:root {
    --primary-color: #003366;
    --primary-light: #004080;
    --accent-color: #e6b800;
    --bg-color: #f0f2f5;
    --chat-bg: #ffffff;
    --bot-msg-bg: #f1f3f4;
    --user-msg-bg: #003366;
    --text-color: #333333;
    --header-height: 120px;
}

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

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    overflow: hidden;
}

#app-container {
    width: 100%;
    max-width: 500px;
    height: 90vh;
    background: var(--chat-bg);
    display: flex;
    flex-direction: column;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    border-radius: 20px;
    position: relative;
    overflow: hidden;
}

/* Header */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 20px;
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.header-content {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo-wrapper {
    width: 60px;
    height: 60px;
    background: white;
    border-radius: 50%;
    padding: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#school-logo {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.title-wrapper h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.4rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.slogan {
    font-size: 0.85rem;
    color: var(--accent-color);
    font-weight: 500;
    margin-top: 2px;
}

.subtitle {
    font-size: 0.75rem;
    opacity: 0.8;
}

/* Chat History */
#chat-history {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 15px;
    background-color: var(--chat-bg);
    position: relative; /* For watermark positioning */
}

/* Watermark Background */
#chat-history::before {
    content: "";
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 250px; /* Adjust size as needed */
    height: 250px;
    background-image: url('school_logo.png');
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    opacity: 0.5; /* 50% opacity as requested */
    pointer-events: none; /* Don't block clicks */
    z-index: 0;
}

/* Ensure messages stay above watermark */
.message {
    z-index: 1;
}

.message {
    max-width: 85%;
    padding: 12px 16px;
    border-radius: 15px;
    font-size: 0.95rem;
    line-height: 1.5;
    position: relative;
}

.bot-message {
    align-self: flex-start;
    background-color: var(--bot-msg-bg);
    color: var(--text-color);
    border-bottom-left-radius: 2px;
}

.user-message {
    align-self: flex-end;
    background-color: var(--user-msg-bg);
    color: white;
    border-bottom-right-radius: 2px;
}

/* Quick Actions */
.quick-actions-container {
    padding: 10px 15px;
    background: white;
    border-top: 1px solid #eee;
    overflow-x: auto;
    white-space: nowrap;
}

.quick-actions {
    display: flex;
    gap: 8px;
}

.quick-btn {
    background: white;
    border: 1.5px solid #ddd;
    padding: 8px 15px;
    border-radius: 20px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s;
    white-space: nowrap;
}

.quick-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: #f0f7ff;
}

/* Input Area */
.input-container {
    padding: 15px;
    background: white;
    border-top: 1px solid #eee;
}

#chat-form {
    display: flex;
    background: #f5f5f5;
    border-radius: 30px;
    padding: 5px 15px;
    align-items: center;
}

#user-input {
    flex: 1;
    border: none;
    background: transparent;
    padding: 10px;
    font-size: 0.95rem;
    outline: none;
}

#send-btn {
    background: var(--primary-color);
    color: white;
    border: none;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: transform 0.2s;
}

#send-btn:hover {
    transform: scale(1.1);
}

#send-btn svg {
    width: 20px;
    height: 20px;
}

/* Animations */
.fade-in {
    animation: fadeIn 0.3s ease-in;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Scrollbar */
#chat-history::-webkit-scrollbar {
    width: 6px;
}
#chat-history::-webkit-scrollbar-thumb {
    background: #ccc;
    border-radius: 3px;
}

/* Loading Dot */
.loading-indicator {
    display: flex;
    gap: 4px;
}
.typing-dot {
    width: 6px;
    height: 6px;
    background: #888;
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out both;
}
.typing-dot:nth-child(1) { animation-delay: -0.32s; }
.typing-dot:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1.0); }
}

/* Mobile Responsiveness */
@media (max-width: 600px) {
    :root {
        --header-height: 110px;
    }

    body {
        padding: 0;
        height: 100vh;
        height: 100dvh;
    }

    #app-container {
        max-width: 100%;
        height: 100vh;
        height: 100dvh;
        border-radius: 0;
    }

    header {
        padding-top: calc(20px + env(safe-area-inset-top));
        padding-bottom: 10px;
        height: auto;
        min-height: var(--header-height);
    }

    .logo-wrapper {
        width: 45px;
        height: 45px;
    }

    .title-wrapper h1 {
        font-size: 1.1rem;
    }

    .slogan {
        font-size: 0.75rem;
    }

    .subtitle {
        font-size: 0.65rem;
    }

    #chat-history {
        padding: 15px;
        gap: 12px;
    }

    .message {
        font-size: 0.9rem;
        padding: 10px 14px;
        max-width: 90%;
    }

    .quick-btn {
        padding: 6px 12px;
        font-size: 0.8rem;
    }

    #user-input {
        font-size: 0.9rem;
        padding: 8px;
    }

    #chat-history::before {
        width: 180px;
        height: 180px;
        opacity: 0.3; /* 모바일에서는 워터마크를 조금 더 흐리게 조절 */
    }
}