/* ========== CSS VARIABLES ========== */
:root {
    /* Spacing Scale (8px system) */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Colors */
    --bg-primary: #050505;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #0a0a0a;
    --border-base: #333;
    --border-muted: #666;
    
    --accent-primary: #8EC07C;
    --accent-warning: #CA8553;
    --accent-error: #ff6b6b;
    
    --text-primary: #ffffff;
    --text-accent: #8EC07C;
    --text-muted: #999;
    --text-dimmed: #666;
    
    /* Typography Scale */
    --font-size-xs: 0.75rem;     /* 12px */
    --font-size-sm: 0.875rem;    /* 14px */
    --font-size-base: 1rem;      /* 16px */
    --font-size-md: 1.125rem;    /* 18px */
    --font-size-lg: 1.25rem;     /* 20px */
    --font-size-xl: 1.5rem;      /* 24px */
    --font-size-2xl: 2rem;       /* 32px */
    
    /* Button Sizes */
    --btn-padding-sm: var(--spacing-sm) var(--spacing-md);
    --btn-padding-md: 12px var(--spacing-lg);
    --btn-padding-lg: var(--spacing-md) var(--spacing-xl);
    
    /* Touch Targets */
    --min-touch-target: 44px;
}

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

body {
    font-family: 'Courier New', monospace;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: var(--font-size-base);
    display: flex;
    justify-content: center;
    align-items: stretch;
    min-height: 100vh;
    padding: 0;
    margin: 0;
    overflow-x: hidden;
}

.container {
    width: 100%;
    height: 100vh;
    height: 100dvh; /* Dynamic viewport height for mobile */
    display: flex;
    flex-direction: column;
    gap: 0;
    overflow: hidden;
}

/* Floating hamburger menu (top-left) */
.fab-menu {
    position: fixed;
    top: var(--spacing-md);
    left: var(--spacing-md);
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-sm);
    z-index: 1500;
}

.fab-toggle {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 2px solid var(--accent-primary);
    color: var(--accent-primary);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: 0 10px 24px rgba(0,0,0,0.45);
    transition: background-color 0.2s ease, transform 0.15s ease;
    -webkit-tap-highlight-color: transparent;
}

.fab-toggle i {
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.fab-toggle.active {
    background: var(--accent-primary);
    color: var(--bg-primary);
    transform: rotate(90deg);
}

.fab-toggle:hover:not(.active) {
    background: #0d0d0d;
    transform: scale(1.02);
}

.fab-toggle:active {
    transform: scale(0.95);
}

.fab-drawer {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
    background: rgba(5, 5, 5, 0.95);
    border: 1px solid var(--accent-primary);
    border-radius: 12px;
    box-shadow: 0 12px 32px rgba(0,0,0,0.5);
    backdrop-filter: blur(6px);
    opacity: 1;
    transform: translateY(0);
    transition: opacity 0.25s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.25s cubic-bezier(0.4, 0, 0.2, 1),
                visibility 0s linear 0s;
    visibility: visible;
}

.fab-drawer[hidden] {
    opacity: 0;
    transform: translateY(-10px);
    visibility: hidden;
    transition: opacity 0.25s cubic-bezier(0.4, 0, 0.2, 1),
                transform 0.25s cubic-bezier(0.4, 0, 0.2, 1),
                visibility 0s linear 0.25s;
}

.fab-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    min-height: var(--min-touch-target);
    border-radius: 10px;
    color: var(--accent-primary);
    text-decoration: none;
    border: 1px solid transparent;
    transition: background-color 0.15s ease, transform 0.15s ease, border-color 0.15s ease;
}

.fab-link i {
    font-size: var(--font-size-md);
}

.fab-link:hover {
    background: rgba(142, 192, 124, 0.12);
    border-color: rgba(142, 192, 124, 0.3);
    transform: scale(1.02);
}

.fab-link:active {
    transform: scale(0.98);
}

.input-wrapper {
    display: flex;
    flex-direction: column;
    background-color: var(--bg-primary);
    flex-shrink: 0;
}

