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

:root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #242424;
    --bg-tertiary: #2d2d2d;
    --text-primary: #e0e0e0;
    --text-secondary: #888;
    --text-muted: #666;
    --accent: #7c9885;
    --accent-hover: #8fad99;
    --user-bg: #3d4f4a;
    --therapist-bg: #2d2d2d;
    --border: #333;
}

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

.container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 800px;
    margin: 0 auto;
}

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

header h1 {
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.session-controls {
    display: flex;
    gap: 0.5rem;
}

/* Buttons */
.btn-primary {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.2s;
}

.btn-primary:hover {
    background: var(--accent-hover);
}

.btn-primary:disabled {
    background: var(--bg-tertiary);
    cursor: not-allowed;
}

.btn-subtle {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-subtle:hover:not(:disabled) {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.btn-subtle:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Main chat area */
main {
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    position: relative;
}

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

/* Start screen */
.start-screen {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    text-align: center;
}

.start-screen p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

.start-screen.hidden {
    display: none;
}

/* Messages */
.message {
    max-width: 80%;
    padding: 1rem 1.25rem;
    border-radius: 12px;
    animation: fadeIn 0.3s ease;
}

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

.message.user {
    background: var(--user-bg);
    align-self: flex-end;
    margin-left: auto;
}

.message.therapist {
    background: var(--therapist-bg);
    align-self: flex-start;
    border: 1px solid var(--border);
}

.message.system {
    background: transparent;
    color: var(--text-muted);
    font-size: 0.9rem;
    text-align: center;
    align-self: center;
    max-width: 100%;
}

/* Typing indicator */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 1rem 1.25rem;
    background: var(--therapist-bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    align-self: flex-start;
    width: fit-content;
}

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

.typing-indicator span:nth-child(2) {
    animation-delay: 0.2s;
}

.typing-indicator span:nth-child(3) {
    animation-delay: 0.4s;
}

@keyframes typing {
    0%, 60%, 100% {
        transform: translateY(0);
        opacity: 0.4;
    }
    30% {
        transform: translateY(-4px);
        opacity: 1;
    }
}

/* Input area */
footer {
    padding: 1rem 1.5rem 1.5rem;
    border-top: 1px solid var(--border);
}

footer.hidden {
    display: none;
}

#message-form {
    display: flex;
    gap: 0.75rem;
    align-items: flex-end;
}

#message-input {
    flex: 1;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 0.875rem 1rem;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: inherit;
    resize: none;
    max-height: 150px;
    line-height: 1.5;
}

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

#message-input::placeholder {
    color: var(--text-muted);
}

#send-btn {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.875rem 1.25rem;
    border-radius: 12px;
    font-size: 1rem;
    cursor: pointer;
    transition: background 0.2s;
    white-space: nowrap;
}

#send-btn:hover:not(:disabled) {
    background: var(--accent-hover);
}

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

/* Scrollbar */
#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-muted);
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        max-width: 100%;
    }

    header {
        padding: 0.75rem 1rem;
    }

    #messages {
        padding: 1rem;
    }

    .message {
        max-width: 90%;
        padding: 0.875rem 1rem;
    }

    footer {
        padding: 0.75rem 1rem 1rem;
    }
}