/* ===========================
   HCAI4IDS Workshop Website
   Main Stylesheet
   =========================== */

:root {
    /* Colors - Professional & Elegant Palette */
    --primary: #1a3a52;        /* Deep academic blue */
    --primary-dark: #102838;   /* Darker blue */
    --secondary: #2c5aa0;      /* Link and emphasis blue */
    --accent: #c75a3a;         /* Restrained warm accent */
    --accent-light: #f0b48c;   /* Soft accent for dark backgrounds */
    --accent-bright: #c75a3a;  /* Keep consistent */
    --success: #27ae60;        /* Teal green */
    --success-light: #58d68d;  /* Light green */
    --text-dark: #2c3e50;      /* Slate text */
    --text-light: #ecf0f1;     /* Off-white */
    --bg-light: #f5f7f9;       /* Soft gray-blue */
    --bg-light-2: #ecf0f1;     /* Light neutral */
    --bg-white: #ffffff;       /* White */
    --border: #bdc3c7;         /* Neutral gray */
    --warning: #d4534f;        /* Warm rust warning */

    /* Typography */
    --font-primary: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-heading: 'Georgia', 'Times New Roman', serif;
    --font-mono: 'Courier New', monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 20px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: var(--font-primary);
    color: var(--text-dark);
    background-color: var(--bg-white);
    line-height: 1.6;
}

/* Container */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-heading);
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--primary);
}

h1 {
    font-size: 3.2rem;
    line-height: 1.2;
}

h2 {
    font-size: 2.4rem;
    line-height: 1.3;
    margin-bottom: var(--spacing-lg);
    border-bottom: 4px solid var(--accent);
    padding-bottom: var(--spacing-md);
}

h3 {
    font-size: 1.8rem;
    margin-bottom: var(--spacing-md);
}

h4 {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-sm);
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--text-dark);
    font-size: 1.1rem;
    line-height: 1.7;
}

a {
    color: var(--secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: var(--accent);
    text-decoration: underline;
}

/* ===========================
   Navigation
   =========================== */

.navbar {
    background-color: var(--primary);
    padding: var(--spacing-sm) 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo h1 {
    font-size: 1.5rem;
    color: var(--text-light);
    margin: 0;
    border: none;
    padding: 0;
}

.logo h1 a {
    color: var(--text-light);
}

.logo h1 a:hover {
    color: var(--text-light);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-menu a {
    color: var(--text-light);
    font-weight: 600;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: var(--accent);
    text-decoration: none;
}

.nav-menu a.active {
    color: var(--accent-light);
}

.nav-dropdown {
    position: relative;
}

.nav-dropdown-label {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    padding: 0;
    border: 0;
    background: transparent;
    color: var(--text-light);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
}

.nav-dropdown-label:hover,
.nav-dropdown-label:focus-visible {
    color: var(--accent);
    outline: none;
}

.nav-dropdown-label.active {
    color: var(--accent-light);
}

.nav-dropdown-label span {
    font-size: 0.75rem;
    transition: transform 0.2s ease;
}

.nav-submenu {
    position: absolute;
    top: calc(100% + var(--spacing-sm));
    left: 0;
    z-index: 120;
    display: none;
    min-width: 255px;
    padding: var(--spacing-xs) 0;
    list-style: none;
    background-color: #173247;
    border-radius: 4px;
    box-shadow: var(--shadow-lg);
}

.nav-submenu::before {
    content: "";
    position: absolute;
    top: calc(-1 * var(--spacing-sm));
    left: 0;
    width: 100%;
    height: var(--spacing-sm);
}

.nav-submenu li {
    margin: 0;
}

.nav-submenu a {
    display: block;
    padding: 0.8rem var(--spacing-md);
    color: var(--text-light);
    font-weight: 500;
    white-space: nowrap;
}