/* Header */
.chat-header {
    text-align: center;
    border: 2px solid var(--accent-primary);
    padding: var(--spacing-lg);
    background-color: var(--bg-primary);
}

.chat-header h1 {
    font-size: var(--font-size-2xl);
    color: var(--accent-primary);
    margin-bottom: var(--spacing-sm);
}

.subtitle {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-md);
}

.back-link {
    color: var(--accent-primary);
    text-decoration: none;
    border: 1px solid var(--accent-primary);
    padding: var(--btn-padding-sm);
    display: inline-block;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.back-link:hover {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    transform: scale(1.02);
}

/* Chat Container */
.chat-container {
    border: 2px solid var(--border-base);
    border-left: none;
    border-right: none;
    background-color: var(--bg-tertiary);
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: var(--spacing-md);
    position: relative;
    -webkit-overflow-scrolling: touch;
    scroll-behavior: smooth;
}

.messages {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* Message Bubbles */
.message {
    max-width: 85%;
    padding: var(--spacing-md);
    border-radius: 8px;
    word-wrap: break-word;
    word-break: break-word;
    animation: fadeIn 0.3s ease-in;
    line-height: 1.5;
}

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

.message.user {
    align-self: flex-end;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-base);
    border-left: 3px solid var(--accent-primary);
    color: var(--text-primary);
}

.message.assistant {
    align-self: flex-start;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-base);
    border-left: 3px solid var(--accent-warning);
    color: var(--text-primary);
}

.message.system {
    align-self: center;
    background-color: transparent;
    border: 1px solid var(--border-muted);
    color: var(--text-muted);
    font-style: italic;
    font-size: var(--font-size-sm);
    text-align: center;
}

.message-time {
    font-size: var(--font-size-xs);
    color: var(--text-muted);
    margin-top: var(--spacing-xs);
    display: block;
}

/* Typing Indicator */
.typing-indicator {
    display: flex;
    gap: var(--spacing-xs);
    padding: 12px;
    align-self: flex-start;
    max-width: 80px;
}

.typing-indicator span {
    width: var(--spacing-sm);
    height: var(--spacing-sm);
    background-color: var(--accent-primary);
    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: 0.5; }
    30% { transform: translateY(-10px); opacity: 1; }
}

/* Input Area */
.input-container {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm);
    background-color: var(--bg-primary);
    border-top: 2px solid var(--border-base);
}

.message-input {
    flex: 1;
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-base);
    color: var(--text-primary);
    font-family: 'Courier New', monospace;
    font-size: var(--font-size-base);
    padding: 12px var(--spacing-md);
    resize: none;
    min-height: var(--min-touch-target);
    max-height: 120px;
    -webkit-appearance: none;
    border-radius: 4px;
}

.message-input:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
    border-color: var(--accent-primary);
}

.send-button {
    background-color: var(--bg-primary);
    border: 2px solid var(--accent-primary);
    color: var(--accent-primary);
    font-family: 'Courier New', monospace;
    font-size: var(--font-size-sm);
    font-weight: bold;
    padding: var(--btn-padding-md);
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.15s ease;
    white-space: nowrap;
    min-height: var(--min-touch-target);
    -webkit-appearance: none;
    border-radius: 4px;
    -webkit-tap-highlight-color: transparent;
}

.send-button:hover:not(:disabled) {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    transform: scale(1.02);
}

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

/* Status Bar */
.status-bar {
    display: flex;
    justify-content: space-between;
    padding: var(--spacing-sm);
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-base);
    font-size: var(--font-size-xs);
    color: var(--text-dimmed);
    flex-shrink: 0;
}

#status-text.error {
    color: var(--accent-error);
}

#status-text.success {
    color: var(--accent-primary);
}

/* Finalize Section */
.finalize-section {
    border: 2px solid var(--accent-warning);
    border-left: none;
    border-right: none;
    padding: var(--spacing-md);
    text-align: center;
    background-color: var(--bg-secondary);
    flex-shrink: 0;
}

