:root {
    --bg-color: var(--tg-theme-bg-color, #ffffff);
    --secondary-bg-color: var(--tg-theme-secondary-bg-color, #f0f0f0);
    --text-color: var(--tg-theme-text-color, #000000);
    --hint-color: var(--tg-theme-hint-color, #999999);
    --link-color: var(--tg-theme-link-color, #2481cc);
    --button-color: var(--tg-theme-button-color, #2481cc);
    --button-text-color: var(--tg-theme-button-text-color, #ffffff);
    --accent-color: #ff9500;
    --danger-color: #ff3b30;
    --success-color: #4cd964;
}

* {
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    user-select: none;
}

/* Utilities */
.hidden { display: none !important; }

/* Top Bar */
.top-bar {
    position: sticky;
    top: 0;
    background-color: var(--secondary-bg-color);
    padding: 10px;
    z-index: 100;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.week-selector {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 5px;
}

.nav-btn {
    background: var(--button-color);
    color: var(--button-text-color);
    border: none;
    border-radius: 50%;
    width: 32px;
    height: 32px;
    font-weight: bold;
    cursor: pointer;
}

.week-range {
    font-weight: 600;
    font-size: 1.1rem;
}

.current-week-link {
    background: none;
    border: none;
    color: var(--link-color);
    font-size: 0.9rem;
    cursor: pointer;
    text-decoration: underline;
}

/* Main Content Area */
main {
    padding: 15px 15px 80px 15px; /* Bottom padding for nav bar */
}

.screen {
    display: none;
}

.screen.active {
    display: block;
}

h2, h3 {
    margin-top: 0;
}

/* Homework Cards */
.homework-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.hw-card {
    background-color: var(--secondary-bg-color);
    border-radius: 12px;
    padding: 12px;
    position: relative;
}

.hw-card.special {
    border-left: 4px solid var(--accent-color);
}

.hw-header {
    display: flex;
    justify-content: space-between;
    font-weight: bold;
    margin-bottom: 5px;
    color: var(--link-color);
}

.hw-author {
    font-size: 0.8rem;
    color: var(--hint-color);
}

.hw-text {
    font-size: 0.95rem;
}

.hw-photo-link {
    display: inline-block;
    margin-top: 8px;
    color: var(--link-color);
    font-size: 0.85rem;
    cursor: pointer;
}

/* Schedule Grid */
.schedule-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.day-column {
    background-color: var(--secondary-bg-color);
    border-radius: 15px;
    padding: 12px;
}

.day-header {
    font-weight: bold;
    font-size: 1.1rem;
    margin-bottom: 10px;
    border-bottom: 1px solid var(--hint-color);
    padding-bottom: 5px;
    display: flex;
    justify-content: space-between;
}

.lesson-row {
    display: flex;
    padding: 8px 0;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}

.lesson-row:last-child {
    border-bottom: none;
}

.lesson-num {
    width: 25px;
    font-weight: bold;
    color: var(--hint-color);
}

.lesson-name {
    flex: 1;
}

.lesson-row.overridden .lesson-name {
    color: var(--accent-color);
}

.lesson-row.cancelled .lesson-name {
    text-decoration: line-through;
    color: var(--danger-color);
}

/* Forms */
.tabs-sub {
    display: flex;
    margin-bottom: 20px;
    background: var(--secondary-bg-color);
    border-radius: 10px;
    overflow: hidden;
}

.sub-tab {
    flex: 1;
    padding: 10px;
    border: none;
    background: none;
    color: var(--text-color);
    cursor: pointer;
}

.sub-tab.active {
    background: var(--button-color);
    color: var(--button-text-color);
    font-weight: bold;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    margin-bottom: 5px;
    color: var(--hint-color);
}

input[type="text"], 
input[type="date"], 
textarea {
    width: 100%;
    padding: 12px;
    border-radius: 10px;
    border: 1px solid var(--hint-color);
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 1rem;
}

.checkbox-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.checkbox-group input {
    width: 20px;
    height: 20px;
}

.submit-btn {
    width: 100%;
    padding: 15px;
    background: var(--button-color);
    color: var(--button-text-color);
    border: none;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: bold;
    cursor: pointer;
}

.secondary-btn {
    width: 100%;
    margin-top: 10px;
    padding: 12px;
    background: none;
    border: 1px solid var(--hint-color);
    color: var(--text-color);
    border-radius: 10px;
    cursor: pointer;
}