.nav-submenu a:hover,
.nav-submenu a:focus-visible {
    color: var(--text-light);
    background-color: rgba(255, 255, 255, 0.1);
    text-decoration: none;
}

.nav-dropdown:hover .nav-submenu,
.nav-dropdown:focus-within .nav-submenu {
    display: block;
}

.nav-dropdown:hover .nav-dropdown-label span,
.nav-dropdown:focus-within .nav-dropdown-label span {
    transform: rotate(180deg);
}

/* ===========================
   Hero Section
   =========================== */

.hero {
    background:
        linear-gradient(90deg, rgba(16, 40, 56, 0.86) 0%, rgba(16, 40, 56, 0.48) 52%, rgba(16, 40, 56, 0.26) 100%),
        linear-gradient(180deg, rgba(16, 40, 56, 0.08) 0%, rgba(16, 40, 56, 0.58) 100%),
        url("../images/hero-human-ai-xr.png") center right / cover no-repeat,
        var(--primary-dark);
    color: var(--text-light);
    padding: calc(var(--spacing-2xl) * 1.35) 0;
    text-align: center;
    min-height: 440px;
    display: flex;
    align-items: center;
}

.hero-content {
    max-width: 980px;
    margin: 0 auto;
    padding: var(--spacing-xl);
    background: rgba(16, 40, 56, 0.50);
    border-radius: 8px;
    box-shadow: 0 24px 60px rgba(0, 0, 0, 0.28);
}

.hero-content h1 {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    font-size: 2.8rem;
    text-shadow: 0 3px 18px rgba(0, 0, 0, 0.45);
}

.tagline {
    font-size: 1.3rem;
    margin-bottom: var(--spacing-lg);
    color: var(--accent-light);
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.45);
}

.event-details {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-light);
    text-shadow: 0 2px 12px rgba(0, 0, 0, 0.45);
}

/* ===========================
   Sections
   =========================== */

section {
    padding: var(--spacing-2xl) 0;
}

section:nth-child(even) {
    background-color: var(--bg-light);
}

.page-header {
    background-color: var(--bg-light);
    padding: var(--spacing-xl) 0;
}

.page-header h1 {
    margin-bottom: var(--spacing-sm);
}

.page-header p {
    max-width: 860px;
}

.page-eyebrow {
    color: var(--accent);
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    margin-bottom: var(--spacing-sm);
}

.page-header + section {
    padding-top: var(--spacing-xl);
}

.page-header-compact {
    padding: var(--spacing-lg) 0;
}

.page-header-compact + .schedule {
    padding-top: var(--spacing-lg);
}

.page-header-compact h1 {
    margin-bottom: var(--spacing-xs);
}

.preliminary-program {
    margin: 0;
    color: var(--text-dark);
    font-size: 1rem;
}

/* About Section */
.about-content {
    max-width: 1080px;
}

.about-lede {
    max-width: 1040px;
    font-size: 1.16rem;
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--spacing-lg);
    margin: var(--spacing-lg) 0 var(--spacing-xl);
}

.about-panel {
    background-color: var(--bg-white);
    border-left: 4px solid var(--secondary);
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-lg);
}

.about-panel h3 {
    color: var(--secondary);
    font-size: 1.5rem;
}

.about-panel p:last-child {
    margin-bottom: 0;
}

.question-list {
    margin: var(--spacing-lg) 0 var(--spacing-xl);
    padding-left: var(--spacing-lg);
}

.question-list li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-xs);
    font-size: 1.05rem;
}

.section-subtitle {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border);
}

.program-committee {
    max-width: 1080px;
}

.program-committee p {
    margin-bottom: 0;
}

.program-committee-list {
    margin: var(--spacing-md) 0 0;
    padding-left: 1.25rem;
}

.program-committee-list:empty {
    display: none;
}

.program-committee-list li {
    margin-bottom: var(--spacing-xs);
    font-size: 1.05rem;
    line-height: 1.55;
}

