:root {
    /* Barvy značky (--color-primary*, --color-secondary*, --focus-ring) jsou ve školní části: school/branding/branding.css */

    /* Status Colors */
    --color-success: #1e8449;
    --color-success-light: #efe;
    --color-success-border: #cfc;
    --color-success-text: #1e7b34;

    --color-warning: #ffc107;
    --color-warning-light: #fff3cd;
    --color-warning-border: #ffc107;
    --color-warning-text: #856404;
    --color-on-warning: #4a3800;

    --color-error: #dc3545;
    --color-error-dark: #c82333;
    --color-error-light: #fee;
    --color-error-border: #fcc;
    --color-error-text: #c33;

    --color-info: #33c;
    --color-info-light: #eef;
    --color-info-border: #ccf;

    --color-delete: #c0392b;
    --color-delete-hover: #a93226;

    /* Neutral Colors */
    --color-text-primary: #333;
    --color-text-secondary: #666;
    --color-text-muted: #6b6b6b;
    --color-text-placeholder: #6b6b6b;
    --color-neutral-text: #495057;
    --color-text-on-dark: #bdc3c7;

    --color-bg-primary: #f5f5f5;
    --color-bg-white: white;
    --color-bg-dark: #2c3e50;
    --color-bg-dark-alt: #34495e;
    --color-bg-hover: #f8f9fa;

    --color-border: #ddd;
    --color-border-light: #ecf0f1;
    --color-neutral-light: #e9ecef;
    --color-neutral-mid: #95a5a6;
    --color-dark: #343a40;
    --color-overlay: rgba(0, 0, 0, 0.5);

    /* Typography */
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-base: 14px;
    --font-size-small: 12px;
    --font-size-medium: 16px;
    --font-size-large: 18px;
    --font-size-xlarge: 20px;
    --font-size-xxlarge: 24px;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 20px;
    --spacing-xl: 30px;
    --spacing-xxl: 40px;
    --touch-target: 44px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
    --radius-full: 999px;

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.2);

    /* Transitions */
    --transition-fast: 0.3s;

    /* Síla podkladu buňky týdenní tabulky (D2, J2) - podíl barvy učitele v color-mix. */
    --cell-tint: 45%;

    /* Minimální šířka sloupce týdenní tabulky (D3, S1) - pod ní se tabulka posouvá. */
    --col-min: 76px;
}

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

/* Viditelnost se řídí atributem hidden — viz UI_CONVENTIONS.md 7.3. */
[hidden] { display: none !important; }

/* Skryje obsah vizuálně, ale necha ho pro čtečky obrazovky - viz 0.6. */
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Read-only režim (role limited) - editační prvky se vůbec nezobrazí. */
.readonly-only {
    display: none;
}

.readonly .edit-only {
    display: none !important;
}

.readonly .readonly-only {
    display: block;
}

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

h1 {
    font-size: var(--font-size-xxlarge);
    margin: 0;
}

h2 {
    font-size: var(--font-size-xlarge);
    color: var(--color-text-primary);
}

.button,
button {
    border: none;
    cursor: pointer;
    font-size: var(--font-size-base);
    transition: background var(--transition-fast);
    font-family: var(--font-family);
}

.card {
    background: var(--color-bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: var(--spacing-md);
}

.block-card {
    background: color-mix(in srgb, var(--cell-color, var(--color-bg-white)) var(--cell-tint), var(--color-bg-white));
    padding: var(--spacing-md);
    margin-bottom: 12px;
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--cell-color, var(--color-border));
    box-shadow: var(--shadow-sm);
}

/* Mobilni karty po dnech (B1, UI_CONVENTIONS.md 9) - nativni <details>/<summary>,
   stav sbaleno/rozbaleno nese otoceni sipky (::before), ne jen barva. */
.day-group-summary {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    min-height: var(--touch-target);
    margin-bottom: var(--spacing-xs);
    padding: 0 var(--spacing-xs);
    cursor: pointer;
    list-style: none;
    border-radius: var(--radius-lg);
}

.day-group-summary::-webkit-details-marker {
    display: none;
}

.day-group-summary::before {
    content: '';
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 6px solid currentColor;
    transform: rotate(-90deg);
    transition: transform var(--transition-fast);
}

.day-group[open] > .day-group-summary::before {
    transform: none;
}

.day-group-summary:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.day-group-title {
    margin: 0;
    font-size: var(--font-size-large);
}

.day-group-count {
    margin-left: auto;
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
}

