/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Layout */
    --header-height: 0px; /* скрываем шапку */
    --nav-height: 56px;

    /* Palette (falls back to Telegram theme params) */
    --bg: var(--tg-theme-bg-color, #0f1115);
    --bg-muted: var(--tg-theme-secondary-bg-color, #151922);
    --text: var(--tg-theme-text-color, #e6e8eb);
    --hint: var(--tg-theme-hint-color, #8a9099);
    --primary: var(--tg-theme-button-color, #2481cc);
    --on-primary: var(--tg-theme-button-text-color, #ffffff);

    /* Components */
    --card-border: rgba(255, 255, 255, 0.08);
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
    --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.35);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

#app {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    /* Глобальный отступ, чтобы весь контент не попадал под фиксированные шапку и навигацию */
    padding-top: calc(var(--header-height) + var(--nav-height));
}

/* Header */
.header {
    background: rgba(21, 25, 34, 0.7);
    backdrop-filter: saturate(120%) blur(10px);
    -webkit-backdrop-filter: saturate(120%) blur(10px);
    border-bottom: 1px solid var(--card-border);
    padding: 1rem;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    min-height: var(--header-height);
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 100%;
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text);
}

.user-info {
    display: none;
}

/* Navigation */
.nav {
    display: flex;
    background: rgba(15, 17, 21, 0.85);
    backdrop-filter: saturate(120%) blur(10px);
    -webkit-backdrop-filter: saturate(120%) blur(10px);
    border-top: 1px solid var(--card-border);
    border-bottom: 1px solid var(--card-border);
    overflow-x: auto;
    padding: 0 0.5rem;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    z-index: 95; /* поверх контента, ниже шапки */
    height: var(--nav-height);
    align-items: center;
}

.nav-btn {
    background: none;
    border: none;
    padding: 3px 1rem 0 1rem; /* слегка опускаем текст вниз */
    height: 100%;
    display: flex;
    align-items: center; /* вертикальное выравнивание по центру */
    justify-content: center;
    font-size: 0.95rem;
    line-height: 1; /* исключаем сдвиги из-за метрик шрифта */
    color: var(--hint);
    cursor: pointer;
    white-space: nowrap;
    transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
    border-bottom: 2px solid transparent; /* резервируем место, чтобы не прыгало */
    -webkit-tap-highlight-color: transparent;
    border-radius: 10px;
}

.nav-btn:hover {
    color: var(--text);
    background: rgba(255, 255, 255, 0.06);
}

.nav-btn:active {
    background: rgba(255, 255, 255, 0.1);
}

.nav-btn.active {
    color: var(--on-primary);
    background: var(--primary);
    border-bottom-color: transparent;
}

/* Main Content */
.main-content {
    flex: 1;
    /* Базовые внутренние отступы секции; смещение уже учтено в #app */
    padding: 16px 1rem 1rem 1rem;
}

.content-section {
    display: none;
}

.content-section.active {
    display: block;
}

/* Welcome Card */
.welcome-card {
    text-align: center;
    margin-bottom: 2rem;
    padding: 2rem;
    background: linear-gradient(180deg, rgba(36, 129, 204, 0.08), rgba(36, 129, 204, 0.03));
    border-radius: 16px;
    border: 1px solid var(--card-border);
    box-shadow: var(--shadow);
}

.time-based-image {
    margin-bottom: 1rem;
}

.time-based-image img {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    object-fit: cover;
}

.welcome-card h2 {
    margin-bottom: 0.5rem;
    color: var(--text);
}

.welcome-card p {
    color: var(--hint);
}

/* Quick Actions */
.quick-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.action-btn {
    background: var(--bg-muted);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 1.25rem 1rem;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    box-shadow: var(--shadow);
}

.action-btn:hover {
    border-color: rgba(36, 129, 204, 0.35);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-icon {
    font-size: 2rem;
}

.action-btn span {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text);
}

/* Locomotive Grid */
.locomotive-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.locomotive-card {
    background: var(--bg-muted);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 1rem;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    text-align: center;
    box-shadow: var(--shadow);
}

.locomotive-card:hover {
    border-color: rgba(36, 129, 204, 0.35);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.card-image {
    margin-bottom: 1rem;
}

.card-image img {
    width: 100%;
    height: 120px;
    object-fit: cover;
    border-radius: 8px;
}

.locomotive-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text);
}

.locomotive-card p {
    font-size: 0.9rem;
    color: var(--tg-theme-hint-color, #6c757d);
}

/* Instruction Categories */
.instruction-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.category-card {
    background: var(--bg-muted);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 1.25rem;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    text-align: center;
    box-shadow: var(--shadow);
}

.category-card:hover {
    border-color: rgba(36, 129, 204, 0.35);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.category-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.category-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text);
}

.category-card p {
    font-size: 0.9rem;
    color: var(--tg-theme-hint-color, #6c757d);
}

/* Links Grid */
.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.link-card {
    background: var(--bg-muted);
    border: 1px solid var(--card-border);
    border-radius: 14px;
    padding: 1.25rem;
    text-decoration: none;
    color: inherit;
    transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    text-align: center;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    box-shadow: var(--shadow);
}

.link-card:hover {
    border-color: rgba(36, 129, 204, 0.35);
    transform: translateY(-2px);
    text-decoration: none;
    color: inherit;
    box-shadow: var(--shadow-hover);
}

.link-icon {
    font-size: 2rem;
}

.link-card h3 {
    margin-bottom: 0.5rem;
    color: var(--text);
}

.link-card p {
    font-size: 0.9rem;
    color: var(--tg-theme-hint-color, #6c757d);
}

/* Section Header */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--card-border);
}