.workshop-parts {
    list-style: none;
    margin: var(--spacing-lg) 0 var(--spacing-xl);
}

.workshop-parts li {
    padding: 0.85rem var(--spacing-md);
    margin-bottom: 0.75rem;
    background-color: var(--bg-light);
    border-left: 4px solid var(--accent);
    border-radius: 4px;
}

.focus-list {
    margin: var(--spacing-lg) 0 var(--spacing-xl);
    padding-left: 1.25rem;
}

.focus-list li {
    margin-bottom: 0.85rem;
    font-size: 1.05rem;
    line-height: 1.65;
}

.outcomes-note {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md) var(--spacing-lg);
    background-color: var(--bg-light);
    border-left: 4px solid var(--secondary);
    border-radius: 4px;
    font-size: 1.02rem;
}

/* Tables */
table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow-sm);
    background-color: var(--bg-white);
}

thead {
    background-color: var(--primary);
    color: var(--text-light);
}

th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 700;
}

td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border);
}

tbody tr:hover {
    background-color: var(--bg-light);
}

/* Dates and Schedule Sections */
.schedule-timeline {
    display: grid;
    gap: var(--spacing-md);
    margin-top: 0;
}

.schedule-block {
    display: grid;
    grid-template-columns: 170px 1fr;
    gap: var(--spacing-lg);
    align-items: stretch;
    background-color: var(--bg-white);
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(189, 195, 199, 0.6);
    border-left: 8px solid var(--secondary);
    overflow: hidden;
}

.schedule-time {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
    color: var(--primary-dark);
    background-color: rgba(44, 90, 160, 0.08);
    font-weight: 800;
    font-size: 1.05rem;
}

.schedule-details {
    padding: var(--spacing-md) var(--spacing-lg);
}

.schedule-details h3 {
    margin-bottom: var(--spacing-xs);
    font-size: 1.35rem;
    color: var(--primary);
}

.schedule-details p {
    margin-bottom: 0;
    font-size: 1rem;
}

.schedule-organizer {
    border-left-color: var(--secondary);
}

.schedule-organizer .schedule-time {
    background-color: rgba(44, 90, 160, 0.12);
}

.schedule-presentation {
    border-left-color: var(--accent);
}

.schedule-presentation .schedule-time {
    background-color: rgba(199, 90, 58, 0.12);
}

.schedule-break {
    border-left-color: #8aa6a3;
}

.schedule-break .schedule-time {
    background-color: rgba(138, 166, 163, 0.16);
}

.schedule-group-work {
    border-left-color: var(--accent);
}

.schedule-group-work .schedule-time {
    background-color: rgba(199, 90, 58, 0.12);
}

.schedule-outcomes {
    border-left-color: var(--accent);
}

.schedule-outcomes .schedule-time {
    background-color: rgba(199, 90, 58, 0.12);
}

.note,
.workshop-note {
    font-size: 0.9rem;
    color: var(--text-dark);
    font-style: italic;
    margin-top: var(--spacing-md);
}

/* Topics Section */
.intro-text {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xl);
    color: var(--text-dark);
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.topic-card {
    background-color: var(--bg-white);
    border-radius: 8px;
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    border-top: 4px solid var(--accent);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.topic-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.topic-card h4 {
    color: var(--secondary);
    font-size: 1.2rem;
    margin-bottom: var(--spacing-md);
}

.topic-card p {
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Call for Participation Section */
.submission-content {
    max-width: 1040px;
}

.submission-section {
    scroll-margin-top: 90px;
    padding: 2.25rem 0;
    background: none !important;
    border-bottom: 1px solid var(--border);
}

.submission-section:first-child {
    padding-top: 0;
}

.submission-section:last-child {
    padding-bottom: 0;
    border-bottom: 0;
}

.submission-section h2 {
    margin-bottom: var(--spacing-md);
    border-bottom-width: 2px;
    padding-bottom: var(--spacing-sm);
}

