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

:root {
    color-scheme: dark;
    --background: #17191f;
    --panel: #22262e;
    --border: #3b414c;
    --green: #769656;
    --green-light: #b8e986;
    --text: #f1f1f1;
    --muted: #a6a9b3;
}

html {
    min-height: 100%;
    background: var(--background);
}

body {
    margin: 0;
    min-height: 100vh;
    min-height: 100dvh;
    background: var(--background);
    color: var(--text);
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
}

button {
    font: inherit;
    touch-action: manipulation;
}

button:focus-visible {
    outline: 3px solid #facc15;
    outline-offset: 3px;
}

/* ---------- ЭКРАНЫ ---------- */
.screen {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
    padding: 24px 20px;
    text-align: center;
}

.hidden {
    display: none !important;
}

/* ---------- ГЛАВНОЕ МЕНЮ ---------- */
.logo {
    margin-top: clamp(45px, 15vh, 120px);
    margin-bottom: 10px;
    font-size: clamp(44px, 12vw, 64px);
    letter-spacing: 1px;
}

.logo span {
    color: var(--green-light);
}

.subtitle {
    margin-bottom: 36px;
    color: var(--muted);
    font-size: 15px;
}

.main-button {
    width: 100%;
    max-width: 320px;
    min-height: 54px;
    padding: 15px 24px;
    border: none;
    border-radius: 12px;
    background: var(--green);
    color: white;
    font-size: 17px;
    font-weight: bold;
    cursor: pointer;
}

.main-button:active,
.mode-card:active,
.controls button:active {
    transform: scale(0.98);
}

/* ---------- ВЫБОР РЕЖИМА ---------- */
#mode-menu h2 {
    margin-top: 10px;
    font-size: 25px;
}

.back-button {
    display: block;
    min-height: 44px;
    margin-bottom: 22px;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: 9px;
    background: var(--panel);
    color: white;
    cursor: pointer;
}

.mode-options {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
    margin-top: 28px;
}

.mode-card {
    min-width: 0;
    min-height: 170px;
    padding: 20px 12px;
    border: 1px solid var(--border);
    border-radius: 14px;
    background: var(--panel);
    color: white;
    cursor: pointer;
}

.mode-icon,
.mode-title,
.mode-description {
    display: block;
}

.mode-icon {
    margin-bottom: 12px;
    font-size: 40px;
}

.mode-title {
    margin-bottom: 8px;
    font-size: 16px;
    font-weight: bold;
}

.mode-description {
    color: var(--muted);
    font-size: 13px;
    line-height: 1.4;
}

/* ---------- ИГРА ---------- */
#game-screen {
    width: 100%;
    max-width: 560px;
    padding: 16px 12px 24px;
}

#game-screen h2 {
    margin: 8px 0 10px;
    font-size: clamp(20px, 5vw, 26px);
}

#status {
    min-height: 22px;
    margin: 0 0 12px;
    color: var(--green-light);
    font-size: 14px;
    line-height: 1.4;
}

/* ---------- ШАХМАТНАЯ ДОСКА ---------- */
.board {
    width: 100%;
    max-width: 536px;
    aspect-ratio: 1 / 1;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(8, minmax(0, 1fr));
    grid-template-rows: repeat(8, minmax(0, 1fr));
    border: 3px solid #30343d;
    overflow: hidden;
    touch-action: manipulation;
}

.square {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 0;
    min-height: 0;
    padding: 0;
    border: none;
    border-radius: 0;
    font-size: clamp(24px, 7vw, 48px);
    cursor: pointer;
    user-select: none;
    -webkit-user-select: none;
}

.light {
    background: #eeeed2;
    color: #fffdf4;
}

.dark {
    background: #769656;
    color: #171717;
}

.square.light,
.square.dark {
    opacity: 1;
    -webkit-text-fill-color: currentColor;
}

.square.selected {
    background: #f6f669;
}

/* Возможный ход */
.square.possible-move::after {
    content: "";
    position: absolute;
    width: 25%;
    height: 25%;
    border-radius: 50%;
    background: rgba(30, 70, 30, 0.55);
    pointer-events: none;
}

/* Возможное взятие */
.square.possible-capture {
    box-shadow: inset 0 0 0 4px rgba(180, 40, 40, 0.75);
}

/* Король под шахом */
.square.in-check {
    background: #e74c3c !important;
    box-shadow: inset 0 0 0 4px #ff7770;
}

/* Фигуры */
.chess-piece {
    display: block;
    width: 100%;
    height: 100%;
    object-fit: contain;
    pointer-events: none;
}

/* ---------- УПРАВЛЕНИЕ ---------- */
.controls {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 10px;
    margin-top: 14px;
}

.controls button {
    min-width: 0;
    min-height: 46px;
    padding: 11px 8px;
    border: none;
    border-radius: 9px;
    background: var(--green);
    color: white;
    font-size: 14px;
    font-weight: bold;
    cursor: pointer;
}

#message {
    min-height: 20px;
    margin: 12px 0 0;
    color: var(--muted);
    text-align: center;
    font-size: 13px;
    line-height: 1.5;
    overflow-wrap: anywhere;
}

/* ---------- НАВЕДЕНИЕ МЫШЬЮ ---------- */
@media (hover: hover) and (pointer: fine) {
    .main-button:hover,
    .controls button:hover {
        background: #8aaa65;
    }

    .mode-card:hover {
        filter: brightness(1.12);
    }
}

/* ---------- ТЕЛЕФОНЫ ---------- */
@media (max-width: 420px) {
    .screen {
        padding-right: 16px;
        padding-left: 16px;
    }

    .mode-options {
        grid-template-columns: 1fr;
        gap: 12px;
        margin-top: 22px;
    }

    .mode-card {
        display: grid;
        grid-template-columns: 48px minmax(0, 1fr);
        grid-template-rows: auto auto;
        column-gap: 10px;
        align-items: center;
        min-height: 88px;
        padding: 14px;
        text-align: left;
    }

    .mode-icon {
        grid-column: 1;
        grid-row: 1 / 3;
        margin: 0;
        font-size: 34px;
    }

    .mode-title {
        grid-column: 2;
        grid-row: 1;
        margin: 0 0 4px;
        font-size: 16px;
    }

    .mode-description {
        grid-column: 2;
        grid-row: 2;
    }

    #game-screen {
        padding: 12px 8px 20px;
    }

    #game-screen > .back-button {
        margin-bottom: 16px;
    }

    .board {
        border-width: 2px;
    }

    .square.possible-capture {
        box-shadow: inset 0 0 0 3px rgba(180, 40, 40, 0.75);
    }
}

/* Очень узкие экраны */
@media (max-width: 340px) {
    .screen {
        padding-right: 10px;
        padding-left: 10px;
    }

    .controls {
        gap: 7px;
    }

    .controls button {
        font-size: 12px;
    }
}