2px);
}

.abstract-item .research-title {
    color: var(--color-dark-blue);
    font-size: 1.4rem;
    margin-bottom: 1rem;
    line-height: 1.7;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--color-light-brown);
}

.abstract-item .research-authors {
    font-size: 0.95rem;
    color: var(--color-brown);
    margin-bottom: 1.5rem;
    font-style: normal;
    font-weight: 500;
}

/* Abstract Text Styling */
.abstract {
    display: block;
    font-size: 0.95rem;
    line-height: 1.8;
    color: #444;
    text-align: justify;
    background-color: var(--color-light-gray);
    padding: 1.75rem;
    border-radius: 6px;
    border-left: 3px solid var(--color-brown);
    font-weight: 400;
    letter-spacing: 0.3px;
}

.abstract-item:first-of-type {
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .abstract-item {
        padding: 1.5rem;
        max-width: 100%;
    }

    .abstract-item .research-title {
        font-size: 1.15rem;
    }

    .abstract {
        padding: 1.25rem;
        font-size: 0.9rem;
        text-align: left;
    }
}

/* ========================================
   TEACHING SECTION
   ======================================== */

.course-item {
    padding: 1.5rem;
    background-color: var(--color-light-gray);
    border-radius: 6px;
    border-left: 4px solid var(--color-brown);
    margin-bottom: 1.5rem;
    transition: var(--transition);
}

.course-item:hover {
    box-shadow: var(--box-shadow-subtle);
    transform: translateX(4px);
}

.teaching-institution {
    color: var(--color-dark-blue);
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.course-name {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
    margin-bottom: 0.5rem;
}

.course-evaluation {
    color: var(--color-brown);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.course-evaluation::before {
    content: "⭐";
}

/* ========================================
   RUNNING PAGE STYLING
   ======================================== */

.running-introduction {
    max-width: 900px;
    margin: 3rem auto 2.5rem auto;
    padding: 2rem;
    background: linear-gradient(135deg, var(--color-light-brown) 0%, var(--color-dark-blue-light) 100%);
    border-radius: 8px;
    border-left: 5px solid var(--color-brown);
    box-shadow: var(--box-shadow-subtle);
}

.running-introduction p {
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--color-dark-blue);
    margin-bottom: 1rem;
    font-weight: 500;
}

.running-introduction p:last-child {
    margin-bottom: 0;
}

/* Running Pictures Gallery */
.running.picture {
    max-width: 600px;
    margin: 0 auto 2.5rem auto;
    padding: 0;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--box-shadow-medium);
    transition: var(--transition);
    background-color: var(--color-white);
}

.running.picture:hover {
    box-shadow: var(--box-shadow-prominent);
    transform: translateY(-4px);
}

.running.picture img {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    max-height: 900px;
    transition: var(--transition);
}

.running.picture:hover img {
    transform: scale(1.02);
}

.running.picture .image-caption {
    margin: 0;
    padding: 1.25rem;
    background-color: var(--color-light-gray);
    color: var(--color-dark-blue);
    font-style: normal;
    font-weight: 600;
    text-align: center;
    font-size: 1rem;
    border-top: 3px solid var(--color-brown);
}

@media (max-width: 668px) {
    .running.picture {
        margin: 0 calc(var(--spacing-unit) * -1) 2rem calc(var(--spacing-unit) * -1);
        border-radius: 0;
    }

    .running.picture img {
        max-height: 900px;
    }

    .running-introduction {
        margin: 2rem var(--spacing-unit);
        padding: 1.5rem;
    }
}

/* Personal Bests Section */
.personal-bests {
    max-width: 900px;
    margin: 3rem auto 3rem auto;
    padding: 0;
}

.personal-bests-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 3px solid var(--color-brown);
}

.personal-bests-header h2 {
    font-size: 2rem;
    color: var(--color-dark-blue);
    font-weight: 700;
}

.personal-best-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    margin-bottom: 1.5rem;
    background: linear-gradient(135deg, var(--color-dark-blue) 0%, rgba(0, 51, 102, 0.85) 100%);
    border-radius: 8px;
    color: var(--color-white);
    box-shadow: var(--box-shadow-medium);
    transition: var(--transition);
    border: 2px solid var(--color-brown);
    position: relative;
    overflow: hidden;
}

.personal-best-item::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
    transition: var(--transition);
    pointer-events: none;
}

.personal-best-item:hover {
    transform: translateY(-6px) scale(1.02);
    box-shadow: var(--box-shadow-prominent);
    border-color: var(--color-white);
}

.personal-best-item:hover::before {
    top: -25%;
    right: -25%;
}

.distance {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    letter-spacing: 0.5px;
    position: relative;
    z-index: 1;
}

.pb-time {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-brown);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
    position: relative;
    z-index: 1;
    letter-spacing: -1px;
}

/* Running Page Grid Layout (Alternative Desktop Layout) */
@media (min-width: 1024px) {
    .personal-bests {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        gap: 2rem;
    }

