/* ==========================================================
   4Arcs Medical Billing — Base Stylesheet
   Professional healthcare / RCM SaaS aesthetic
   ========================================================== */

:root {
    --color-primary: #0b5c76;
    --color-primary-dark: #073e4f;
    --color-primary-light: #e4f2f5;
    --color-accent: #1a8f7b;
    --color-accent-dark: #146d5e;
    --color-text: #1c2b33;
    --color-text-muted: #57707a;
    --color-bg: #f6f9fa;
    --color-white: #ffffff;
    --color-border: #dbe5e8;
    --color-danger: #b3261e;
    --color-warning: #a5670a;
    --color-success: #1a7a4c;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 3px rgba(15, 45, 55, 0.08);
    --shadow-md: 0 6px 20px rgba(15, 45, 55, 0.10);
    --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --max-width: 1140px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: var(--font-base);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.55;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3, h4 {
    line-height: 1.25;
    margin: 0 0 0.6em 0;
    font-weight: 700;
    color: var(--color-primary-dark);
}
h1 { font-size: clamp(1.8rem, 3.2vw, 2.6rem); }
h2 { font-size: clamp(1.4rem, 2.4vw, 1.9rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1em 0; color: var(--color-text-muted); }

.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ---------------- Header ---------------- */
.site-header {
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 100;
}
.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 14px;
    padding-bottom: 14px;
    flex-wrap: wrap;
    gap: 10px;
}
.brand {
    display: flex;
    flex-direction: column;
    line-height: 1.15;
}
.brand-name {
    font-weight: 800;
    font-size: 1.15rem;
    color: var(--color-primary-dark);
    text-decoration: none;
}
.brand-tagline {
    font-size: 0.72rem;
    color: var(--color-text-muted);
    letter-spacing: 0.03em;
    text-transform: uppercase;
}
.main-nav {
    display: flex;
    align-items: center;
    gap: 22px;
    flex-wrap: wrap;
}
.main-nav a {
    color: var(--color-text);
    font-weight: 500;
    font-size: 0.95rem;
}
.main-nav a:hover { color: var(--color-primary); text-decoration: none; }

.nav-toggle { display: none; }

/* ---------------- Buttons ---------------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 13px 24px;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.98rem;
    cursor: pointer;
    border: 2px solid transparent;
    text-decoration: none;
    transition: transform 0.05s ease, background 0.15s ease, box-shadow 0.15s ease;
    line-height: 1.1;
}
.btn:hover { text-decoration: none; }
.btn:active { transform: translateY(1px); }

.btn-primary {
    background: var(--color-accent);
    color: #fff;
}
.btn-primary:hover { background: var(--color-accent-dark); }

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

.btn-small { padding: 8px 14px; font-size: 0.85rem; }
.btn-block { width: 100%; }
.btn-danger { background: var(--color-danger); color: #fff; }
.btn-outline { background: #fff; border-color: var(--color-border); color: var(--color-text); }

/* ---------------- Cards ---------------- */
.card {
    background: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    padding: 28px;
}

/* ---------------- Forms ---------------- */
label {
    display: block;
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 6px;
    color: var(--color-text);
}
input[type="text"],
input[type="email"],
input[type="tel"],
input[type="number"],
input[type="date"],
input[type="password"],
input[type="url"],
select,
textarea {
    width: 100%;
    padding: 12px 14px;
    border: 1.5px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-family: inherit;
    background: #fff;
    color: var(--color-text);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}
.form-group { margin-bottom: 18px; }
.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
.field-error {
    color: var(--color-danger);
    font-size: 0.82rem;
    margin-top: 5px;
    display: none;
}
.field-error.visible { display: block; }
input.has-error, select.has-error { border-color: var(--color-danger); }
.field-hint { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 4px; }

.alert {
    padding: 14px 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 18px;
    font-size: 0.92rem;
}
.alert-error { background: #fdecea; color: var(--color-danger); border: 1px solid #f6c6c1; }
.alert-success { background: #e8f6ee; color: var(--color-success); border: 1px solid #bfe6cf; }
.alert-info { background: var(--color-primary-light); color: var(--color-primary-dark); border: 1px solid #bfe0e8; }

/* ---------------- Tags ---------------- */
.tag {
    display: inline-block;
    font-size: 0.68rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    padding: 2px 8px;
    border-radius: 20px;
    text-transform: uppercase;
    vertical-align: middle;
}
.tag-calculated { background: #e4f2f5; color: var(--color-primary); }
.tag-estimated { background: #fff3e0; color: var(--color-warning); }
.tag-input { background: #eef2ff; color: #3b4bb8; }
.tag-review { background: #fdecea; color: var(--color-danger); }

/* ---------------- Footer ---------------- */
.site-footer {
    background: var(--color-primary-dark);
    color: #cfe4ea;
    margin-top: 60px;
    padding: 40px 0 24px;
}
.site-footer a { color: #cfe4ea; }
.footer-links {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    margin-bottom: 16px;
}
.footer-note {
    font-size: 0.82rem;
    color: #9ec2cb;
    border-top: 1px solid rgba(255,255,255,0.12);
    padding-top: 16px;
    margin-top: 16px;
}

/* ---------------- Utility ---------------- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.section { padding: 60px 0; }
.section-alt { background: var(--color-white); }
.badge-soft {
    display: inline-block;
    background: var(--color-primary-light);
    color: var(--color-primary-dark);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    text-transform: uppercase;
    margin-bottom: 14px;
}

/* ---------------- Responsive ---------------- */
@media (max-width: 900px) {
    .form-row { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
    .main-nav {
        display: none;
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        gap: 14px;
        padding-top: 12px;
    }
    .main-nav.open { display: flex; }
    .nav-toggle {
        display: inline-flex;
        align-items: center;
        justify-content: center;
        width: 40px;
        height: 40px;
        border: 1px solid var(--color-border);
        border-radius: var(--radius-sm);
        background: #fff;
        font-size: 1.1rem;
        cursor: pointer;
    }
}

@media (max-width: 400px) {
    .container { padding: 0 14px; }
    .card { padding: 18px; }
}