.submission-section h3 {
    margin-top: var(--spacing-lg);
    font-size: 1.45rem;
}

#call-for-contributions .intro-text {
    margin-bottom: var(--spacing-md);
}

.dates-list,
.guidelines-list {
    margin: var(--spacing-md) 0;
    border-top: 1px solid var(--border);
}

.date-row {
    display: grid;
    grid-template-columns: 220px 175px minmax(280px, 1fr);
    gap: var(--spacing-md);
    align-items: center;
    padding: 0.72rem 0;
    border-bottom: 1px solid var(--border);
}

.date-label,
.guideline-label {
    color: var(--primary);
    font-weight: 700;
}

.date-value {
    color: var(--secondary);
    font-weight: 800;
}

.date-row-primary .date-label,
.date-row-primary .date-value {
    color: var(--accent);
}

.date-description {
    font-size: 0.96rem;
    line-height: 1.5;
}

.guideline-row {
    display: grid;
    grid-template-columns: 190px minmax(300px, 1fr);
    gap: var(--spacing-md);
    align-items: baseline;
    padding: 0.68rem 0;
    border-bottom: 1px solid var(--border);
}

.guideline-detail {
    font-size: 0.98rem;
    line-height: 1.5;
}

.deadline-note {
    margin: var(--spacing-sm) 0 0;
    color: var(--text-dark);
    font-size: 0.94rem;
}

.deadline-note strong {
    color: var(--accent);
}

.contribution-focus-list {
    max-width: 1080px;
    margin: var(--spacing-lg) 0;
    padding-left: 1.35rem;
}

.contribution-focus-list li {
    padding: 0 0 var(--spacing-sm) var(--spacing-xs);
    font-size: 1.05rem;
    line-height: 1.65;
}

.contribution-focus-list strong {
    color: var(--primary);
}

.plain-info-list {
    margin: var(--spacing-lg) 0;
    padding-left: 1.35rem;
}

.plain-info-list li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-xs);
    font-size: 1.05rem;
}

/* Call-to-Action Buttons */
.cta-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin: var(--spacing-lg) 0;
}

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: 4px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
    text-decoration: none;
    cursor: pointer;
    border: 2px solid transparent;
}

.btn-primary {
    background-color: var(--secondary);
    color: var(--text-light);
    font-size: 1.05rem;
    padding: var(--spacing-md) var(--spacing-xl);
}

.btn-primary:hover {
    background-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    text-decoration: none;
}

.btn-secondary {
    background-color: transparent;
    color: var(--secondary);
    border: 2px solid var(--secondary);
}

.btn-secondary:hover {
    background-color: var(--secondary);
    color: var(--text-light);
    text-decoration: none;
}

.btn-disabled {
    cursor: default;
    opacity: 0.68;
}

.btn-disabled:hover {
    background-color: var(--secondary);
    transform: none;
    box-shadow: none;
}

/* Outcomes Section */
.outcomes-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.outcome-item {
    background-color: var(--bg-white);
    padding: var(--spacing-lg);
    border-radius: 8px;
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--secondary);
}

.outcome-item h4 {
    color: var(--secondary);
}

/* Accepted Submissions Section */
.accepted-submissions {
    min-height: 300px;
}

.accepted-status {
    max-width: 900px;
    margin: 0;
    padding: var(--spacing-md) 0;
    border-top: 2px solid var(--secondary);
    border-bottom: 1px solid var(--border);
}

.accepted-status strong {
    color: var(--primary);
}

/* Organizers Section */
.organizers-grid {
    display: grid;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
    max-width: 1280px;
}

.organizer-card {
    background-color: var(--bg-white);
    border-radius: 8px;
    padding: var(--spacing-md);
    box-shadow: var(--shadow-md);
    text-align: left;
    transition: transform 0.3s ease;
    border-top: 3px solid var(--secondary);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    grid-column: span 2;
    min-height: 100%;
}

