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

:root {
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #252525;
    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --user-bubble: #3b82f6;
    --assistant-bubble: #2a2a2a;
    --border: #333;
    --danger: #ef4444;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    height: 100vh;
    display: flex;
    flex-direction: column;
    position: relative;
}

header {
    text-align: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border);
}

header h1 {
    font-size: 1.75rem;
    font-weight: 600;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.chat-container {
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.messages {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.message {
    display: flex;
    animation: fadeIn 0.3s ease;
}

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

.message.user {
    justify-content: flex-end;
}

.message-content {
    max-width: 80%;
    padding: 0.625rem 1rem;
    border-radius: 1.25rem;
    white-space: pre-wrap;
    word-wrap: break-word;
}

.message.user .message-content {
    background: var(--user-bubble);
    border-bottom-right-radius: 0.25rem;
}

.message.assistant .message-content {
    background: var(--assistant-bubble);
    border-bottom-left-radius: 0.25rem;
}

.message.assistant .message-content code {
    background: var(--bg-primary);
    padding: 0.125rem 0.375rem;
    border-radius: 0.25rem;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.875em;
}

.message.assistant .message-content pre {
    background: var(--bg-primary);
    padding: 1rem;
    border-radius: 0.5rem;
    overflow-x: auto;
    margin: 0.5rem 0;
}

.message.assistant .message-content pre code {
    background: none;
    padding: 0;
}

.typing-indicator {
    display: flex;
    gap: 0.25rem;
    padding: 1rem 1.25rem;
}

.typing-indicator span {
    width: 8px;
    height: 8px;
    background: var(--text-secondary);
    border-radius: 50%;
    animation: bounce 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

.input-container {
    padding: 1rem 1.5rem 1.5rem;
    border-top: 1px solid var(--border);
    background: var(--bg-primary);
}

.input-wrapper {
    display: flex;
    gap: 0.75rem;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 1.5rem;
    padding: 0.5rem 0.5rem 0.5rem 1.25rem;
    align-items: flex-end;
}

.input-wrapper:focus-within {
    border-color: var(--accent);
}

textarea {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    resize: none;
    outline: none;
    max-height: 150px;
    padding: 0.5rem 0;
    font-family: inherit;
    line-height: 1.5;
}

textarea::placeholder {
    color: var(--text-secondary);
}

#sendBtn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background: var(--accent);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    transition: background 0.2s, transform 0.1s;
}

#sendBtn:hover {
    background: var(--accent-hover);
}

#sendBtn:active {
    transform: scale(0.95);
}

#sendBtn:disabled {
    background: var(--bg-tertiary);
    cursor: not-allowed;
}

#sendBtn svg {
    width: 18px;
    height: 18px;
}

.settings-btn {
    position: absolute;
    top: 1.5rem;
    right: 1rem;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.settings-btn:hover {
    color: var(--text-primary);
    border-color: var(--text-secondary);
}

.settings-btn svg {
    width: 20px;
    height: 20px;
}

.modal {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    z-index: 100;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-secondary);
    border-radius: 1rem;
    width: 100%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    border: 1px solid var(--border);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
}

.modal-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    line-height: 1;
}

.close-btn:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
}

.setting-group {
    margin-bottom: 1.5rem;
}

.setting-group:last-child {
    margin-bottom: 0;
}

.setting-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.setting-group textarea,
.setting-group input[type="text"] {
    width: 100%;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    padding: 0.75rem;
    color: var(--text-primary);
    font-size: 0.9375rem;
    font-family: inherit;
    resize: vertical;
}

.setting-group textarea:focus,
.setting-group input:focus {
    outline: none;
    border-color: var(--accent);
}

.setting-group input[type="range"] {
    width: 100%;
    margin-top: 0.5rem;
}

.setting-group small {
    display: block;
    margin-top: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.8125rem;
}

.danger-btn {
    background: var(--danger);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-size: 0.9375rem;
    font-weight: 500;
    transition: opacity 0.2s;
}

.danger-btn:hover {
    opacity: 0.9;
}

.error-message {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid var(--danger);
    color: var(--danger);
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    margin: 0.5rem 0;
    font-size: 0.875rem;
}

/* Scrollbar styling */
.messages::-webkit-scrollbar {
    width: 6px;
}

.messages::-webkit-scrollbar-track {
    background: transparent;
}

.messages::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.messages::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Login Screen */
.login-screen {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 200;
}

.login-box {
    text-align: center;
    padding: 2.5rem;
    background: var(--bg-secondary);
    border-radius: 1rem;
    border: 1px solid var(--border);
    width: 100%;
    max-width: 360px;
    margin: 1rem;
}

.login-box h1 {
    font-size: 2rem;
    font-weight: 600;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.5rem;
}

.login-box > p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.pin-input-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

#pinInput {
    width: 100%;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    padding: 0.875rem 1rem;
    color: var(--text-primary);
    font-size: 1.125rem;
    text-align: center;
    letter-spacing: 0.25em;
}

#pinInput:focus {
    outline: none;
    border-color: var(--accent);
}

#pinSubmit {
    width: 100%;
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.875rem 1.5rem;
    border-radius: 0.5rem;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background 0.2s;
}

#pinSubmit:hover {
    background: var(--accent-hover);
}

.pin-error {
    color: var(--danger);
    font-size: 0.875rem;
    margin-top: 1rem;
    min-height: 1.25rem;
}

/* Logout button */
.logout-btn {
    position: absolute;
    top: 1.5rem;
    right: 4rem;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.logout-btn:hover {
    color: var(--danger);
    border-color: var(--danger);
}

.logout-btn svg {
    width: 18px;
    height: 18px;
}

/* Mobile adjustments */
@media (max-width: 640px) {
    .message-content {
        max-width: 90%;
    }

    header {
        padding: 1rem;
    }

    header h1 {
        font-size: 1.5rem;
    }

    .input-container {
        padding: 0.75rem 1rem 1rem;
    }

    .logout-btn {
        right: 3.5rem;
    }
}