/* =======================
   RESET
======================= */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Segoe UI", sans-serif;
}

body {
    background: #0f172a;
    color: #fff;
    overflow-x: hidden;
}

/* =======================
   NAVBAR
======================= */
.navbar {
    position: sticky;
    top: 0;
    width: 100%;
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.nav-container {
    max-width: 1200px;
    margin: auto;
    padding: 15px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-box img {
    width: 45px;
    height: 45px;
    border-radius: 10px;
}

.logo-title {
    font-size: 18px;
    font-weight: 700;
}

.logo-subtitle {
    font-size: 12px;
    color: #94a3b8;
}

.nav-links {
    display: flex;
    gap: 20px;
}

.nav-link {
    color: #cbd5e1;
    text-decoration: none;
    font-size: 14px;
    transition: 0.3s;
}

.nav-link:hover {
    color: #38bdf8;
}

.mobile-menu {
    display: none;
    font-size: 20px;
    background: none;
    border: none;
    color: #fff;
}

/* =======================
   MAIN LAYOUT FIX
======================= */
.main-wrapper {
    width: 100%;
    min-height: calc(100vh - 80px);
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 40px 15px;
}

/* =======================
   CARD
======================= */
.main-card {
    width: 100%;
    max-width: 850px;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 20px;
    padding: 25px;
    backdrop-filter: blur(15px);
}

/* =======================
   HEADER
======================= */
.header {
    text-align: center;
    margin-bottom: 20px;
}

.header-icon {
    font-size: 40px;
    color: #38bdf8;
    margin-bottom: 10px;
}

.main-title {
    font-size: 24px;
    font-weight: bold;
}

.main-description {
    font-size: 14px;
    color: #94a3b8;
    margin-top: 8px;
}

/* =======================
   UPLOAD BOX
======================= */
.upload-box {
    margin-top: 20px;
    border: 2px dashed rgba(255,255,255,0.2);
    border-radius: 15px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: 0.3s;
}

.upload-box:hover {
    border-color: #38bdf8;
    transform: scale(1.02);
}

.upload-icon {
    font-size: 35px;
    color: #38bdf8;
    margin-bottom: 10px;
}

.upload-title {
    font-size: 16px;
    font-weight: 600;
}

.upload-text {
    font-size: 13px;
    color: #94a3b8;
}

/* =======================
   FILE LIST
======================= */
.file-section {
    margin-top: 20px;
}

.file-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.file-header h3 {
    font-size: 16px;
}

.file-header span {
    background: #38bdf8;
    padding: 2px 8px;
    border-radius: 10px;
    font-size: 12px;
    margin-left: 8px;
}

.file-header button {
    background: #ef4444;
    border: none;
    padding: 6px 12px;
    color: #fff;
    border-radius: 8px;
    cursor: pointer;
}

#file-list li {
    background: rgba(255,255,255,0.07);
    margin: 8px 0;
    padding: 10px;
    border-radius: 10px;
    display: flex;
    justify-content: space-between;
}

/* =======================
   OUTPUT
======================= */
.output-section {
    margin-top: 15px;
}

.output-section input {
    width: 100%;
    padding: 10px;
    border-radius: 10px;
    border: none;
    outline: none;
    background: rgba(255,255,255,0.08);
    color: #fff;
}

/* =======================
   BUTTONS
======================= */
.button-section {
    margin-top: 15px;
    display: flex;
    gap: 10px;
}

button {
    padding: 10px 15px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-weight: bold;
}

#merge-btn {
    background: #38bdf8;
    color: #000;
}

#download-btn {
    background: #22c55e;
    color: #000;
}

/* =======================
   LOADER
======================= */
/* LOADER FIX - CLEAN VERSION */
.loader-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.7);
    display: none;   /* default hidden */
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.loader-overlay.active {
    display: flex;
}

.loader-box {
    text-align: center;
}

.loader {
    width: 40px;
    height: 40px;
    border: 4px solid #fff;
    border-top: 4px solid #38bdf8;
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: auto;
}

@keyframes spin {
    100% { transform: rotate(360deg); }
}

/* =======================
   FOOTER
======================= */
.footer {
    text-align: center;
    padding: 30px;
    color: #94a3b8;
}