.organizer-card:nth-last-child(2):nth-child(4) {
    grid-column: 2 / span 2;
}

.organizer-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.organizer-header {
    display: grid;
    grid-template-columns: 68px 1fr;
    gap: var(--spacing-sm);
    align-items: center;
    min-height: 78px;
}

.organizer-image {
    width: 68px;
    height: 68px;
    border-radius: 50%;
    background-color: var(--bg-light-2);
    border: 1px solid rgba(44, 90, 160, 0.16);
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary);
    font-size: 1.2rem;
    font-weight: 700;
    overflow: hidden;
}

.organizer-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.organizer-name {
    font-size: 1.12rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.25rem;
}

.organizer-affiliation {
    color: var(--secondary);
    font-weight: 600;
    margin-bottom: 0.2rem;
}

.organizer-bio {
    font-size: 0.9rem;
    line-height: 1.52;
    margin-bottom: 0;
}

.organizer-email {
    font-size: 0.9rem;
    color: var(--secondary);
    overflow-wrap: anywhere;
}

/* ===========================
   Footer
   =========================== */

.footer {
    background-color: var(--primary);
    color: var(--text-light);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

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

.footer-section h4 {
    color: var(--accent-light);
    margin-bottom: var(--spacing-md);
}

.footer p,
.footer .copyright {
    color: var(--text-light);
}

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

.footer-section li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: var(--text-light);
}

.footer-section a:hover {
    color: var(--accent);
}

.copyright {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    margin: 0;
}

.footer-maintainer {
    text-align: center;
    font-size: 0.85rem;
    margin: var(--spacing-xs) 0 0;
}

.footer-maintainer a {
    color: var(--text-light);
}

.footer-maintainer a:hover {
    color: var(--accent);
}

/* ===========================
   Responsive Design
   =========================== */

@media (max-width: 1100px) {
    .organizers-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        max-width: 900px;
    }

    .organizer-card,
    .organizer-card:nth-last-child(2):nth-child(4) {
        grid-column: auto;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--spacing-sm);
    }

    .nav-content {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

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

    .nav-submenu {
        position: static;
        display: none;
        min-width: min(300px, calc(100vw - 2rem));
        margin-top: var(--spacing-sm);
        text-align: left;
    }

    .nav-dropdown:focus-within .nav-submenu,
    .nav-dropdown:hover .nav-submenu {
        display: block;
    }

    h1 {
        font-size: 1.8rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .hero-content h1 {
        font-size: 1.8rem;
    }

    .hero-content {
        padding: var(--spacing-lg);
    }

    .tagline {
        font-size: 1.1rem;
    }

    section {
        padding: var(--spacing-xl) 0;
    }

    .topics-grid,
    .about-grid,
    .outcomes-content,
    .organizers-grid {
        grid-template-columns: 1fr;
    }

    .organizer-card,
    .organizer-card:nth-last-child(2):nth-child(4) {
        grid-column: auto;
    }

    .cta-buttons {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    table {
        font-size: 0.9rem;
    }

    th, td {
        padding: var(--spacing-sm);
    }

    .date-row,
    .guideline-row {
        grid-template-columns: 1fr;
        gap: 0.3rem;
    }

    .schedule-block {
        grid-template-columns: 1fr;
    }

    .schedule-time {
        justify-content: flex-start;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    h1 {
        font-size: 1.5rem;
    }

    h2 {
        font-size: 1.2rem;
    }

    .hero {
        padding: var(--spacing-xl) 0;
        min-height: 360px;
    }

    section {
        padding: var(--spacing-lg) 0;
    }
}

/* ===========================
   Utility Classes
   =========================== */

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

.mt-md {
    margin-top: var(--spacing-md);
}

.mb-md {
    margin-bottom: var(--spacing-md);
}

.mt-lg {
    margin-top: var(--spacing-lg);
}

.mb-lg {
    margin-bottom: var(--spacing-lg);
}