/* ===== CSS Variables ===== */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-primary-light: #dbeafe;

    --color-discours: #7c3aed;
    --color-discours-light: #ede9fe;
    --color-session: #0891b2;
    --color-session-light: #cffafe;
    --color-comm: #059669;
    --color-comm-light: #d1fae5;
    --color-pause: #f59e0b;
    --color-pause-light: #fef3c7;
    --color-logistique: #6b7280;
    --color-logistique-light: #f3f4f6;

    --color-room-brea: #ec4899;
    --color-room-chagall: #8b5cf6;
    --color-room-cezanne: #06b6d4;
    --color-room-matisse: #f97316;
    --color-bg: #f8fafc;
    --color-surface: #ffffff;
    --color-text: #1e293b;
    --color-text-muted: #64748b;
    --color-border: #e2e8f0;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);

    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ===== Header ===== */
.header {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

.header__title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.header__subtitle {
    font-size: 1rem;
    opacity: 0.9;
    font-weight: 400;
}

/* ===== Day Navigation ===== */
.day-nav {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.day-tabs {
    display: flex;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) 0;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.day-tabs::-webkit-scrollbar {
    display: none;
}

.day-tab {
    flex: 1;
    min-width: fit-content;
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    background: transparent;
    color: var(--color-text-muted);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: all 0.2s ease;
    white-space: nowrap;
}

.day-tab:hover {
    background: var(--color-primary-light);
    color: var(--color-primary);
}

.day-tab.active {
    background: var(--color-primary);
    color: white;
}

.day-tab__date {
    display: block;
    font-size: 0.75rem;
    font-weight: 400;
    opacity: 0.8;
    margin-top: 2px;
}

/* ===== Room Legend ===== */
.room-legend {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: var(--spacing-md);
}

.legend-title {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.legend-items {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.legend-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.legend-dot--brea { background-color: var(--color-room-brea); }
.legend-dot--chagall { background-color: var(--color-room-chagall); }
.legend-dot--cezanne { background-color: var(--color-room-cezanne); }
.legend-dot--matisse { background-color: var(--color-room-matisse); }

/* ===== Main Content ===== */
.main {
    flex: 1;
    padding: var(--spacing-md) 0 var(--spacing-2xl);
}

.schedule {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* ===== Time Block ===== */
.time-block {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.time-block__header {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
}

.time-block__time {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    min-width: 100px;
}

.time-block__line {
    flex: 1;
    height: 1px;
    background: var(--color-border);
}

.time-block__events {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

/* ===== Event Card ===== */
.event-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    border-left: 4px solid var(--color-border);
    overflow: hidden;
    transition: all 0.2s ease;
}

.event-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.event-card--discours { border-left-color: var(--color-discours); }
.event-card--session { border-left-color: var(--color-session); }
.event-card--comm { border-left-color: var(--color-comm); }
.event-card--pause { border-left-color: var(--color-pause); }
.event-card--logistique { border-left-color: var(--color-logistique); }

.event-card__inner {
    padding: var(--spacing-md);
}

.event-card__header {
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.event-card__badge {
    display: inline-flex;
    align-items: center;
    padding: 2px 8px;
    border-radius: var(--radius-sm);
    font-size: 0.625rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.event-card__badge--discours {
    background: var(--color-discours-light);
    color: var(--color-discours);
}

.event-card__badge--session {
    background: var(--color-session-light);
    color: var(--color-session);
}

.event-card__badge--comm {
    background: var(--color-comm-light);
    color: var(--color-comm);
}

.event-card__badge--pause {
    background: var(--color-pause-light);
    color: var(--color-pause);
}

.event-card__badge--logistique {
    background: var(--color-logistique-light);
    color: var(--color-logistique);
}

.event-card__room {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.event-card__room::before {
    content: '';
    width: 8px;
    height: 8px;
    border-radius: 50%;
}

.event-card__room--brea::before { background-color: var(--color-room-brea); }
.event-card__room--chagall::before { background-color: var(--color-room-chagall); }
.event-card__room--cezanne::before { background-color: var(--color-room-cezanne); }
.event-card__room--matisse::before { background-color: var(--color-room-matisse); }

.event-card__title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.4;
    margin-bottom: var(--spacing-xs);
}

.slide-link {
    text-decoration: none;
    font-size: 0.9em;
    vertical-align: middle;
    margin-left: 0.25em;
    opacity: 0.8;
    transition: opacity 0.15s;
}

.slide-link:hover {
    opacity: 1;
}

.event-card__time {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.event-card__speaker {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    font-style: italic;
}

.event-card__chair {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-align: right;
}

.event-card__description {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-top: var(--spacing-sm);
    white-space: pre-line;
}

