/* --- 全域設定與顏色變數 --- */
:root {
    --grass-green-dark: #2d6a4f;
    --grass-green-main: #40916c;
    --grass-green-light: #52b788;
    --grass-green-bg: #f0f4f0;
    --text-color: #1b4332;
    --border-color: #d8e9e0;
    --container-bg: #ffffff;
    --header-bg: #40916c;
    --header-text: #ffffff;
    --app-vh: 100dvh;
}

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

html {
    height: var(--app-vh);
    container-type: size;
}

body {
    height: 100%;
    font-family: "Noto Sans TC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    background-color: var(--grass-green-bg);
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

/* --- 主要 App 容器 --- */
.app-container {
    width: 100%;
    height: 100%;
    max-width: 1280px;
    max-height: 720px;
    background-color: var(--container-bg);
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: height 0.3s ease, max-height 0.3s ease;
    /* 確保子元素的圓角正確顯示 */
}

header {
    background-color: var(--header-bg);
    color: var(--header-text);
    padding: 12px 24px;
    text-align: center;
    font-size: 1.5rem;
    font-weight: 600;
    flex-shrink: 0;
}

/* --- 主要內容區 --- */
.main-content {
    flex-grow: 1;
    padding: 20px;
    padding-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    min-height: 0;
}

textarea {
    width: 100%;
    padding: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    line-height: 1.6;
    background-color: #fdfdfd;
    color: var(--text-color);
    resize: none;
    flex-grow: 1;
    min-height: 200px;
}

textarea:focus {
    outline: none;
    border-color: var(--grass-green-main);
    box-shadow: 0 0 0 3px rgba(64, 145, 108, 0.2);
}

/* --- 按鈕 --- */
.button-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-shrink: 0;
    gap: 12px;
}

.button-group-left,
.button-group-right {
    display: flex;
    gap: 8px;
}

.action-button {
    background-color: var(--grass-green-main);
    color: white;
    border: none;
    font-size: 0.9rem;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s ease;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 16px;
    border-radius: 8px;
    font-weight: 500;
}

.action-button:hover {
    background-color: var(--grass-green-dark);
    transform: translateY(-1px);
}

.action-button:active {
    transform: translateY(0);
}

.action-button.outline {
    background-color: transparent;
    border: 1px solid var(--grass-green-main);
    color: var(--grass-green-main);
}

.action-button.outline:hover {
    background-color: var(--grass-green-main);
    color: white;
}

.copy-feedback {
    font-size: 0.9rem;
    color: var(--grass-green-main);
    text-align: center;
    visibility: hidden;
    opacity: 0;
    transition: opacity 0.3s ease, visibility 0s 0.3s;
}

/* --- 手機版響應式設計 (寬度 <= 768px) --- */
@media (max-width: 768px) {
    body {
        padding: 0;
    }

    .app-container {
        max-height: min(60vh, 400px);
        height: auto;
        /* 避免填滿整個螢幕，較小的行動裝置也能留白 */
        border-radius: 0;
    }

    header {
        padding-top: 16px;
        /* 給狀態列留點空間 */
        font-size: 1.4rem;
    }

    .main-content {
        padding: 12px;
        gap: 12px;
        flex: 1;
    }

    .action-button {
        padding: 12px 14px;
        font-size: 0.85rem;
    }

    .button-group-left,
    .button-group-right {
        gap: 6px;
    }
    @container (max-height: 600px) {
        body {
            align-items: flex-start;
            justify-content: flex-start;
        }
        .app-container {
            max-height: none;
            height: 100%;
        }
    }
}