/* B5: sedy box poznamek dne (shared/components.css) prvni pod <summary> */
.day-group > .week-day-notes {
    margin-bottom: var(--spacing-sm);
}

/* Karta bez ucitele (B1) - jako .week-cell--no-teacher: sedy okraj, bez podkladu */
.block-card--no-teacher {
    --cell-color: var(--color-neutral-mid);
    background: var(--color-bg-white);
}

.block-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.block-title {
    font-size: var(--font-size-large);
    font-weight: bold;
}

.block-time {
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
}

.block-teacher {
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
    margin-bottom: var(--spacing-xs);
}

.block-content {
    margin-top: var(--spacing-sm);
    color: var(--color-text-secondary);
}

.block-meta {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-sm);
    font-size: 13px;
    color: var(--color-text-muted);
}

.block-card--editable {
    cursor: pointer;
    transition: box-shadow var(--transition-fast);
}

.block-card--editable:hover {
    box-shadow: var(--shadow-md);
}

.block-card--editable:focus-visible {
    box-shadow: var(--shadow-md), var(--focus-ring);
}

/* Dva pohledy na rozvrh (U1 krok 3, W7/W20) - karty a tabulka (#week-table,
   shared/components.css) se vykresluji obe zaroven, CSS prepina, ktera je
   viditelna. Hlasky "tyden nedostupny" a prazdny stav v #blocks-list
   zustavaji viditelne na vsech sirkach - skryvaji se karty i skupiny dnu (B1). */
@media (min-width: 768px), print {
    #blocks-list .block-card {
        display: none;
    }

    #blocks-list .day-group {
        display: none;
    }
}

@media screen and (max-width: 767px) {
    #week-table {
        display: none;
    }

    #print-week-btn {
        display: none;
    }

    /* B5: inline pole poznamky dne - dotykova plocha 44 px (8.4) */
    .day-note-form input:not([type="checkbox"]) {
        min-height: var(--touch-target);
    }
}

/* Tisk (U1 krok 4, W10/W45/W47) - v tisku se z celeho listu zobrazuje jen
   #week-table (shared/components.css resi jeji vlastni tiskovy vzhled a
   @page). #blocks-list samotne se neschovava cele - hlasky "tyden
   nedostupny"/prazdny stav v nem maji zustat viditelne i v tisku, skryvaji
   se jen karty uvnitr (.block-card, dole).
   #add-block-bar ma !important (W47) - updateAddBlockBar() v app.js nastavuje
   viditelnost pres inline style.display na tomtez elementu, ktery bez
   !important vyhraje nad timto pravidlem i uvnitr @media print.
   main ztraci max-width/margin/padding jen v tisku (W45), aby tabulka
   vyuzila celou sirku papiru - papir voli uzivatel v dialogu tisku, A3 je
   jen doporuceni (UI_CONVENTIONS.md 9, D1) - mimo tisk zustava main beze zmeny
   (viz pravidlo main {} vyse v tomto souboru). */
@media print {
    #archa-header,
    header,
    .dashboard-zone,
    #loading,
    .block-card,
    #week-info,
    .modal-overlay {
        display: none;
    }

    #add-block-bar {
        display: none !important;
    }

    .changes-panel {
        display: none;
    }

    main {
        max-width: none;
        margin: 0;
        padding: 0;
    }
}

/* P4 krok 5: panel "Zmeny po uzamceni" nad rozvrhem. Bez display na samotnem panelu - atribut hidden musi platit. */
.changes-panel {
    margin-bottom: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-white);
    border: 1px solid var(--color-warning-border);
    border-left: 4px solid var(--color-warning-border);
    border-radius: var(--radius-lg);
}

.changes-panel-summary {
    min-height: var(--touch-target);
    display: flex;
    align-items: center;
    cursor: pointer;
    font-weight: bold;
    border-radius: var(--radius-lg);
}

.changes-panel-summary:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.changes-panel-hint {
    margin: var(--spacing-xs) 0 var(--spacing-sm);
}

.changes-panel-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.changes-panel-item {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--spacing-xs) var(--spacing-sm);
    width: 100%;
    min-height: var(--touch-target);
    padding: var(--spacing-xs) var(--spacing-sm);
    background: none;
    border: 0;
    border-radius: var(--radius-md);
    font: inherit;
    color: inherit;
    text-align: left;
    cursor: pointer;
}

.changes-panel-item:hover {
    background: var(--color-bg-hover);
}

.changes-panel-item:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.changes-panel-title {
    font-weight: bold;
}

