:root {
    --color-text: #333333;
    --color-background: #F1F7F3;
    --color-accent: #2C6E49;
    --color-border: #A8C4B0;
    --font-size-base: 16px;
    --font-size-h1: 28px;
    --font-size-h2: 22px;
    --font-size-h3: 18px;
    --spacing-unit: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN", Meiryo, sans-serif;
    font-size: var(--font-size-base);
    color: var(--color-text);
    background-color: var(--color-background);
    margin: 0;
    padding: 0;
    line-height: 1.7;
}

h1 {
    font-size: var(--font-size-h1);
}

h2 {
    font-size: var(--font-size-h2);
}

h3 {
    font-size: var(--font-size-h3);
}

.page-wrapper {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    background-color: #DCEEE2;
}

header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--color-border);
}

.site-title a {
    text-decoration: none;
    color: var(--color-accent);
    font-size: 24px;
    font-weight: bold;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 24px;
    padding: 0;
    margin: 0;
}

.main-nav a {
    text-decoration: none;
    color: var(--color-accent);
}

    .main-nav a:hover {
        text-decoration: underline;
    }

.hamburger-icon {
    display: none;
    background: none !important;
    color: var(--color-text) !important;
    border: none;
    font-size: 24px;
    cursor: pointer;
    padding: 0;
}



.right-sidebar {
    width: 200px;
    flex-shrink: 0;
}




@media (max-width: 1100px) {
    header {
        flex-wrap: wrap;
    }

    .hamburger-icon {
        display: block;
    }

    .main-nav {
        width: 100%;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }

        .main-nav.is-open {
            max-height: 300px;
        }

        .main-nav ul {
            flex-direction: column;
            gap: 0;
            margin-top: 12px;
        }

        .main-nav li {
            border-top: 1px solid #ddd;
        }

        .main-nav a {
            display: block;
            padding: 14px 0;
        }

    .content-layout {
        flex-direction: column;
    }


    .right-sidebar {
        width: 100%;
    }



}

.content-layout {
    display: flex;
    gap: 24px;
    padding-top: 24px;
    padding-bottom: 24px;
}

.main-content {
    flex: 1;
}





.history-area ul {
    list-style: none;
    padding: 0;
    margin: 0;
}


footer {
    border-top: 1px solid var(--color-border);
    padding-top: 16px;
    padding-bottom: 16px;
}

.color-swatch {
    display: inline-block;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    margin-right: 8px;
    cursor: pointer;
    border: 2px solid var(--color-border);
}



.nickname-area {
    background-color: #F7F7F7;
    padding: 10px;
    border-radius: 8px;
    margin: 24px 0;
}

    .nickname-area h3 {
        margin-top: 0;
    }






.room-list h3 {
    color: var(--color-accent);
    font-size: 16px;
    margin-top: 24px;
    margin-bottom: 8px;
    border-bottom: 2px solid var(--color-accent);
    padding-bottom: 4px;
}





.room-item {
    display: flex;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--color-border);
}

.room-name {
    font-weight: bold;
    width: 30%;
    flex-shrink: 0;
    margin-right: 16px;
}

.room-members {
    flex: 1;
    color: #666666;
}

.room-count {
    color: var(--color-accent);
    font-weight: bold;
    width: 60px;
    text-align: right;
}

button {
    background-color: var(--color-accent);
    color: #FFFFFF;
    border: none;
    padding: 10px 20px;
    border-radius: 4px;
    font-size: var(--font-size-base);
    cursor: pointer;
}

    button:hover {
        opacity: 0.85;
    }

input[type="text"] {
    padding: 10px;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    font-size: var(--font-size-base);
    box-sizing: border-box;
}

    input[type="text"]:focus {
        outline: none;
        border-color: var(--color-accent);
    }




.nickname-input-row {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 0px;
}


.nickname-input {
    width: 200px;
}







#startChatBtn {
    display: block;
    margin-top: 12px;
    position: relative;
    top: -6px;
}




p a {
    color: var(--color-accent);
    text-decoration: none;
}

    p a:hover {
        text-decoration: underline;
    }

.intro-and-nickname {
    display: flex;
    gap: 24px;
}

.how-to-start,
.nickname-area {
    
}


.how-to-start {
    flex: 0.6;
}

.nickname-area {
    flex: 1.5;
}









@media (max-width: 600px) {
    .intro-and-nickname {
        flex-direction: column;
    }
}





.icon-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 16px;
}





#iconColorPicker {
    width: 0px;
    height: 32px;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: 0px 16px 0px 4px;
    color: transparent;
    background-color: #FFFFFF;
    cursor: pointer;
}

.icon-color-select {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 16px;
    position: relative;
    width: fit-content;
}






    .icon-color-select::after {
        content: "▼";
        position: absolute;
        right: 8px;
        top: 50%;
        transform: translateY(-50%);
        pointer-events: none;
        font-size: 10px;
        color: var(--color-text);
    }





.icon-choice {
    width: 48px;
    height: 48px;
    color: #CCCCCC;
    border: 2px solid #DDDDDD;
    padding: 4px;
    box-sizing: border-box;
}

    .icon-choice.selected {
        color: var(--color-accent);
        border-color: var(--color-accent);
    }



.btn-enter {
    display: inline-block;
    background-color: var(--color-accent);
    color: #FFFFFF;
    padding: 4px 12px;
    border-radius: 4px;
    text-decoration: none;
    font-size: 14px;
    margin-left: 16px;
}

    .btn-enter:hover {
        opacity: 0.85;
    }






.custom-warning {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background-color: #FF6B6B;
    color: #FFFFFF;
    padding: 12px 24px;
    border-radius: 4px;
    z-index: 1000;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}