:root {
    --font-sans: "Inter", sans-serif;
    --text-color: rgb(25, 25, 24);
    --bg-color: #fafafa;
    --border-color: rgba(55, 53, 47, 0.12);
    --space-8: 8px;
    --space-12: 12px;
    --space-16: 16px;
    --space-20: 20px;
    --space-24: 24px;
    --space-32: 32px;

    /* App Specific */
    --text-muted: rgba(25, 25, 24, 0.9);
    --selection-color: rgba(35, 131, 226, 0.28);
    --caret-color: rgb(55, 53, 47);
    --hover-surface: rgba(55, 53, 47, 0.08);
    --primary-blue: #2383E2;
    --primary-blue-hover: #1B6DC1;
    --primary-blue-active: #155A9E;
}

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

body {
    font-family: var(--font-sans);
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.55;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

* {
    font-family: "Inter", ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--space-32) var(--space-24);
}

/* ========== APP HEADER ========== */
.app-header {
    text-align: center;
    margin-bottom: var(--space-24);
    padding: var(--space-16) var(--space-24);
    margin: calc(-1 * var(--space-32)) calc(-1 * var(--space-24)) var(--space-24);
}

.app-header__title {
    font-size: 36px;
    font-weight: 700;
    line-height: 1.15;
    letter-spacing: -0.025em;
    color: var(--text-color);
    margin: 0;
    padding-bottom: var(--space-16);
}

.app-header__title::after {
    content: "";
    display: block;
    width: 40%;
    height: 1px;
    background: var(--border-color);
    margin: var(--space-16) auto 0;
}

.input-section {
    background: #fff;
    border: 0.5px solid var(--border-color);
    border-radius: 12px;
    padding: 32px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    margin-bottom: 40px;
}

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

label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-muted);
}

textarea,
select {
    width: 100%;
    padding: 12px;
    border: 0.5px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    font-family: inherit;
    color: var(--text-color);
    background: #fcfcfc;
    transition: border-color 0.2s;
}

textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary-blue);
    background: #fff;
}

.optional-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 16px;
    margin-bottom: 24px;
}

@media (max-width: 600px) {
    .optional-inputs {
        grid-template-columns: 1fr;
    }
}

.primary-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: "Inter", ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    font-size: 16px;
    font-weight: 500;
    padding: 10px 20px;
    border-radius: 50px;
    background: #000000;
    color: white;
    border: none;
    cursor: pointer;
    transition: background 0.2s;
    width: 100%;
    white-space: nowrap;
}

.primary-button:hover:not(:disabled) {
    background: #1a1a1a;
}

.primary-button:active:not(:disabled) {
    background: #333333;
}

.primary-button:disabled {
    background: #ccc;
    cursor: not-allowed;
}

.secondary-button {
    font-size: 14px;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 6px;
    background: white;
    color: var(--text-color);
    border: 0.5px solid var(--border-color);
    cursor: pointer;
    transition: background 0.2s;
}

.secondary-button:hover {
    background: var(--hover-surface);
}

.result-section {
    background: #fff;
    border: 0.5px solid var(--border-color);
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
    border-bottom: 0.5px solid var(--border-color);
    padding-bottom: 16px;
}

.result-header h2 {
    font-size: 28px;
    font-weight: 600;
}

.hidden {
    display: none;
}

.loading {
    text-align: center;
    padding: 40px;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--primary-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 16px;
}

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

/* Markdown Styling */
.markdown-body h3 {
    font-size: 22px;
    font-weight: 600;
    margin: 32px 0 16px;
    padding-bottom: 8px;
    border-bottom: 0.5px solid var(--border-color);
}

.markdown-body p {
    margin-bottom: 16px;
    font-size: 18px;
}

.markdown-body ul,
.markdown-body ol {
    margin-bottom: 16px;
    padding-left: 24px;
}

.markdown-body li {
    margin-bottom: 8px;
}

.markdown-body hr {
    border: none;
    border-top: 0.5px solid var(--border-color);
    margin: 32px 0;
}

.markdown-body strong {
    font-weight: 600;
}

footer {
    margin-top: 80px;
    text-align: center;
    color: rgba(25, 25, 24, 0.4);
    font-size: 14px;
}

@media (max-width: 768px) {
    .container {
        padding: var(--space-24) var(--space-16);
    }

    .app-header {
        padding: var(--space-12) var(--space-16);
        margin: calc(-1 * var(--space-24)) calc(-1 * var(--space-16)) var(--space-20);
    }

    .app-header__title {
        font-size: 28px;
    }
}