/* ===========================
   GENERAL RESET & BASE STYLES
============================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #fdfdfd;
    color: #333;
    line-height: 1.6;
}

/* ===========================
   HEADER & HERO SECTION
============================ */
header {
    text-align: center;
    padding: 50px 20px 40px 20px;
    background: linear-gradient(120deg, #6c63ff, #3f3d56);
    color: #fff;
    position: relative;
}

header .profile-photo {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    border: 4px solid #fff;
    margin-bottom: 15px;
    object-fit: cover;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1rem;
    margin-bottom: 20px;
}

header .btn {
    background-color: #fff;
    color: #6c63ff;
    padding: 10px 25px;
    border-radius: 25px;
    text-decoration: none;
    font-weight: bold;
    transition: 0.3s;
}

header .btn:hover {
    background-color: #f0f0f0;
}

/* ===========================
   NAVIGATION
============================ */
nav {
    display: flex;
    justify-content: center;
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

nav a {
    text-decoration: none;
    color: #333;
    padding: 15px 25px;
    font-weight: bold;
    transition: 0.3s;
}

nav a:hover {
    color: #6c63ff;
}

/* ===========================
   SECTIONS
============================ */
section {
    max-width: 1000px;
    margin: 50px auto;
    padding: 0 20px;
}

section h2 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 2rem;
    color: #6c63ff;
}

/* ===========================
   SKILLS
============================ */
.skill-box {
    display: inline-block;
    background-color: #e0e0ff;
    color: #3f3d56;
    padding: 10px 20px;
    margin: 5px;
    border-radius: 20px;
    font-weight: bold;
}

/* ===========================
   PROJECT CARDS
============================ */
.project-card {
    background-color: #fff;
    border-radius: 15px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    padding: 20px;
    margin-bottom: 20px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}

.project-card h3 {
    color: #6c63ff;
    margin-bottom: 10px;
}

.project-card p {
    margin-bottom: 10px;
}

.btn-small {
    text-decoration: none;
    color: #fff;
    background-color: #6c63ff;
    padding: 8px 20px;
    border-radius: 20px;
    font-weight: bold;
    transition: 0.3s;
}

.btn-small:hover {
    background-color: #5348c8;
}

/* ===========================
   CALCULATOR
============================ */
.calculator {
    max-width: 400px;
    margin: 0 auto;
    background-color: #f3f3f3;
    padding: 20px;
    border-radius: 15px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

#sci-display {
    width: 100%;
    padding: 15px;
    font-size: 1.2rem;
    margin-bottom: 10px;
    border-radius: 10px;
    border: 1px solid #ccc;
}

.keys-sci {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

.keys-sci button {
    padding: 15px 0;
    font-size: 1rem;
    border: none;
    border-radius: 10px;
    background-color: #6c63ff;
    color: #fff;
    cursor: pointer;
    transition: 0.3s;
}

.keys-sci button:hover {
    background-color: #5348c8;
}

.keys-sci .clear, .keys-sci .del {
    background-color: #ff5959;
}

.keys-sci .clear:hover, .keys-sci .del:hover {
    background-color: #e03e3e;
}

.keys-sci .equals {
    grid-column: span 2;
    background-color: #00b894;
}

.keys-sci .equals:hover {
    background-color: #009f7f;
}

.keys-sci .zero {
    grid-column: span 2;
}

/* ===========================
   CONTACT
============================ */
.btn-whatsapp {
    display: inline-block;
    background-color: #25D366;
    color: #fff;
    padding: 10px 25px;
    border-radius: 25px;
    text-decoration: none;
    font-weight: bold;
    transition: 0.3s;
    margin-bottom: 15px;
}

.btn-whatsapp:hover {
    background-color: #1da851;
}

section#contact p {
    text-align: center;
    margin-bottom: 10px;
}

/* ===========================
   FOOTER
============================ */
footer {
    text-align: center;
    padding: 20px;
    background-color: #f3f3f3;
    color: #333;
}

