/* =============================================================================
   CSS Variables & Theme
   ============================================================================= */

:root {
    /* Colors - Dark theme inspired by terminals */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a25;
    --bg-elevated: #22222f;
    
    --text-primary: #f0f0f5;
    --text-secondary: #9090a0;
    --text-muted: #606075;
    
    --accent-primary: #00d4aa;
    --accent-secondary: #00b894;
    --accent-glow: rgba(0, 212, 170, 0.3);
    
    --error: #ff6b6b;
    --error-bg: rgba(255, 107, 107, 0.1);
    
    --user-bubble: #1e3a5f;
    --agent-bubble: #1a1a25;
    
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    
    /* Typography */
    --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    /* Spacing */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 400ms ease;
}

/* =============================================================================
   Reset & Base
   ============================================================================= */

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-display);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow: hidden;
}

input, button {
    font-family: inherit;
    font-size: inherit;
}

/* =============================================================================
   Screen States
   ============================================================================= */

.screen {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.screen.hidden {
    display: none;
}

/* =============================================================================
   Login Screen
   ============================================================================= */

#login-screen {
    display: grid;
    grid-template-columns: 1fr 1fr;
    min-height: 100vh;
}

@media (max-width: 900px) {
    #login-screen {
        grid-template-columns: 1fr;
    }
    
    .login-decoration {
        display: none;
    }
}

.login-container {
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: 3rem;
    max-width: 480px;
    margin: 0 auto;
    width: 100%;
}

.login-header {
    margin-bottom: 3rem;
    text-align: center;
}

.logo {
    color: var(--accent-primary);
    margin-bottom: 1.5rem;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.login-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--accent-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-header .subtitle {
    color: var(--text-secondary);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

#login-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
}

.input-group input {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem 1.25rem;
    color: var(--text-primary);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

.input-group input:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.input-group input::placeholder {
    color: var(--text-muted);
}

.btn-primary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-secondary) 100%);
    color: var(--bg-primary);
    border: none;
    border-radius: var(--radius-md);
    padding: 1rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    margin-top: 0.5rem;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px var(--accent-glow);
}

.btn-primary:active {
    transform: translateY(0);
}

.error-message {
    color: var(--error);
    font-size: 0.875rem;
    text-align: center;
    min-height: 1.25rem;
    background: var(--error-bg);
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    display: none;
}

.error-message.visible {
    display: block;
    animation: shake 0.4s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-8px); }
    75% { transform: translateX(8px); }
}

/* Login decoration */
.login-decoration {
    background: var(--bg-secondary);
    position: relative;
    overflow: hidden;
}

.grid-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(var(--border-color) 1px, transparent 1px),
        linear-gradient(90deg, var(--border-color) 1px, transparent 1px);
    background-size: 50px 50px;
    mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

.login-decoration::before {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: pulse 4s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.5; transform: translate(-50%, -50%) scale(1); }
    50% { opacity: 0.8; transform: translate(-50%, -50%) scale(1.1); }
}

/* =============================================================================
   Chat Screen
   ============================================================================= */

#chat-screen {
    display: flex;
    flex-direction: column;
    height: 100vh;
    background: var(--bg-primary);
}

/* Chat Header */
.chat-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.5rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.logo-small {
    color: var(--accent-primary);
}

.header-info h2 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.125rem;
}

.status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.75rem;
    color: var(--text-secondary);
    font-family: var(--font-mono);
}

.status-dot {
    width: 8px;
    height: 8px;
    background: var(--accent-primary);
    border-radius: 50%;
    animation: blink 2s ease-in-out infinite;
}

@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.btn-icon {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.625rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    color: var(--text-primary);
    border-color: var(--border-hover);
    background: var(--bg-tertiary);
}

/* Chat Container */
.chat-container {
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

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

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

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

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

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

/* Welcome Message */
.welcome-message {
    text-align: center;
    padding: 3rem 2rem;
    max-width: 400px;
    margin: auto;
}

.welcome-icon {
    color: var(--accent-primary);
    margin-bottom: 1.5rem;
    opacity: 0.8;
}

.welcome-message h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.welcome-message p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Message Bubbles */
.message {
    display: flex;
    flex-direction: column;
    max-width: 80%;
    animation: messageIn 0.3s ease;
}

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

.message.user {
    align-self: flex-end;
}

.message.agent {
    align-self: flex-start;
}

.message-bubble {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-lg);
    line-height: 1.5;
    word-wrap: break-word;
}

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

.message.agent .message-bubble {
    background: var(--agent-bubble);
    border: 1px solid var(--border-color);
    border-bottom-left-radius: var(--radius-sm);
}

.message-time {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-top: 0.375rem;
    font-family: var(--font-mono);
}

.message.user .message-time {
    text-align: right;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 1rem 1.25rem;
    background: var(--agent-bubble);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    border-bottom-left-radius: var(--radius-sm);
    width: fit-content;
}

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

.typing-indicator span:nth-child(1) { animation-delay: 0s; }
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes typingBounce {
    0%, 60%, 100% {
        transform: translateY(0);
        background: var(--text-muted);
    }
    30% {
        transform: translateY(-8px);
        background: var(--accent-primary);
    }
}

/* Chat Input */
.chat-input-container {
    padding: 1rem 1.5rem 1.5rem;
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    flex-shrink: 0;
}

#chat-form {
    margin-bottom: 0.75rem;
}

.input-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 0.5rem 0.5rem 0.5rem 1.25rem;
    transition: all var(--transition-fast);
}

.input-wrapper:focus-within {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

#message-input {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-size: 1rem;
    padding: 0.5rem 0;
    resize: none;
    min-height: 24px;
    max-height: 150px;
    line-height: 1.5;
    font-family: inherit;
    overflow-y: auto;
}

#message-input:focus {
    outline: none;
}

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

.btn-send {
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-primary);
    border: none;
    border-radius: var(--radius-md);
    padding: 0.75rem;
    color: var(--bg-primary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-send:hover:not(:disabled) {
    background: var(--accent-secondary);
    transform: scale(1.05);
}

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

.chat-disclaimer {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
    font-family: var(--font-mono);
}

/* Error State for Messages */
.message.error .message-bubble {
    background: var(--error-bg);
    border: 1px solid var(--error);
    color: var(--error);
}

/* =============================================================================
   Responsive
   ============================================================================= */

@media (max-width: 600px) {
    .login-container {
        padding: 2rem 1.5rem;
    }
    
    .chat-messages {
        padding: 1rem;
    }
    
    .message {
        max-width: 90%;
    }
    
    .chat-input-container {
        padding: 1rem;
    }
}