/* ========================================
   CSS Variables & Reset
   ======================================== */
:root {
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a2e;
    --bg-input: #16162a;

    --text-primary: #e8e8f0;
    --text-secondary: #9898b0;
    --text-muted: #5a5a78;

    --accent-purple: #a78bfa;
    --accent-indigo: #6366f1;
    --accent-blue: #818cf8;

    --border-color: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.12);

    --glass-bg: rgba(18, 18, 26, 0.7);
    --glass-border: rgba(255, 255, 255, 0.08);

    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 24px;

    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   App Layout
   ======================================== */
.app {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    overflow: hidden;
}

/* ========================================
   Ambient Background Blobs
   ======================================== */
.bg-blob {
    position: fixed;
    border-radius: 50%;
    filter: blur(120px);
    opacity: 0.35;
    pointer-events: none;
    z-index: 0;
    animation: float 20s ease-in-out infinite;
}

.blob-1 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, #6366f1 0%, transparent 70%);
    top: -100px;
    right: -100px;
    animation-delay: 0s;
}

.blob-2 {
    width: 350px;
    height: 350px;
    background: radial-gradient(circle, #a78bfa 0%, transparent 70%);
    bottom: 100px;
    left: -150px;
    animation-delay: -7s;
}

.blob-3 {
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, #818cf8 0%, transparent 70%);
    top: 40%;
    right: -80px;
    animation-delay: -14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -20px) scale(1.05); }
    66% { transform: translate(-20px, 15px) scale(0.95); }
}

/* ========================================
   Header
   ======================================== */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 10;
    position: relative;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: var(--radius-md);
    border: 1px solid rgba(99, 102, 241, 0.2);
}

.header-title {
    font-size: 1.1rem;
    font-weight: 600;
    letter-spacing: -0.02em;
    background: linear-gradient(135deg, var(--accent-purple), var(--accent-indigo));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.btn-clear {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-clear:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--border-hover);
    color: var(--text-primary);
}

/* ========================================
   Chat Area
   ======================================== */
.chat-area {
    flex: 1;
    overflow-y: auto;
    padding: 0;
    position: relative;
    z-index: 1;
    scroll-behavior: smooth;
}

.chat-area::-webkit-scrollbar {
    width: 6px;
}

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

.chat-area::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.08);
    border-radius: 3px;
}

.chat-area::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.15);
}

/* ========================================
   Welcome Screen
   ======================================== */
.welcome {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 80px 24px 40px;
    animation: fadeInUp 0.6s ease-out;
}

.welcome.hidden {
    display: none;
}

.welcome-icon {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(99, 102, 241, 0.08);
    border-radius: 50%;
    border: 1px solid rgba(99, 102, 241, 0.15);
    margin-bottom: 24px;
    animation: pulse-glow 3s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 0 20px rgba(99, 102, 241, 0.1); }
    50% { box-shadow: 0 0 40px rgba(99, 102, 241, 0.25); }
}

.welcome h2 {
    font-size: 1.6rem;
    font-weight: 600;
    letter-spacing: -0.03em;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.welcome p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.suggestions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    max-width: 600px;
}

.suggestion {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 400;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.suggestion:hover {
    background: rgba(99, 102, 241, 0.08);
    border-color: rgba(99, 102, 241, 0.25);
    color: var(--accent-purple);
    transform: translateY(-1px);
}

/* ========================================
   Messages
   ======================================== */
.messages {
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.message {
    display: flex;
    gap: 12px;
    padding: 16px 0;
    animation: fadeInUp 0.35s ease-out;
    max-width: 100%;
}

.message-avatar {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 600;
    margin-top: 2px;
}

.message.user .message-avatar {
    background: linear-gradient(135deg, #6366f1, #4f46e5);
    color: white;
}

.message.assistant .message-avatar {
    background: rgba(167, 139, 250, 0.12);
    border: 1px solid rgba(167, 139, 250, 0.2);
    color: var(--accent-purple);
}

.message-body {
    flex: 1;
    min-width: 0;
}

.message-role {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 6px;
    color: var(--text-muted);
}

.message.user .message-role {
    color: var(--accent-blue);
}

.message.assistant .message-role {
    color: var(--accent-purple);
}

.message-content {
    font-size: 0.92rem;
    line-height: 1.7;
    color: var(--text-primary);
    word-wrap: break-word;
    overflow-wrap: break-word;
}

.message-content p {
    margin-bottom: 12px;
}

.message-content p:last-child {
    margin-bottom: 0;
}

.message-content code {
    background: rgba(99, 102, 241, 0.1);
    border: 1px solid rgba(99, 102, 241, 0.15);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'Fira Code', 'Cascadia Code', monospace;
    font-size: 0.85em;
    color: var(--accent-purple);
}

.message-content pre {
    background: rgba(0, 0, 0, 0.4);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 14px 18px;
    margin: 12px 0;
    overflow-x: auto;
    font-size: 0.84rem;
    line-height: 1.6;
}

.message-content pre code {
    background: none;
    border: none;
    padding: 0;
    color: var(--text-primary);
}

/* Typing indicator */
.typing-indicator {
    display: flex;
    gap: 4px;
    padding: 4px 0;
}

.typing-indicator span {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent-purple);
    opacity: 0.4;
    animation: typing-bounce 1.4s ease-in-out infinite;
}

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

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

@keyframes typing-bounce {
    0%, 60%, 100% { transform: translateY(0); opacity: 0.4; }
    30% { transform: translateY(-6px); opacity: 1; }
}

/* Cursor blink on streaming text */
.streaming .message-content::after {
    content: '▊';
    animation: blink 0.8s step-end infinite;
    color: var(--accent-purple);
    margin-left: 2px;
}

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

/* ========================================
   Input Area
   ======================================== */
.input-area {
    padding: 12px 24px 20px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-top: 1px solid var(--glass-border);
    z-index: 10;
    position: relative;
}

.input-form {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.input-wrapper {
    display: flex;
    align-items: flex-end;
    gap: 8px;
    width: 100%;
    background: var(--bg-input);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 6px 6px 6px 18px;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.input-wrapper:focus-within {
    border-color: rgba(99, 102, 241, 0.4);
    box-shadow: var(--shadow-sm), 0 0 0 3px rgba(99, 102, 241, 0.08);
}

.input-wrapper textarea {
    flex: 1;
    background: none;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.92rem;
    line-height: 1.5;
    padding: 8px 0;
    resize: none;
    max-height: 150px;
    min-height: 24px;
}

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

.btn-send {
    flex-shrink: 0;
    width: 38px;
    height: 38px;
    border-radius: var(--radius-md);
    border: none;
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-purple));
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    opacity: 0.4;
}

.btn-send:not(:disabled) {
    opacity: 1;
}

.btn-send:not(:disabled):hover {
    transform: scale(1.05);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

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

.disclaimer {
    font-size: 0.72rem;
    color: var(--text-muted);
    letter-spacing: 0.01em;
}

/* ========================================
   Animations
   ======================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 640px) {
    .header {
        padding: 12px 16px;
    }

    .messages {
        padding: 16px;
    }

    .input-area {
        padding: 10px 16px 16px;
    }

    .welcome {
        padding: 60px 20px 30px;
    }

    .welcome h2 {
        font-size: 1.3rem;
    }

    .suggestions {
        flex-direction: column;
        align-items: center;
    }
}