:root {
    --grad-start: #0f201d; /* Deep fjord night */
    --grad-mid: #143b35; /* Fading moss */
    --grad-end: #0a1715; /* Glacial abyss */
    --text-main: #f0fdf4; /* Icy white */
    --accent-color: #4ade80; /* Soft bright green */
    --secondary-color: #a7f3d0; /* Glacial mint */
    --sys-bubble: rgba(52, 211, 153, 0.15);
    --sys-border: rgba(52, 211, 153, 0.3);
    --usr-bubble: rgba(255, 255, 255, 0.15);
    --usr-border: rgba(255, 255, 255, 0.3);
    --glass-border: rgba(255, 255, 255, 0.15);
    --glow-accent: rgba(74, 222, 128, 0.3);
    --glow-secondary: rgba(167, 243, 208, 0.4);
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    color: var(--text-main);
    background: linear-gradient(135deg, var(--grad-start), var(--grad-mid), var(--grad-end));
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

.app-container {
    width: 100%;
    max-width: 600px;
    height: 90vh;
    display: flex;
    flex-direction: column;
    border-radius: 20px;
    background: rgba(15, 23, 42, 0.5);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    overflow: hidden;
    position: relative;
}

.glass-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid var(--glass-border);
}

.glass-header h1 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: 2px;
    background: -webkit-linear-gradient(45deg, var(--accent-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

.glow-btn {
    background: linear-gradient(45deg, var(--accent-color), var(--secondary-color));
    border: none;
    color: #022c22;
    padding: 10px 20px;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 800;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px var(--glow-accent);
}

.glow-btn:hover {
    transform: translateY(-2px) scale(1.05);
    box-shadow: 0 6px 20px var(--glow-secondary);
}

.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: 2rem;
    display: flex;
    flex-direction: column;
}

.chat-container::-webkit-scrollbar {
    width: 6px;
}
.chat-container::-webkit-scrollbar-thumb {
    background-color: rgba(255,255,255,0.2);
    border-radius: 10px;
}

.chat-box {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.message {
    max-width: 80%;
    padding: 12px 20px;
    border-radius: 20px;
    animation: fadeIn 0.4s ease-out forwards;
    line-height: 1.5;
    font-size: 1.1rem;
    word-break: break-all;
}

.system-msg {
    align-self: flex-start;
    background: var(--sys-bubble);
    border: 1px solid var(--sys-border);
    border-bottom-left-radius: 0;
}

.user-msg {
    align-self: flex-end;
    background: var(--usr-bubble);
    border: 1px solid var(--usr-border);
    border-bottom-right-radius: 0;
}

.input-area {
    padding: 1.5rem;
    background: rgba(0, 0, 0, 0.2);
    border-top: 1px solid var(--glass-border);
}

#game-form {
    display: flex;
    gap: 10px;
}

input[type="text"] {
    flex: 1;
    padding: 15px 20px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    background: rgba(255, 255, 255, 0.05);
    color: white;
    font-size: 1.1rem;
    outline: none;
    transition: all 0.3s;
}

input[type="text"]:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 10px var(--glow-accent);
    background: rgba(255, 255, 255, 0.1);
}

input[type="text"]:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

#submit-btn {
    background: transparent;
    border: 1px solid var(--secondary-color);
    color: var(--secondary-color);
    padding: 0 25px;
    border-radius: 30px;
    cursor: pointer;
    font-weight: bold;
    font-size: 1rem;
    transition: all 0.3s;
}

#submit-btn:hover:not(:disabled) {
    background: var(--secondary-color);
    color: #022c22;
    box-shadow: 0 0 15px var(--glow-secondary);
}

#submit-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    border-color: gray;
    color: gray;
}

.error-msg {
    color: #f87171;
    font-size: 0.9rem;
    margin-top: 10px;
    min-height: 1.2em;
    text-align: center;
}

/* Modal styling */
.modal {
    position: absolute;
    top: 0; left: 0; width: 100%; height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(5px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}

.modal:not(.hidden) {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    background: rgba(10, 25, 22, 0.9);
    padding: 40px;
    border-radius: 20px;
    text-align: center;
    border: 1px solid var(--accent-color);
    box-shadow: 0 0 30px var(--glow-accent);
    max-width: 80%;
    transform: translateY(20px);
    transition: transform 0.3s;
}

.modal:not(.hidden) .modal-content {
    transform: translateY(0);
}

.modal h2 {
    font-size: 2rem;
    margin-top: 0;
    background: -webkit-linear-gradient(45deg, var(--secondary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    color: transparent;
}

.modal p {
    font-size: 1.1rem;
    margin-bottom: 30px;
}

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

/* Typing indicator */
.typing-indicator {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 12px 20px;
    border-radius: 20px;
    background: var(--sys-bubble);
    align-self: flex-start;
    border: 1px solid var(--sys-border);
    border-bottom-left-radius: 0;
}

.typing-dot {
    width: 6px;
    height: 6px;
    background: var(--text-main);
    border-radius: 50%;
    animation: typing 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 typing {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}