    .personal-best-item {
        margin-bottom: 0;
    }
}

@media (max-width: 768px) {
    .personal-best-item {
        padding: 1.5rem;
    }

    .pb-time {
        font-size: 2rem;
    }

    .distance {
        font-size: 1rem;
    }

    .personal-bests {
        padding: 0 var(--spacing-unit);
    }
}

/* ========================================
   CV & CONTACT SECTION
   ======================================== */

.cv-download {
    background: linear-gradient(135deg, var(--color-light-brown) 0%, var(--color-dark-blue-light) 100%);
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    border: 2px solid var(--color-brown);
    box-shadow: var(--box-shadow-subtle);
}

.cv-download p {
    margin-bottom: 1.5rem;
    color: var(--color-dark-blue);
    font-weight: 500;
    font-size: 1.05rem;
}

.btn {
    display: inline-block;
    padding: 0.85rem 1.75rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-size: 0.95rem;
    text-align: center;
}

.btn-primary {
    background-color: var(--color-brown);
    color: var(--color-white);
    box-shadow: var(--box-shadow-subtle);
}

.btn-primary:hover {
    background-color: rgb(122, 81, 0);
    box-shadow: var(--box-shadow-medium);
    transform: translateY(-3px);
}

.btn-primary:active {
    transform: translateY(-1px);
}

.contact-content {
    background: linear-gradient(135deg, var(--color-light-gray) 0%, #ffffff 100%);
    padding: 2rem;
    border-radius: 8px;
    border: 1px solid var(--color-border);
    box-shadow: var(--box-shadow-subtle);
}

.contact-content p {
    font-weight: 600;
    color: var(--color-dark-blue);
    margin-bottom: 1rem;
    font-size: 1.05rem;
}

.contact-content ul {
    list-style: none;
}

.contact-content li {
    padding: 0.75rem 0;
    color: #555;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.contact-content li::before {
    content: "→";
    color: var(--color-brown);
    font-weight: bold;
}

.contact-content a {
    color: var(--color-brown);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.contact-content a:hover {
    color: var(--color-dark-blue);
    text-decoration: underline;
}

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

.footer {
    background: linear-gradient(180deg, var(--color-dark-blue) 0%, rgba(0, 51, 102, 0.95) 100%);
    color: var(--color-white);
    padding: 3rem 0 1.5rem 0;
    margin-top: 3rem;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.08);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    color: var(--color-brown);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.75rem;
}

.footer-section a {
    color: var(--color-white);
    text-decoration: none;
    transition: var(--transition);
    opacity: 0.9;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.footer-section a:hover {
    color: var(--color-brown);
    opacity: 1;
    transform: translateX(3px);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 1.5rem;
    text-align: center;
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.85rem;
}

@media (max-width: 768px) {
    .footer-content {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .footer {
        padding: 2rem 0 1rem 0;
    }
}

/* ========================================
   UTILITY CLASSES
   ======================================== */

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

.text-muted {
    color: #666;
    font-size: 0.9rem;
}

.text-highlight {
    color: var(--color-brown);
    font-weight: 600;
}

.mb-1 {
    margin-bottom: 0.5rem;
}

.mb-2 {
    margin-bottom: 1rem;
}

.mb-3 {
    margin-bottom: 1.5rem;
}

.mb-4 {
    margin-bottom: 2rem;
}

.mt-1 {
    margin-top: 0.5rem;
}

.mt-2 {
    margin-top: 1rem;
}

.mt-4 {
    margin-top: 2rem;
}

.p-2 {
    padding: 1rem;
}

.p-3 {
    padding: 1.5rem;
}

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

@media (max-width: 480px) {
    .site-title {
        font-size: 1.75rem;
    }

    .page-header h2 {
        font-size: 1.3rem;
    }

    .research-title {
        font-size: 1rem;
    }

    .container {
        padding: 0 0.75rem;
    }

    .nav-list {
        gap: 0.75rem;
        padding: 0.5rem 0;
    }

    .btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.9rem;
    }

    .footer-section h3 {
        font-size: 1rem;
    }

    .running-introduction {
        margin: 1.5rem var(--spacing-unit);
        padding: 1.25rem;
    }

    .running-introduction p {
        font-size: 0.95rem;
    }
}

/* ========================================
   PRINT STYLES
   ======================================== */

@media print {
    .navbar,
    .footer,
    .skip-link {
        display: none;
    }

    .abstract-item {
        page-break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ccc;
    }

    .running.picture {
        page-break-inside: avoid;
        box-shadow: none;
    }

    .personal-best-item {
        page-break-inside: avoid;
        box-shadow: none;
        border: 1px solid #333;
        background: white;
        color: #333;
    }

    .pb-time {
        color: var(--color-dark-blue);
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
    }

    .abstract {
        background-color: transparent;
        border: none;
        padding: 0;
    }
}