.changes-panel-when-block,
.changes-panel-editor {
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
}

/* Kratke zvyrazneni bloku po kliknuti v panelu (JS odebere tridu po ~2 s) */
.is-highlighted {
    outline: 3px solid var(--color-primary-dark);
    outline-offset: 2px;
}

.block-edit-modal-meta {
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
    margin-bottom: 16px;
}

.color-badge {
    display: inline-block;
    width: 40px;
    height: 24px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
}

#limited-banner {
    display: none;
    background: var(--color-warning-light);
    border-left: 4px solid var(--color-warning-border);
    padding: var(--spacing-md) var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-md);
}

#limited-banner p {
    margin: 0;
    color: var(--color-warning-text);
    font-size: var(--font-size-base);
    line-height: 1.6;
}

/* N3 (6.66): lista nevyplnenych bloku; [hidden] musi platit i pres display: flex. */
.unfilled-bar {
    display: flex; gap: var(--spacing-sm); margin-bottom: var(--spacing-lg);
    padding: var(--spacing-sm) var(--spacing-md); background: var(--color-warning-light);
    border-left: 4px solid var(--color-warning-border); color: var(--color-warning-text); box-shadow: var(--shadow-md);
}
.unfilled-bar[hidden] { display: none; }
.unfilled-bar-list { flex: 1; min-width: 0; margin: 0; padding: 0; list-style: none; }
.unfilled-bar-list li {
    display: flex; flex-wrap: wrap; align-items: center; gap: var(--spacing-xs) var(--spacing-sm);
    min-height: var(--touch-target); overflow-wrap: anywhere;
}
.unfilled-bar button {
    min-height: var(--touch-target); min-width: var(--touch-target); padding: 0 var(--spacing-sm);
    background: none; border: 0; border-radius: var(--radius-md); font: inherit; color: inherit; cursor: pointer;
}
.unfilled-bar-open { text-decoration: underline; font-weight: bold; }
.unfilled-bar button:focus-visible { outline: none; box-shadow: var(--focus-ring); }
@media print { .unfilled-bar { display: none; } }

/* N3-R6: nevyplneny blok - teckovany vnitrni outline (vyplni zustava barva ucitele; fokus je box-shadow). */
.block-unfilled { outline: 2px dotted var(--color-warning-text); outline-offset: -3px; }
@media print { .block-unfilled { outline: none; } }

header {
    background: var(--color-bg-white);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: var(--spacing-lg);
}

#week-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    color: var(--color-text-secondary);
    font-size: var(--font-size-base);
}

/* D7 R2: lista tydne (index: <header>, student: #week-info) zustava pri rolovani nahore.
   z-index 40: nad rozvrhem, pod rozbalenym menu hlavicky (50), modaly (1000+) a toasty (1100).
   Jen na obrazovce - tisk lištu skryva (@media print vyse). Skoky na blok/den (panel zmen,
   fokus) maji scroll-margin-top, aby necil neskoncil pod lištou. */
@media screen {
    /* Rezerva na lištu pro skoky a fokus - jedna hodnota pro styles.css i components.css (D8). */
    :root {
        --week-bar-offset: 6rem;
    }

    .week-bar-sticky {
        position: sticky;
        top: 0;
        z-index: 40;
    }

    #week-info.week-bar-sticky {
        background: var(--color-bg-primary);
        border-bottom: 1px solid var(--color-border);
        padding: var(--spacing-xs) 0;
    }

    .block-card,
    .day-group {
        scroll-margin-top: var(--week-bar-offset);
    }

    /* Fokus z klavesnice (WCAG 2.4.11) - prohlizec roluje s rezervou na lištu */
    html:has(.week-bar-sticky) {
        scroll-padding-top: var(--week-bar-offset);
    }
}

#location-select {
    padding: 5px 10px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    font-size: var(--font-size-small);
    font-family: var(--font-family);
    background: var(--color-bg-white);
    color: var(--color-text-primary);
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
}

#loading,
.loading {
    text-align: center;
    padding: var(--spacing-xxl);
    color: var(--color-text-secondary);
}

.placeholder-text {
    text-align: center;
    color: var(--color-text-placeholder);
    font-size: var(--font-size-medium);
    padding: 60px var(--spacing-lg);
}

#add-block-bar {
    margin-bottom: var(--spacing-lg);
}

#add-block-frozen-note {
    margin-top: var(--spacing-sm);
}