/* =======================
   RESPONSIVE
======================= */
@media (max-width: 768px) {

    .nav-links {
        display: none;
    }

    .mobile-menu {
        display: block;
    }

    .main-card {
        padding: 15px;
    }

    .upload-box {
        padding: 25px 15px;
    }

    .main-title {
        font-size: 20px;
    }
}

/* MOBILE MENU ACTIVE */
.nav-links.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 70px;
    right: 20px;
    background: #0f172a;
    padding: 10px;
    border-radius: 10px;
}

/* =======================
   MOBILE MENU FIX
======================= */

@media (max-width: 768px) {

    .nav-links {
        position: absolute;
        top: 70px;
        right: 20px;
        background: #0f172a;
        flex-direction: column;
        width: 200px;
        padding: 15px;
        border-radius: 12px;

        display: none; /* IMPORTANT */
        box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    }

    .nav-links.active {
        display: flex; /* THIS is what JS triggers */
    }

    .nav-link {
        padding: 10px 0;
    }
}



/* =========================
   SAFE PROFESSIONAL FOOTER
========================= */

/* FOOTER RGB TOP BORDER */

.footer{
    position: relative;
    margin-top: 60px;
    padding: 50px 20px;
    background: #0e0e0f;
    overflow: hidden;
}

/* ANIMATED RGB LINE */
.footer::before{
    content: "";
    position: absolute;
    top: 0;
    left: -100%;
    width: 200%;
    height: 2px;

    background: linear-gradient(
        90deg,
        #ff0000,
        #ff9900,
        #ffee00,
        #00ff00,
        #00ffff,
        #0066ff,
        #aa00ff,
        #ff0000
    );

    animation: rgbMove 4s linear infinite;
}

/* RGB ANIMATION */
@keyframes rgbMove{
    0%{
        transform: translateX(0);
    }

    100%{
        transform: translateX(50%);
    }
}

.footer-container {
    max-width: 1100px;
    margin: auto;
}

/* GRID */
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 40px;
    align-items: start;
}

/* LEFT */
.footer-left {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-brand img {
    width: 45px;
    height: 45px;
    border-radius: 10px;
}

.footer-title {
    font-size: 18px;
    color: #fff;
    font-weight: 700;
}

.footer-subtitle {
    font-size: 12px;
    color: #94a3b8;
}

.footer-text {
    font-size: 13px;
    color: #94a3b8;
    line-height: 1.6;
}

/* CENTER */
.footer-links {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer-links h3 {
    font-size: 15px;
    color: #fff;
    margin-bottom: 8px;
}

.footer-links a {
    text-decoration: none;
    color: #94a3b8;
    font-size: 14px;
    transition: 0.2s;
}

.footer-links a:hover {
    color: #38bdf8;
}

/* RIGHT */
/* =========================
   SOCIAL ICON FIX (PC ONLY)
========================= */

.footer-right {
    display: flex;
    flex-direction: column;
    justify-content: flex-start; /* important fix */
    gap: 12px;
}

/* push social icons properly */
.footer-social {
    display: flex;
    gap: 10px;
    margin-left: 60px;
    margin-top: auto;   /* 👈 THIS FIXES PC POSITION */
    padding-top: 15px;
}

/* optional: keeps balance clean */
.footer-right h3 {
    margin-bottom: 5px;
}

/* SOCIAL */
.footer-social {
    display: flex;
    gap: 10px;
    margin-top: 10px;
}

.footer-social a {
    width: 36px;
    height: 36px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(255,255,255,0.08);
    border-radius: 8px;
    color: #fff;
    transition: 0.2s;
}

.footer-social a:hover {
    background: #38bdf8;
    color: #0f172a;
}

/* COPYRIGHT */
.copyright {
    font-size: 12px;
    color: #64748b;
    margin-top: 10px;
}

/* =========================
   RESPONSIVE
========================= */

@media (max-width: 900px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }

    .footer-left {
        grid-column: span 2;
        text-align: center;
        align-items: center;
    }

    .footer-brand {
        justify-content: center;
    }
}

@media (max-width: 600px) {
    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .footer-social {
        justify-content: center;
        margin-right: 60px;
    }

    .footer-left {
        grid-column: auto;
    }
}