:root {
    --primary-color: #4f46e5;
    --primary-hover: #4338ca;
    --secondary-color: #64748b;
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --card-bg: rgba(255, 255, 255, 0.95);
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #e2e8f0;
    --radius: 12px;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Pretendard', sans-serif;
    background: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text-main);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 40px 20px;
}

.container {
    width: 100%;
    max-width: 800px;
    display: flex;
    flex-direction: column;
    gap: 30px;
}

header {
    text-align: center;
    margin-bottom: 10px;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 8px;
}

.logo i {
    font-size: 2rem;
    color: var(--primary-color);
}

header h1 {
    font-size: 2.2rem;
    font-weight: 800;
    letter-spacing: -0.5px;
}

header p {
    color: var(--text-muted);
    font-size: 1.1rem;
}

.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
    border: 1px solid rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
}

.input-group {
    margin-bottom: 24px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-main);
}

.input-group label i {
    margin-right: 6px;
    color: var(--primary-color);
}

input[type="text"], textarea {
    width: 100%;
    padding: 14px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.2s;
}

input[type="text"]:focus, textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.1);
}

textarea {
    height: 160px;
    resize: vertical;
}

.primary-btn {
    width: 100%;
    padding: 16px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: background-color 0.2s, transform 0.1s;
    position: relative;
}

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

.primary-btn:active {
    transform: scale(0.99);
}

.secondary-btn {
    padding: 8px 16px;
    background-color: white;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s;
}

.secondary-btn:hover {
    background-color: #f8fafc;
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.hidden {
    display: none;
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f1f5f9;
}

.result-content {
    line-height: 1.8;
    white-space: pre-wrap;
    color: #334155;
    font-size: 1.05rem;
}

/* Loader Styles */
.loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 0.8s linear infinite;
}

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

.loading .btn-text, .loading i {
    display: none;
}

.loading .loader {
    display: block;
}

footer {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 20px;
}

@media (max-width: 600px) {
    .card {
        padding: 20px;
    }
}