/* ===========================
   ANIMATIONS
============================ */
.fade-in {
    animation: fadeIn 1.5s ease forwards;
    opacity: 0;
}

.slide-up {
    animation: slideUp 1.2s ease forwards;
    opacity: 0;
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
    from {
        opacity: 0;
        transform: translateY(30px);
    }
}

/* ===========================
   RESPONSIVE
============================ */
@media screen and (max-width: 768px) {
    nav {
        flex-direction: column;
    }

    .keys-sci {
        grid-template-columns: repeat(4, 1fr);
    }
}
/* =========================
   GLOBAL STYLES
========================= */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Segoe UI", Tahoma, Arial, sans-serif;
}

body {
  background: #f4f7fb;
  color: #333;
  line-height: 1.6;
}

/* =========================
   LINKS
========================= */
a {
  color: #1e5eff;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* =========================
   AUTH PAGES (LOGIN / REGISTER)
========================= */
.login-container,
.register-container {
  max-width: 400px;
  margin: 80px auto;
  background: #ffffff;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

.login-container h2,
.register-container h2 {
  text-align: center;
  margin-bottom: 20px;
  color: #1e5eff;
}

.login-container form,
.register-container form {
  display: flex;
  flex-direction: column;
}

.login-container input,
.register-container input {
  padding: 12px;
  margin-bottom: 15px;
  border: 1px solid #ccc;
  border-radius: 6px;
  font-size: 15px;
}

.login-container input:focus,
.register-container input:focus {
  outline: none;
  border-color: #1e5eff;
}

.login-container button,
.register-container button {
  background: #1e5eff;
  color: #ffffff;
  padding: 12px;
  border: none;
  border-radius: 6px;
  font-size: 16px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.login-container button:hover,
.register-container button:hover {
  background: #1648c9;
}

.login-container p,
.register-container p {
  text-align: center;
  margin-top: 15px;
  font-size: 14px;
}

/* =========================
   LIBRARY PAGE
========================= */
.library-header {
  background: linear-gradient(135deg, #1e5eff, #3f7cff);
  color: #ffffff;
  padding: 25px;
  text-align: center;
}

.library-header h1 {
  font-size: 28px;
  margin-bottom: 5px;
}

.library-header p {
  font-size: 15px;
  opacity: 0.9;
}

/* =========================
   LIBRARY CONTENT
========================= */
.library-container {
  max-width: 1100px;
  margin: 40px auto;
  padding: 0 20px;
}

.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

/* =========================
   BOOK CARD
========================= */
.book-card {
  background: #ffffff;
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.08);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.book-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.12);
}

.book-card h3 {
  font-size: 18px;
  margin-bottom: 10px;
  color: #1e5eff;
}

.book-card p {
  font-size: 14px;
  margin-bottom: 15px;
  color: #555;
}

.book-card a {
  display: inline-block;
  background: #1e5eff;
  color: #ffffff;
  padding: 8px 14px;
  border-radius: 5px;
  font-size: 14px;
  transition: background 0.3s ease;
}

.book-card a:hover {
  background: #1648c9;
}

/* =========================
   LOGOUT BUTTON
========================= */
.logout-btn {
  display: inline-block;
  margin: 30px auto;
  background: #ff3b3b;
  color: #ffffff;
  padding: 10px 18px;
  border: none;
  border-radius: 6px;
  font-size: 15px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.logout-btn:hover {
  background: #d62f2f;
}

/* =========================
   FOOTER
========================= */
footer {
  margin-top: 60px;
  padding: 20px;
  text-align: center;
  font-size: 14px;
  color: #777;
}

/* =========================
   RESPONSIVE
========================= */
@media (max-width: 500px) {
  .login-container,
  .register-container {
    margin: 40px 15px;
    padding: 25px;
  }

  .library-header h1 {
    font-size: 22px;
  }
}