.finalize-section p {
    margin-bottom: 12px;
    color: var(--text-primary);
    font-size: var(--font-size-sm);
}

.finalize-button,
.continue-button {
    font-family: 'Courier New', monospace;
    font-size: var(--font-size-sm);
    font-weight: bold;
    padding: var(--btn-padding-md);
    cursor: pointer;
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.15s ease;
    margin: var(--spacing-xs);
    min-height: var(--min-touch-target);
    -webkit-appearance: none;
    border-radius: 4px;
    -webkit-tap-highlight-color: transparent;
}

.finalize-button {
    background-color: var(--bg-primary);
    border: 2px solid var(--accent-warning);
    color: var(--accent-warning);
}

.finalize-button:hover {
    background-color: var(--accent-warning);
    color: var(--bg-primary);
    transform: scale(1.02);
}

.continue-button {
    background-color: var(--bg-primary);
    border: 2px solid var(--accent-primary);
    color: var(--accent-primary);
}

.continue-button:hover {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
    transform: scale(1.02);
}

/* Scrollbar Styling */
.chat-container::-webkit-scrollbar {
    width: 10px;
}

.chat-container::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

.chat-container::-webkit-scrollbar-thumb {
    background: var(--border-base);
    border-radius: 5px;
}

.chat-container::-webkit-scrollbar-thumb:hover {
    background: var(--accent-primary);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .hide-on-mobile {
        display: none !important;
    }

    body {
        height: 100vh;
        height: 100dvh;
        overflow: hidden;
        position: fixed;
        width: 100%;
    }

    .container {
        gap: 0;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        height: 100vh;
        height: 100dvh;
        overflow: hidden;
    }
    
    .input-wrapper {
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        z-index: 1000;
        background-color: #050505;
        box-shadow: 0 -2px 10px rgba(0,0,0,0.5);
    }
    
    .chat-container {
        padding: var(--spacing-sm);
        padding-bottom: 200px;
        overflow-y: auto;
        height: calc(100vh - 160px);
        height: calc(100dvh - 160px);
    }

    .message {
        max-width: 90%;
        padding: var(--spacing-sm) 12px;
        font-size: 15px;
    }

    .input-container {
        padding: var(--spacing-sm);
        gap: var(--spacing-sm);
        background-color: var(--bg-primary);
    }

    .message-input {
        font-size: var(--font-size-base);
        padding: var(--spacing-sm);
        min-height: var(--min-touch-target);
    }

    .send-button {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: var(--font-size-xs);
        min-width: 70px;
    }

    .status-bar {
        font-size: var(--font-size-xs);
        padding: var(--spacing-xs) var(--spacing-sm);
    }

    .finalize-section {
        padding: 12px;
    }

    .finalize-button,
    .continue-button {
        display: block;
        width: 100%;
        margin: var(--spacing-xs) 0;
        font-size: var(--font-size-sm);
    }

    .typing-indicator {
        max-width: 60px;
        padding: var(--spacing-sm);
    }

    .typing-indicator span {
        width: var(--spacing-xs);
        height: var(--spacing-xs);
    }
}

/* Landscape mobile */
@media (max-width: 768px) and (orientation: landscape) {
    .chat-container {
        padding: var(--spacing-sm);
    }

    .message {
        font-size: var(--font-size-sm);
    }

    .input-container {
        padding: var(--spacing-xs);
    }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
    .send-button,
    .finalize-button,
    .continue-button {
        min-height: 48px;
    }

    .message-input {
        min-height: 48px;
    }
}

/* ========== ACCESSIBILITY ========== */
*:focus-visible {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

button:focus-visible,
.fab-toggle:focus-visible {
    outline: 3px solid var(--accent-primary);
    outline-offset: 3px;
}

/* Loading states */
.loading {
    opacity: 0.6;
    cursor: wait;
    pointer-events: none;
}

button.loading::after {
    content: '...';
    animation: ellipsis 1.5s infinite;
}

@keyframes ellipsis {
    0% { content: '.'; }
    33% { content: '..'; }
    66% { content: '...'; }
}