/* Admin tabs */
.admin-tab {
    background: var(--bg-muted);
    border: 1px solid var(--card-border);
    color: var(--text);
    border-radius: 8px;
    padding: 0.4rem 0.8rem;
    cursor: pointer;
}
.admin-tab.active {
    background: var(--primary);
    color: var(--on-primary);
}

/* Убираем линию и отступы, если заголовок отсутствует */
.section-header:empty {
    border-bottom: none;
    padding-bottom: 0;
    margin-bottom: 0;
}

.section-header h2 {
    color: var(--text);
}

.back-btn {
    background: var(--primary);
    color: var(--on-primary);
    border: none;
    border-radius: 8px;
    padding: 0.5rem 1rem;
    cursor: pointer;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.back-btn:hover {
    filter: brightness(0.95);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.55);
    z-index: 1000;
}

.modal-content {
    background: var(--tg-theme-bg-color, #ffffff);
    /* центрируем по вертикали/горизонтали с учётом фиксированной шапки */
    margin: auto;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border-radius: 12px;
    max-height: calc(100vh - 4rem);
    max-width: min(960px, 92vw);
    width: calc(100vw - 2rem);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-hover);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid var(--tg-theme-hint-color, #e9ecef);
}

.modal-header h3 {
    color: var(--tg-theme-text-color, #000000);
}

.modal-actions {
    display: flex;
    gap: 1rem; /* увеличили расстояние между стрелкой и крестиком */
    align-items: center;
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--tg-theme-hint-color, #6c757d);
}

.modal-back {
    background: none;
    border: none;
    font-size: 1.25rem;
    cursor: pointer;
    color: var(--tg-theme-hint-color, #6c757d);
    line-height: 1; /* убираем визуальное "подчёркивание" из-за метрик шрифта */
    position: relative;
    top: -1px; /* слегка приподнимаем стрелку */
}

.modal-body {
    flex: 1;
    padding: 1rem;
    overflow-y: auto;
}

/* Document viewer */
.doc-viewer {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

/* Document list */
.documents-list {
    display: grid;
    gap: 0.6rem;
    margin-top: 0.75rem;
}

.document-item { width: 100%; }

.document-btn {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    flex-wrap: nowrap; /* стандартное поведение: текст не переносится под иконку */
    background: var(--bg-muted);
    color: var(--text);
    border: 1px solid var(--card-border);
    border-radius: 12px;
    padding: 0.95rem 1rem;
    cursor: pointer;
    transition: transform 0.15s ease, box-shadow 0.2s ease, border-color 0.2s ease;
    text-align: left;
}
.documents-list .document-btn { flex-wrap: nowrap; }
#adminContent .document-btn { flex-wrap: wrap; }

/* Avatars in admin list */
.avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    overflow: hidden;
    background: var(--tg-theme-secondary-bg-color, #e9ecef);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: var(--tg-theme-text-color, #333);
}
.avatar img { width: 100%; height: 100%; object-fit: cover; display: block; }
.avatar-fallback { display: inline-block; font-size: 0.9rem; }

/* Админ разметка строк */
.admin-user { display: flex; align-items: center; gap: 0.75rem; flex: 1; min-width: 0; }
.admin-actions { display: flex; gap: 0.5rem; flex-wrap: wrap; justify-content: flex-end; width: 100%; margin-top: 0.5rem; }

.document-btn:hover {
    border-color: rgba(36, 129, 204, 0.35);
    box-shadow: var(--shadow);
}

.doc-icon { font-size: 1.15rem; }

.doc-name {
    font-size: 1.12rem;
    font-weight: 600;
    color: var(--text);
}

/* Remove white tap highlight */
a, button, .document-btn, .nav-btn, .action-btn { -webkit-tap-highlight-color: transparent; }

.doc-iframe {
    width: 100%;
    height: 70vh;
    border: 1px solid var(--tg-theme-hint-color, #e9ecef);
    border-radius: 8px;
    background: #fff;
}

.doc-actions {
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem; /* расстояние между кнопками */
}

/* Images inside locomotive details modal */
.locomotive-details {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

.locomotive-image img {
    width: 100%;
    height: auto;
    max-height: 45vh;
    object-fit: contain;
    border-radius: 8px;
    background: var(--tg-theme-secondary-bg-color, #f8f9fa);
}

@media (min-width: 768px) {
    .locomotive-details {
        grid-template-columns: 1fr 1fr;
        align-items: start;
    }
}

/* Loading */
.loading-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 2000;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.loading-spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--tg-theme-hint-color, #e9ecef);
    border-top: 4px solid var(--tg-theme-button-color, #2481cc);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-overlay p {
    color: var(--tg-theme-text-color, #ffffff);
    font-size: 1.1rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 0.5rem;
        text-align: center;
    }
    
    .nav {
        padding: 0 0.5rem;
    }
    
    .nav-btn {
        padding: 0.8rem 1rem;
        font-size: 0.8rem;
    }
    
    .main-content {
        padding: 0.5rem;
    }
    
    .quick-actions {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .locomotive-grid,
    .instruction-categories,
    .links-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        max-height: calc(100vh - 2rem);
        width: calc(100vw - 1.5rem);
    }
}

@media (max-width: 480px) {
    .quick-actions {
        grid-template-columns: 1fr;
    }
    
    .action-btn {
        padding: 1rem;
    }
    
    .btn-icon {
        font-size: 1.5rem;
    }
}

/* Dark theme support */
@media (prefers-color-scheme: dark) {
    :root {
        --tg-theme-bg-color: #1a1a1a;
        --tg-theme-text-color: #ffffff;
        --tg-theme-hint-color: #6c757d;
        --tg-theme-secondary-bg-color: #2d2d2d;
        --tg-theme-button-color: #2481cc;
        --tg-theme-button-text-color: #ffffff;
    }
}