/* Vision zone */
.vision-upload-zone {
    text-align: center;
    padding: 40px 20px;
    border: 2px dashed var(--hint-color);
    border-radius: 20px;
    margin-bottom: 20px;
}

.vision-btn {
    padding: 15px 25px;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: bold;
    font-size: 1rem;
}

.vision-results-container {
    background: var(--secondary-bg-color);
    padding: 15px;
    border-radius: 15px;
}

/* Admin Table */
.table-responsive {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    text-align: left;
    padding: 10px;
    border-bottom: 1px solid var(--hint-color);
    font-size: 0.85rem;
}

.admin-tool-btn {
    background: var(--link-color);
    color: white;
    border: none;
    padding: 8px 12px;
    border-radius: 5px;
    font-size: 0.8rem;
    cursor: pointer;
}

.rollback-btn {
    background: var(--accent-color);
}

.ban-btn {
    background: var(--danger-color);
}

/* Bottom Nav */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: 70px;
    background-color: var(--secondary-bg-color);
    display: flex;
    justify-content: space-around;
    align-items: center;
    border-top: 1px solid rgba(0,0,0,0.1);
    z-index: 1000;
}

.nav-item {
    background: none;
    border: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--hint-color);
    cursor: pointer;
    flex: 1;
}

.nav-item.active {
    color: var(--link-color);
}

.nav-item .icon {
    font-size: 1.5rem;
}

.nav-item .label {
    font-size: 0.75rem;
    margin-top: 2px;
}

/* Modal */
.modal {
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.9);
    display: flex;
    justify-content: center;
    align-items: center;
}

.modal-content {
    max-width: 90%;
    max-height: 90%;
    border-radius: 10px;
}

.modal .close {
    position: absolute;
    top: 20px;
    right: 35px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
}

/* Group selector (schedule screen) */
.group-selector {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 12px;
    background: var(--secondary-bg-color);
    border-radius: 10px;
    padding: 8px 10px;
}

.group-selector-label {
    font-size: 0.9rem;
    font-weight: 600;
}

.group-option {
    border: 1px solid var(--hint-color);
    background: none;
    color: var(--text-color);
    border-radius: 20px;
    padding: 6px 12px;
    font-size: 0.85rem;
    cursor: pointer;
}

.group-option.active {
    background: var(--button-color);
    color: var(--button-text-color);
    border-color: var(--button-color);
}

/* Admin base-schedule editor */
.admin-hint {
    font-size: 0.85rem;
    color: var(--hint-color);
    margin: 6px 0 12px;
}

.bs-day {
    background: var(--secondary-bg-color);
    border-radius: 12px;
    padding: 10px;
    margin-bottom: 10px;
}

.bs-day-title {
    font-weight: bold;
    font-size: 0.95rem;
    margin-bottom: 6px;
}

.bs-row {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 6px;
}

.bs-num {
    min-width: 28px;
    font-weight: 600;
    color: var(--hint-color);
}

.bs-subject {
    flex: 1;
    padding: 6px 8px;
    border: 1px solid var(--hint-color);
    border-radius: 8px;
    background: var(--bg-color);
    color: var(--text-color);
    font-size: 0.9rem;
}

.bs-save {
    background: var(--success-color);
    color: white;
    border: none;
    border-radius: 8px;
    padding: 6px 10px;
    cursor: pointer;
}

/* Litrus toggle (Wed lessons 5-6: Литература <-> Русский язык) */
.litrus-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    background: var(--secondary-bg-color);
    border-radius: 12px;
    padding: 12px 14px;
    margin-bottom: 12px;
}

.litrus-toggle-label {
    font-size: 0.95rem;
}

/* Switch */
.switch {
    position: relative;
    display: inline-block;
    width: 52px;
    height: 30px;
    flex: 0 0 auto;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.switch .slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--hint-color);
    border-radius: 30px;
    transition: background-color 0.2s;
}

.switch .slider:before {
    position: absolute;
    content: "";
    height: 22px;
    width: 22px;
    left: 4px;
    bottom: 4px;
    background-color: #ffffff;
    border-radius: 50%;
    transition: transform 0.2s;
}

.switch input:checked + .slider {
    background-color: var(--button-color);
}

.switch input:checked + .slider:before {
    transform: translateX(22px);
}