/* Clickable cards */
.event-card--clickable {
    cursor: pointer;
}

.event-card--clickable .event-card__title::after {
    content: ' \2192';
    opacity: 0;
    transition: opacity 0.2s ease;
}

.event-card--clickable:hover .event-card__title::after {
    opacity: 0.5;
}

/* ===== Parallel Sessions Grid ===== */
.parallel-sessions {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-sm);
}

/* ===== Parallel Events (pause + poster) ===== */
.parallel-events {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
}

/* ===== Overview Mode ===== */
.overview-day {
    margin-bottom: var(--spacing-2xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 2px solid var(--color-border);
}

.overview-day:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.overview-day__title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-primary);
    display: inline-block;
}

.overview-day__schedule {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.time-block--compact .event-card {
    box-shadow: none;
}

.time-block--compact .event-card__inner {
    padding: var(--spacing-sm) var(--spacing-md);
}

.time-block--compact .event-card__title {
    font-size: 0.875rem;
}

/* ===== Session Details (Nested talks) ===== */
.session-talks {
    background: var(--color-bg);
    padding: var(--spacing-md);
    border-top: 1px solid var(--color-border);
}

.talk-item {
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--color-border);
}

.talk-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.talk-item__time {
    font-size: 0.75rem;
    color: var(--color-comm);
    font-weight: 500;
    margin-bottom: 2px;
}

.talk-item__title {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 2px;
    cursor: pointer;
}

.talk-item__title:hover {
    color: var(--color-primary);
}

.talk-item__speaker {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

/* ===== Modal ===== */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: flex-end;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.modal[aria-hidden="false"] {
    opacity: 1;
    visibility: visible;
}

.modal__backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
}

.modal__content {
    position: relative;
    background: var(--color-surface);
    width: 100%;
    max-height: 90vh;
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    overflow: hidden;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.modal[aria-hidden="false"] .modal__content {
    transform: translateY(0);
}

.modal__close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    width: 32px;
    height: 32px;
    border: none;
    background: var(--color-bg);
    border-radius: 50%;
    font-size: 1.25rem;
    color: var(--color-text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    z-index: 1;
}

.modal__close:hover {
    background: var(--color-border);
    color: var(--color-text);
}

.modal__body {
    padding: var(--spacing-xl);
    padding-top: var(--spacing-2xl);
    overflow-y: auto;
    max-height: 90vh;
}

.modal__badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
}

.modal__title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.modal__meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
}

.modal__meta-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.modal__meta-icon {
    font-size: 1rem;
}

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

.modal__section-title {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}

.modal__speaker {
    font-size: 1rem;
    color: var(--color-text);
}

.modal__description {
    font-size: 0.9375rem;
    color: var(--color-text);
    line-height: 1.7;
    white-space: pre-line;
}

/* ===== Footer ===== */
.footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    text-align: center;
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

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

/* Tablet and up */
@media (min-width: 640px) {
    .header {
        padding: var(--spacing-2xl) 0;
    }

    .header__title {
        font-size: 2.25rem;
    }

    .header__subtitle {
        font-size: 1.125rem;
    }

    .day-tab {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: 1rem;
    }

    .parallel-sessions {
        grid-template-columns: repeat(2, 1fr);
    }

    .modal__content {
        max-width: 600px;
        margin: auto;
        border-radius: var(--radius-xl);
        max-height: 85vh;
    }

    .modal {
        align-items: center;
        padding: var(--spacing-xl);
    }

    .modal__content {
        transform: translateY(20px) scale(0.95);
    }

    .modal[aria-hidden="false"] .modal__content {
        transform: translateY(0) scale(1);
    }
}

/* Desktop */
@media (min-width: 1024px) {
    .container {
        padding: 0 var(--spacing-xl);
    }

    .parallel-sessions {
        grid-template-columns: repeat(3, 1fr);
    }

    .time-block {
        flex-direction: row;
        gap: var(--spacing-lg);
    }

    .time-block__header {
        flex-direction: column;
        align-items: flex-start;
        min-width: 80px;
        padding: var(--spacing-md) 0 0 0;
    }

    .time-block__line {
        display: none;
    }

    .time-block__events {
        flex: 1;
    }

    .event-card__title {
        font-size: 1.0625rem;
    }
}

/* Large Desktop */
@media (min-width: 1280px) {
    .header__title {
        font-size: 2.5rem;
    }
}

/* ===== Print Styles ===== */
@media print {
    .header {
        background: none;
        color: var(--color-text);
        border-bottom: 2px solid var(--color-text);
    }

    .day-nav {
        position: static;
        box-shadow: none;
    }

    .event-card {
        box-shadow: none;
        border: 1px solid var(--color-border);
        break-inside: avoid;
    }

    .modal, .footer {
        display: none;
    }
}