@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Poppins:wght@400;500;600;700&display=swap');

:root {
    /* Design System Tokens */
    --primary-color: #6366f1;
    --primary-hover: #4f46e5;
    --accent-color: #a855f7;

    /* Light Mode Palette */
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --card-border: #e2e8f0;
    --input-bg: #f1f5f9;
    --input-border: #e2e8f0;

    /* Chat Bubbles */
    --chat-bubble-user-bg: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    --chat-bubble-user-text: #ffffff;
    --chat-bubble-ai-bg: #f1f5f9;
    --chat-bubble-ai-text: var(--text-primary);

    /* User Specific Tokens */
    --checker-color: #f1f5f9;

    /* UI Scale */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 24px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

body.dark-mode {
    --bg-color: #0f172a;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --card-bg: #1e293b;
    --card-border: #334155;
    --input-bg: #0f172a;
    --input-border: #334155;

    --chat-bubble-ai-bg: #334155;
    --chat-bubble-ai-text: #ffffff;

    --checker-color: #334155;
}

/* Reset & Base */
*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: antialiased;
}

/* Layout */
.main-wrapper {
    width: 100%;
    max-width: 700px;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* 
 * LOGO DISPLAY AREA 
 * Includes Checkerboard Pattern (User Customization)
 */
.logo-display-area {
    position: relative;
    width: 100%;
    min-height: 380px;
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);

    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);

    /* User's Checkerboard Pattern */
    background-image:
        linear-gradient(45deg, var(--checker-color) 25%, transparent 25%),
        linear-gradient(-45deg, var(--checker-color) 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, var(--checker-color) 75%),
        linear-gradient(-45deg, transparent 75%, var(--checker-color) 75%);
    background-size: 20px 20px;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0px;

    padding: 40px 40px 100px 40px;
    /* Bottom padding for floating controls */
}

#main-logo {
    display: block;
    max-width: 90%;
    max-height: 250px;
    width: auto;
    height: auto;
    z-index: 2;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.1));
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Empty State */
.empty-state {
    text-align: center;
    color: var(--text-secondary);
    z-index: 1;
    max-width: 320px;
}

.empty-state svg {
    width: 56px;
    height: 56px;
    margin-bottom: 20px;
    opacity: 0.6;
    color: var(--text-secondary);
}

.empty-state h3 {
    margin: 0 0 8px 0;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    font-family: 'Poppins', sans-serif;
    letter-spacing: -0.02em;
}

.empty-state p {
    margin: 0;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* 
 * CONTROLS DOCK 
 * Floating Absolute Position (User Customization)
 */
.controls {
    position: absolute;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%) translateY(0);

    display: flex;
    align-items: center;
    gap: 8px;

    z-index: 10;
    background: var(--card-bg);
    padding: 6px;
    border-radius: var(--radius-md);
    border: 1px solid var(--card-border);
    box-shadow: 0 8px 16px -4px rgba(0, 0, 0, 0.1);

    transition: transform 0.3s ease, opacity 0.3s ease;
}

.controls.hidden {
    transform: translateX(-50%) translateY(20px);
    opacity: 0;
    pointer-events: none;
}

.mode-btn {
    appearance: none;
    background: white;
    color: var(--text-secondary);
    padding: 10px 20px;
    /* Matched reference padding */
    border-radius: var(--radius-sm);
    border: 1px solid var(--card-border);
    /* Matched reference border */
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.mode-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: white;
}

.mode-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.export-btn {
    background: var(--text-primary);
    color: var(--bg-color);
    margin-left: 8px;
    font-weight: 600;
}

.export-btn:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
    box-shadow: 0 4px 6px -1px rgba(99, 102, 241, 0.4);
}

/* Chat Panel */
.chat-panel {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: var(--radius-lg);
    padding: 24px;
    height: 360px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    box-shadow: var(--shadow-sm);
    transition: border-color 0.3s ease;
}

.chat-panel:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.chat-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--card-border);
    padding-bottom: 16px;
}

.chat-header .label {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--text-secondary);
    letter-spacing: 0.08em;
    display: flex;
    align-items: center;
    gap: 6px;
}

.chat-history {
    flex: 1;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 16px;
    padding-right: 8px;
    scroll-behavior: smooth;
}

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

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

.chat-history::-webkit-scrollbar-thumb {
    background-color: var(--card-border);
    border-radius: 10px;
}

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

.message {
    padding: 12px 16px;
    border-radius: 18px;
    font-size: 0.95rem;
    line-height: 1.5;
    max-width: 85%;
    position: relative;
    animation: fadeIn 0.3s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(5px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.ai {
    align-self: flex-start;
    background: var(--chat-bubble-ai-bg);
    color: var(--chat-bubble-ai-text);
    border-bottom-left-radius: 4px;
}

.message.user {
    align-self: flex-end;
    background: var(--chat-bubble-user-bg);
    color: var(--chat-bubble-user-text);
    border-bottom-right-radius: 4px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.message.error {
    align-self: center;
    background: #fee2e2;
    color: #ef4444;
    border: 1px solid #fecaca;
}

/* Input Area */
.input-area {
    display: flex;
    gap: 12px;
    position: relative;
    background: var(--card-bg);
    padding-top: 8px;
}

textarea {
    flex: 1;
    padding: 14px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--input-border);
    background: var(--input-bg);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    font-size: 0.95rem;
    line-height: 1.5;
    outline: none;
    resize: none;
    height: 52px;
    /* Fixed height for single line look, expands visually if needed but we keep it simple */
    transition: all 0.2s ease;
}

textarea:focus {
    border-color: var(--primary-color);
    background: var(--card-bg);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.send-btn {
    width: 52px;
    height: 52px;
    background: var(--text-primary);
    color: var(--bg-color);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.send-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    background: var(--text-secondary);
}

/* Overlays */
.loading-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-lg);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    z-index: 20;
}

body.dark-mode .loading-overlay {
    background: rgba(30, 41, 59, 0.85);
}

.loading-overlay.active {
    opacity: 1;
    pointer-events: all;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--card-border);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* Toast */
.toast {
    position: fixed;
    top: 32px;
    left: 50%;
    transform: translateX(-50%) translateY(-20px);
    background: var(--text-primary);
    color: var(--bg-color);
    padding: 12px 24px;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 600;
    opacity: 0;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    pointer-events: none;
    z-index: 200;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
    display: flex;
    align-items: center;
    gap: 10px;
}

.toast.visible {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* Auth Overlay */
.auth-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(15, 23, 42, 0.75);
    backdrop-filter: blur(12px);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.3s ease;
}

.auth-overlay.hidden {
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
}

.auth-card {
    background: var(--card-bg);
    padding: 48px;
    border-radius: 32px;
    border: 1px solid var(--card-border);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    text-align: center;
    max-width: 420px;
    width: 90%;
    animation: slideUp 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes slideUp {
    from {
        transform: translateY(40px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.auth-input {
    width: 100%;
    padding: 16px;
    margin: 24px 0;
    border: 1px solid var(--input-border);
    border-radius: var(--radius-md);
    background: var(--input-bg);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.2s;
}

.auth-input:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.auth-btn {
    width: 100%;
    padding: 16px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    font-weight: 600;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    transition: filter 0.2s, transform 0.2s;
}

.auth-btn:hover {
    filter: brightness(1.1);
    transform: translateY(-1px);
}

.reset-key-btn {
    font-size: 0.75rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    text-decoration: underline;
    opacity: 0.8;
    transition: opacity 0.2s;
}

.reset-key-btn:hover {
    opacity: 1;
    color: var(--primary-color);
}